# kb

id: animal-20260505-4
file: data/en.wikipedia.org/wiki/Animal-4.md
category: reference
title: Animal
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Animal
date_saved: 2026-05-05T07:15:04.727619+00:00
instance: kb-cron
parent: animal-20260505-0
summary:
The human population exploits a large number of other animal species for food, both of domesticated livestock species in animal husbandry and, mainly at sea, by hunting wild species. Marine fish of many species are caught commercially for food. A smaller number of species are farmed commercially. Humans and their livestock make up more than 90% of the biomass of all terrestrial vertebrates, and almost as much as all insects combined. Invertebrates including cephalopods, crustaceans, insects—principally bees and silkworms—and bivalve or gastropod molluscs are hunted or farmed for food, fibres. Chickens, cattle, sheep, pigs, and other animals are raised as livestock for meat across the world. Animal fibres such as wool and silk are used to make textiles, while animal sinews have been used as lashings and bindings, and leather is widely used to make shoes and other items. Animals have been hunted and farmed for their fur to make items such as coats and hats. Dyestuffs including carmine (cochineal), shellac, and kermes have been made from the bodies of insects. Working animals including cattle and horses have been used for work and transport from the first days of agriculture. Animals such as the fruit fly Drosophila melanogaster serve a


id: archaea-20260505-0
file: data/en.wikipedia.org/wiki/Archaea-0.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
Archaea ( ar-KEE-ə) is a domain of organisms. Traditionally, Archaea included only its prokaryotic members, but has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even though the domain Archaea cladistically includes eukaryotes, the term archaea (sing. archaeon ar-KEE-on; from Ancient Greek ἀρχαῖον arkhaîon 'ancient') in English still generally refers specifically to prokaryotic members of Archaea. Archaea were initially classified as bacteria, receiving the name archaebacteria (, in the Archaebacteria kingdom), but this term has fallen out of use. Archaeal cells have unique properties distinguishing them from Bacteria and Eukaryota, including: cell membranes made of ether-linked lipids; metabolisms such as methanogenesis; and a unique motility structure known as an archaellum. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been identified only by their gene sequences in environmental samples. It is unknown whether they can produce endospores. Archaea are often similar to bacteria in size and shape, although a few have very different shapes, such as the flat, square cells of Haloquadratum walsbyi. Despite this, archaea possess genes and several metabolic pathways that are more closely related to those of


id: archaea-20260505-1
file: data/en.wikipedia.org/wiki/Archaea-1.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
The classification of archaea, and of prokaryotes in general, is a rapidly moving and contentious field. Current classification systems aim to organize archaea into groups of organisms that share structural features and common ancestors. These classifications rely heavily on the use of the sequence of ribosomal RNA genes to reveal relationships among organisms (molecular phylogenetics). Most of the culturable and well-investigated species of archaea are members of two main kingdoms, the Methanobacteriati and the Thermoproteati (formerly TACK). Other groups have been tentatively created, such as the peculiar species Nanoarchaeum equitans – discovered in 2003 and assigned its own phylum, the Nanoarchaeota (reassigned to Nanobdellota in 2023). A new phylum "Korarchaeota" (now Thermoproteota) has also been proposed, containing a small group of unusual thermophilic species sharing features of both the main phyla. Other detected species of archaea are only distantly related to any of these groups, such as the Archaeal Richmond Mine acidophilic nanoorganisms (ARMAN, comprising Micrarchaeota and Parvarchaeota), which were discovered in 2006 and are some of the smallest organisms known. A superphylum – "TACK" (now kingdom Thermoproteati) – which includes the Thaumarchaeota (now Nitrososphaerota), "Augarchaeota", Crenarchaeota (now Thermoproteota), and "Korarchaeota" (now Thermoproteota) was proposed in 2011 to be related


id: archaea-20260505-2
file: data/en.wikipedia.org/wiki/Archaea-2.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
Archaea were split off as a third domain because of the large differences in their ribosomal RNA structure. The particular molecule 16S rRNA is key to the production of proteins in all organisms. Because this function is so central to life, organisms with mutations in their 16S rRNA are unlikely to survive, leading to great (but not absolute) stability in the structure of this polynucleotide over generations. 16S rRNA is large enough to show organism-specific variations, but still small enough to be compared quickly. In 1977, Carl Woese, a microbiologist studying the genetic sequences of organisms, developed a new comparison method that involved splitting the RNA into fragments that could be sorted and compared with other fragments from other organisms. The more similar the patterns between species, the more closely they are related. Woese used his new rRNA comparison method to categorize and contrast different organisms. He compared a variety of species and happened upon a group of methanogens with rRNA vastly different from any known prokaryotes or eukaryotes. These methanogens were much more similar to each other than to other organisms, leading Woese to propose the new domain of Archaea. His experiments showed that the archaea were genetically more


id: archaea-20260505-3
file: data/en.wikipedia.org/wiki/Archaea-3.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
The evolutionary relationship between archaea and eukaryotes remains unclear. Aside from the similarities in cell structure and function that are discussed below, many genetic trees group the two. Complicating factors include claims that the relationship between eukaryotes and the archaeal phylum Thermoproteota is closer than the relationship between the Methanobacteriati and the phylum Thermoproteota and the presence of archaea-like genes in certain bacteria, such as Thermotoga maritima, from horizontal gene transfer. The standard hypothesis states that the ancestor of the eukaryotes diverged early from the Archaea, and that eukaryotes arose through symbiogenesis, the fusion of an archaean and a eubacterium, which formed the mitochondria; this hypothesis explains the genetic similarities between the groups. The eocyte hypothesis instead posits that Eukaryota emerged relatively late from the Archaea. A lineage of archaea discovered in 2015, Lokiarchaeum (of the proposed new phylum "Lokiarchaeota"), named for a hydrothermal vent called Loki's Castle in the Arctic Ocean, was found to be the most closely related to eukaryotes known at that time. It has been called a transitional organism between prokaryotes and eukaryotes. Several sister phyla of "Lokiarchaeota" have since been found ("Thorarchaeota", "Odinarchaeota", "Heimdallarchaeota"), all together comprising a newly proposed supergroup "Asgard". Details of the


id: archaea-20260505-4
file: data/en.wikipedia.org/wiki/Archaea-4.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
They have membranes composed of glycerol-ether lipids, whereas bacteria and eukaryotes have membranes composed mainly of glycerol-ester lipids. The difference is the type of bond that joins the lipids to the glycerol moiety; the two types are shown in yellow in the figure at the right. In ester lipids, this is an ester bond, whereas in ether lipids this is an ether bond. The stereochemistry of the archaeal glycerol moiety is the mirror image of that found in other organisms. The glycerol moiety can occur in two forms that are mirror images of one another, called enantiomers. Just as a right hand does not fit easily into a left-handed glove, enantiomers of one type generally cannot be used or made by enzymes adapted for the other. The archaeal phospholipids are built on a backbone of sn-glycerol-1-phosphate, which is an enantiomer of sn-glycerol-3-phosphate, the phospholipid backbone found in bacteria and eukaryotes. This suggests that archaea use entirely different enzymes for synthesizing phospholipids as compared to bacteria and eukaryotes. Such enzymes developed very early in life's history, indicating an early split from the other two domains. Archaeal lipid tails differ from those of other organisms in that they are based upon long


id: archaea-20260505-5
file: data/en.wikipedia.org/wiki/Archaea-5.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
Archaea are genetically distinct from bacteria and eukaryotes, with up to 15% of the proteins encoded by any one archaeal genome being unique to the domain, although most of these unique genes have no known function. Of the remainder of the unique proteins that have an identified function, most belong to the Methanobacteriati and are involved in methanogenesis. The proteins that archaea, bacteria and eukaryotes share form a common core of cell function, relating mostly to transcription, translation, and nucleotide metabolism. Other characteristic archaeal features are the organization of genes of related function – such as enzymes that catalyze steps in the same metabolic pathway into novel operons, and large differences in tRNA genes and their aminoacyl tRNA synthetases. Transcription in archaea more closely resembles eukaryotic than bacterial transcription, with the archaeal RNA polymerase being very close to its equivalent in eukaryotes, while archaeal translation shows signs of both bacterial and eukaryotic equivalents. Although archaea have only one type of RNA polymerase, its structure and function in transcription seems to be close to that of the eukaryotic RNA polymerase II, with similar protein assemblies (the general transcription factors) directing the binding of the RNA polymerase to a gene's promoter, but


id: archaea-20260505-6
file: data/en.wikipedia.org/wiki/Archaea-6.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
Archaea reproduce asexually by binary or multiple fission, fragmentation, or budding; mitosis and meiosis do not occur, so if a species of archaea exists in more than one form, all have the same genetic material. Cell division is controlled in a cell cycle; after the cell's chromosome is replicated and the two daughter chromosomes separate, the cell divides. In the genus Sulfolobus, the cycle has characteristics that are similar to both bacterial and eukaryotic systems. The chromosomes replicate from multiple starting points (origins of replication) using DNA polymerases that resemble the equivalent eukaryotic enzymes. In Methanobacteriati the cell division protein FtsZ, which forms a contracting ring around the cell, and the components of the septum that is constructed across the center of the cell, are similar to their bacterial equivalents. In cren- and thaumarchaea, the cell division machinery Cdv fulfills a similar role. This machinery is related to the eukaryotic ESCRT-III machinery which, while best known for its role in cell sorting, also has been seen to fulfill a role in separation between divided cell, suggesting an ancestral role in cell division. Both bacteria and eukaryotes, but not archaea, make spores. Some species of Haloarchaea undergo phenotypic switching and grow


id: archaea-20260505-7
file: data/en.wikipedia.org/wiki/Archaea-7.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
Archaea exist in a broad range of habitats, are recognized as a major part of global ecosystems, and may represent about 20% of microbial cells in the oceans. However, the first-discovered archaeans were extremophiles. Indeed, some archaea survive high temperatures, often above 100 °C (212 °F), as found in geysers, black smokers, and oil wells. Other common habitats include very cold habitats and highly saline, acidic, or alkaline water, but archaea include mesophiles that grow in mild conditions, in swamps and marshland, sewage, the oceans, the intestinal tract of animals, and soils. Similar to PGPR, Archaea are considered a source of plant growth promotion as well. Extremophile archaea are members of four main physiological groups. These are the halophiles, thermophiles, alkaliphiles, and acidophiles. These groups are not comprehensive or phylum-specific, nor are they mutually exclusive, since some archaea belong to several groups. Nonetheless, they are a useful starting point for classification. Halophiles, including the genus Halobacterium, live in extremely saline environments such as salt lakes and outnumber their bacterial counterparts at salinities greater than 20–25%. Thermophiles grow best at temperatures above 45 °C (113 °F), in places such as hot springs; hyperthermophilic archaea grow optimally at temperatures greater than 80


id: archaea-20260505-8
file: data/en.wikipedia.org/wiki/Archaea-8.md
category: reference
title: Archaea
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Archaea
date_saved: 2026-05-05T07:15:06.056512+00:00
instance: kb-cron
parent: archaea-20260505-0
summary:
==== Commensalism ==== Some archaea are commensals, benefiting from an association without helping or harming the other organism. For example, the methanogen Methanobrevibacter smithii is by far the most common archaean in the human flora, making up about one in ten of the prokaryotes in the human gut. In termites and in humans, these methanogens may in fact be mutualists, interacting with other microbes in the gut to aid digestion. Archaean communities associate with a range of other organisms, such as on the surface of corals, and in the region of soil that surrounds plant roots (the rhizosphere). ==== Parasitism ==== Although Archaea do not have a historical reputation of being pathogens, Archaea are often found with similar genomes to more common pathogens like E. coli, showing metabolic links and evolutionary history with today's pathogens. Archaea have been inconsistently detected in clinical studies because of the lack of categorization of Archaea into more specific species. The reduced genome of Candidatus Sukunaarchaeum mirabile suggests it is a specialized parasite highly dependant on its dinoflagellate host. == Significance in technology and industry == Extremophile archaea, particularly those resistant either to heat or to extremes of acidity and alkalinity, are a source of


id: autotroph-20260505-0
file: data/en.wikipedia.org/wiki/Autotroph-0.md
category: reference
title: Autotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Autotroph
date_saved: 2026-05-05T07:15:07.302269+00:00
instance: kb-cron
parent: autotroph-20260505-0
summary:
An autotroph is an organism that can convert abiotic sources of energy into energy stored in organic compounds, which can be used by other organisms. Autotrophs produce complex organic compounds (such as carbohydrates, fats, and proteins) using carbon from simple substances such as carbon dioxide, generally using energy from light or inorganic chemical reactions. Autotrophs do not need a living source of carbon or energy and are the producers in a food chain, such as plants on land or algae in water. Autotrophs can reduce carbon dioxide to make organic compounds for biosynthesis and as stored chemical fuel. Most autotrophs use water as the reducing agent, but some can use other hydrogen compounds such as hydrogen sulfide. The primary producers can convert the energy in the light (phototroph and photoautotroph) or the energy in inorganic chemical compounds (chemotrophs or chemolithotrophs) to build organic molecules, which are usually accumulated in the form of biomass and will be used as carbon and energy source by other organisms (e.g. heterotrophs and mixotrophs). The photoautotrophs are the main primary producers, converting the energy of the light into chemical energy through photosynthesis, ultimately building organic molecules from carbon dioxide, an inorganic carbon source. Examples of


id: autotroph-20260505-1
file: data/en.wikipedia.org/wiki/Autotroph-1.md
category: reference
title: Autotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Autotroph
date_saved: 2026-05-05T07:15:07.302269+00:00
instance: kb-cron
parent: autotroph-20260505-0
summary:
Without primary producers, organisms that are capable of producing energy on their own, the biological systems of Earth would be unable to sustain themselves. Plants, along with other primary producers, produce the energy that other living beings consume, and the oxygen that they breathe. It is thought that the first organisms on Earth were primary producers located on the ocean floor. Autotrophs are fundamental to the food chains of all ecosystems in the world. They take energy from the environment in the form of sunlight or inorganic chemicals and use it to create fuel molecules such as carbohydrates. This mechanism is called primary production. Other organisms, called heterotrophs, take in autotrophs as food to carry out functions necessary for their life. Thus, heterotrophs – all animals, almost all fungi, and most bacteria and protozoa – depend on autotrophs, or primary producers, for the raw materials and fuel they need. Heterotrophs obtain energy by breaking down carbohydrates or oxidizing organic molecules (carbohydrates, fats, and proteins) obtained in food. Carnivorous organisms rely on autotrophs indirectly, as the nutrients obtained from their heterotrophic prey come from autotrophs they have consumed. Most ecosystems are supported by the autotrophic primary production of plants and cyanobacteria


id: bacteria-20260505-0
file: data/en.wikipedia.org/wiki/Bacteria-0.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
Bacteria are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in mutualistic, commensal and parasitic relationships with plants and animals. Most bacteria have not been characterised and there are many species that cannot be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology. Like all animals, humans carry vast numbers (approximately 1013 to 1014) of bacteria. Most are in the gut, though there are


id: bacteria-20260505-1
file: data/en.wikipedia.org/wiki/Bacteria-1.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
== Habitat == Bacteria are ubiquitous, living in every possible habitat on the planet including soil, underwater, deep in Earth's crust and even such extreme environments as acidic hot springs and radioactive waste. There are thought to be approximately 2×1030 bacteria on Earth, forming a biomass that is only exceeded by plants. They are abundant in lakes and oceans, in arctic ice, and geothermal springs where they provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. They live on and in plants and animals. Most do not cause diseases, are beneficial to their environments, and are essential for life. The soil is a rich source of bacteria and a few grams contain around a thousand million of them. They are all essential to soil ecology, breaking down toxic waste and recycling nutrients. They are even found in the atmosphere and one cubic metre of air holds around one hundred million bacterial cells. The oceans and seas harbour around 3 × 1026 bacteria which provide up to 50% of the oxygen humans breathe. Only around 2% of bacterial species have been fully studied. == Morphology == Size. Bacteria display a wide


id: bacteria-20260505-2
file: data/en.wikipedia.org/wiki/Bacteria-2.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
Bacteria do not have a membrane-bound nucleus, and their genetic material is typically a single circular bacterial chromosome of DNA located in the cytoplasm in an irregularly shaped body called the nucleoid. The nucleoid contains the chromosome with its associated proteins and RNA. Like all other organisms, bacteria contain ribosomes for the production of proteins, but the structure of the bacterial ribosome is different from that of eukaryotes and archaea. Its translation process is also different. Some bacteria produce intracellular nutrient storage granules, such as glycogen, polyphosphate, sulfur or polyhydroxyalkanoates. Bacteria such as the photosynthetic cyanobacteria, produce internal gas vacuoles, which they use to regulate their buoyancy, allowing them to move up or down into water layers with different light intensities and nutrient levels. === Extracellular structures === Around the outside of the cell membrane is the cell wall. Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by peptides containing D-amino acids. Bacterial cell walls are different from the cell walls of plants and fungi, which are made of cellulose and chitin, respectively. The cell wall of bacteria is also distinct from that of archaea, which do not contain peptidoglycan. The


id: bacteria-20260505-3
file: data/en.wikipedia.org/wiki/Bacteria-3.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
Bacteria exhibit an extremely wide variety of metabolic types. The distribution of metabolic traits within a group of bacteria has traditionally been used to define their taxonomy, but these traits often do not correspond with modern genetic classifications. Bacterial metabolism is classified into nutritional groups on the basis of three major criteria: the source of energy, the electron donors used, and the source of carbon used for growth. Phototrophic bacteria derive energy from light using photosynthesis, while chemotrophic bacteria breaking down chemical compounds through oxidation, driving metabolism by transferring electrons from a given electron donor to a terminal electron acceptor in a redox reaction. Chemotrophs are further divided by the types of compounds they use to transfer electrons. Bacteria that derive electrons from inorganic compounds such as hydrogen, carbon monoxide, or ammonia are called lithotrophs, while those that use organic compounds are called organotrophs. Still, more specifically, aerobic organisms use oxygen as the terminal electron acceptor, while anaerobic organisms use other compounds such as nitrate, sulfate, or carbon dioxide. Many bacteria, called heterotrophs, derive their carbon from other organic carbon. Others, such as cyanobacteria and some purple bacteria, are autotrophic, meaning they obtain cellular carbon by fixing carbon dioxide. In


id: bacteria-20260505-4
file: data/en.wikipedia.org/wiki/Bacteria-4.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
Most bacteria have a single circular chromosome that can range in size from only 160,000 base pairs in the endosymbiotic bacteria Carsonella ruddii, to 12,200,000 base pairs (12.2 Mbp) in the soil-dwelling bacteria Sorangium cellulosum, to 16.0 Mbp in another soil-dwelling bacteria, Minicystis rosea. There are many exceptions to this; for example, some Streptomyces and Borrelia species contain a single linear chromosome, while some bacteria including species of Vibrio contain more than one chromosome. Some bacteria contain plasmids, small extra-chromosomal molecules of DNA that may contain genes for various useful functions such as antibiotic resistance, metabolic capabilities, or various virulence factors. Whether they have a single chromosome or more than one, almost all bacteria have a haploid genome. This means that they have only one copy of each gene encoding proteins. This is in contrast to eukaryotes, which are diploid or polyploid, meaning they have two or more copies of each gene. This means that unlike humans, who may still be able to create a protein if the gene becomes mutated (since the human genome has an extra copy in each cell), a bacterium will be completely unable to create the protein if its gene incurs an inactivating mutation. Bacterial


id: bacteria-20260505-5
file: data/en.wikipedia.org/wiki/Bacteria-5.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
A few bacteria have chemical systems that generate light. This bioluminescence often occurs in bacteria that live in association with fish, and the light probably serves to attract fish or other large animals. Bacteria often function as multicellular aggregates known as biofilms, exchanging a variety of molecular signals for intercell communication and engaging in coordinated multicellular behaviour. The communal benefits of multicellular cooperation include a cellular division of labour, accessing resources that cannot effectively be used by single cells, collectively defending against antagonists, and optimising population survival by differentiating into distinct cell types. For example, bacteria in biofilms can have more than five hundred times the increased resistance to antibacterial agents than individual "planktonic" bacteria of the same species. One type of intercellular communication by a molecular signal is called quorum sensing. Quorum sensing determines whether the local population is dense enough to support investment in processes that are only successful if large numbers of similar organisms behave similarly, such as excreting digestive enzymes or emitting light. Quorum sensing enables bacteria to coordinate gene expression and to produce, release, and detect autoinducers or pheromones that accumulate with the growth in cell population. == Classification and identification == Classification seeks to


id: bacteria-20260505-6
file: data/en.wikipedia.org/wiki/Bacteria-6.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
=== Valid phyla === The following phyla have been validly published according to the Prokaryotic Code; phyla that do not belong to any kingdom are shown in bold: === Candidate phyla === The following phyla have been proposed, but have not been validly published according to the Prokaryotic Code; phyla that do not belong to any kingdom are shown in bold: == Interactions with other organisms == Despite their apparent simplicity, bacteria can form complex associations with other organisms. These symbiotic associations can be divided into parasitism, mutualism and commensalism. === Commensals === The word "commensalism" is derived from the word "commensal", meaning "eating at the same table" and all plants and animals are colonised by commensal bacteria. In humans and other animals, trillions of them live on the skin, the airways, the gut and other orifices. Referred to as "normal flora", or "commensals", these bacteria usually cause no harm but may occasionally invade other sites of the body and cause infection. Escherichia coli is a commensal in the human gut but can cause urinary tract infections. Similarly, streptococci, which are part of the normal flora of the human mouth, can cause heart disease. === Predators === Some species of


id: bacteria-20260505-7
file: data/en.wikipedia.org/wiki/Bacteria-7.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
Each species of pathogen has a characteristic spectrum of interactions with its human hosts. Some organisms, such as Staphylococcus or Streptococcus, can cause skin infections, pneumonia, meningitis and sepsis, a systemic inflammatory response producing shock, massive vasodilation and death. Yet these organisms are also part of the normal human flora and usually exist on the skin or in the nose without causing any disease at all. Other organisms invariably cause disease in humans, such as Rickettsia, which are obligate intracellular parasites able to grow and reproduce only within the cells of other organisms. One species of Rickettsia causes typhus, while another causes Rocky Mountain spotted fever. Chlamydia, another phylum of obligate intracellular parasites, contains species that can cause pneumonia or urinary tract infection and may be involved in coronary heart disease. Some species, such as Pseudomonas aeruginosa, Burkholderia cenocepacia, and Mycobacterium avium, are opportunistic pathogens and cause disease mainly in people who are immunosuppressed or have cystic fibrosis. Some bacteria produce toxins, which cause diseases. These are endotoxins, which come from broken bacterial cells, and exotoxins, which are produced by bacteria and released into the environment. The bacterium Clostridium botulinum for example, produces a powerful exotoxin that cause respiratory paralysis,


id: bacteria-20260505-8
file: data/en.wikipedia.org/wiki/Bacteria-8.md
category: reference
title: Bacteria
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bacteria
date_saved: 2026-05-05T07:15:08.686083+00:00
instance: kb-cron
parent: bacteria-20260505-0
summary:
Bacteria were first observed by the Dutch microscopist Antonie van Leeuwenhoek in 1676, using a single-lens microscope of his own design. Leeuwenhoek did not recognize bacteria as a distinct category of microorganisms, referring to all microorganisms that he observed, including bacteria, protists, and microscopic animals, as animalcules. He published his observations in a series of letters to the Royal Society of London. Bacteria were Leeuwenhoek's most remarkable microscopic discovery. Their size was just at the limit of what his simple lenses could resolve, and, in one of the most striking hiatuses in the history of science, no one else would see them again for over a century. His observations also included protozoans, and his findings were looked at again in the light of the more recent findings of cell theory. Christian Gottfried Ehrenberg introduced the word "bacterium" in 1828. In fact, his Bacterium was a genus that contained non-spore-forming rod-shaped bacteria, as opposed to Bacillus, a genus of spore-forming rod-shaped bacteria defined by Ehrenberg in 1835. Louis Pasteur demonstrated in 1859 that the growth of microorganisms causes the fermentation process and that this growth is not due to spontaneous generation (yeasts and molds, commonly associated with fermentation, are not bacteria,


id: biofact-biology-20260505-0
file: data/en.wikipedia.org/wiki/Biofact_(biology)-0.md
category: reference
title: Biofact (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biofact_(biology)
date_saved: 2026-05-05T07:15:09.903564+00:00
instance: kb-cron
parent: biofact-biology-20260505-0
summary:
In biology, a biofact is dead material of a once-living organism. In 1943, the protozoologist Bruno M. Klein of Vienna (1891–1968) coined the term in his article Biofakt und Artefakt in the microscopy journal Mikrokosmos, though at that time it was not adopted by the scientific community. Klein's concept of biofact stressed the dead materials produced by living organisms as sheaths, such as shells. The word biofact is now widely used in the zoo/aquarium world, but was first used by Lisbeth Bornhofft in 1993 in the Education Department at the New England Aquarium, Boston, to refer to preserved items such as animal bones, skins, molts and eggs. The Accreditation Standards and Related Policies of the Association of Zoos and Aquariums states that biofacts can be useful education tools, and are preferable to live animals because of potential ethical considerations. == See also == Biofact (archaeology) == References ==


id: bioliteracy-20260505-0
file: data/en.wikipedia.org/wiki/Bioliteracy-0.md
category: reference
title: Bioliteracy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bioliteracy
date_saved: 2026-05-05T07:15:11.133438+00:00
instance: kb-cron
parent: bioliteracy-20260505-0
summary:
Bioliteracy is the ability to understand and engage with biological topics. The concept is used particularly in the contexts of biotechnology and biodiversity. == Description == In the biotechnology context, bioliteracy is considered important for promoting the biotechnology industry and the development of biological engineering products. It has also been defined as "the concept of imbuing people, personnel, or teams with an understanding of and comfort with biology and biotechnology." The use in the context of biodiversity is somewhat distinct, focusing on improving awareness of different organisms with the goal of conservation. Citizen science initiatives, such as iNaturalist, are considered effective ways to increase bioliteracy, engaging students with the direct observation of nature. == References ==


id: biological-target-20260505-0
file: data/en.wikipedia.org/wiki/Biological_target-0.md
category: reference
title: Biological target
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biological_target
date_saved: 2026-05-05T07:15:12.337114+00:00
instance: kb-cron
parent: biological-target-20260505-0
summary:
A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets are proteins and nucleic acids. The definition is context-dependent, and can refer to the biological target of a pharmacologically active drug compound, the receptor target of a hormone (like insulin), or some other target of an external stimulus. Biological targets are most commonly proteins such as enzymes, ion channels, and receptors, but in recent years DNA's and RNA's became more targeted than in the past. == Mechanism == The external stimulus (i.e., the drug or ligand) physically binds to ("hits") the biological target. The interaction between the substance and the target may be: noncovalent – A relatively weak interaction between the stimulus and the target where no chemical bond is formed between the two interacting partners and hence the interaction is completely reversible. reversible covalent – A chemical reaction occurs between the stimulus and target in which the stimulus becomes chemically bonded to the target, but the reverse reaction also readily occurs in which the bond can be broken.


id: biomarker-20260505-0
file: data/en.wikipedia.org/wiki/Biomarker-0.md
category: reference
title: Biomarker
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biomarker
date_saved: 2026-05-05T07:15:13.536230+00:00
instance: kb-cron
parent: biomarker-20260505-0
summary:
In biomedical contexts, a biomarker, or biological marker, is a measurable indicator of some biological state or condition. Biomarkers are often measured and evaluated using blood, urine, or soft tissues to examine normal biological processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention. Biomarkers are used in many scientific fields. == Medicine == Biomarkers used in the medical field, are a part of a relatively new clinical toolset categorized by their clinical applications. The four main classes are molecular, physiologic, histologic and radiographic biomarkers. All four types of biomarkers have a clinical role in narrowing or guiding treatment decisions and follow a sub-categorization of being either predictive, prognostic, or diagnostic. === Predictive === Predictive molecular, cellular, or imaging biomarkers that pass validation can serve as a method of predicting clinical outcomes. Predictive biomarkers are used to help optimize ideal treatments, and often indicate the likelihood of benefiting from a specific therapy. For example, in metastatic colorectal cancer, predictive biomarkers can serve as a way of evaluating and improving patient survival rates and in the individual case by case scenario, they can serve as a way of sparing patients from needless toxicity that arises from cancer treatment plans. Common examples


id: biomarker-20260505-1
file: data/en.wikipedia.org/wiki/Biomarker-1.md
category: reference
title: Biomarker
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biomarker
date_saved: 2026-05-05T07:15:13.536230+00:00
instance: kb-cron
parent: biomarker-20260505-0
summary:
== Research == Biomarkers for precision medicine are a part of a relatively new behavioral and clinical toolset. In terms of the behavioral toolset, biomarkers are increasingly being used to motivate health behavior change, particularly in diabetes, cardiovascular diseases, and obesity research. Most research to date uses biomarkers that are easily measured, including weight, blood pressure, and glucose; these biomarkers may reflect the impacts of diet, physical activity, and smoking reduction. However, the methods by which feedback from biomarkers are used in intervention research are varied, and their effectiveness remains unclear. In reference to the clinical toolset, only two predictive biomarkers are implemented clinically in the case of metastatic colorectal cancer. In this case, the lack of data beyond retrospective studies and successful biomarker-driven approaches may be a factor in using biomarker studies due to the attrition of subjects in clinical trials. The field of biomarker research is also expanding to include a combinatorial approach to identifying biomarkers from multiple sources. Combining biomarkers from various data allows for the possibility of developing panels that evaluate treatment response based on many biomarkers at a single time. One such area of expanding research in multiple-factor biomarkers is mitochondrial DNA sequencing. Mutations in


id: biomarker-20260505-2
file: data/en.wikipedia.org/wiki/Biomarker-2.md
category: reference
title: Biomarker
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biomarker
date_saved: 2026-05-05T07:15:13.536230+00:00
instance: kb-cron
parent: biomarker-20260505-0
summary:
Biomarkers are being used to identify the effects of water contamination on aquatic organisms. Benthic macro-invertebrates reside in the sediment on the bottoms of streams, which is where many contaminants settle. These organisms have high exposure to the contamination, which makes them good study species when detecting pollutant concentrations and pollution impacts on an ecosystem. There are a variety of biomarkers within an aquatic organism that can be measured, depending on the contaminant or the response in question. There are also a variety of contaminants within water bodies. To analyze the impact of a pollutant on an organism, the biomarker must respond to a specific contaminant within a specific time frame or at a certain concentration. The biomarkers used to detect pollution in aquatic organisms can be enzymatic or non-enzymatic. Rachel Carson, the author of Silent Spring, raised the issue of using organochlorine pesticides and discussed the possible negative effects that said pesticides have on living organisms. Her book raised ethical issues against chemical corporations that were controlling the general reception of the effect of pesticides on the environment, which pioneered the need for ecotoxicological studies. Ecotoxicologial studies could be considered the precursors to biomarker studies. Biomarkers are used to


id: biosignal-20260505-0
file: data/en.wikipedia.org/wiki/Biosignal-0.md
category: reference
title: Biosignal
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biosignal
date_saved: 2026-05-05T07:15:14.749681+00:00
instance: kb-cron
parent: biosignal-20260505-0
summary:
A biosignal is any signal in a living organism that can be continually measured and monitored. The term biosignal is often used to refer to bioelectrical signals, but it may refer to both electrical and non-electrical signals. The usual understanding is to refer only to time-varying signals, although spatial parameter variations (e.g. the nucleotide sequence determining the genetic code) are sometimes subsumed as well. == Electrical biosignals == Electrical biosignals, or bioelectrical time signals, usually refers to the change in electric current produced by the sum of an electrical potential difference across a specialized tissue, organ or cell system like the nervous system. Thus, among the best-known bioelectrical signals are: Electroencephalogram (EEG) Electrocardiogram (ECG) Electromyogram (EMG) Electrooculogram (EOG) Electroretinogram (ERG) Electrogastrogram (EGG) Galvanic skin response (GSR) or electrodermal activity (EDA) EEG, ECG, EOG and EMG are measured with a differential amplifier which registers the difference between two electrodes attached to the skin. However, the galvanic skin response measures electrical resistance and the Magnetoencephalography (MEG) measures the magnetic field induced by electrical currents (electroencephalogram) of the brain. With the development of methods for remote measurement of electric fields using new sensor technology, electric biosignals such as EEG and ECG can be


id: biosignature-20260505-0
file: data/en.wikipedia.org/wiki/Biosignature-0.md
category: reference
title: Biosignature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biosignature
date_saved: 2026-05-05T07:15:15.960639+00:00
instance: kb-cron
parent: biosignature-20260505-0
summary:
A biosignature is a phenomenon that can be explained by biological processes where all possible abiotic causes of this phenomenon have been eliminated. This term is mainly used in the field of astrobiology in the search for past or present extraterrestrial life, from planets and moons in the Solar System to exoplanets. Candidate biosignatures strongly indicate some of the earliest known life forms, aid studies of the origin of life on Earth as well as the possibility of life on Mars, Venus and elsewhere in the universe. == History == The term "biosignature" and its definition have evolved over time. In the 1960s, the phrase "life detection" was used as seen in two Nature papers "A physical basis for life detection experiments," by James. E. Lovelock (1965) and "Signs of Life: Criterion-system of exobiology," by Joshua Lederberg (1965). In 1973, Joon H. Rho used the term "biomarker" in his paper, "A search for porphyrin biomarkers in nonesuch shale and extraterrestrial samples" to describe a fossil organic compound that can be traced back to a specific organism. In medicine, biomarker (medicine) has a different definition. In 1995, the term biosignature was first used by the NASA Exobiology Program office (now the


id: biosignature-20260505-1
file: data/en.wikipedia.org/wiki/Biosignature-1.md
category: reference
title: Biosignature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biosignature
date_saved: 2026-05-05T07:15:15.960639+00:00
instance: kb-cron
parent: biosignature-20260505-0
summary:
==== Human limitations ==== Observational or technological limitations may also limit the detectability of a potential biosignature. Telescope resolution maybe insufficient to resolve spectral features needed to distinguish between biological signals and false positives. In addition, observatories and telescopes are designed by multidisciplinary teams, resulting in instrumentation that reflects compromises among a variety of scientific priorities. As a result, optimizing instruments for biosignature detection may requires trade-offs with capabilities aimed at other science goals. == General examples == === Geomicrobiology === The ancient record on Earth provides an opportunity to see what geochemical signatures are produced by microbial life and how these signatures are preserved over geologic time. Some related disciplines such as geochemistry, geobiology, and geomicrobiology often use biosignatures to determine if living organisms are or were present in a sample. These possible biosignatures include: (a) microfossils and stromatolites; (b) molecular structures (biomarkers) and isotopic compositions of carbon, nitrogen and hydrogen in organic matter; (c) multiple sulfur and oxygen isotope ratios of minerals; and (d) abundance relationships and isotopic compositions of redox-sensitive metals (e.g., Fe, Mo, Cr, and rare earth elements). For example, the particular fatty acids measured in a sample can indicate which types of bacteria and archaea


id: biosignature-20260505-2
file: data/en.wikipedia.org/wiki/Biosignature-2.md
category: reference
title: Biosignature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biosignature
date_saved: 2026-05-05T07:15:15.960639+00:00
instance: kb-cron
parent: biosignature-20260505-0
summary:
=== Atmospheric === The atmospheric properties of exoplanets are of particular importance, as atmospheres provide the most likely observables for the near future, including habitability indicators and biosignatures. Over billions of years, the processes of life on a planet would result in a mixture of chemicals unlike anything that could form in an ordinary chemical equilibrium. For example, large amounts of oxygen and small amounts of methane are generated by life on Earth. An exoplanet's color—or reflectance spectrum—can also be used as a biosignature due to the effect of pigments that are uniquely biologic in origin such as the pigments of phototrophic and photosynthetic life forms. Scientists use the Earth as an example of this when looked at from far away (see Pale Blue Dot) as a comparison to worlds observed outside of the Solar System. Ultraviolet radiation on life forms could also induce biofluorescence in visible wavelengths that may be detected by the new generation of space observatories under development. Some scientists have reported methods of detecting hydrogen and methane in extraterrestrial atmospheres. Habitability indicators and biosignatures must be interpreted within a planetary and environmental context. For example, the presence of oxygen and methane together could indicate the kind


id: biosignature-20260505-3
file: data/en.wikipedia.org/wiki/Biosignature-3.md
category: reference
title: Biosignature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biosignature
date_saved: 2026-05-05T07:15:15.960639+00:00
instance: kb-cron
parent: biosignature-20260505-0
summary:
===== Ozone in the Martian Atmosphere ===== Mars has traces of ozone (including a seasonal ozone layer over the south pole in winter) and oxygen in its atmosphere both byproducts of life on Earth but explained by photochemistry on Mars. Mariner 7 detected ozone in 1971 and in 1976 by the Viking biological experiments. Significant levels of oxygen were detected in Gale Crater by Curiosity Rover in 2019 with seasonal variability that has not fully been explained. Studies indicate that the Martian atmosphere was once oxygen-rich. Today they are no longer considered valid biosignatures and are proposed to be the result of photodissociation of carbon dioxide. ===== Methane in the Martian Atmosphere ===== Martian methane is an area of ongoing research. With life being the strongest source of methane on Earth, continued observation of such a disequilibrium could be a viable biosignature. Current photochemical models cannot explain the reported rapid variations in space and time. Neither its fast appearance nor disappearance have been explained. Because of its tendency to be destroyed in the atmosphere by photochemistry, excess methane could indicate that there must be an active source. Since 2004 there have been several detection claims of methane in the Mars


id: biosignature-20260505-4
file: data/en.wikipedia.org/wiki/Biosignature-4.md
category: reference
title: Biosignature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biosignature
date_saved: 2026-05-05T07:15:15.960639+00:00
instance: kb-cron
parent: biosignature-20260505-0
summary:
===== ExoMars Orbiter ===== The 2016 ExoMars Trace Gas Orbiter (TGO) is a Mars telecommunications orbiter and atmospheric gas analyzer mission. It delivered the Schiaparelli EDM lander and then began to settle into its science orbit to map the sources of methane on Mars and other gases, and in doing so, will help select the landing site for the Rosalind Franklin rover to be launched in 2028. The primary objective of the Rosalind Franklin rover mission is the search for biosignatures on the surface and subsurface by using a drill able to collect samples down to a depth of 2 metres (6.6 ft), away from the destructive radiation that bathes the surface. ===== Mars 2020 ===== The Mars 2020 rover, which launched in 2020, is intended to investigate an astrobiologically relevant ancient environment on Mars, investigate its surface geological processes and history, including the assessment of its past habitability, the possibility of past life on Mars, and potential for preservation of biosignatures within accessible geological materials. In addition, it will cache the most interesting samples for possible future transport to Earth. In 2024, Perseverance found a rock, called Cheyava Falls, during its exploration of the Jezero Crater. The rover's instruments


id: biosignature-20260505-5
file: data/en.wikipedia.org/wiki/Biosignature-5.md
category: reference
title: Biosignature
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biosignature
date_saved: 2026-05-05T07:15:15.960639+00:00
instance: kb-cron
parent: biosignature-20260505-0
summary:
Voyager 1 (1979): The first close-up photos of Europa are taken. Scientists propose that a subsurface ocean could cause the tectonic-like marks on the surface. Galileo (1997): The magnetometer aboard this probe detected a subtle change in the magnetic field near Europa. This was later interpreted as a disruption in the expected magnetic field due to the current induction in a conducting layer on Europa. The composition of this conducting layer is consistent with a salty subsurface ocean. Hubble Space Telescope (2012): An image was taken of Europa which showed evidence for a plume of water vapor coming off the surface. The Europa Clipper probe includes instruments to help confirm the existence and composition of a subsurface ocean and thick icy layer. In addition, the instruments will be used to map and study surface features that may indicate tectonic activity due to a subsurface ocean. ===== Dragonfly ===== NASA's Dragonfly lander/aircraft concept is proposed to launch in 2028 and would seek evidence of biosignatures on the organic-rich surface and atmosphere of Titan, as well as study its possible prebiotic primordial soup. Titan is the largest moon of Saturn and is widely believed to have a large subsurface ocean consisting of


id: catabiosis-20260505-0
file: data/en.wikipedia.org/wiki/Catabiosis-0.md
category: reference
title: Catabiosis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Catabiosis
date_saved: 2026-05-05T07:15:17.204749+00:00
instance: kb-cron
parent: catabiosis-20260505-0
summary:
Catabiosis is the process of growing older, aging and physical degradation. The word comes from Greek "kata"—down, against, reverse and "biosis"—way of life and is generally used to describe senescence and degeneration in living organisms and biophysics of aging in general. One of the popular catabiotic theories is the entropy theory of aging, where aging is characterized by thermodynamically favourable increase in structural disorder. Living organisms are open systems that take free energy from the environment and offload their entropy as waste. However, basic components of living systems—DNA, proteins, lipids and sugars—tend towards the state of maximum entropy while continuously accumulating damages causing catabiosis of the living structure. Catabiotic force on the contrary is the influence exerted by living structures on adjoining cells, by which the latter are developed in harmony with the primary structures. == References == == External links == Onpedia definition of catabiosis Catabiotic force Dictionary.com - Catabiosis


id: chemotroph-20260505-0
file: data/en.wikipedia.org/wiki/Chemotroph-0.md
category: reference
title: Chemotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chemotroph
date_saved: 2026-05-05T07:15:18.454829+00:00
instance: kb-cron
parent: chemotroph-20260505-0
summary:
A chemotroph is an organism that obtains energy by the oxidation of electron donors in their environments. These molecules can be organic (chemoorganotrophs) or inorganic (chemolithotrophs). The chemotroph designation is in contrast to phototrophs, which use photons. Chemotrophs can be either autotrophic or heterotrophic. Chemotrophs can be found in areas where electron donors are present in high concentration, for instance around hydrothermal vents. Some examples of chemotrophic organisms include iron-oxiding bacteria and methanogenic archaea. == Chemoautotroph == Chemoautotrophs are autotrophic organisms that can rely on chemosynthesis, i.e. deriving biological energy from chemical reactions of environmental inorganic substrates and synthesizing all necessary organic compounds from carbon dioxide. Chemoautotrophs can use inorganic energy sources such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia or organic sources to produce energy. Most chemoautotrophs are prokaryotic extremophiles, bacteria, or archaea that live in otherwise hostile environments (such as deep sea vents) and are the primary producers in such ecosystems. Chemoautotrophs generally fall into several groups: methanogens, sulfur oxidizers and reducers, nitrifiers, anammox bacteria, and thermoacidophiles. An example of one of these prokaryotes would be Sulfolobus. Chemolithotrophic growth can be very fast, such as Hydrogenovibrio crunogenus with a doubling time around one hour.


id: eukaryote-20260505-0
file: data/en.wikipedia.org/wiki/Eukaryote-0.md
category: reference
title: Eukaryote
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eukaryote
date_saved: 2026-05-05T07:15:19.756158+00:00
instance: kb-cron
parent: eukaryote-20260505-0
summary:
The eukaryotes () are the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of life forms alongside the two groups of prokaryotes: the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but given their generally much larger size, their collective global biomass is much larger than that of prokaryotes. The eukaryotes emerged within the archaeal phylum Promethearchaeota. Ignoring mitochondrial DNA (which is bacterial rather than archaeal), this would imply only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among the Archaea. Eukaryotes first emerged during the Paleoproterozoic, likely as flagellated cells. The leading evolutionary theory is they were created by symbiogenesis between an anaerobic Promethearchaeota archaeon and an aerobic proteobacterium, which formed the mitochondria. A second episode of symbiogenesis with a cyanobacterium created the plants, with chloroplasts. Eukaryotic cells contain membrane-bound organelles such as the nucleus, the endoplasmic reticulum, and the Golgi apparatus. Eukaryotes may be either unicellular or multicellular. In comparison, prokaryotes are typically unicellular. Unicellular eukaryotes are sometimes called protists. Eukaryotes can reproduce both asexually through mitosis and sexually through


id: eukaryote-20260505-1
file: data/en.wikipedia.org/wiki/Eukaryote-1.md
category: reference
title: Eukaryote
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eukaryote
date_saved: 2026-05-05T07:15:19.756158+00:00
instance: kb-cron
parent: eukaryote-20260505-0
summary:
Plants and various groups of algae have plastids as well as mitochondria. Plastids, like mitochondria, have their own DNA and are developed from endosymbionts, in this case cyanobacteria. They usually take the form of chloroplasts which, like cyanobacteria, contain chlorophyll and produce organic compounds (such as glucose) through photosynthesis. Others are involved in storing food. Although plastids probably had a single origin, not all plastid-containing groups are closely related. Instead, some eukaryotes have obtained them from other eukaryotes through secondary endosymbiosis or ingestion. The capture and sequestering of photosynthetic cells and chloroplasts, kleptoplasty, occurs in many types of modern eukaryotic organisms. === Cytoskeletal structures === The cytoskeleton provides stiffening structure and points of attachment for motor structures that enable the cell to move, change shape, or transport materials. The motor structures are microfilaments of actin and actin-binding proteins. These include α-actinin, fimbrin, and filamin in submembranous cortical layers and bundles. Motor proteins of microtubules, dynein and kinesin, and myosin of actin filaments, make the network dynamic. Many eukaryotes have long slender motile cytoplasmic projections, called flagella, or multiple shorter structures called cilia. These organelles are variously involved in movement, feeding, and sensation. They are composed mainly of tubulin, and are


id: eukaryote-20260505-2
file: data/en.wikipedia.org/wiki/Eukaryote-2.md
category: reference
title: Eukaryote
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Eukaryote
date_saved: 2026-05-05T07:15:19.756158+00:00
instance: kb-cron
parent: eukaryote-20260505-0
summary:
=== Phylogeny === By the early 21st century, a rough consensus started to emerge from phylogenomic studies. The majority of eukaryotes can be placed in one of two large clades dubbed Amorphea (similar in composition to the unikont hypothesis) and the Diphoda (formerly bikonts), which includes plants and most algal lineages. A third major grouping, the Excavata, has been abandoned as a formal group as it was found to be paraphyletic. The proposed phylogeny below includes two groups of excavates (Discoba and Metamonada), and incorporates the 2021 proposal that picozoans are close relatives of rhodophytes. The Provora are a group of microbial predators discovered in 2022. TSAR is a possible clade that would contain Telonemia and the SAR supergroup. One view of the great kingdoms and their stem groups. The Metamonada are hard to place, being sister possibly to Discoba or to Malawimonadida or being a paraphyletic group external to all other eukaryotes. Eukaryotes are thought to have emerged within the archaeal phylum Promethearchaeota. === Origin of eukaryotes === The origin of the eukaryotic cell, or eukaryogenesis, is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The last eukaryotic common


id: facilitation-cascade-20260505-0
file: data/en.wikipedia.org/wiki/Facilitation_cascade-0.md
category: reference
title: Facilitation cascade
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Facilitation_cascade
date_saved: 2026-05-05T07:15:21.359452+00:00
instance: kb-cron
parent: facilitation-cascade-20260505-0
summary:
A facilitation cascade is a sequence of ecological interactions that occur when a species benefits a second species that in turn has a positive effect on a third species. These facilitative interactions can take the form of amelioration of environmental stress and/or provision of refuge from predation. Autogenic ecosystem engineering species, structural species, habitat-forming species, and foundation species are associated with the most commonly recognized examples of facilitation cascades, sometimes referred to as a habitat cascades. Facilitation generally is a much broader concept that includes all forms of positive interactions including pollination, seed dispersal, and co-evolved commensalism and mutualistic relationships, such as between cnidarian hosts and Symbiodinium in corals, and between algae and fungi in lichens. As such, facilitation cascades are widespread through all of the earth's major biomes with consistently positive effects on the abundance and biodiversity of associated organisms. == Overview == Facilitation cascades occur when prevalent foundation species, or less abundant but ecologically important keystone species, are involved in a hierarchy of positive interactions and consist of a primary facilitator which positively affects one or more secondary facilitators which support a suite of beneficiary species. Facilitation cascades at a minimum have a primary and secondary facilitator, although


id: facilitation-cascade-20260505-1
file: data/en.wikipedia.org/wiki/Facilitation_cascade-1.md
category: reference
title: Facilitation cascade
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Facilitation_cascade
date_saved: 2026-05-05T07:15:21.359452+00:00
instance: kb-cron
parent: facilitation-cascade-20260505-0
summary:
=== Transitional (intertidal) === On the cobblestone beaches of New England, cordgrasse ameliorates physical stress for the establishment of ribbed mussels which further facilitating increased diversity within the intertidal ecosystem as secondary foundation species. This is the interaction from which the facilitation cascade concept was formed. This complex habitat has also shown how facilitation cascades can increases invasibility because non-native crabs live on and among ribbed mussels, providing a mechanisms to explain positive relationships between native diversity and invasion success, and the co-existence of native and invasive species through differential use of microhabitats associated with the cascade. In salt marshes, the same species of cordgrass and mussels have also been shown to increase biodiversity, multifunctionality, and resilience to disturbance. Oyster reefs stabilize the intertidal environment by reducing sediment erosion. This enhances growth of marsh grasses which act as secondary foundation species, facilitating invertebrates including bivalves, insects and birds. The places with oyster reefs and intertidal marshes have been observed to support a higher biodiversity and abundance of inhabitants compared to sites inhabited by only one of those foundation species. Mangrove forests along the coast of Australia trap drifting seaweed among their pneumatophores, which this seaweed supports many mollusks through habitat


id: facilitation-cascade-20260505-2
file: data/en.wikipedia.org/wiki/Facilitation_cascade-2.md
category: reference
title: Facilitation cascade
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Facilitation_cascade
date_saved: 2026-05-05T07:15:21.359452+00:00
instance: kb-cron
parent: facilitation-cascade-20260505-0
summary:
=== Temporal variation === The strength of facilitation cascades can also vary across temporal scales. Spatial scale can be influenced by how rapidly a foundation species grows or reproduces, as well as how long the effect of facilitation takes to impact other species within the system. This can be due to the time necessary for a foundation species to reach a minimum individual or patch size to create a facilitative effect for the system, lags in the demographic response in the beneficiary species to the positive effects of a facilitator, or seasonality or some other temporal variability in the stress that the facilitator ameliorates. Phenological matching or mismatching of life cycles may also influence the co-occurrence of participants in a facilitation cascade and therefore the strength of their interaction. For example, hatching of insects that coincides with flowering of the plants they pollinate which are in turn used as habitat for other species later in that year. === Dispersal and movement === Movement of organisms can mediate the occurrence and importance of facilitation cascades in three ways. First, movement of a facilitative species to a location with another facilitative species can bring together the components for a facilitation cascade. For


id: facilitation-cascade-20260505-3
file: data/en.wikipedia.org/wiki/Facilitation_cascade-3.md
category: reference
title: Facilitation cascade
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Facilitation_cascade
date_saved: 2026-05-05T07:15:21.359452+00:00
instance: kb-cron
parent: facilitation-cascade-20260505-0
summary:
==== Pollution ==== The introduction of harmful or toxic substances into the environment is a threat to facilitation cascades. Nutrient pollution may initially appear to benefit facilitation cascades by stimulating growth of habitat forming species, but ultimately negative effects associated with excess biomass, such as physically smothering and biogeochemical stressors including oxygen depletion and sulfide toxicity, can overwhelm the facilitation cascade. For example, excessive amounts of nutrients can stimulate prolific growth of secondary foundation species such as seaweed in otherwise oligotrophic seagrass systems, resulting in altered competitive hierarchies where the seaweed outcompetes the seagrass. In other instances, eutrophication can lead to an outright replacement of habitat dominants, such as when macroalgae replaces corals on reefs, leading to a change or loss in components of a facilitation cascade and there a shift in the broader community. ==== Disease ==== Disease prevalence and severity are predicted to increase in response to global changes, though its impacts on facilitation cascades remain relatively understudied. High endemic biodiversity, such as that favored by a facilitation cascade, generally decreases the risk of pathogen transmission. However, disease outbreaks that impact a facilitator can reduce its density or alter its phenotype, thereby reducing habitat complexity which dampens its


id: facultative-20260505-0
file: data/en.wikipedia.org/wiki/Facultative-0.md
category: reference
title: Facultative
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Facultative
date_saved: 2026-05-05T07:15:22.612139+00:00
instance: kb-cron
parent: facultative-20260505-0
summary:
Facultative means "optional" or "discretionary" (antonym obligate), and is used mainly in biology. It is seen in topics including: Facultative anaerobe, an organism that can use oxygen but also has anaerobic methods of energy production. Facultative biotroph, an organism, often a fungus, that can live as a saprotroph but also form mutualisms with other organisms at different times of its life cycle. Facultative biped, an animal that is capable of walking or running on two legs as well as walking or running on four limbs or more, as appropriate Facultative carnivore, a carnivore that does not depend solely on animal flesh for food but also can subsist on non-animal food. Compare this with the term omnivore Facultative heterochromatin, tightly packed but non-repetitive DNA in the form of Heterochromatin, but which can lose its condensed structure and become transcriptionally active Facultative lagoon, a type of stabilization pond used in biological treatment of industrial and domestic wastewater Facultative necrophage, an animal that feeds on carrion but retains the traits needed to find and consume other food sources Facultative parasite, a parasite that can complete its life cycle without depending on a host Facultative photoperiodic plant, a plant that will eventually flower regardless


id: flux-biology-20260505-0
file: data/en.wikipedia.org/wiki/Flux_(biology)-0.md
category: reference
title: Flux (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Flux_(biology)
date_saved: 2026-05-05T07:15:23.812857+00:00
instance: kb-cron
parent: flux-biology-20260505-0
summary:
In general, flux in biology relates to movement of a substance between compartments. There are several cases where the concept of flux is important. The movement of molecules across a membrane: in this case, flux is defined by the rate of diffusion or transport of a substance across a permeable membrane. Except in the case of active transport, net flux is directly proportional to the concentration difference across the membrane, the surface area of the membrane, and the membrane permeability constant. In ecology, flux is often considered at the ecosystem level – for instance, accurate determination of carbon fluxes using techniques like eddy covariance (at a regional and global level) is essential for modeling the causes and consequences of global warming. Metabolic flux refers to the rate of flow of metabolites through a biochemical network, along a linear metabolic pathway, or through a single enzyme. A calculation may also be made of carbon flux or flux of other elemental components of biomolecules (e.g. nitrogen). The general unit of flux is chemical mass /time (e.g., micromole/minute; mg/kg/minute). Flux rates are dependent on a number of factors, including: enzyme concentration; the concentration of precursor, product, and intermediate metabolites; post-translational modification of enzymes;


id: gracility-20260505-0
file: data/en.wikipedia.org/wiki/Gracility-0.md
category: reference
title: Gracility
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Gracility
date_saved: 2026-05-05T07:15:26.372103+00:00
instance: kb-cron
parent: gracility-20260505-0
summary:
Gracility is slenderness, the condition of being gracile, which means slender. It derives from the Latin adjective gracilis (masculine or feminine), or gracile (neuter), which in either form means slender, and when transferred for example to discourse takes the sense of "without ornament", "simple" or various similar connotations. In Glossary of Botanic Terms, B. D. Jackson speaks dismissively of an entry in earlier dictionary of A. A. Crozier as follows: "Gracilis (Lat.), slender. Crozier has the needless word 'gracile'". However, his objection would be hard to sustain in current usage; apart from the fact that gracile is a natural and convenient term, it is hardly a neologism. The Shorter Oxford English Dictionary gives the source date for that usage as 1623 and indicates the word is misused (through association with grace) for "gracefully slender". This misuse is unfortunate at least, because the terms gracile and grace are unrelated: the etymological root of grace is the Latin word gratia from gratus, meaning 'pleasing', and has nothing to do with slenderness or thinness. == In biology == In biology, the term is in common use, whether as English or Latin: The term gracile and its opposite, robust—occur in discussion of the morphology


id: haplotype-block-20260505-0
file: data/en.wikipedia.org/wiki/Haplotype_block-0.md
category: reference
title: Haplotype block
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haplotype_block
date_saved: 2026-05-05T07:15:27.632738+00:00
instance: kb-cron
parent: haplotype-block-20260505-0
summary:
In genetics, a haplotype block is a region of an organism's genome in which there is little evidence of a history of genetic recombination, and which contain only a small number of distinct haplotypes. According to the haplotype-block model, such blocks should show high levels of linkage disequilibrium and be separated from one another by numerous recombination events. The boundaries of haplotype blocks cannot be directly observed; they must instead be inferred indirectly through the use of algorithms. However, some evidence suggests that different algorithms for identifying haplotype blocks give very different results when used on the same data, though another study suggests that their results are generally consistent. The National Institutes of Health funded the HapMap project to catalog haplotype blocks throughout the human genome. == Definition == There are two main ways that the term "haplotype block" is defined: one based on whether a given genomic sequence displays higher linkage disequilibrium than a predetermined threshold, and one based on whether the sequence consists of a minimum number of single nucleotide polymorphisms (SNPs) that explain a majority of the common haplotypes in the sequence (or a lower-than-usual number of unique haplotypes). In 2001, Patil et al. proposed the following


id: heterotroph-20260505-0
file: data/en.wikipedia.org/wiki/Heterotroph-0.md
category: reference
title: Heterotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Heterotroph
date_saved: 2026-05-05T07:15:28.864372+00:00
instance: kb-cron
parent: heterotroph-20260505-0
summary:
A heterotroph (; from Ancient Greek ἕτερος (héteros), meaning "other", and τροφή (trophḗ), meaning "nourishment") is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly matter from other organisms. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but not producers. Living organisms that are heterotrophic include most animals, all fungi, some bacteria and protists, and many parasitic plants. The term heterotroph arose in microbiology in 1946 as part of a classification of microorganisms based on their type of nutrition. The term is now used in many fields, such as ecology, in describing the food chain. Heterotrophs occupy the second and third trophic levels of the food chain while autotrophs occupy the first trophic level. Heterotrophs may be subdivided according to their energy source. If the heterotroph uses chemical energy, it is a chemoheterotroph (e.g., humans and mushrooms). If it uses light for energy, then it is a photoheterotroph (e.g., haloquadratum walsbyi and green non-sulfur bacteria). Heterotrophs represent one of the two mechanisms of nutrition (trophic levels), the other being autotrophs (auto = self, troph = nutrition). Autotrophs use energy from sunlight (photoautotrophs) or oxidation of inorganic compounds (lithoautotrophs)


id: heterotroph-20260505-1
file: data/en.wikipedia.org/wiki/Heterotroph-1.md
category: reference
title: Heterotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Heterotroph
date_saved: 2026-05-05T07:15:28.864372+00:00
instance: kb-cron
parent: heterotroph-20260505-0
summary:
== Origin and diversification == The chemical origin of life hypothesis suggests that life originated in a prebiotic soup with heterotrophs. The summary of this theory is as follows: early Earth had a highly reducing atmosphere and energy sources such as electrical energy in the form of lightning, which resulted in reactions that formed simple organic compounds, which further reacted to form more complex compounds and eventually resulted in life. Alternative theories of an autotrophic origin of life contradict this theory. The theory of a chemical origin of life beginning with heterotrophic life was first proposed in 1924 by Alexander Ivanovich Oparin, and eventually published "The Origin of Life." It was independently proposed for the first time in English in 1929 by John Burdon Sanderson Haldane. While these authors agreed on the gasses present and the progression of events to a point, Oparin championed a progressive complexity of organic matter prior to the formation of cells, while Haldane had more considerations about the concept of genes as units of heredity and the possibility of light playing a role in chemical synthesis (autotrophy). Evidence grew to support this theory in 1953, when Stanley Miller conducted an experiment in which he added


id: heterotroph-20260505-2
file: data/en.wikipedia.org/wiki/Heterotroph-2.md
category: reference
title: Heterotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Heterotroph
date_saved: 2026-05-05T07:15:28.864372+00:00
instance: kb-cron
parent: heterotroph-20260505-0
summary:
Many heterotrophs are chemoorganoheterotrophs that use organic carbon (e.g. glucose) as their carbon source, and organic chemicals (e.g. carbohydrates, lipids, proteins) as their electron sources. Heterotrophs function as consumers in food chain: they obtain these nutrients from saprotrophic, parasitic, or holozoic nutrients. They break down complex organic compounds (e.g., carbohydrates, fats, and proteins) produced by autotrophs into simpler compounds (e.g., carbohydrates into glucose, fats into fatty acids and glycerol, and proteins into amino acids). They release the chemical energy of nutrient molecules by oxidizing carbon and hydrogen atoms from carbohydrates, lipids, and proteins to carbon dioxide and water, respectively. They can catabolize organic compounds by respiration, fermentation, or both. Fermenting heterotrophs are either facultative or obligate anaerobes that carry out fermentation in low oxygen environments, in which the production of ATP is commonly coupled with substrate-level phosphorylation and the production of end products (e.g. alcohol, CO2, sulfide). These products can then serve as the substrates for other bacteria in the anaerobic digestion, and be converted into CO2 and CH4, which is an important step for the carbon cycle for removing organic fermentation products from anaerobic environments. Heterotrophs can undergo respiration, in which ATP production is coupled with oxidative phosphorylation. This


id: heterotroph-20260505-3
file: data/en.wikipedia.org/wiki/Heterotroph-3.md
category: reference
title: Heterotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Heterotroph
date_saved: 2026-05-05T07:15:28.864372+00:00
instance: kb-cron
parent: heterotroph-20260505-0
summary:
== Impacts on Biogeochemical Cycles == Heterotrophs, organisms that obtain energy and carbon by consuming organic matter, are vital parts of Earth's biogeochemical cycles particularly in the carbon, nitrogen, and sulfur cycles. Their metabolic activities impact the processing and cycling of elements through ecosystems and the biosphere. Heterotrophs are key players in the carbon cycle, acting as both consumers and decomposers. They release carbon dioxide (CO2) into the atmosphere through respiration, contributing to a large portion of carbon dioxide emissions. This process makes carbon available for autotrophs, who can fix carbon through photosynthesis or chemosynthesis. This circulation supports the continuous cycling of carbon between organic and inorganic forms. Heterotrophic organisms contribute to key processes in the nitrogen cycle like ammonification, the conversion of organic nitrogen to ammonia, and denitrification, the reduction of nitrate and the release of nitrogen gas to the atmosphere. Heterotrophic microorganisms are essential in the mineralization of organic compounds containing nitrogen. Through deamination, they convert organic nitrogen to ammonium (NH4+), which can be further oxidized by lithotrophs into forms available to plants. Similarly, desulfurylation by heterotrophs transforms organic sulfur into hydrogen sulfide (H2S), which is then oxidized by lithotrophs and phototrophs, contributing to the sulfur cycle. The


id: hindgut-fermentation-20260505-0
file: data/en.wikipedia.org/wiki/Hindgut_fermentation-0.md
category: reference
title: Hindgut fermentation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hindgut_fermentation
date_saved: 2026-05-05T07:15:30.125848+00:00
instance: kb-cron
parent: hindgut-fermentation-20260505-0
summary:
Hindgut fermentation is a digestive process seen in monogastric herbivores (animals with a simple, single-chambered stomach). Cellulose is digested with the aid of symbiotic microbes including bacteria, archaea, and eukaryotes. The microbial fermentation occurs in the digestive organs that follow the small intestine: the cecum and large intestine. Examples of hindgut fermenters include proboscideans and large odd-toed ungulates such as horses and rhinos, as well as small animals such as rodents, rabbits and koalas. In contrast, foregut fermentation is the form of cellulose digestion seen in ruminants such as cattle which have a four-chambered stomach, as well as in sloths, macropodids, some monkeys, and one bird, the hoatzin. == Cecum == Hindgut fermenters generally have a cecum and large intestine that are much larger and more complex than those of a foregut fermenter. Research on small cecum fermenters such as flying squirrels, rabbits and lemurs has revealed these mammals to have a GI tract about 10-13 times the length of their body. This is due to the high intake of fiber and other hard to digest compounds that are characteristic to the diet of monogastric herbivores. Easily digestible food is processed in the gastrointestinal tract & expelled as regular feces.


id: homeostasis-20260505-0
file: data/en.wikipedia.org/wiki/Homeostasis-0.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
In biology, homeostasis (British also homoeostasis; HOH-mee-ə-STAY-sis) is the state of steady internal physical and chemical conditions maintained by living organisms. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium, and calcium ions, as well as the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Each of these variables is controlled by one or more regulators or homeostatic mechanisms, which together maintain life. Homeostasis is brought about by a natural resistance to change when already in its optimal conditions, and equilibrium is maintained by many regulatory mechanisms; it is thought to be the central motivation for all organic action. All homeostatic control mechanisms have at least three interdependent components for the variable being regulated: a receptor, a control center, and an effector. The receptor is the sensing component that monitors and responds to changes in the environment, either external or internal. Receptors include thermoreceptors and mechanoreceptors. Control centers include the respiratory center and the renin-angiotensin system.


id: homeostasis-20260505-1
file: data/en.wikipedia.org/wiki/Homeostasis-1.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
If an entity is homeostatically controlled it does not imply that its value is necessarily absolutely steady in health. Core body temperature is, for instance, regulated by a homeostatic mechanism with temperature sensors in, amongst others, the hypothalamus of the brain. However, the set point of the regulator is regularly reset. For instance, core body temperature in humans varies during the course of the day (i.e. has a circadian rhythm), with the lowest temperatures occurring at night, and the highest in the afternoons. Other normal temperature variations include those related to the menstrual cycle. The temperature regulator's set point is reset during infections to produce a fever. Organisms are capable of adjusting somewhat to varied conditions such as temperature changes or oxygen levels at altitude, by a process of acclimatisation. Homeostasis does not govern every activity in the body. For instance, the signal (be it via neurons or hormones) from the sensor to the effector is, of necessity, highly variable in order to convey information about the direction and magnitude of the error detected by the sensor. Similarly, the effector's response needs to be highly adjustable to reverse the error – in fact it should be very nearly in proportion


id: homeostasis-20260505-2
file: data/en.wikipedia.org/wiki/Homeostasis-2.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
Blood sugar levels are regulated within fairly narrow limits. In mammals, the primary sensors for this are the beta cells of the pancreatic islets. The beta cells respond to a rise in the blood sugar level by secreting insulin into the blood and simultaneously inhibiting their neighboring alpha cells from secreting glucagon into the blood. This combination (high blood insulin levels and low glucagon levels) act on effector tissues, the chief of which is the liver, fat cells, and muscle cells. The liver is inhibited from producing glucose, taking it up instead, and converting it to glycogen and triglycerides. The glycogen is stored in the liver, but the triglycerides are secreted into the blood as very low-density lipoprotein (VLDL) particles which are taken up by adipose tissue, there to be stored as fats. The fat cells take up glucose through special glucose transporters (GLUT4), whose numbers in the cell wall are increased as a direct effect of insulin acting on these cells. The glucose that enters the fat cells in this manner is converted into triglycerides (via the same metabolic pathways as are used by the liver) and then stored in those fat cells together with the VLDL-derived triglycerides that


id: homeostasis-20260505-3
file: data/en.wikipedia.org/wiki/Homeostasis-3.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
Changes in the levels of oxygen, carbon dioxide, and plasma pH are sent to the respiratory center, in the brainstem where they are regulated. The partial pressure of oxygen and carbon dioxide in the arterial blood is monitored by the peripheral chemoreceptors (PNS) in the carotid artery and aortic arch. A change in the partial pressure of carbon dioxide is detected as altered pH in the cerebrospinal fluid by central chemoreceptors (CNS) in the medulla oblongata of the brainstem. Information from these sets of sensors is sent to the respiratory center which activates the effector organs – the diaphragm and other muscles of respiration. An increased level of carbon dioxide in the blood, or a decreased level of oxygen, will result in a deeper breathing pattern and increased respiratory rate to bring the blood gases back to equilibrium. Too little carbon dioxide, and, to a lesser extent, too much oxygen in the blood can temporarily halt breathing, a condition known as apnea, which freedivers use to prolong the time they can stay underwater. The partial pressure of carbon dioxide is more of a deciding factor in the monitoring of pH. However, at high altitude (above 2500 m) the monitoring of


id: homeostasis-20260505-4
file: data/en.wikipedia.org/wiki/Homeostasis-4.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
The plasma ionized calcium (Ca2+) concentration is very tightly controlled by a pair of homeostatic mechanisms. The sensor for the first one is situated in the parathyroid glands, where the chief cells sense the Ca2+ level by means of specialized calcium receptors in their membranes. The sensors for the second are the parafollicular cells in the thyroid gland. The parathyroid chief cells secrete parathyroid hormone (PTH) in response to a fall in the plasma ionized calcium level; the parafollicular cells of the thyroid gland secrete calcitonin in response to a rise in the plasma ionized calcium level. The effector organs of the first homeostatic mechanism are the bones, the kidney, and, via a hormone released into the blood by the kidney in response to high PTH levels in the blood, the duodenum and jejunum. Parathyroid hormone (in high concentrations in the blood) causes bone resorption, releasing calcium into the plasma. This is a very rapid action which can correct a threatening hypocalcemia within minutes. High PTH concentrations cause the excretion of phosphate ions via the urine. Since phosphates combine with calcium ions to form insoluble salts (see also bone mineral), a decrease in the level of phosphates in the blood,


id: homeostasis-20260505-5
file: data/en.wikipedia.org/wiki/Homeostasis-5.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
=== Sodium concentration === The homeostatic mechanism which controls the plasma sodium concentration is rather more complex than most of the other homeostatic mechanisms described on this page. The sensor is situated in the juxtaglomerular apparatus of kidneys, which senses the plasma sodium concentration in a surprisingly indirect manner. Instead of measuring it directly in the blood flowing past the juxtaglomerular cells, these cells respond to the sodium concentration in the renal tubular fluid after it has already undergone a certain amount of modification in the proximal convoluted tubule and loop of Henle. These cells also respond to rate of blood flow through the juxtaglomerular apparatus, which, under normal circumstances, is directly proportional to the arterial blood pressure, making this tissue an ancillary arterial blood pressure sensor. In response to a lowering of the plasma sodium concentration, or to a fall in the arterial blood pressure, the juxtaglomerular cells release renin into the blood. Renin is an enzyme which cleaves a decapeptide (a short protein chain, 10 amino acids long) from a plasma α-2-globulin called angiotensinogen. This decapeptide is known as angiotensin I. It has no known biological activity. However, when the blood circulates through the lungs a pulmonary capillary


id: homeostasis-20260505-6
file: data/en.wikipedia.org/wiki/Homeostasis-6.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
The total amount of water in the body needs to be kept in balance. Fluid balance involves keeping the fluid volume stabilized, and also keeping the levels of electrolytes in the extracellular fluid stable. Fluid balance is maintained by the process of osmoregulation and by behavior. Osmotic pressure is detected by osmoreceptors in the median preoptic nucleus in the hypothalamus. Measurement of the plasma osmolality to give an indication of the water content of the body, relies on the fact that water losses from the body, (through unavoidable water loss through the skin which is not entirely waterproof and therefore always slightly moist, water vapor in the exhaled air, sweating, vomiting, normal feces and especially diarrhea) are all hypotonic, meaning that they are less salty than the body fluids (compare, for instance, the taste of saliva with that of tears. The latter has almost the same salt content as the extracellular fluid, whereas the former is hypotonic with respect to the plasma. Saliva does not taste salty, whereas tears are decidedly salty). Nearly all normal and abnormal losses of body water therefore cause the extracellular fluid to become hypertonic. Conversely, excessive fluid intake dilutes the extracellular fluid causing the hypothalamus


id: homeostasis-20260505-7
file: data/en.wikipedia.org/wiki/Homeostasis-7.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
=== Neurotransmission === Inhibitory neurons in the central nervous system play a homeostatic role in the balance of neuronal activity between excitation and inhibition. Inhibitory neurons using GABA, make compensating changes in the neuronal networks preventing runaway levels of excitation. An imbalance between excitation and inhibition is seen to be implicated in a number of neuropsychiatric disorders. === Neuroendocrine system === The neuroendocrine system is the mechanism by which the hypothalamus maintains homeostasis, regulating metabolism, reproduction, eating and drinking behaviour, energy utilization, osmolarity and blood pressure. The regulation of metabolism, is carried out by hypothalamic interconnections to other glands. Three endocrine glands of the hypothalamic–pituitary–gonadal axis (HPG axis) often work together and have important regulatory functions. Two other regulatory endocrine axes are the hypothalamic–pituitary–adrenal axis (HPA axis) and the hypothalamic–pituitary–thyroid axis (HPT axis). The liver also has many regulatory functions of the metabolism. An important function is the production and control of bile acids. Too much bile acid can be toxic to cells and its synthesis can be inhibited by activation of FXR a nuclear receptor. === Gene regulation === At the cellular level, homeostasis is carried out by several mechanisms including transcriptional regulation that can alter the activity of


id: homeostasis-20260505-8
file: data/en.wikipedia.org/wiki/Homeostasis-8.md
category: reference
title: Homeostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Homeostasis
date_saved: 2026-05-05T07:15:31.436253+00:00
instance: kb-cron
parent: homeostasis-20260505-0
summary:
== Biosphere == In the Gaia hypothesis, James Lovelock stated that the entire mass of living matter on Earth (or any planet with life) functions as a vast homeostatic superorganism that actively modifies its planetary environment to produce the environmental conditions necessary for its own survival. In this view, the entire planet maintains several homeostasis (the primary one being temperature homeostasis). Whether this sort of system is present on Earth is open to debate. However, some relatively simple homeostatic mechanisms are generally accepted. For example, it is sometimes claimed that when atmospheric carbon dioxide levels rise, certain plants may be able to grow better and thus act to remove more carbon dioxide from the atmosphere. However, warming has exacerbated droughts, making water the actual limiting factor on land. When sunlight is plentiful and the atmospheric temperature climbs, it has been claimed that the phytoplankton of the ocean surface waters, acting as global sunshine, and therefore heat sensors, may thrive and produce more dimethyl sulfide (DMS). The DMS molecules act as cloud condensation nuclei, which produce more clouds, and thus increase the atmospheric albedo, and this feeds back to lower the temperature of the atmosphere. However, rising sea temperature has stratified


id: hybrid-biology-20260505-0
file: data/en.wikipedia.org/wiki/Hybrid_(biology)-0.md
category: reference
title: Hybrid (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hybrid_(biology)
date_saved: 2026-05-05T07:15:32.895326+00:00
instance: kb-cron
parent: hybrid-biology-20260505-0
summary:
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different varieties, subspecies, species or genera through sexual reproduction. Generally, it means that each cell has genetic material from two different organisms, whereas an individual where some cells are derived from a different organism is called a chimera. Hybrids are not always intermediates between their parents such as in blending inheritance (a now discredited theory in modern genetics by particulate inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species must be for their offspring to be classified as a hybrid, since crosses between species within the same genera are often treated differently from crosses between more distantly related taxa. Species are reproductively isolated by strong barriers to hybridization, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization


id: hybrid-biology-20260505-1
file: data/en.wikipedia.org/wiki/Hybrid_(biology)-1.md
category: reference
title: Hybrid (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hybrid_(biology)
date_saved: 2026-05-05T07:15:32.895326+00:00
instance: kb-cron
parent: hybrid-biology-20260505-0
summary:
=== Animal and plant breeding === From the point of view of animal and plant breeders, there are several kinds of hybrid formed from crosses within a species, such as between different breeds. Single cross hybrids result from the cross between two true-breeding organisms which produces an F1 hybrid (first filial generation). The cross between two different homozygous lines produces an F1 hybrid that is heterozygous; having two alleles, one contributed by each parent and typically one is dominant and the other recessive. Typically, the F1 generation is also phenotypically homogeneous, producing offspring that are all similar to each other. Double cross hybrids result from the cross between two different F1 hybrids (i.e., there are four unrelated grandparents). Three-way cross hybrids result from the cross between an F1 hybrid and an inbred line. Triple cross hybrids result from the crossing of two different three-way cross hybrids. Top cross (or "topcross") hybrids result from the crossing of a top quality or pure-bred male and a lower quality female, intended to improve the quality of the offspring, on average. Population hybrids result from the crossing of plants or animals in one population with those of another population. These include interspecific hybrids or


id: hybrid-biology-20260505-2
file: data/en.wikipedia.org/wiki/Hybrid_(biology)-2.md
category: reference
title: Hybrid (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hybrid_(biology)
date_saved: 2026-05-05T07:15:32.895326+00:00
instance: kb-cron
parent: hybrid-biology-20260505-0
summary:
A few animal species are the result of hybridization. The Lonicera fly is a natural hybrid. The American red wolf appears to be a hybrid of the gray wolf and the coyote, although its taxonomic status has been a subject of controversy. The European edible frog is a semi-permanent hybrid between pool frogs and marsh frogs; its population requires the continued presence of at least one of the parent species. Cave paintings indicate that the European bison is a natural hybrid of the aurochs and the steppe bison. Plant hybridization is more commonplace compared to animal hybridization. Many crop species are hybrids, including notably the polyploid wheats: some have four sets of chromosomes (tetraploid) or six (hexaploid), while other wheat species have (like most eukaryotic organisms) two sets (diploid), so hybridization events likely involved the doubling of chromosome sets, causing immediate genetic isolation. Hybridization may be important in speciation in some plant groups. However, homoploid hybrid speciation (not increasing the number of sets of chromosomes) may be rare: by 1997, only eight natural examples had been fully described. Experimental studies suggest that hybridization offers a rapid route to speciation, a prediction confirmed by the fact that early generation hybrids and


id: hybrid-biology-20260505-3
file: data/en.wikipedia.org/wiki/Hybrid_(biology)-3.md
category: reference
title: Hybrid (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hybrid_(biology)
date_saved: 2026-05-05T07:15:32.895326+00:00
instance: kb-cron
parent: hybrid-biology-20260505-0
summary:
In agriculture and animal husbandry, the Green Revolution's use of conventional hybridization increased yields by breeding high-yielding varieties. The replacement of locally indigenous breeds, compounded with unintentional cross-pollination and crossbreeding (genetic mixing), has reduced the gene pools of various wild and indigenous breeds resulting in the loss of genetic diversity. Since the indigenous breeds are often well-adapted to local extremes in climate and have immunity to local pathogens, this can be a significant genetic erosion of the gene pool for future breeding. Therefore, commercial plant geneticists strive to breed "widely adapted" cultivars to counteract this tendency. == Different taxa == === In animals === ==== Mammals ==== Familiar examples of equid hybrids are the mule, a cross between a female horse and a male donkey, and the hinny, a cross between a female donkey and a male horse. Pairs of complementary types like the mule and hinny are called reciprocal hybrids. Polar bears and brown bears are another case of a hybridizing species pairs, and introgression among non-sister species of bears appears to have shaped the Ursidae family tree. Among many other mammal crosses are hybrid camels, crosses between a bactrian camel and a dromedary. There are many examples of


id: hybrid-biology-20260505-4
file: data/en.wikipedia.org/wiki/Hybrid_(biology)-4.md
category: reference
title: Hybrid (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hybrid_(biology)
date_saved: 2026-05-05T07:15:32.895326+00:00
instance: kb-cron
parent: hybrid-biology-20260505-0
summary:
Plant species hybridize more readily than animal species, and the resulting hybrids are fertile more often. Many plant species are the result of hybridization, combined with polyploidy, which duplicates the chromosomes. Chromosome duplication allows orderly meiosis and so viable seed can be produced. Plant hybrids are generally given names that include an "×" (not in italics), such as Platanus × hispanica for the London plane, a natural hybrid of P. orientalis (oriental plane) and P. occidentalis (American sycamore). The parent's names may be kept in their entirety, as seen in Prunus persica × Prunus americana, with the female parent's name given first, or if not known, the parent's names given alphabetically. Plant species that are genetically compatible may not hybridize in nature for various reasons, including geographical isolation, differences in flowering period, or differences in pollinators. Species that are brought together by humans in gardens may hybridize naturally, or hybridization can be facilitated by human efforts, such as altered flowering period or artificial pollination. Hybrids are sometimes created by humans to produce improved plants that have some of the characteristics of each of the parent species. Much work is now being done with hybrids between crops and their wild relatives


id: hybrid-incompatibility-20260505-0
file: data/en.wikipedia.org/wiki/Hybrid_incompatibility-0.md
category: reference
title: Hybrid incompatibility
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hybrid_incompatibility
date_saved: 2026-05-05T07:15:34.128889+00:00
instance: kb-cron
parent: hybrid-incompatibility-20260505-0
summary:
Hybrid incompatibility is a phenomenon in plants and animals, wherein offspring produced by the mating of two different species or populations have reduced viability and/or are less able to reproduce. Examples of hybrids include mules and ligers from the animal world, and subspecies of the Asian rice crop Oryza sativa from the plant world. Multiple models have been developed to explain this phenomenon. Recent research suggests that the source of this incompatibility is largely genetic, as combinations of genes and alleles prove lethal to the hybrid organism. Incompatibility is not solely influenced by genetics, however, and can be affected by environmental factors such as temperature. The genetic underpinnings of hybrid incompatibility may provide insight into factors responsible for evolutionary divergence between species. == Background == Hybrid incompatibility occurs when the offspring of two closely related species are not viable or suffer from infertility. Charles Darwin posited that hybrid incompatibility is not a product of natural selection, stating that the phenomenon is an outcome of the hybridizing species diverging, rather than something that is directly acted upon by selective pressures. The underlying causes of the incompatibility can be varied: earlier research focused on things like changes in ploidy in plants. More


id: individuation-20260505-0
file: data/en.wikipedia.org/wiki/Individuation-0.md
category: reference
title: Individuation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Individuation
date_saved: 2026-05-05T07:15:35.415660+00:00
instance: kb-cron
parent: individuation-20260505-0
summary:
The principle of individuation, or principium individuationis, describes the manner in which a thing is identified as distinct from other things. The concept appears in numerous fields and is encountered in works of Leibniz, Carl Jung, Gunther Anders, Gilbert Simondon, Bernard Stiegler, Friedrich Nietzsche, Arthur Schopenhauer, David Bohm, Henri Bergson, Gilles Deleuze, and Manuel DeLanda. == Usage == The word individuation occurs with different meanings and connotations in different fields. === In philosophy === Philosophically, "individuation" expresses the general idea of how a thing is identified as an individual thing that "is not something else". This includes how an individual person is held to be different from other elements in the world and how a person is distinct from other persons. By the seventeenth century, philosophers began to associate the question of individuation or what brings about individuality at any one time with the question of identity or what constitutes sameness at different points in time. === In Jungian psychology === In analytical psychology, individuation is the process by which the individual self develops out of an undifferentiated unconscious – seen as a developmental psychic process during which innate elements of personality, the components of the immature psyche, and the


id: individuation-20260505-1
file: data/en.wikipedia.org/wiki/Individuation-1.md
category: reference
title: Individuation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Individuation
date_saved: 2026-05-05T07:15:35.415660+00:00
instance: kb-cron
parent: individuation-20260505-0
summary:
According to Jungian psychology, individuation (German: Individuation) is a process of psychological integration. "In general, it is the process by which individual beings are formed and differentiated [from other human beings]; in particular, it is the development of the psychological individual as a being distinct from the general, collective psychology." Individuation is a process of transformation whereby the personal and collective unconscious are brought into consciousness (e.g., by means of dreams, active imagination, or free association) to be assimilated into the whole personality. It is a completely natural process that is necessary for the integration of the psyche. Individuation has a holistic healing effect on the person, both mentally and physically. In addition to Jung's theory of complexes, his theory of the individuation process forms conceptions of an unconscious filled with mythic images, a non-sexual libido, the general types of extraversion and introversion, the compensatory and prospective functions of dreams, and the synthetic and constructive approaches to fantasy formation and utilization. "The symbols of the individuation process . . . mark its stages like milestones, prominent among them for Jungians being the shadow, the wise old man . . . and lastly the anima in man and the animus in


id: individuation-20260505-2
file: data/en.wikipedia.org/wiki/Individuation-2.md
category: reference
title: Individuation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Individuation
date_saved: 2026-05-05T07:15:35.415660+00:00
instance: kb-cron
parent: individuation-20260505-0
summary:
== In collectivistic cultures == Research indicates that individuation is culturally mediated: in collectivist societies, expressions of individuation "take the lead" or "seek attention" rather than follow a singular independent pattern. Concepts like "integrative individuation" emphasize maintaining relational bonds rather than complete separation. Collectivist norms tend to discourage standing out, meaning individuation is often constrained or reshaped according to cultural values. == See also == Akrasia Deindividuation Identical particles Identity formation Indiscernibles Individualistic culture Nekyia Positive disintegration Principle of individuation Rationalization (sociology) Self-actualization == References == == Bibliography == Gilbert Simondon, Du mode d'existence des objets techniques (Méot, 1958; Paris: Aubier, 1989, second edition). (in French) Gilbert Simondon, On the Mode of Existence of Technical Objects, Part 1, link to PDF of 1980 translation. Gilbert Simondon, L'individu et sa genèse physico-biologique (l'individuation à la lumière des notions de forme et d'information) (Paris: PUF, 1964; J.Millon, coll. Krisis, 1995, second edition). (in French) Gilbert Simondon, The Individual and Its Physico-Biological Genesis, Part 1, Part 2, links to HTML files of unpublished 2007 translation. Gilbert Simondon, L'Individuation psychique et collective (1964; Paris: Aubier, 1989). (in French) Bernard Stiegler, Acting Out. Bernard Stiegler, Temps et individuation technique, psychique, et collective dans l’oeuvre de


id: landrace-20260505-0
file: data/en.wikipedia.org/wiki/Landrace-0.md
category: reference
title: Landrace
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Landrace
date_saved: 2026-05-05T07:15:39.109121+00:00
instance: kb-cron
parent: landrace-20260505-0
summary:
A landrace is a domesticated, locally adapted, often traditional variety of a species of animal or plant that has developed over time, through adaptation to its natural and cultural environment of agriculture and pastoralism, and due to isolation from other populations of the species. Landraces are distinct from cultivars and from standard breeds.| Landrace dogs are commonly referenced. They typically have distinct ecological and behavioral characteristics that evolutionally developed in certain nations and locales, especially those with a history of colonization. A significant proportion of farmers around the world grow landrace crops, and most plant landraces are associated with traditional agricultural systems. Landraces of many crops have probably been grown for millennia. Increasing reliance upon modern plant cultivars that are bred to be uniform has led to a reduction in biodiversity, because most of the genetic diversity of domesticated plant species lies in landraces and other traditionally used varieties. Some farmers using scientifically improved varieties also continue to raise landraces for agronomic reasons that include better adaptation to the local environment, lower fertilizer requirements, lower cost, and better disease resistance. Cultural and market preferences for landraces include culinary uses and product attributes such as texture, color, or ease of use.


id: landrace-20260505-1
file: data/en.wikipedia.org/wiki/Landrace-1.md
category: reference
title: Landrace
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Landrace
date_saved: 2026-05-05T07:15:39.109121+00:00
instance: kb-cron
parent: landrace-20260505-0
summary:
=== Autochthonous and allochthonous landraces === A landrace native to, or produced for a long time within the agricultural system in which it is found is referred to as an autochthonous landrace, while a more recently introduced one is termed an allochthonous landrace. Within academic agronomy, the term autochthonous landrace is sometimes used with a more technical, productivity-related definition, synthesized by A. C. Zeven from previous definitions beginning with Mansholt's: "an autochthonous landrace is a variety with a high capacity to tolerate biotic and abiotic stress, resulting in a high yield stability and an intermediate yield level under a low input agricultural system." The terms autochthonous and allochthonous are most often applied to plants, with animals more often being referred to as indigenous or native. Examples of references in sources to long-term local landraces of livestock include constructions such as "indigenous landraces of sheep", and "Leicester Longwool sheep were bred to the native landraces of the region". Some usage of autochthonous does occur in reference to livestock, e.g. "autochthonous races of cattle such as the Asturian mountain cattle – Ratina and Casina – and Tudanca cattle." == Biodiversity and conservation == A significant proportion of farmers around the world grow


id: landrace-20260505-2
file: data/en.wikipedia.org/wiki/Landrace-2.md
category: reference
title: Landrace
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Landrace
date_saved: 2026-05-05T07:15:39.109121+00:00
instance: kb-cron
parent: landrace-20260505-0
summary:
The label landrace includes regional cultigens that are genetically heterogeneous, but with enough characteristics in common to permit their recognition as a group. These characteristics are used by farmers to manage diversity and purity within landraces. In some cultures, the development of new landraces is typically limited to members of specific social groups, such as women or shaman. Maintaining existing landraces, like developing new landraces, requires that farmers be able to identify crop-specific characteristics and that those characteristics are passed on to following generations. Over time, the process of identifying the distinguishing characteristic or features of a new landrace is reinforced by cultivation processes; for example, descendants of a plant that is notably drought tolerant may become iteratively more so through selective breeding as farmers regard it as better for dry areas and prioritize planting it in those locations. This is one way in which farming systems can develop a portfolio of landraces over time that have specific ecological niches and uses. Conversely, modern cultivars can also be developed into a landrace over time when farmers save seed and practice selective breeding. Although landraces are often discussed once they have become endemic to a particular geographical region, landraces have always


id: liana-20260505-0
file: data/en.wikipedia.org/wiki/Liana-0.md
category: reference
title: Liana
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Liana
date_saved: 2026-05-05T07:15:41.589127+00:00
instance: kb-cron
parent: liana-20260505-0
summary:
A liana ( lee-ANN-ə, also -⁠AH-nə) is a long-stemmed woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the canopy in search of direct sunlight. The word liana does not refer to a taxonomic grouping, but rather a habit of plant growth—much like tree or shrub. It comes from standard French liane, itself from an Antilles French dialect word meaning 'to sheave'. == Ecology == Lianas are characteristic of tropical moist broadleaf forests (especially seasonal forests), but may be found in temperate rainforests and temperate deciduous forests. There are also temperate lianas, for example the members of the Clematis or Vitis (wild grape) genera. Lianas can form bridges in the forest canopy, providing arboreal animals—including ants and many other invertebrates, lizards, rodents, sloths, monkeys, and lemurs—with paths through the forest. For example, in the Eastern tropical forests of Madagascar many lemurs achieve higher mobility from the web of lianas draped among the vertical tree species. Many lemurs prefer trees with lianas because of their roots. Lianas are parasitic, they do not derive nutrients directly from host trees, but live on and indirectly derive


id: earliest-known-life-forms-20260505-0
file: data/en.wikipedia.org/wiki/Earliest_known_life_forms-0.md
category: reference
title: Earliest known life forms
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Earliest_known_life_forms
date_saved: 2026-05-05T07:15:42.867278+00:00
instance: kb-cron
parent: earliest-known-life-forms-20260505-0
summary:
The earliest known life forms on Earth may be as old as 4.1 billion years (or Ga) according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. The earliest evidence of life found in a stratigraphic unit, not just a single mineral grain, is the 3.7 Ga metasedimentary rocks containing graphite from the Isua Supracrustal Belt in Greenland. The earliest direct known life on Earth are stromatolite fossils which have been found in 3.480-billion-year-old geyserite uncovered in the Dresser Formation of the Pilbara Craton of Western Australia. Various microfossils of microorganisms have been found in 3.4 Ga rocks, including 3.465-billion-year-old Apex chert rocks from the same Australian craton region, and in 3.42 Ga hydrothermal vent precipitates from Barberton, South Africa. Much later in the geologic record, likely starting in 1.73 Ga, preserved molecular compounds of biologic origin are indicative of aerobic life. Therefore, the earliest time for the origin of life on Earth is at least 3.5 billion years ago and possibly as early as 4.1 billion years ago—not long after the oceans formed 4.5 billion years ago and after the formation of the Earth 4.54 billion years ago. == Biospheres == Earth


id: earliest-known-life-forms-20260505-1
file: data/en.wikipedia.org/wiki/Earliest_known_life_forms-1.md
category: reference
title: Earliest known life forms
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Earliest_known_life_forms
date_saved: 2026-05-05T07:15:42.867278+00:00
instance: kb-cron
parent: earliest-known-life-forms-20260505-0
summary:
Stromatolites are laminated sedimentary structures created by photosynthetic organisms as they establish a microbial mat on a sediment surface. An important distinction for biogenicity is their convex-up structures and wavy laminations, which are typical of microbial communities who build preferentially toward the sun. A disputed report of stromatolites is from the 3.7 Ga Isua metasediments that show convex-up, conical, and domical morphologies. Further mineralogical analysis disagrees with the initial findings of internal convex-up laminae, a critical criterion for stromatolite identification, suggesting that the structures may be deformation features (i.e. boudins) caused by extensional tectonics in the Isua Supracrustal Belt. The earliest direct evidence of life are stromatolites found in 3.48 billion-year-old chert in the Dresser formation of the Pilbara Craton in Western Australia. Several features in these fossils are difficult to explain with abiotic processes, for example, the thickening of laminae over flexure crests that is expected from more sunlight. Sulfur isotopes from barite veins in the stromatolites also favor a biologic origin. However, while most scientists accept their biogenicity, abiotic explanations for these fossils cannot be fully discarded due to their hydrothermal depositional environment and debated geochemical evidence. Most archean stromatolites older than 3.0 Ga are found in Australia


id: earliest-known-life-forms-20260505-2
file: data/en.wikipedia.org/wiki/Earliest_known_life_forms-2.md
category: reference
title: Earliest known life forms
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Earliest_known_life_forms
date_saved: 2026-05-05T07:15:42.867278+00:00
instance: kb-cron
parent: earliest-known-life-forms-20260505-0
summary:
While current geochemical evidence dates the origin of life to possibly as early as 4.1 Ga, and fossil evidence shows life at 3.5 Ga, some researchers speculate that life may have started nearly 4.5 billion years ago. According to biologist Stephen Blair Hedges, "If life arose relatively quickly on Earth ... then it could be common in the universe." The possibility that terrestrial life forms may have been seeded from outer space has been considered. In January 2018, a study found that 4.5 billion-year-old meteorites found on Earth contained liquid water along with prebiotic complex organic substances that may be ingredients for life. === Hydrothermal vents === Hydrothermal vents have long been hypothesized to be the grounds from which life originated. The properties of ancient hydrothermal vents, such as the geochemistry, pressure, and temperatures, have the potential to create organic molecules from inorganic molecules. In experiments performed by NASA, it was shown that the organic compounds formate and methane could be created from inorganics in the conditions of ancient hydrothermal vents. The production of organic molecules could have led to the formation of more complex organic molecules, such as amino acids that can eventually form RNA or DNA. === Darwin's


id: live-crown-20260505-0
file: data/en.wikipedia.org/wiki/Live_crown-0.md
category: reference
title: Live crown
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Live_crown
date_saved: 2026-05-05T07:15:44.042313+00:00
instance: kb-cron
parent: live-crown-20260505-0
summary:
The live crown is the top part of a tree, the part that has green leaves (as opposed to the bare trunk, bare branches, and dead leaves). The ratio of the size of a tree's live crown to its total height is used in estimating its health and its level of competition with neighboring trees. This is referred to as the Live Crown Ratio (LCR). == References ==


id: matriphagy-20260505-0
file: data/en.wikipedia.org/wiki/Matriphagy-0.md
category: reference
title: Matriphagy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Matriphagy
date_saved: 2026-05-05T07:15:55.810435+00:00
instance: kb-cron
parent: matriphagy-20260505-0
summary:
Matriphagy is the consumption of the mother by her offspring. The behavior generally takes place within the first few weeks of life and has been documented in some species of insects, nematode worms, pseudoscorpions, and other arachnids as well as in caecilian amphibians. The specifics of how matriphagy occurs varies among different species. However, the process is best-described in the desert spider (Stegodyphus lineatus), where the mother harbors nutritional resources for her young through food consumption. The mother can regurgitate small portions of food for her growing offspring, but between 1–2 weeks after hatching, the progeny capitalize on this food source by eating her alive. Typically, offspring only feed on their biological mother as opposed to other females in the population. In other arachnid species, matriphagy occurs after the ingestion of nutritional eggs known as trophic eggs (e.g. Black lace-weaver Amaurobius ferox, crab spider Australomisidia ergandros). It involves different techniques for killing the mother, such as transfer of poison via biting and sucking to cause a quick death (e.g. Black lace-weaver) or continuous sucking of the hemolymph, resulting in a more gradual death (e.g. Crab spider). The behavior is less well described but follows a similar pattern in species such


id: matriphagy-20260505-1
file: data/en.wikipedia.org/wiki/Matriphagy-1.md
category: reference
title: Matriphagy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Matriphagy
date_saved: 2026-05-05T07:15:55.810435+00:00
instance: kb-cron
parent: matriphagy-20260505-0
summary:
==== Anechura harmandi ==== Anechura harmandi is the only species of earwigs that has been currently documented to exhibit matriphagy. Mothers in this particular species of earwigs have been found to reproduce during colder temperatures. This is mainly for the purpose of avoiding predation and maximizing their offspring's survival, since females are unable to produce a second clutch. Due to the cold temperature, there is a scarcity of available nutrients when the offspring hatch, which is why the offspring end up consuming their mother. === Pseudoscorpions === ==== Paratemnoides nidificator ==== Matriphagy in this species of pseudoscorpions is usually observed during times of food scarcity. After their offspring hatch, mothers exit their nests and wait to be consumed. Offspring follow their mothers out of the nest where they grab onto her legs and proceed to feed through her leg joints, similar to that of Australomisidia ergandros. Females of this species are able to produce more than one clutch of offspring if their first clutch was unsuccessful. Matriphagy in this species has been predicted to prevent cannibalism between siblings as well. == Evolution == The adaptive value of matriphagy is based on the benefits provided to the offspring and the costs


id: matriphagy-20260505-2
file: data/en.wikipedia.org/wiki/Matriphagy-2.md
category: reference
title: Matriphagy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Matriphagy
date_saved: 2026-05-05T07:15:55.810435+00:00
instance: kb-cron
parent: matriphagy-20260505-0
summary:
The Taita African caecilian Boulengerula taitana is an oviparous (egg-laying) caecilian whose skin transforms in brooding females to supply nutrients to growing offspring. The offspring are born with specific dentition that they can use to peel and eat the outer epidermal layer of their mother's skin. Young move around their mother's bodies, using their lower jaws to lift and peel the mother's skin while vigorously pressing their heads against her abdomen. To account for this, the epidermis of brooding females can be up to twice the thickness of non-brooding females. Viviparous (developing in the mother) caecilians on the other hand, have specialized fetal dentition which can be used for scraping lipid-rich secretions and cellular materials from the maternal oviduct lining. The ringed caecilian Siphonops annulatus, an oviparous caecilian, exhibits characteristics similar to viviparous caecilians. Mothers have paler skin tones than non-attending females, suggesting that offspring feed on glandular secretions on the mother's skin—a process that resembles mammalian lactation. This scraping method is different from the peeling actions performed by oviparous caecilians. For both oviparous and viviparous caecilians, delayed investment is a common benefit. Providing nutrition through the skin allows for redirection of nutrients, yielding fewer and larger offspring than caecilians


id: modularity-biology-20260505-0
file: data/en.wikipedia.org/wiki/Modularity_(biology)-0.md
category: reference
title: Modularity (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Modularity_(biology)
date_saved: 2026-05-05T07:15:56.996480+00:00
instance: kb-cron
parent: modularity-biology-20260505-0
summary:
Modularity refers to the ability of a system to organize discrete, individual units that can overall increase the efficiency of network activity and, in a biological sense, facilitates selective forces upon the network. Modularity is observed in all model systems, and can be studied at nearly every scale of biological organization, from molecular interactions all the way up to the whole organism. == Evolution of Modularity == The exact evolutionary origins of biological modularity has been debated since the 1990s. In the mid 1990s, Günter Wagner argued that modularity could have arisen and been maintained through the interaction of four evolutionary modes of action: [1] Selection for the rate of adaptation: If different complexes evolve at different rates, then those evolving more quickly reach fixation in a population faster than other complexes. Thus, common evolutionary rates could be forcing the genes for certain proteins to evolve together while preventing other genes from being co-opted unless there is a shift in evolutionary rate. [2] Constructional selection: When a gene exists in many duplicated copies, it may be maintained because of the many connections it has (also termed pleiotropy). There is evidence that this is so following whole genome duplication, or duplication


id: molluscivore-20260505-0
file: data/en.wikipedia.org/wiki/Molluscivore-0.md
category: reference
title: Molluscivore
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molluscivore
date_saved: 2026-05-05T07:15:58.235461+00:00
instance: kb-cron
parent: molluscivore-20260505-0
summary:
A molluscivore is a carnivorous animal that specialises in feeding on molluscs such as gastropods, bivalves, brachiopods and cephalopods. Known molluscivores include numerous predatory (and often cannibalistic) molluscs, (e.g. octopuses, murexes, decollate snails and oyster drills), arthropods such as crabs and firefly larvae, and vertebrates such as fish, birds and mammals. Molluscivory is performed in a variety of ways with some animals highly adapted to this method of feeding. A similar behaviour, durophagy, describes the feeding of animals that consume hard-shelled or exoskeleton bearing organisms, such as corals, shelled molluscs, or crabs. == Description == Molluscivory can be performed in several ways: In some cases, the mollusc prey are simply swallowed entire, including the shell, whereupon the prey is killed through suffocation and/or exposure to digestive enzymes. Only cannibalistic sea slugs, snail-eating cone shells of the taxon Coninae, and some sea anemones use this method. One method, used especially by vertebrate molluscivores, is to break the shell, either by exerting force on the shell until it breaks, often by biting the shell, like with oyster crackers, mosasaurs, and placodonts, or hammering at the shell, e.g. oystercatchers and crabs, or by simply dashing the mollusc on a rock (e.g. song thrushes,


id: molluscivore-20260505-1
file: data/en.wikipedia.org/wiki/Molluscivore-1.md
category: reference
title: Molluscivore
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molluscivore
date_saved: 2026-05-05T07:15:58.235461+00:00
instance: kb-cron
parent: molluscivore-20260505-0
summary:
Cone snails: Some cone snails hunt and eat other kinds of snails, such as cowries, olive shells, turbo snails, and conch snails, while others will eat other cone snails. Conus marmoreus and Conus omaria are able to kill and swallow prey that are larger than themselves; some Conus species can swallow prey that weigh up to half of their own weight. Snails' bodies are attached to their shell by a columellar muscle that holds onto the columella, the axis of the snail. This muscle also allows the snail to retract back into its shell. If this muscle is broken, the snail will lose its shell and die. It is hard to detach this muscle in a live snail, or even in a dead snail. It is thought that the conotoxins in the venom of cone snails are able to completely relax this muscle so that the body can be pulled out from its shell. The cone snail uses its foot to hold the shell of its prey. Using a strong, steady pulling motion, the body of the snail can be forced out and then swallowed whole. Complete digestion of a snail can take many hours, even days. Starfish: Primitive starfish,


id: monoclonality-20260505-0
file: data/en.wikipedia.org/wiki/Monoclonality-0.md
category: reference
title: Monoclonality
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Monoclonality
date_saved: 2026-05-05T07:15:59.386578+00:00
instance: kb-cron
parent: monoclonality-20260505-0
summary:
In biology, monoclonality refers to the state of a line of cells that have been derived from a single clonal origin. Thus, "monoclonal cells" can be said to form a single clone. The term monoclonal comes from Ancient Greek monos 'alone, single' and klonos 'clone'. The process of replication can occur in vivo, or may be stimulated in vitro for laboratory manipulations. The use of the term typically implies that there is some method to distinguish between the cells of the original population from which the single ancestral cell is derived, such as a random genetic alteration, which is inherited by the progeny. Common usages of this term include: Monoclonal antibody: a single hybridoma cell, which by chance includes the appropriate V(D)J recombination to produce the desired antibody, is cloned to produce a large population of identical cells. In informal laboratory jargon, the monoclonal antibodies isolated from cell culture supernatants of these hybridoma clones (hybridoma lines) are simply called monoclonals. Monoclonal neoplasm (tumor): A single aberrant cell which has undergone carcinogenesis reproduces itself into a cancerous mass. Monoclonal plasma cell (also called plasma cell dyscrasia): A single aberrant plasma cell which has undergone carcinogenesis reproduces itself, which in some cases


id: monogastric-20260505-0
file: data/en.wikipedia.org/wiki/Monogastric-0.md
category: reference
title: Monogastric
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Monogastric
date_saved: 2026-05-05T07:16:00.599009+00:00
instance: kb-cron
parent: monogastric-20260505-0
summary:
A monogastric organism defines one of the many types of digestive tracts found among different species of animals. The defining feature of a monogastric is that it has a simple single-chambered stomach (one stomach). A monogastric can be classified as an herbivore, an omnivore (facultative carnivore), or a carnivore (obligate carnivore). Herbivores have a plant-based diet, omnivores have a plant and meat-based diet, and carnivores only eat meat. Examples of monogastric herbivores include horses, rabbits, and guinea pigs. Examples of monogastric omnivores include humans, pigs, and hamsters. Furthermore, there are monogastric carnivores such as cats and seals. A monogastric digestive tract is slightly different from other types of digestive tracts such as a ruminant and avian. Ruminant organisms have a four-chambered complex stomach and avian organisms have a two-chambered stomach. An example of a ruminant and avian are cattle and chickens. == Digestive System == The digestive system of a monogastric is a one way tract that can be divided into two section: the foregut and the hindgut. The foregut consists of the mouth, esophagus, stomach, and small intestine. The hindgut consists of the large intestine, cecum, colon, and rectum. Each organ has its own role in the break down


id: mycobiota-20260505-0
file: data/en.wikipedia.org/wiki/Mycobiota-0.md
category: reference
title: Mycobiota
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mycobiota
date_saved: 2026-05-05T07:16:02.079658+00:00
instance: kb-cron
parent: mycobiota-20260505-0
summary:
Mycobiota (plural noun, no singular) are a group of all the fungi present in a particular geographic region (e.g. "the mycobiota of Ireland") or habitat type (e.g. "the mycobiota of cocoa"). An analogous term for Mycobiota is funga. == Human mycobiota == Mycobiota exist on the surface and in the gastrointestinal system of humans. There are as many as sixty-six genera and 184 species in the gastrointestinal tract of healthy people. Most of these are in the Candida genera. Though found to be present on the skin and in the gi tract in healthy individuals, the normal resident mycobiota can become pathogenic in those who are immunocompromised. Such multispecies infections lead to higher mortalities. In addition hospital-acquired infections by C. albicans have become a cause of major health concerns. A high mortality rate of 40-60% is associated with systemic infection. The best-studied of these are Candida species due to their ability to become pathogenic in immunocompromised and even in healthy hosts. Yeasts are also present on the skin, such as Malassezia species, where they consume oils secreted from the sebaceous glands. Pityrosporum (Malassezia) ovale, which is lipid-dependent and found only on humans. P. ovale was later divided into two species,


id: natural-competence-20260505-0
file: data/en.wikipedia.org/wiki/Natural_competence-0.md
category: reference
title: Natural competence
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Natural_competence
date_saved: 2026-05-05T07:16:03.334926+00:00
instance: kb-cron
parent: natural-competence-20260505-0
summary:
In microbiology, genetics, cell biology, and molecular biology, competence is the ability of a cell to alter its genetics by taking up extracellular DNA from its environment through a process called transformation. Competence can be differentiated between natural competence and induced or artificial competence. Natural competence is a genetically specified ability of bacteria that occurs under natural conditions as well as in the laboratory. Artificial competence arises when cells in laboratory cultures are treated to make them transiently permeable to DNA. Competence allows for rapid adaptation and DNA repair of the cell. == History == Natural competence was discovered by Frederick Griffith in 1928, when he showed that a preparation of killed cells of a pathogenic bacterium contained something that could transform related non-pathogenic cells into the pathogenic type. In 1944 Oswald Avery, Colin MacLeod, and Maclyn McCarty demonstrated that this 'transforming factor' was pure DNA. This was the first compelling evidence that DNA carries the genetic information of the cell. Since then, natural competence has been studied in a number of different bacteria, particularly Bacillus subtilis, Streptococcus pneumoniae, Neisseria gonorrhoeae, Haemophilus influenzae and members of the Acinetobacter genus. Areas of active research include the mechanisms of DNA transport, the


id: natural-competence-20260505-1
file: data/en.wikipedia.org/wiki/Natural_competence-1.md
category: reference
title: Natural competence
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Natural_competence
date_saved: 2026-05-05T07:16:03.334926+00:00
instance: kb-cron
parent: natural-competence-20260505-0
summary:
=== Hypothesis of DNA as food === The second hypothesis, DNA as food, relies on the fact that cells that take up DNA inevitably acquire the nucleotides the DNA consists of, and, because nucleotides are needed for DNA and RNA synthesis and are expensive to synthesize, these may make a significant contribution to the cell's energy budget. Some naturally competent bacteria also secrete nucleases into their surroundings, and all bacteria can take up the free nucleotides these nucleases generate from environmental DNA. The energetics of DNA uptake are not understood in any system, so it is difficult to compare the efficiency of nuclease secretion to that of DNA uptake and internal degradation. In principle the cost of nuclease production and the uncertainty of nucleotide recovery must be balanced against the energy needed to synthesize the uptake machinery and to pull DNA in. Other important factors are the likelihoods that nucleases and competent cells will encounter DNA molecules, the relative inefficiencies of nucleotide uptake from the environment and from the periplasm (where one strand is degraded by competent cells), and the advantage of producing ready-to-use nucleotide monophosphates from the other strand in the cytoplasm. Another complicating factor is the self-bias of


id: obligate-20260505-0
file: data/en.wikipedia.org/wiki/Obligate-0.md
category: reference
title: Obligate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Obligate
date_saved: 2026-05-05T07:16:05.776718+00:00
instance: kb-cron
parent: obligate-20260505-0
summary:
As an adjective, obligate means "by necessity" (antonym facultative) and is used mainly in biology in phrases such as: Obligate aerobe, an organism that cannot survive without oxygen Obligate anaerobe, an organism that cannot survive in the presence of oxygen Obligate air-breather, a term used in fish physiology to describe those that respire entirely from the atmosphere Obligate biped, an animal that relies solely on walking or running on its two hind limbs for locomotion Obligate carnivore, an organism dependent for survival on a diet of animal flesh. Obligate chimerism, a kind of organism with two distinct sets of DNA, always Obligate hibernation, a state of inactivity in which some organisms survive conditions of insufficiently available resources. Obligately intracellular parasite, a parasitic microorganism that cannot reproduce without entering a suitable host cell Obligate necrophage, an animal that uses carrion as its sole or main food source and depends on carrion for survival or reproduction Obligate parasite, a parasite that cannot reproduce without exploiting a suitable host Obligate photoperiodic plant, a plant that requires sufficiently long or short nights before it initiates flowering, germination or similarly functions Obligate scavenger, an animal that uses decaying biomass (e.g. carrion, dead plant material) as


id: oophagy-20260505-0
file: data/en.wikipedia.org/wiki/Oophagy-0.md
category: reference
title: Oophagy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oophagy
date_saved: 2026-05-05T07:16:07.109473+00:00
instance: kb-cron
parent: oophagy-20260505-0
summary:
Oophagy ( oh-OFF-ə-jee) or ovophagy, literally "egg eating", is the practice of embryos feeding on eggs produced by the ovary while still inside the mother's uterus. The word oophagy is formed from the classical Greek ᾠόν (ōion, "egg") and classical Greek φᾱγεῖν (phāgein, "to eat"). In contrast, adelphophagy is the cannibalism of a multi-celled embryo. Oophagy is thought to occur in all sharks in the order Lamniformes and has been recorded in the bigeye thresher (Alopias superciliosus), the pelagic thresher (A. pelagicus), the shortfin mako (Isurus oxyrinchus) and the porbeagle (Lamna nasus) among others. It also occurs in the tawny nurse shark (Nebrius ferrugineus), and in the family Pseudotriakidae. This practice may lead to larger embryos or prepare the embryo for a predatory lifestyle. There are variations in the extent of oophagy among the different shark species. The grey nurse shark (Carcharias taurus) practices intrauterine cannibalism, the first developed embryo consuming both additional eggs and any other developing embryos. Slender smooth-hounds (Gollum attenuatus), form egg capsules which contain 30-80 ova, within which only one ovum develops; the remaining ova are ingested and their yolks stored in its external yolk sac. The embryo then proceeds to develop normally, without ingesting further


id: paratype-20260505-0
file: data/en.wikipedia.org/wiki/Paratype-0.md
category: reference
title: Paratype
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Paratype
date_saved: 2026-05-05T07:16:09.515534+00:00
instance: kb-cron
parent: paratype-20260505-0
summary:
In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). Often there is more than one paratype. Paratypes are usually held in museum research collections. The exact meaning of the term paratype when it is used in zoology is not the same as the meaning when it is used in botany. In both cases however, this term is used in conjunction with holotype. == Zoology == In zoological nomenclature, a paratype is officially defined as "Each specimen of a type series other than the holotype." In turn, this definition relies on the definition of a "type series". A type series is the material (specimens of organisms) that was cited in the original publication of the new species or subspecies, and was not excluded from being type material by the author (this exclusion can be implicit, e.g., if an author mentions "paratypes" and then subsequently mentions "other material examined", the latter are not included in the type series), nor referred to as a variant, or only dubiously


id: perennation-20260505-0
file: data/en.wikipedia.org/wiki/Perennation-0.md
category: reference
title: Perennation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Perennation
date_saved: 2026-05-05T07:16:13.223016+00:00
instance: kb-cron
parent: perennation-20260505-0
summary:
In botany, perennation is the ability of organisms, particularly plants, to survive from one germinating season to another, especially under unfavourable conditions such as drought or winter cold. It typically involves development of a perennating organ, which stores enough nutrients to sustain the organism during the unfavourable season, and develops into one or more new plants the following year. Perennation is done by stem in plants to tide over unfavourable condition. Common forms of perennating organs are storage organs (e.g. bulbs, tubers, rhizomes and corm), buds and oxalis . Perennation is closely related with vegetative reproduction, as the organisms commonly use the same organs for both survival and reproduction. == See also == Overwintering Plant pathology Sclerotium Turion (botany) == References ==


id: permissiveness-endocrinology-20260505-0
file: data/en.wikipedia.org/wiki/Permissiveness_(endocrinology)-0.md
category: reference
title: Permissiveness (endocrinology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Permissiveness_(endocrinology)
date_saved: 2026-05-05T07:16:15.770918+00:00
instance: kb-cron
parent: permissiveness-endocrinology-20260505-0
summary:
In endocrinology, permissiveness is a biochemical phenomenon in which the presence of one hormone is required in order for another hormone to exert its full effects on a target cell. Hormones can interact in permissive, synergistic, or antagonistic ways. The chemical classes of hormones include amines, polypeptides, glycoproteins and steroids. Permissive hormones act as precursors to active hormones and may be classified as either prohormones or prehormones. It stimulate the formation of receptors of that hormone. == Examples == Thyroid hormone increases the number of beta-adrenergic receptors available for epinephrine at the latter's target cell, thereby increasing epinephrine's effect on that cell. Specially in cardiac cell. Without the thyroid hormone, epinephrine would have only a weak effect. Cortisol is required for the response of vascular and bronchial smooth muscle to catecholamines. Cortisol is also required for the lipolytic effect of catecholamines, ACTH, and growth hormone on fat cells. Cortisol is also required for the calorigenic effects of glucagon and catecholamines. The effects of a hormone in the body depend on its concentration. Permissive actions of glucocorticoids like cortisol generally occur at low concentrations. Abnormally high amounts of a hormone can result in atypical effects. Glucocorticoids function by attaching to cytoplasmic


id: photoautotroph-20260505-0
file: data/en.wikipedia.org/wiki/Photoautotroph-0.md
category: reference
title: Photoautotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photoautotroph
date_saved: 2026-05-05T07:16:16.929231+00:00
instance: kb-cron
parent: photoautotroph-20260505-0
summary:
Photoautotrophs are organisms that can utilize light energy from sunlight, and elements (such as carbon) from inorganic compounds, to produce organic materials needed to sustain their own metabolism (i.e. autotrophy). Such biological activities are known as photosynthesis, and examples of such organisms include plants, algae and cyanobacteria. Eukaryotic photoautotrophs absorb photonic energy through the photopigment chlorophyll (a porphyrin derivative) in their endosymbiont chloroplasts, while prokaryotic photoautotrophs use chlorophylls and bacteriochlorophylls present in free-floating cytoplasmic thylakoids. Plants, algae, and cyanobacteria perform oxygenic photosynthesis that produces oxygen as a byproduct, while some bacteria perform anoxygenic photosynthesis. == Origin and the Great Oxidation Event == Chemical and geological evidence indicate that photosynthetic cyanobacteria existed about 2.6 billion years ago and anoxygenic photosynthesis had been taking place since a billion years before that. Oxygenic photosynthesis was the primary source of free oxygen and led to the Great Oxidation Event roughly 2.4 to 2.1 billion years ago during the Neoarchean-Paleoproterozoic boundary. Although the end of the Great Oxidation Event was marked by a significant decrease in gross primary productivity that eclipsed extinction events, the development of aerobic respiration enabled more energetic metabolism of organic molecules, leading to symbiogenesis and the evolution of eukaryotes, and allowing


id: photoheterotroph-20260505-0
file: data/en.wikipedia.org/wiki/Photoheterotroph-0.md
category: reference
title: Photoheterotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photoheterotroph
date_saved: 2026-05-05T07:16:18.165326+00:00
instance: kb-cron
parent: photoheterotroph-20260505-0
summary:
Photoheterotrophs (Gk: photo = light, hetero = (an)other, troph = nourishment) are heterotrophic phototrophs—that is, they are organisms that use light for energy, but cannot use carbon dioxide as their sole carbon source. Consequently, they use organic compounds from the environment to satisfy their carbon requirements; these compounds include carbohydrates, fatty acids, and alcohols. Examples of photoheterotrophic organisms include purple non-sulfur bacteria, green non-sulfur bacteria, and heliobacteria. These microorganisms are ubiquitous in aquatic habitats, occupy unique niche-spaces, and contribute to global biogeochemical cycling. Recent research has also indicated that the oriental hornet and some aphids may be able to use light to supplement their energy supply. Some recent research has even found hints of photoheterotrophy in a few eukaryotes, though it's still being studied. == Research == Studies have shown that mammalian mitochondria can also capture light and synthesize ATP when mixed with pheophorbide, a light-capturing metabolite of chlorophyll. Research demonstrated that the same metabolite when fed to the worm Caenorhabditis elegans leads to increase in ATP synthesis upon light exposure, along with an increase in life span. Furthermore, inoculation experiments suggest that mixotrophic Ochromonas danica (i.e., Golden algae)—and comparable eukaryotes—favor photoheterotrophy in oligotrophic (i.e., nutrient-limited) aquatic habitats. This preference


id: photoheterotroph-20260505-1
file: data/en.wikipedia.org/wiki/Photoheterotroph-1.md
category: reference
title: Photoheterotroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photoheterotroph
date_saved: 2026-05-05T07:16:18.165326+00:00
instance: kb-cron
parent: photoheterotroph-20260505-0
summary:
=== Distribution and niche partitioning === Photoheterotrophs are found in many different water-based environments like oceans, lakes, and even rice paddies. They tend to live near the surface of the water, where there's enough light but not much carbon dioxide. Photoheterotrophs—either 1) cyanobacteria (i.e. facultative heterotrophs in nutrient-limited environments like Synechococcus and Prochlorococcus), 2) aerobic anoxygenic photoheterotrophic bacteria (AAP; employing bacteriochlorophyll-based reaction centers), 3) proteorhodopsin (PR)-containing bacteria and archaea, and 4) heliobacteria (i.e., the only phototroph with bacteriochlorophyll g pigments, or Gram-positive membrane) are found in various aquatic habitats including oceans, stratified lakes, rice fields, and environmental extremes. In oceans' photic zones, up to 10% of bacterial cells are capable of AAP, whereas greater than 50% of net marine microorganisms house PR—reaching up to 90% in coastal biomes. As demonstrated in inoculation experiments, photoheterotrophy may provide these planktonic microbes competitive advantages 1) relative to chemoheterotrophs in oligotrophic (i.e., nutrient-poor) environments via increased nutrient use-efficiency (i.e., organic carbon fuels biosynthesis, excessively, versus energy production) and 2) by eliminating investment in physiologically costly autotrophic enzymes/complexes (RuBisCo and PSII). Furthermore, in Arctic oceans, AAP and PR photoheterotrophs are prominent in ice-covered regions during wintertime per light scarcity. Lastly, seasonal turnover has been observed


id: photokinesis-20260505-0
file: data/en.wikipedia.org/wiki/Photokinesis-0.md
category: reference
title: Photokinesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photokinesis
date_saved: 2026-05-05T07:16:19.384164+00:00
instance: kb-cron
parent: photokinesis-20260505-0
summary:
Photokinesis is a change in the velocity of movement of an organism as a result of changes in light intensity. The alteration in speed is independent of the direction from which the light is shining. Photokinesis is described as positive if the velocity of travel is greater with an increase in light intensity and negative if the velocity is slower. If a group of organisms with a positive photokinetic response is swimming in a partially shaded environment, there will be fewer organisms per unit of volume in the sunlit portion than in the shaded parts. This may be beneficial for the organisms if it is unfavourable to their predators, or it may be propitious to them in their quest for prey. In photosynthetic prokaryotes, the mechanism for photokinesis appears to be an energetic process. In cyanobacteria, for example, an increase in illumination results in an increase of photophosphorylation which enables an increase in metabolic activity. However the behaviour is also found among eukaryotic microorganisms, including those like Astasia longa which are not photosynthetic, and in these, the mechanism is not fully understood. In Euglena gracilis, the rate of swimming has been shown to speed up with increased light intensity until


id: photoperiodism-20260505-0
file: data/en.wikipedia.org/wiki/Photoperiodism-0.md
category: reference
title: Photoperiodism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photoperiodism
date_saved: 2026-05-05T07:16:20.769311+00:00
instance: kb-cron
parent: photoperiodism-20260505-0
summary:
Photoperiod is the change of day length over the seasons. Earth's rotation around its axis produces 24-hour changes in light (daytime) and dark (night) cycles on Earth. The length of the light and dark in each phase varies across the seasons due to the axial tilt of Earth. The photoperiod defines the length of the light. For example, in summer the length of light could be 16 hours while the dark is 8 hours, whereas in winter the length of day could be 8 hours, while the dark is 16 hours. Importantly, the axial tilt of the Earth causes the opposing seasons in the Northern and Southern Hemispheres. Photoperiodism is the physiological reaction of organisms to the length of light or a dark period. It occurs in plants and animals. Plant photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light and dark periods. They are classified under three groups according to the photoperiods: short-day plants, long-day plants, and day-neutral plants. In animals, photoperiodism (sometimes called seasonality) is the suite of physiological changes that occur in response to changes in day length. This allows animals to respond to a temporally changing environment associated


id: photoperiodism-20260505-1
file: data/en.wikipedia.org/wiki/Photoperiodism-1.md
category: reference
title: Photoperiodism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Photoperiodism
date_saved: 2026-05-05T07:16:20.769311+00:00
instance: kb-cron
parent: photoperiodism-20260505-0
summary:
Kenaf (Hibiscus cannabinus) Marijuana (Cannabis) Cotton (Gossypium) Rice (Oryza) Sorghum (Sorghum bicolor) Green gram (Mung bean, Vigna radiata) Soybeans (Glycine max) === Day-neutral plants === Day-neutral plants, such as cucumbers, roses, tomatoes, and Ruderalis (autoflowering cannabis) do not initiate flowering based on photoperiodism. Instead, they may initiate flowering after attaining a certain overall developmental stage or age, or in response to alternative environmental stimuli, such as vernalisation (a period of low temperature). == Animals == Day length, and thus knowledge of the season of the year, is vital to many animals. A number of biological and behavioural changes are dependent on this knowledge. Together with temperature changes, photoperiod provokes changes in the color of fur and feathers, migration, entry into hibernation, sexual behaviour, and even the resizing of organs. In insects, sensitivity to photoperiod has been proven to be initiated by photoreceptors located in the brain. Photoperiod can affect insects at different life stages, serving as an environmental cue for physiological processes such as diapause induction and termination, and seasonal morphs. In the water strider Aquarius paludum, for instance, photoperiod conditions during nymphal development have been shown to trigger seasonal changes in wing frequency and also induce diapause, although the


id: phototaxis-20260505-0
file: data/en.wikipedia.org/wiki/Phototaxis-0.md
category: reference
title: Phototaxis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Phototaxis
date_saved: 2026-05-05T07:16:22.043277+00:00
instance: kb-cron
parent: phototaxis-20260505-0
summary:
Phototaxis is a kind of taxis, or locomotory movement, that occurs when a whole organism moves towards or away from a stimulus of light. This is advantageous for phototrophic organisms as they can orient themselves most efficiently to receive light for photosynthesis. Phototaxis is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite. Phototaxis has been described in microorganisms and algea, insects and other invertebrates, and vertebrates. Typically nocturnal insects can show positive phototaxis, while nocturnal mammals often show negative phototaxis. == Phototaxis in bacteria and archea == Phototaxis can be advantageous for phototrophic bacteria as they can orient themselves most efficiently to receive light for photosynthesis. Phototaxis is called positive if the movement is in the direction of increasing light intensity and negative if the direction is opposite. Two types of positive phototaxis are observed in prokaryotes (bacteria and archea). The first is called "scotophobotaxis" (from the word "scotophobia"), which is observed only under a microscope. This occurs when a bacterium swims by chance out of the area illuminated by the microscope. Entering darkness signals the cell to reverse flagella rotation direction and reenter the light. The second


id: phototaxis-20260505-1
file: data/en.wikipedia.org/wiki/Phototaxis-1.md
category: reference
title: Phototaxis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Phototaxis
date_saved: 2026-05-05T07:16:22.043277+00:00
instance: kb-cron
parent: phototaxis-20260505-0
summary:
The ability to link light perception to control of motility is found in a very wide variety of prokaryotes, indicating that this ability must confer a range of physiological advantages. Most directly, the light environment is crucial to phototrophs as their energy source. Phototrophic prokaryotes are extraordinarily diverse, with a likely role for horizontal gene transfer in spreading phototrophy across multiple phyla. Thus, different groups of phototrophic prokaryotes may have little in common apart from their exploitation of light as an energy source, but it should be advantageous for any phototroph to be able to relocate in search of better light environments for photosynthesis. To do this efficiently requires the ability to control motility in response to integrated information on the intensity of light, the spectral quality of light and the physiological status of the cell. A second major reason for light-controlled motility is to avoid light at damaging intensities or wavelengths: this factor is not confined to photosynthetic bacteria since light (especially in the UV region) can be dangerous to all prokaryotes, primarily because of DNA and protein damage and inhibition of the translation machinery by light-generated reactive oxygen species. Finally, light signals potentially contain rich and complex information


id: phototaxis-20260505-2
file: data/en.wikipedia.org/wiki/Phototaxis-2.md
category: reference
title: Phototaxis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Phototaxis
date_saved: 2026-05-05T07:16:22.043277+00:00
instance: kb-cron
parent: phototaxis-20260505-0
summary:
Some protists (unicellular eukaryotes) can also move toward or away from light, by coupling their locomotion strategy with a light-sensing organ. Eukaryotes evolved for the first time in the history of life the ability to follow light direction in three dimensions in open water. The strategy of eukaryotic sensory integration, sensory processing and the speed and mechanics of tactic responses is fundamentally different from that found in prokaryotes. Both single-celled and multi-cellular eukaryotic phototactic organisms have a fixed shape, are polarized, swim in a spiral and use cilia for swimming and phototactic steering. Signalling can happen via direct light-triggered ion currents, adenylyl cyclases or trimeric G-proteins. The photoreceptors used can also be very different (see below). However, signalling in all cases eventually modifies the beating activity of cilia. The mechanics of phototactic orientation is analogous in all eukaryotes. A photosensor with a restricted view angle rotates to scan the space and signals periodically to the cilia to alter their beating, which will change the direction of the helical swimming trajectory. Three-dimensional phototaxis can be found in five out of the six eukaryotic major groups (opisthokonts, Amoebozoa, plants, chromalveolates, excavates, rhizaria). Pelagic phototaxis is present in green algae – it is


id: phototaxis-20260505-3
file: data/en.wikipedia.org/wiki/Phototaxis-3.md
category: reference
title: Phototaxis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Phototaxis
date_saved: 2026-05-05T07:16:22.043277+00:00
instance: kb-cron
parent: phototaxis-20260505-0
summary:
Phototaxis has been well studied in the marine ragworm Platynereis dumerilii. Both Platynereis dumerilii trochophore and its metatrochophore larvae are positively phototactic. Phototaxis is mediated by simple eyespots that consists of a pigment cell and a photoreceptor cell. The photoreceptor cell synapses directly onto ciliated cells, which are used for swimming. The eyespots do not give spatial resolution, therefore the larvae are rotating to scan their environment for the direction where the light is coming from. Platynereis dumerilii larvae (nectochaete) can switch between positive and negative phototaxis. Phototaxis there is mediated by two pairs of more complex pigment cup eyes. These eyes contain more photoreceptor cells that are shaded by pigment cells forming a cup. The photoreceptor cells do not synapse directly onto ciliated cells or muscle cells but onto inter-neurons of a processing center. This way the information of all four eye cups can be compared and a low-resolution image of four pixels can be created telling the larvae where the light is coming from. This way the larva does not need to scan its environment by rotating. This is an adaption for living on the bottom of the sea the lifestyle of the larva while scanning rotation is


id: phototaxis-20260505-4
file: data/en.wikipedia.org/wiki/Phototaxis-4.md
category: reference
title: Phototaxis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Phototaxis
date_saved: 2026-05-05T07:16:22.043277+00:00
instance: kb-cron
parent: phototaxis-20260505-0
summary:
== Light based vertical movement == A depth can also be selected based on light levels: The brightness decreases with depth, but depends on the weather (e.g. whether it is sunny or cloudy) and the time of the day. Also the color depends on the water depth and dissolved and suspended matter. The only consistent factor is that at a given place, deeper water is darker. In water, light attenuates differently for each wavelength. The UV, violet (> 420 nm), and red (< 500 nm) wavelengths disappear before blue light (470 nm), which penetrates clear water the deepest. The wavelength composition is constant for each depth and is almost independent of time of the day and the weather. To gauge depth, an animal would need two photopigments sensitive to different wavelengths to compare different ranges of the spectrum. Such pigments may be expressed in different structures. Such different structures are found in the polychaete Torrea candida. Its eyes have a main and two accessory retinae. The accessory retinae sense UV-light (λmax = 400 nm) and the main retina senses blue-green light (λmax = 560 nm). If the light sensed from all retinae is compared, the depth can be estimated, and


id: phototroph-20260505-0
file: data/en.wikipedia.org/wiki/Phototroph-0.md
category: reference
title: Phototroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Phototroph
date_saved: 2026-05-05T07:16:23.246471+00:00
instance: kb-cron
parent: phototroph-20260505-0
summary:
Phototrophs (from Ancient Greek φῶς, φωτός (phôs, phōtós) 'light' and τροφή (trophḗ) 'nourishment') are organisms that carry out photon capture to acquire energy. They use the energy from light to carry out various cellular metabolic processes. It is a common misconception that phototrophs are obligatorily photosynthetic. Many, but not all, phototrophs photosynthesize: they anabolically convert carbon dioxide into biomolecules to be utilized structurally (e.g. cellulose and membrane lipids), functionally (e.g. vitamins, nucleotides, and amino acids), or as a source for later catabolic processes (e.g. starches, sugars and fats). All phototrophs either use electron transport chains or direct proton pumping to establish an electrochemical gradient, which is utilized by ATP synthase to provide adenosine triphosphate (ATP) for the cell. Phototrophs can be either autotrophs or heterotrophs. If their electron and hydrogen donors are inorganic compounds (e.g., Na2S2O3, as in some purple sulfur bacteria, or H2S, as in some green sulfur bacteria) they can be also called lithotrophs, and so, some photoautotrophs are also called photolithoautotrophs. Examples of phototroph organisms are Rhodobacter capsulatus, Chromatium, and Chlorobium. == History == Originally used with a different meaning, the term took its current definition after Lwoff and collaborators (1946). == Photoautotroph == Most well-known phototrophs


id: phototropism-20260505-0
file: data/en.wikipedia.org/wiki/Phototropism-0.md
category: reference
title: Phototropism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Phototropism
date_saved: 2026-05-05T07:16:24.492344+00:00
instance: kb-cron
parent: phototropism-20260505-0
summary:
In biology, phototropism, formerly called heliotropism, is the growth of an organism in response to a light stimulus. Phototropism is most often observed in plants, but can also occur in other organisms such as fungi. The cells on the plant that are farthest from the light contain a hormone called auxin that reacts when phototropism occurs. This causes the plant to have elongated cells on the furthest side from the light. Phototropism is one of the many plant tropisms, or movements, which respond to external stimuli. Growth towards a light source is called positive phototropism, while growth away from light is called negative phototropism. Negative phototropism is not to be confused with skototropism, which is defined as the growth towards darkness, whereas negative phototropism can refer to either the growth away from a light source or towards the darkness. Most plant shoots exhibit positive phototropism, and rearrange their chloroplasts in the leaves to maximize photosynthetic energy and promote growth. Some vine shoot tips exhibit negative phototropism, which allows them to grow towards dark, solid objects and climb them. The combination of phototropism and gravitropism allow plants to grow in the correct direction. == Mechanism == There are several signaling molecules


id: phototropism-20260505-1
file: data/en.wikipedia.org/wiki/Phototropism-1.md
category: reference
title: Phototropism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Phototropism
date_saved: 2026-05-05T07:16:24.492344+00:00
instance: kb-cron
parent: phototropism-20260505-0
summary:
=== Five models of auxin distribution in phototropism === In 2012, Sakai and Haga outlined how different auxin concentrations could be arising on shaded and lighted side of the stem, giving birth to phototropic response. Five models in respect to stem phototropism have been proposed, using Arabidopsis thaliana as the study plant. First model In the first model incoming light deactivates auxin on the light side of the plant allowing the shaded part to continue growing and eventually bend the plant over towards the light. Second model In the second model light inhibits auxin biosynthesis on the light side of the plant, thus decreasing the concentration of auxin relative to the unaffected side. Third model In the third model there is a horizontal flow of auxin from both the light and dark side of the plant. Incoming light causes more auxin to flow from the exposed side to the shaded side, increasing the concentration of auxin on the shaded side and thus more growth occurring. Fourth model In the fourth model it shows the plant receiving light to inhibit auxin basipetal down to the exposed side, causing the auxin to only flow down the shaded side. Fifth model Model five


id: postglacial-vegetation-20260505-0
file: data/en.wikipedia.org/wiki/Postglacial_vegetation-0.md
category: reference
title: Postglacial vegetation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Postglacial_vegetation
date_saved: 2026-05-05T07:16:27.073439+00:00
instance: kb-cron
parent: postglacial-vegetation-20260505-0
summary:
Postglacial vegetation refers to plants that colonize the newly exposed substrate after a glacial retreat. The term "postglacial" typically refers to processes and events that occur after the departure of glacial ice or glacial climates. == Climate Influence == Climate change is the main force behind changes in species distribution and abundance. Repeated changes in climate throughout the Quaternary Period are thought to have had a significant impact on the current vegetation species diversity present today. Functional and phylogenetic diversity are considered to be closely related to changing climatic conditions and this indicates that trait differences are extremely important in long term responses to climate change. During the transition from the last glaciation of the Pleistocene to the Holocene period, climate warming resulted in the expansion of taller plants and larger seed bearing plants which resulted in lower proportions of vegetation regeneration. Hence, low temperatures can be strong environmental filters that prevent tall and large-seeded plants from establishing in postglacial environments. Throughout Europe vegetation dynamics within the first half of the Holocene appear to have been influenced mainly by climate and the reorganization of atmospheric circulation associated with the disappearance of the North American ice sheet. This is evident in


id: predation-rates-20260505-0
file: data/en.wikipedia.org/wiki/Predation_rates-0.md
category: reference
title: Predation rates
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Predation_rates
date_saved: 2026-05-05T07:16:28.250216+00:00
instance: kb-cron
parent: predation-rates-20260505-0
summary:
The term predation rate refers to the frequency with which an organism captures and consumes its prey in an ecosystem. Coupled with the kill rate, the predation rate drives the population dynamics of predation. This statistic is related to Predator–prey dynamics and may be influenced by several factors. In order for predation to occur, a predator and its prey must encounter one another. A low concentration of prey decreases the likelihood of such encounters. The prey encounter rate is determined by the abundance of organisms and a predator’s ability to locate its prey. Covering more territory increases the likelihood that a predator will meet its prey. In areas of low prey density, predators are adapted to be more motile, engage in filter feeding, or use attractants such as chemical lures. If predation increased simply with prey concentration, the relationship would be linear until a limit is reached. This scenario is represented by Holling's type I functional response, which is rarely observed in nature. Several factors affect this relationship, including handling time (the time required for a predator to consume its prey), selective feeding behaviors, and learning. In contrast, Holling's type II and type III functional responses account for the time


id: prehensility-20260505-0
file: data/en.wikipedia.org/wiki/Prehensility-0.md
category: reference
title: Prehensility
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Prehensility
date_saved: 2026-05-05T07:16:29.527669+00:00
instance: kb-cron
parent: prehensility-20260505-0
summary:
Prehensility is the quality of an appendage or organ that has adapted for grasping or holding. The word is derived from the Latin term prehendere, meaning "to grasp". The ability to grasp is likely derived from a number of different origins. The most common are tree-climbing and the need to manipulate food. == Examples == Appendages that can become prehensile include: == Uses == Prehensility affords animals a great natural advantage in manipulating their environment for feeding, climbing, digging, and defense. It enables many animals, such as primates, to use tools to complete tasks that would otherwise be impossible without highly specialized anatomy. For example, chimpanzees have the ability to use sticks to obtain termites and grubs in a manner similar to human fishing. However, not all prehensile organs are applied to tool use; the giraffe tongue, for instance, is instead used in feeding and self-cleaning. == See also == Robot end effector == References ==


id: proteostasis-20260505-0
file: data/en.wikipedia.org/wiki/Proteostasis-0.md
category: reference
title: Proteostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Proteostasis
date_saved: 2026-05-05T07:16:30.910694+00:00
instance: kb-cron
parent: proteostasis-20260505-0
summary:
Proteostasis is the dynamic regulation of a balanced, functional proteome. The proteostasis network includes competing and integrated biological pathways within cells that control the biogenesis, folding, trafficking, and degradation of proteins present within and outside the cell. Loss of proteostasis is central to understanding the cause of diseases associated with excessive protein misfolding and degradation leading to loss-of-function phenotypes, as well as aggregation-associated degenerative disorders. Therapeutic restoration of proteostasis may treat or resolve these pathologies. Cellular proteostasis is key to ensuring successful development, healthy aging, resistance to environmental stresses, and to minimize homeostatic perturbations from pathogens such as viruses. Cellular mechanisms for maintaining proteostasis include regulated protein translation, chaperone assisted protein folding, and protein degradation pathways. Adjusting each of these mechanisms based on the need for specific proteins is essential to maintain all cellular functions relying on a correctly folded proteome. == Mechanisms of proteostasis == === The roles of the ribosome in proteostasis === One of the first points of regulation for proteostasis is during translation. This regulation is accomplished via the structure of the ribosome, a complex central to translation. Its characteristics shape the way the protein folds, and influence the protein's future interactions. The synthesis of a


id: proteostasis-20260505-1
file: data/en.wikipedia.org/wiki/Proteostasis-1.md
category: reference
title: Proteostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Proteostasis
date_saved: 2026-05-05T07:16:30.910694+00:00
instance: kb-cron
parent: proteostasis-20260505-0
summary:
=== Cytosolic heat shock response === The cytosolic heat shock response (HSR) is mainly mediated by the transcription factor family HSF (heat shock family). HSF is constitutively bound by Hsp90. Upon a proteotoxic stimulus Hsp90 is recruited away from HSF, which can then bind to heat response elements in the DNA and upregulate gene expression of proteins involved in the maintenance of proteostasis. === ER unfolded protein response === The unfolded protein response (UPR) in the ER is activated by imbalances of unfolded proteins inside the ER and the proteins mediating protein homeostasis. Different "detectors" - such as IRE1, ATF6 and PERK - can recognize misfolded proteins in the ER and mediate transcriptional responses which help alleviate the effects of ER stress. === Mitochondrial unfolded protein response === The mitochondrial unfolded protein response detects imbalances in protein stoichiometry of mitochondrial proteins and misfolded proteins. The expression of mitochondrial chaperones is upregulated by the activation of the transcription factors ATF1 and/or DVE-1 with UBL5. === Systemic stress signaling === Stress responses can also be triggered in a non-cell autonomous fashion by intercellular communication. The stress that is sensed in one tissue could thereby be communicated to other tissues to protect the


id: proteostasis-20260505-2
file: data/en.wikipedia.org/wiki/Proteostasis-2.md
category: reference
title: Proteostasis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Proteostasis
date_saved: 2026-05-05T07:16:30.910694+00:00
instance: kb-cron
parent: proteostasis-20260505-0
summary:
=== Pharmacologic intervention in proteostasis === There are two main approaches that have been used for therapeutic development targeting the proteostatic network: pharmacologic chaperones and proteostasis regulators. The principle behind designing pharmacologic chaperones for intervention in diseases of proteostasis is to design small molecules that stabilize proteins exhibiting borderline stability. Previously, this approach has been used to target and stabilize G-protein coupled receptors, neurotransmitter receptors, glycosidases, lysosomal storage proteins, and the mutant CFTR protein that causes cystic fibrosis and transthyretin, which can misfiled and aggregate leading to amyloidoses. Vertex Pharmaceuticals and Pfizer sell regulatory agency approved pharmacologic chaperones for ameliorating cystic fibrosis and the transthyretin amyloidoses, respectively. Amicus sells a regulatory agency approved pharmacologic chaperone for Fabry disease–a lysosomal storage disease. The principle behind proteostasis regulators is different. These molecules alter the biology of protein folding and/or degradation by altering the stoichiometry of the proteostasis network components in a given sub cellular compartment. For example, some proteostasis regulators initiate stress responsive signaling, such as the unfolded protein response, which transcriptionally reprograms the endoplasmic reticulum proteostasis network. It has been suggested that this approach could even be applied prophylactically, such as upregulating certain protective pathways before experiencing an anticipated severe cellular


id: psammon-20260505-0
file: data/en.wikipedia.org/wiki/Psammon-0.md
category: reference
title: Psammon
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Psammon
date_saved: 2026-05-05T07:16:32.210054+00:00
instance: kb-cron
parent: psammon-20260505-0
summary:
Psammon (from Greek "psammos", "sand") is an ecological community of organisms inhabiting coastal sand. It consists of biota buried in moist sediments. Psammon is also sometimes considered a part of benthos due to its near-bottom distribution. Psammon term is commonly used to refer to freshwater reservoirs such as lakes. == See also == Epipsammon == References ==


id: psammophyte-20260505-0
file: data/en.wikipedia.org/wiki/Psammophyte-0.md
category: reference
title: Psammophyte
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Psammophyte
date_saved: 2026-05-05T07:16:33.528329+00:00
instance: kb-cron
parent: psammophyte-20260505-0
summary:
A psammophyte is a plant that grows in sandy and often unstable soils. Psammophytes are commonly found growing on beaches, deserts, and sand dunes. Because they thrive in these challenging or inhospitable habitats, psammophytes are considered extremophiles, and are further classified as a type of psammophile. == Etymology == The word "psammophyte" consists of two Greek roots, psamm-, meaning "sand", and -phyte, meaning "plant". The term "psammophyte" first entered English in the early twentieth century via German botanical terminology. == Description == Psammophytes are found in many different plant families, so may not share specific morphological or phytochemical traits. They also come in a variety of plant life-forms, including annual ephemerals, perennials, subshrubs, hemicryptophytes, and many others. What the many diverse psammophytes have in common is a resilience to harsh or rapidly fluctuating environmental factors, such as shifting soils, strong winds, intense sunlight exposure, or saltwater exposure, depending on the habitat. Psammophytes often have specialized traits, such as unusually tenacious or resilient roots that enable them to anchor and thrive despite various environmental stressors. Those growing in arid regions have evolved highly efficient physiological mechanisms that enable them to survive despite limited water availability, similar to those in other xerophytes.


id: pyrrolizidine-alkaloid-sequestration-20260505-0
file: data/en.wikipedia.org/wiki/Pyrrolizidine_alkaloid_sequestration-0.md
category: reference
title: Pyrrolizidine alkaloid sequestration
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pyrrolizidine_alkaloid_sequestration
date_saved: 2026-05-05T07:16:34.807727+00:00
instance: kb-cron
parent: pyrrolizidine-alkaloid-sequestration-20260505-0
summary:
Pyrrolizidine alkaloid sequestration by insects is a strategy to facilitate defense and mating. Various species of insects have been known to use molecular compounds from plants for their own defense and even as their pheromones or precursors to their pheromones. A few Lepidoptera have been found to sequester chemicals from plants which they retain throughout their life and some members of Erebidae are examples of this phenomenon. Starting in the mid-twentieth century researchers investigated various members of Arctiidae, and how these insects sequester pyrrolizidine alkaloids (PAs) during their life stages, and use these chemicals as adults for pheromones or pheromone precursors. PAs are also used by members of the Arctiidae for defense against predators throughout the life of the insect. == Overview == Pyrrolizidine alkaloids are a group of chemicals produced by plants as secondary metabolites, all of which contain a pyrrolizidine nucleus. This nucleus is made up of two pyrrole rings bonded by one carbon and one nitrogen. There are two forms in which PAs can exist and will readily interchange between: a pro-toxic free base form, also called a tertiary amine, or in a non-toxic form of N-oxide. Researchers have collected data that strongly suggests that PAs can


id: range-state-20260505-0
file: data/en.wikipedia.org/wiki/Range_state-0.md
category: reference
title: Range state
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Range_state
date_saved: 2026-05-05T07:16:36.174449+00:00
instance: kb-cron
parent: range-state-20260505-0
summary:
Range state is a term generally used in zoogeography and conservation biology to refer to any nation that exercises jurisdiction over any part of a range which a particular species, taxon or biotope inhabits, or crosses or overflies at any time on its normal migration route. The term is often expanded to also include, particularly in international waters, any nation with vessels flying their flag that engage in exploitation (e.g. hunting, fishing, capturing) of that species. Countries in which a species occurs only as a vagrant or ‘accidental’ visitor outside of its normal range or migration route are not usually considered range states. Because governmental conservation policy is often formulated on a national scale, and because in most countries, both governmental and private conservation organisations are also organised at the national level, the range state concept is often used by international conservation organizations in formulating their conservation and campaigning policy. An example of one such organization is the Convention on the Conservation of Migratory Species of Wild Animals (CMS, or the “Bonn Convention”). It is a multilateral treaty focusing on the conservation of critically endangered and threatened migratory species, their habitats and their migration routes. Because such habitats and/or migration


id: redundancy-principle-biology-20260505-0
file: data/en.wikipedia.org/wiki/Redundancy_principle_(biology)-0.md
category: reference
title: Redundancy principle (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Redundancy_principle_(biology)
date_saved: 2026-05-05T07:16:37.452192+00:00
instance: kb-cron
parent: redundancy-principle-biology-20260505-0
summary:
The redundancy principle in biology expresses the need of many copies of the same entity (cells, molecules, ions) to fulfill a biological function. Examples are numerous: disproportionate numbers of spermatozoa during fertilization compared to one egg, large number of neurotransmitters released during neuronal communication compared to the number of receptors, large numbers of released calcium ions during transient in cells, and many more in molecular and cellular transduction or gene activation and cell signaling. This redundancy is particularly relevant when the sites of activation are physically separated from the initial position of the molecular messengers. The redundancy is often generated for the purpose of resolving the time constraint of fast-activating pathways. It can be expressed in terms of the theory of extreme statistics to determine its laws and quantify how the shortest paths are selected. The main goal is to estimate these large numbers from physical principles and mathematical derivations. When a large distance separates the source and the target (a small activation site), the redundancy principle explains that this geometrical gap can be compensated by large number. Had nature used less copies than normal, activation would have taken a much longer time, as finding a small target by chance


id: redundancy-principle-biology-20260505-1
file: data/en.wikipedia.org/wiki/Redundancy_principle_(biology)-1.md
category: reference
title: Redundancy principle (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Redundancy_principle_(biology)
date_saved: 2026-05-05T07:16:37.452192+00:00
instance: kb-cron
parent: redundancy-principle-biology-20260505-0
summary:
where the boundary ∂ Ω {\displaystyle \partial \Omega } contains NR binding sites ∂ Ω i ⊂ ∂ Ω {\displaystyle \partial \Omega _{i}\subset \partial \Omega } ( ∂ Ω a = ⋃ i = 1 N R ∂ Ω i , ∂ Ω r = ∂ Ω − ∂ Ω a {\displaystyle \partial \Omega _{a}=\bigcup \limits _{i=1}^{N_{R}}\partial \Omega _{i},\ \partial \Omega _{r}=\partial \Omega -\partial \Omega _{a}} ). The single particle survival probability is Pr { t 1 > t } = ∫ Ω p ( x , t ) d x , {\displaystyle \Pr\{t_{1}>t\}=\int \limits _{\Omega }p(x,t)dx,} so that Pr { τ 1 = t } = d d t Pr { τ 1 < t } = N ( Pr { t 1 > t } ) N − 1 Pr { t 1 = t } , {\displaystyle \Pr\{\tau ^{1}=t\}={\frac {d}{dt}}\Pr\{\tau ^{1}<t\}=N(\Pr\{t_{1}>t\})^{N-1}\Pr \limits \{t_{1}=t\},} where Pr { t 1 = t } = ∮ ∂ Ω a ∂ p ( x , t ) ∂ n d S x {\displaystyle \Pr\{t_{1}=t\}={\oint _{\partial \Omega _{a}}}{\frac {\partial p(x,t)}{\partial n}}\,dS_{x}} and Pr { t 1 = t } = N R ∮ ∂ Ω 1 ∂ p ( x , t


id: redundancy-principle-biology-20260505-2
file: data/en.wikipedia.org/wiki/Redundancy_principle_(biology)-2.md
category: reference
title: Redundancy principle (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Redundancy_principle_(biology)
date_saved: 2026-05-05T07:16:37.452192+00:00
instance: kb-cron
parent: redundancy-principle-biology-20260505-0
summary:
Pr { t 1 > t | y } = ∫ 0 a p ( x , t | y ) d x d s ∼ 1 − max 2 t π [ e − y 2 / 4 t y , e − ( a − y ) 2 / 4 t a − y ] as t → 0 {\displaystyle \Pr\{t_{1}>t\,|\,y\}=\int \limits \limits _{0}^{a}p(x,t\,|\,y)\,dxds\sim 1-\max {\frac {2{\sqrt {t}}}{\sqrt {\pi }}}\left[{\frac {e^{-y^{2}/4t}}{y}},{\frac {e^{-(a-y)^{2}/4t}}{a-y}}\right]\quad {\mbox{as}}\ t\to 0} , where the maximum occurs at δ = {\displaystyle \delta =} min[y,a-y] for 0<y<a (the shortest ray from y to the boundary). All other integrals can be computed explicitly, leading to τ ¯ 1 = ∫ 0 ∞ [ Pr { t 1 > t } ] N d t ≈ ∫ 0 ∞ exp ⁡ { N ln ⁡ ( 1 − 8 t δ π e − δ 2 / 16 t ) } d t ≈ δ 2 16 D ln ⁡ 2 N π for N ≫ 1. {\displaystyle {\bar {\tau }}^{1}=\int \limits \limits _{0}^{\infty }\left[\Pr\{t_{1}>t\}\right]^{N}dt\approx \int \limits \limits _{0}^{\infty }\exp \left\{N\ln \left(1-{\frac {8{\sqrt {t}}}{\delta {\sqrt {\pi }}}}e^{-\delta ^{2}/16t}\right)\right\}dt\approx {\frac {\delta ^{2}}{16D\ln {\frac {2N}{\sqrt {\pi }}}}}\quad {\mbox{for}}\ N\gg 1.}


id: redundancy-principle-biology-20260505-3
file: data/en.wikipedia.org/wiki/Redundancy_principle_(biology)-3.md
category: reference
title: Redundancy principle (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Redundancy_principle_(biology)
date_saved: 2026-05-05T07:16:37.452192+00:00
instance: kb-cron
parent: redundancy-principle-biology-20260505-0
summary:
⟨ τ ( n ) ⟩ = ∫ 0 ∞ exp ⁡ { n log ⁡ ∫ Ω p ( x , t | y ) d x } d t = ∫ 0 ∞ τ σ P r { Path σ ∈ S n ( y ) , τ σ = t } d t , {\displaystyle \langle \tau ^{(n)}\rangle =\int \limits \limits _{0}^{\infty }\exp \left\{n\log \int \limits _{\Omega }p(x,t|y)\,dx\right\}dt=\int _{0}^{\infty }\tau _{\sigma }Pr\{{\hbox{ Path }}\sigma \in S_{n}(y),\tau _{\sigma }=t\}dt,} where S n ( y ) {\displaystyle S_{n}(y)} is the ensemble of shortest paths selected among n Brownian trajectories, starting at point y and exiting between time t and t+dt from the domain Ω {\displaystyle \Omega } . The probability P r { Path σ ∈ S n } {\displaystyle Pr\{{\hbox{ Path }}\sigma \in S_{n}\}} is used to show that the empirical stochastic trajectories of S n {\displaystyle S_{n}} concentrate near the shortest paths starting from y and ending at the small absorbing window ∂ Ω a {\displaystyle \partial \Omega _{a}} , under the condition that ϵ = | ∂ Ω a | | ∂ Ω | ≪ 1 {\displaystyle \epsilon ={\frac {|\partial \Omega _{a}|}{|\partial \Omega |}}\ll 1} .


id: redundancy-principle-biology-20260505-4
file: data/en.wikipedia.org/wiki/Redundancy_principle_(biology)-4.md
category: reference
title: Redundancy principle (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Redundancy_principle_(biology)
date_saved: 2026-05-05T07:16:37.452192+00:00
instance: kb-cron
parent: redundancy-principle-biology-20260505-0
summary:
where the integral is taken over all paths starting at y(0) and exiting at time m Δ t {\displaystyle m\Delta t} . This formula suggests that when n is large, only the paths that minimize the integrant will contribute. For large n, this formula suggests that paths that will contribute the most are the ones that will minimize the exponent, which allows selecting the paths for which the energy functional is minimal, that is E = min X ∈ P t ∫ 0 T x ˙ 2 d s , {\displaystyle E=\min _{X\in {\mathcal {P}}_{t}}\int \limits _{0}^{T}{\dot {x}}^{2}ds,} where the integration is taken over the ensemble of regular paths P t {\displaystyle {\mathcal {P}}_{t}} inside Ω {\displaystyle \Omega } starting at y and exiting in ∂ Ω a {\displaystyle \partial \Omega _{a}} , defined as P T = { P ( 0 ) = y , P ( T ) ∈ ∂ Ω a and P ( s ) ∈ Ω and 0 ≤ s ≤ T } . {\displaystyle {\mathcal {P}}_{T}=\{P(0)=y,P(T)\in \partial \Omega _{a}{\hbox{ and }}P(s)\in \Omega {\hbox{ and }}0\leq s\leq T\}.} This formal argument shows that the random paths associated to the fastest exit time are concentrated near


id: reproductive-interference-20260505-0
file: data/en.wikipedia.org/wiki/Reproductive_interference-0.md
category: reference
title: Reproductive interference
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Reproductive_interference
date_saved: 2026-05-05T07:16:39.962893+00:00
instance: kb-cron
parent: reproductive-interference-20260505-0
summary:
Reproductive interference is the interaction between individuals of different species during mate acquisition that leads to a reduction of fitness in one or more of the individuals involved. The interactions occur when individuals make mistakes or are unable to recognise their own species, labelled as ‘incomplete species recognition'. Reproductive interference has been found within a variety of taxa, including insects, mammals, birds, amphibians, marine organisms, and plants. There are seven causes of reproductive interference, namely signal jamming, heterospecific rivalry, misdirected courtship, heterospecific mating attempts, erroneous female choice, heterospecific mating, and hybridisation. All types have fitness costs on the participating individuals, generally from a reduction in reproductive success, a waste of gametes, and the expenditure of energy and nutrients. These costs are variable and dependent on numerous factors, such as the cause of reproductive interference, the sex of the parent, and the species involved. Reproductive interference occurs between species that occupy the same habitat and can play a role in influencing the coexistence of these species. It differs from competition as reproductive interference does not occur due to a shared resource. Reproductive interference can have ecological consequences, such as through the segregation of species both spatially and temporally. It can also


id: reproductive-interference-20260505-1
file: data/en.wikipedia.org/wiki/Reproductive_interference-1.md
category: reference
title: Reproductive interference
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Reproductive_interference
date_saved: 2026-05-05T07:16:39.962893+00:00
instance: kb-cron
parent: reproductive-interference-20260505-0
summary:
Auditory signalling in the gray treefrog (Hyla versicolor) and the Cope's gray treefrogs (Hyla chrysoscelis) – The success of reproduction is dependent on a female’s ability to correctly identify and respond to the advertisement call of a potential mate. At a breeding site with high densities of males, the male’s chorus may overlap with heterospecific calls, making it difficult for the female to successfully locate a mate. When the advertisement calls of the male gray treefrog and male Cope’s gray treefrog overlap, female gray treefrogs make mistakes and choose the heterospecific call. The amount of errors the female makes is dependent on the amount of overlap between signals. Female Cope’s gray treefrogs can better differentiate the signals and are only significantly affected when heterospecifics completely overlap conspecific male signals. However, female Cope’s gray treefrogs prefer conspecific male signals that have less overlap (i.e. less interference). Furthermore, females have longer response times to overlapped calls, where it takes longer for them to choose a mate. Signal jamming can affect both males and females as difficulties in identifying and locating a mate reduces their mating frequencies. Females may have more costs if they mate with a male of a lower quality, and


id: reproductive-interference-20260505-2
file: data/en.wikipedia.org/wiki/Reproductive_interference-2.md
category: reference
title: Reproductive interference
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Reproductive_interference
date_saved: 2026-05-05T07:16:39.962893+00:00
instance: kb-cron
parent: reproductive-interference-20260505-0
summary:
Atlantic salmon (Salmo salar) – Atlantic salmon that were once native to Lake Ontario were reintroduced to the lake to study their spawning interactions with other species of fish, including the chinook salmon, coho salmon, and brown trout. Chinook salmon interacted with Atlantic salmon the most, where male chinooks attempted to court female Atlantic salmon. Male chinooks also chased away, and in some interactions, behaved aggressively towards other Atlantic salmon that approached female Atlantic salmon. A male brown trout was also observed to court a female Atlantic salmon. Misdirected courtship towards the Atlantic salmon can cause problems in waters that the Atlantic salmon currently occupy, and towards conservation efforts to reintroduce the Atlantic salmon to Lake Ontario. Implications of misdirected courtship on the Atlantic salmon can cause the delay or prevention of spawning, and the hybridisation of the Atlantic salmon with other species. === Heterospecific mating attempts === Heterospecific mating attempts occur when males attempt to mate with females of a different species, regardless of whether courtship occurs. During each mating attempt, sperm transfer may or may not occur. Both sexes have costs when a heterospecific attempts to mate. Costs associated with heterospecific mating attempts include wasted energy, time, and


id: reproductive-interference-20260505-3
file: data/en.wikipedia.org/wiki/Reproductive_interference-3.md
category: reference
title: Reproductive interference
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Reproductive_interference
date_saved: 2026-05-05T07:16:39.962893+00:00
instance: kb-cron
parent: reproductive-interference-20260505-0
summary:
==== Examples ==== Spider mites – two closely related Panonychus mites: the Panonychus citri and Panonychus mori, are generally geographically segregated and on occasion co-exist. However, the co-existence is not stable as the Panonychus mori is eventually excluded. The exclusion is a result of reproductive interference and also due to the higher reproductive rate of the Panonychus citri. Heterospecific mating occurs between the two species which can produce infertile eggs or infertile hybrid females. Furthermore, females are not able to produce female offspring after mating with a heterospecific. In addition to the wastage of energy, time, and gametes, the inability to produce female offspring after heterospecific mating skews the sex ratio of the co-existing populations. The high costs associated with heterospecific mating along with the higher reproductive rate of the Panonychus citri lead to the displacement of the Panonychus mori. Black-legged meadow katydid (Orchelimum nigripes) and the handsome meadow katydid (Orchelimum pulchellum) – The two closely related species of katydid have the same habitat preferences and co-exist along the Potomac River. Females of both species that mate heterospecifically have a large reduction in fecundity compared to conspecific pairings. Heterospecific mating either produces no eggs or male hybrids that may be


id: retinalophototroph-20260505-0
file: data/en.wikipedia.org/wiki/Retinalophototroph-0.md
category: reference
title: Retinalophototroph
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Retinalophototroph
date_saved: 2026-05-05T07:16:41.252337+00:00
instance: kb-cron
parent: retinalophototroph-20260505-0
summary:
A retinalophototroph is one of two different types of phototrophs, and are named for retinal-binding proteins (microbial rhodopsins) they utilize for cell signaling and converting light into energy. Like all phototrophs, retinalophototrophs absorb photons to initiate their cellular processes. In contrast with chlorophototrophs, retinalophototrophs do not use chlorophyll or an electron transport chain to power their chemical reactions. This means retinalophototrophs are incapable of traditional carbon fixation, a fundamental photosynthetic process that transforms inorganic carbon (carbon contained in molecular compounds like carbon dioxide) into organic compounds. For this reason, experts consider them to be less efficient than their chlorophyll-using counterparts, chlorophototrophs. == Energy conversion == Retinalophototrophs achieve adequate energy conversion via a proton-motive force. In retinalophototrophs, proton-motive force is generated from rhodopsin-like proteins, primarily bacteriorhodopsin and proteorhodopsin, acting as proton pumps along a cellular membrane. To capture photons needed for activating a protein pump, retinalophototrophs employ organic pigments known as carotenoids, namely beta-carotenoids. Beta-carotenoids present in retinalophototrophs are unusual candidates for energy conversion, but they possess high Vitamin-A activity necessary for retinaldehyde, or retinal, formation. Retinal, a chromophore molecule configured from Vitamin A, is formed when bonds between carotenoids are disrupted in a process called cleavage. Due to its acute


id: rimose-20260505-0
file: data/en.wikipedia.org/wiki/Rimose-0.md
category: reference
title: Rimose
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Rimose
date_saved: 2026-05-05T07:16:42.501491+00:00
instance: kb-cron
parent: rimose-20260505-0
summary:
Rimose is an adjective used to describe a surface that is cracked or fissured. The term is often used in describing crustose lichens. A rimose surface of a lichen is sometimes contrasted to the surface being areolate. Areolate is an extreme form of being rimose, where the cracks or fissures are so deep that they create island-like pieces called areoles, which look the "islands" of mud on the surface of a dry lake bed. Rimose and areolate are contrasted with being verrucose, or "warty". Verrucose surfaces have warty bumps which are distinct, but not separated by cracks. In mycology the term describes mushrooms whose caps crack in a radial pattern, as commonly found in the genera Inocybe and Inosperma. == References ==


id: runt-20260505-0
file: data/en.wikipedia.org/wiki/Runt-0.md
category: reference
title: Runt
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Runt
date_saved: 2026-05-05T07:16:43.749383+00:00
instance: kb-cron
parent: runt-20260505-0
summary:
A runt is an animal that is unusually small for its species. In veterinary medicine, a runt may also be described using terms such as low-birth weight, intrauterine growth restriction, and small for gestational age. An animal may be defined as small for gestational age (SGA) depending on different criteria, such as size in comparison to littermates', as percent of maternal body weight, as a specific neonate weight threshold for the breed or species, and as different body proportions displayed by runts. Runts face many challenges in comparison to their normal birth weight peers - they are more likely to contract diseases, and die in the neonatal period, have lower glycogen stores, have developmental delays, insulin resistance, hypothermia, and low blood pressure. Runts are also associated with economic losses in farm animals - SGA adult cows give smaller milk yields and have infertility, intrauterine growth restricted (IUGR) piglets have modifications in their muscle tissue that may affect the taste of their meat, adult IUGR sows have smaller litter sizes and lower birth weight piglets in their litters and adult low birth weight ewes may have poorer quality fleeces. == Causes == SGA has been best studied in pigs, both due


id: smash-and-grab-biology-20260505-0
file: data/en.wikipedia.org/wiki/Smash_and_Grab_(biology)-0.md
category: reference
title: Smash and Grab (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Smash_and_Grab_(biology)
date_saved: 2026-05-05T07:16:44.953153+00:00
instance: kb-cron
parent: smash-and-grab-biology-20260505-0
summary:
Smash and Grab is the name given to a technique developed by Charles S. Hoffman and Fred Winston used in molecular biology to rescue plasmids from yeast transformants into Escherichia coli, also known as E. coli, in order to amplify and purify them. In addition, it can be used to prepare yeast genomic DNA (and DNA from tissue samples) for Southern blot analyses or polymerase chain reaction (PCR). == References ==


id: sociome-20260505-0
file: data/en.wikipedia.org/wiki/Sociome-0.md
category: reference
title: Sociome
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Sociome
date_saved: 2026-05-05T07:16:46.170901+00:00
instance: kb-cron
parent: sociome-20260505-0
summary:
The Sociome is a concept used by scientists in Biology and Sociology referring to the dimensions of existence that are social. The term is also an indication of the convergence of systems biology and the study of society as a complex system that has begun to occur among early 21st Century scientists. Just as the phenome is typically thought of as the set of expressed phenotypes of an organism, the sociome can be thought of as the set of observed characteristics of societies. For example, while all societies consisting of humans might be thought of as having the potential to become egalitarian social democracies, not all observed societies are egalitarian or social democracies. Thus, the sociome can also be thought of indirectly as an ideal type of the unrealized potential of any given organization of social beings. == Origin of term == The first known usage of the term sociome was in 2001 by Daichi Kamiyama. The term has also been utilized by sociologist Adam Thomas Perzynski. The two scientists differ in their usage. Kamiyama's study describes a new scientific "era of the sociome (Sociology[+ome])" characterized by the study of the social activities of molecules. This usage is an anthropomorphism


id: storage-organ-20260505-0
file: data/en.wikipedia.org/wiki/Storage_organ-0.md
category: reference
title: Storage organ
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Storage_organ
date_saved: 2026-05-05T07:16:48.570582+00:00
instance: kb-cron
parent: storage-organ-20260505-0
summary:
A storage organ is a part of a plant specifically modified for storage of energy (generally in the form of carbohydrates) or water. Storage organs often grow underground, where they are better protected from attack by herbivores. Plants that have an underground storage organ are called geophytes in the Raunkiær plant life-form classification system. Storage organs often, but not always, act as perennating organs which enable plants to survive adverse conditions (such as cold, excessive heat, lack of light or drought). == Relationship to perennating organ == Storage organs may act as perennating organs ('perennating' as in perennial, meaning "through the year", used in the sense of continuing beyond the year and in due course lasting for multiple years). These are used by plants to survive adverse periods in the plant's life-cycle (e.g. caused by cold, excessive heat, lack of light or drought). During these periods, parts of the plant die and then when conditions become favourable again, re-growth occurs from buds in the perennating organs. For example, geophytes growing in woodland under deciduous trees (e.g. bluebells, trilliums) die back to underground storage organs during summer when tree leaf cover restricts light and water is less available. However, perennating organs


id: substrate-biology-20260505-0
file: data/en.wikipedia.org/wiki/Substrate_(biology)-0.md
category: reference
title: Substrate (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Substrate_(biology)
date_saved: 2026-05-05T07:16:49.725303+00:00
instance: kb-cron
parent: substrate-biology-20260505-0
summary:
In biology, a substrate is the surface on which an organism (such as a plant, fungus, or animal) lives. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock (its substrate) can be itself a substrate for an animal that lives on top of the algae. Inert substrates are used as growing support materials in the hydroponic cultivation of plants. In biology substrates are often activated by the nanoscopic process of substrate presentation. == In agriculture and horticulture == Cellulose substrate Expanded clay aggregate (LECA) Rock wool Potting soil Soil == In animal biotechnology == === Requirements for animal cell and tissue culture === Requirements for animal cell and tissue culture are the same as described for plant cell, tissue and organ culture (In Vitro Culture Techniques: The Biotechnological Principles). Desirable requirements are (i) air conditioning of a room, (ii) hot room with temperature recorder, (iii) microscope room for carrying out microscopic work where different types of microscopes should be installed, (iv) dark room, (v) service room, (vi) sterilization room for sterilization of glassware and culture media, and (vii) preparation room for media preparation, etc. In addition the storage areas should


id: subvariety-botany-20260505-0
file: data/en.wikipedia.org/wiki/Subvariety_(botany)-0.md
category: reference
title: Subvariety (botany)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Subvariety_(botany)
date_saved: 2026-05-05T07:16:51.293257+00:00
instance: kb-cron
parent: subvariety-botany-20260505-0
summary:
A subvariety (Latin: subvarietas) in botanical nomenclature is a taxonomic rank. They are rarely used to classify organisms. == Plant taxonomy == Subvariety is ranked: below that of variety (varietas) above that of form (forma). Subvariety is an infraspecific taxon. === Name === Its name consists of three parts: a genus name (genera) a specific epithet (species) an infraspecific epithet (subvariety) To indicate the subvariety rank, the abbreviation "subvar." is put before the infraspecific epithet. == References ==


id: suctorial-20260505-0
file: data/en.wikipedia.org/wiki/Suctorial-0.md
category: reference
title: Suctorial
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Suctorial
date_saved: 2026-05-05T07:16:52.681651+00:00
instance: kb-cron
parent: suctorial-20260505-0
summary:
Suctorial pertains to the adaptation for sucking or suction, as possessed by marine parasites such as the Cookiecutter shark, specifically in a specialised lip organ enabling attachment to the host. Suctorial organs of a different form are possessed by the Solifugae arachnids, enabling the climbing of smooth, vertical surfaces. Another variation on the suctorial organ can be found as part of the glossa proboscis of Masarinae (pollen wasps), enabling nectar feeding from the deep and narrow corolla of flowers. == References ==


id: syngameon-20260505-0
file: data/en.wikipedia.org/wiki/Syngameon-0.md
category: reference
title: Syngameon
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Syngameon
date_saved: 2026-05-05T07:16:54.005494+00:00
instance: kb-cron
parent: syngameon-20260505-0
summary:
Syngameon refers to groups of taxa that frequently engage in natural hybridization and lack strong reproductive barriers that prevent interbreeding. Syngameons are more common in plants than animals, with approximately 25% of plant species and 10% of animal species producing natural hybrids. The most well known syngameons include irises of the California Pacific Coast and white oaks of the Eastern United States. Hybridization within a syngameon is typically not equally distributed among species and few species often dominate patterns of hybridization. The term syngameon comes from the root word syngamy coined by Edward Bagnall Poulton to define groups that freely interbreed. He also coined the word asyngamy referring to groups that do not freely interbreed (with the substantive noun forms Syngamy and Asyngamy). The term syngameon was first used by Johannes Paulus Lotsy, who used it to describe a habitually interbreeding community that was reproductively isolated from other habitually interbreeding communities. Syngameon was used interchangeably with the term species to describe groups of closely related individuals that interbreed to varying degrees. A more specific definition of syngameon has been given to groups of taxa that frequently engage in natural hybridization and lack strong morphological differences that could be used to


id: temperature-sensitive-mutant-20260505-0
file: data/en.wikipedia.org/wiki/Temperature-sensitive_mutant-0.md
category: reference
title: Temperature-sensitive mutant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Temperature-sensitive_mutant
date_saved: 2026-05-05T07:16:55.194576+00:00
instance: kb-cron
parent: temperature-sensitive-mutant-20260505-0
summary:
Temperature-sensitive mutations are variants of genes that allow the organism to function normally at low temperatures but alter its function at higher temperatures. Cold-sensitive mutants are variants of genes that allow normal function of the organism at higher temperatures but altered function at low temperatures. == Mechanism == Most temperature-sensitive mutations affect proteins, and cause loss of protein function at the non-permissive temperature. The permissive temperature is one at which the protein typically can fold properly or remain properly folded. At higher temperatures, the protein is unstable and ceases to function properly. These mutations are usually recessive in diploid organisms. Temperature -sensitive mutations arrange a reversible mechanism and can reduce particular gene products at varying stages of growth, which is easily done by changing the temperature of growth. == Permissive temperature == The permissive temperature is the temperature at which a temperature-sensitive mutation gene product takes on a normal, functional phenotype. When a temperature-sensitive mutant is grown in a permissive condition, the mutant gene product behaves normally (meaning that the phenotype is not observed), even if there is a mutant allele present. This results in the survival of the cell or organism,as if it were a wild type strain. In


id: temperature-sensitive-mutant-20260505-1
file: data/en.wikipedia.org/wiki/Temperature-sensitive_mutant-1.md
category: reference
title: Temperature-sensitive mutant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Temperature-sensitive_mutant
date_saved: 2026-05-05T07:16:55.194576+00:00
instance: kb-cron
parent: temperature-sensitive-mutant-20260505-0
summary:
== Evolutionary Effects == Temperature is an environmental factor that influences the evolution of organisms by shaping their genetic variation, physiological traits, adaptations, and survivability. As global temperatures increase due to climate change, species have to adapt to these changes through mutations that affect protein function, such as temperature sensitive mutations. Specifically, higher temperatures can increase mutation rates, alter the stability of proteins, and influence natural selection. These factors can lead to evolutionary changes in populations over time. However, when adapting to these higher temperatures, organisms often experience trade-offs, which are compromises where gaining an advantage in one trait leads to a disadvantage in another. Higher temperatures can directly influence mutation rates by increasing the rate of spontaneous mutations leading to more errors during DNA replication or increased exposure to mutagens. Studies have shown that these effects are potentially due to enhanced metabolic rates. More specifically, a study involving Daphnia pulex found that spontaneous mutations had varied fitness effects under different thermal conditions, which suggests that temperature plays a role in shaping mutational impacts. In addition, this heightened mutation rate provides a broader range of genetic diversity for natural selection to act upon, allowing populations to adapt more rapidly. However,


id: temperature-sensitive-mutant-20260505-2
file: data/en.wikipedia.org/wiki/Temperature-sensitive_mutant-2.md
category: reference
title: Temperature-sensitive mutant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Temperature-sensitive_mutant
date_saved: 2026-05-05T07:16:55.194576+00:00
instance: kb-cron
parent: temperature-sensitive-mutant-20260505-0
summary:
=== Bacteriophage === An infection of an Escherichia coli host cell by a bacteriophage (phage) T4 temperature -ensitive (TS) conditionally lethal mutant at a high restrictive temperature generally leads to no phage growth. However, a co-infection under restrictive conditions with two TS mutants defective in different genes generally leads to robust growth because of intergenic complementation. The discovery of TS mutants of phage T4 and the employment of such mutants in complementation tests contributed to the identification of many of the genes in this organism. Because multiple copies of a polypeptide specified by a gene often form multimers, mixed infections with two different TS mutants defective in the same gene often lead to mixed multimers and partial restoration of function, a phenomenon referred to as intragenic complementation. Intragenic complementation of TS mutants defective in the same gene can provide information on the structural organization of the multimer. The growth of phage TS mutants under partially restrictive conditions has been used to identify the functions of genes. Thus, genes employed in the repair of DNA damages were identified, as well as genes affecting genetic recombination. For example, growing a TS DNA repair mutant at an intermediate temperature will allow some progeny


id: thanatocoenosis-20260505-0
file: data/en.wikipedia.org/wiki/Thanatocoenosis-0.md
category: reference
title: Thanatocoenosis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Thanatocoenosis
date_saved: 2026-05-05T07:16:56.407377+00:00
instance: kb-cron
parent: thanatocoenosis-20260505-0
summary:
Thanatocoenosis (from Greek language thanatos - death and koinos - common) are all the embedded fossils at a single discovery site. This site may be referred to as a "death assemblage". Such groupings are composed of fossils of organisms which may not have been associated during life, often originating from different habitats. Examples include marine fossils having been brought together by a water current or animal bones having been deposited by a predator. A site containing thanatocoenosis elements can also lose clarity in its faunal history by more recent intruding factors such as burrowing microfauna or stratigraphic disturbances born from anthropogenic methods. This term differs from a related term, biocoenosis, which refers to an assemblage in which all organisms within the community interacted and lived together in the same habitat while alive. A biocoenosis can lead to a thanatocoenosis if disrupted significantly enough to have its dead/fossilized matter scattered. A death community/thanatocoenosis is developed by multiple taphonomic processes (those being ones relating to the different ways in which organismal remains pass through strata and are decomposed and preserved) that are generally categorized into two groups: biostratinomy and diagenesis. As a whole, thanatocoenoses are divided into two categories as well: autochthonous


id: tiller-botany-20260505-0
file: data/en.wikipedia.org/wiki/Tiller_(botany)-0.md
category: reference
title: Tiller (botany)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Tiller_(botany)
date_saved: 2026-05-05T07:16:57.738914+00:00
instance: kb-cron
parent: tiller-botany-20260505-0
summary:
A tiller is a shoot that arises from the base of a grass plant. The term refers to all shoots that grow after the initial parent shoot grows from a seed. Tillers are segmented, each segment possessing its own two-part leaf. They are involved in vegetative propagation and, in some cases, also seed production. "Tillering" refers to the production of side shoots and is a property possessed by many species in the grass family. This enables them to produce multiple stems (tillers) starting from the initial single seedling. This ensures the formation of dense tufts and multiple seed heads. Tillering rates are heavily influenced by soil water quantity. When soil moisture is low, grasses tend to develop more sparse and deep root systems (as opposed to dense, lateral systems). Thus, in dry soils, tillering is inhibited: the lateral nature of tillering is not supported by lateral root growth. == See also == Crown (botany) == References ==


id: toxin-20260505-0
file: data/en.wikipedia.org/wiki/Toxin-0.md
category: reference
title: Toxin
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Toxin
date_saved: 2026-05-05T07:16:59.029271+00:00
instance: kb-cron
parent: toxin-20260505-0
summary:
A toxin is a naturally occurring poison produced by metabolic activities of living cells or organisms. They occur especially as proteins, often conjugated. The term was first used by organic chemist Ludwig Brieger (1849–1919), derived from toxic. Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. They vary greatly in their toxicity, ranging from usually minor (such as a bee sting) to potentially fatal even at extremely low doses (such as botulinum toxin). == Terminology == Toxins are often distinguished from other chemical agents strictly based on their biological origin. Less strict understandings embrace naturally occurring inorganic toxins, such as arsenic. Other understandings embrace synthetic analogs of naturally occurring organic poisons as toxins, and may or may not embrace naturally occurring inorganic poisons. It is important to confirm usage if a common understanding is critical. Toxins are a subset of toxicants. The term toxicant is preferred when the poison is man-made and therefore artificial. The human and scientific genetic assembly of a natural-based toxin should be considered a toxin as it is identical to its natural counterpart.


id: toxin-20260505-1
file: data/en.wikipedia.org/wiki/Toxin-1.md
category: reference
title: Toxin
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Toxin
date_saved: 2026-05-05T07:16:59.029271+00:00
instance: kb-cron
parent: toxin-20260505-0
summary:
== Research == In general, when scientists determine the amount of a substance that may be hazardous for humans, animals and/or the environment they determine the amount of the substance likely to trigger effects and if possible establish a safe level. In Europe, the European Food Safety Authority produced risk assessments for more than 4,000 substances in over 1,600 scientific opinions and they provide open access summaries of human health, animal health and ecological hazard assessments in their OpenFoodTox database. The OpenFoodTox database can be used to screen potential new foods for toxicity. The Toxicology and Environmental Health Information Program (TEHIP) at the United States National Library of Medicine (NLM) maintains a comprehensive toxicology and environmental health web site that includes access to toxins-related resources produced by TEHIP and by other government agencies and organizations. This web site includes links to databases, bibliographies, tutorials, and other scientific and consumer-oriented resources. TEHIP also is responsible for the Toxicology Data Network (TOXNET), an integrated system of toxicology and environmental health databases that are available free of charge on the web. TOXMAP is a Geographic Information System (GIS) that is part of TOXNET. TOXMAP uses maps of the United States to help users


id: tropical-vegetation-20260505-0
file: data/en.wikipedia.org/wiki/Tropical_vegetation-0.md
category: reference
title: Tropical vegetation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Tropical_vegetation
date_saved: 2026-05-05T07:17:00.247154+00:00
instance: kb-cron
parent: tropical-vegetation-20260505-0
summary:
Tropical vegetation, plant life that occurs in climates that are warm year-round, is in general more biologically diverse than in other latitudes. Some tropical areas may receive abundant rain the whole year round, while others have long dry seasons which last several months and may vary in length and intensity with geographic location. These seasonal droughts have a great impact on the vegetation, such as in the Madagascar spiny forests. Rainforest vegetation can often be categorized into five layers. The top layer is the emergents, the upper tree layer, with the largest and widest trees in all the forest, commonly 50 m (160 ft) and higher. These trees tend to have very large canopies so they can be fully exposed to sunlight. A layer below that is the canopy, or middle tree layer, averaging 30–40 m (98–131 ft) in height. Here there are more compact trees and vegetation. These trees, shaded, tend to be slenderer. The third layer is the lower tree area. These trees tend to be around 5–10 m (16–33 ft) high and tightly compacted. The trees found in the third layer include young trees with the potential to grow into larger canopy trees, and "palmoids" or "corner


id: understory-20260505-0
file: data/en.wikipedia.org/wiki/Understory-0.md
category: reference
title: Understory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Understory
date_saved: 2026-05-05T07:17:01.485664+00:00
instance: kb-cron
parent: understory-20260505-0
summary:
In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but above the forest floor. Only a small percentage of light penetrates the canopy, so understory vegetation is generally shade-tolerant. The understory typically consists of trees stunted through lack of light, other small trees with low light requirements, saplings, shrubs, vines, and undergrowth. Small trees such as holly and dogwood are understory specialists. In temperate deciduous forests, many understory plants start into growth earlier in the year than the canopy trees, to make use of the greater availability of light at that particular time of year. A gap in the canopy caused by the death of a tree stimulates the potential emergent trees into competitive growth as they grow upward to fill the gap. These trees tend to have straight trunks and few lower branches. At the same time, the bushes, undergrowth, and plant life on the forest floor become denser. The understory experiences greater humidity than the canopy, and the shaded ground does not vary in temperature as much as open ground. This causes a proliferation of


id: vagrancy-biology-20260505-0
file: data/en.wikipedia.org/wiki/Vagrancy_(biology)-0.md
category: reference
title: Vagrancy (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Vagrancy_(biology)
date_saved: 2026-05-05T07:17:02.728436+00:00
instance: kb-cron
parent: vagrancy-biology-20260505-0
summary:
Vagrancy is a phenomenon in biology whereby an individual animal (usually a bird) appears well outside its normal range; they are known as vagrants. The term accidental is sometimes also used. There are a number of poorly understood factors which might cause an animal to become a vagrant, including internal causes such as navigation errors (endogenous vagrancy) and external causes such as severe weather (exogenous vagrancy). Vagrancy events may lead to colonisation and eventually to speciation. == Birds == In the Northern Hemisphere, adult birds (possibly inexperienced younger adults) of many species are known to continue past their normal breeding range during their spring migration and end up in areas further north (such birds are termed spring overshoots). In autumn, some young birds, instead of heading to their usual wintering grounds, take "incorrect" courses and migrate through areas which are not on their normal migration path. For example, Siberian passerines which normally winter in Southeast Asia are commonly found in Northwest Europe, e.g. Arctic warblers in Britain. This is reverse migration, where the birds migrate in the opposite direction to that expected (say, flying north-west instead of south-east). The causes of this are unknown, but genetic mutation or other anomaly


id: woody-plant-20260505-0
file: data/en.wikipedia.org/wiki/Woody_plant-0.md
category: reference
title: Woody plant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Woody_plant
date_saved: 2026-05-05T07:17:03.874797+00:00
instance: kb-cron
parent: woody-plant-20260505-0
summary:
A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposed to herbaceous plants that die back to the ground until spring. == Characteristics == Woody plants include trees, shrubs, or lianas. These are usually perennials whose stems and larger roots are reinforced with wood produced from secondary xylem. The main stem, larger branches, and roots of these plants are usually covered by a layer of bark. Wood is a structural tissue that allows woody plants to grow from above-ground stems year after year, thus making some woody plants the largest and tallest terrestrial plants. Woody plants, like herbaceous perennials, typically have a dormant period of the year when growth does not take place. This occurs in temperate and continental areas due to freezing temperatures and lack of daylight during the winter months. Meanwhile, dormancy in subtropical and tropical climates is due to the dry season; when low precipitation limits water available for growth. The dormant period will be accompanied by abscission (if the plant is deciduous). Evergreen plants do not lose all their leaves at once


id: xerophile-20260505-0
file: data/en.wikipedia.org/wiki/Xerophile-0.md
category: reference
title: Xerophile
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Xerophile
date_saved: 2026-05-05T07:17:05.175036+00:00
instance: kb-cron
parent: xerophile-20260505-0
summary:
A xerophile (from Ancient Greek ξηρός (xerós), meaning "dry", and φίλος (phílos), meaning "loving") is an extremophilic organism that can grow and reproduce in conditions with a low availability of water, also known as water activity. Xerophiles are "xerotolerant", meaning tolerant of dry conditions. They can often survive in environments with water activity below 0.8; above which is typical for most life on Earth. Typically xerotolerance is used with respect to matrix drying, where a substance has a low water concentration. These environments include arid desert soils. The term osmophile, or osmotolerant, is typically applied to microorganisms that can grow in solutions with high solute concentrations (salts, sugars), such as halophiles. == Physics of water activity == Water activity, a thermodynamical value denoted aw, is defined as the partial water vapor pressure p in equilibrium with the substance relative to (divided by) the (partial) vapor pressure of pure water p* at the same temperature: a w ≡ p p ∗ {\displaystyle a_{w}\equiv {\frac {p}{p^{*}}}} The thermodynamical water activity is thus equal to the relative humidity (RH), and the chemical activity of pure water is equal to one: aw = 1.0. When the atmosphere above a substance, or a solution, is


id: z-value-temperature-20260505-0
file: data/en.wikipedia.org/wiki/Z-value_(temperature)-0.md
category: reference
title: Z-value (temperature)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Z-value_(temperature)
date_saved: 2026-05-05T07:17:06.519599+00:00
instance: kb-cron
parent: z-value-temperature-20260505-0
summary:
"F0" is defined as the number of equivalent minutes of steam sterilization at temperature 121.1 °C (250 °F) delivered to a container or unit of product calculated using a z-value of 10 °C. The term F-value or "FTref/z" is defined as the equivalent number of minutes to a certain reference temperature (Tref) for a certain control microorganism with an established Z-value. Z-value is a term used in microbial thermal death time calculations. It is the number of degrees the temperature has to be increased to achieve a tenfold (i.e. 1 log10) reduction in the D-value. The D-value of an organism is the time required in a given medium, at a given temperature, for a ten-fold reduction in the number of organisms. It is useful when examining the effectiveness of thermal inactivations under different conditions, for example in food cooking and preservation. The z-value is a measure of the change of the D-value with varying temperature, and is a simplified version of an Arrhenius equation and it is equivalent to z=2.303 RT Tref/E. The z-value of an organism in a particular medium is the temperature change required for the D-value to change by a factor of ten, or put another way,


id: actor-analysis-20260505-0
file: data/en.wikipedia.org/wiki/Actor_analysis-0.md
category: reference
title: Actor analysis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Actor_analysis
date_saved: 2026-05-05T07:17:08.242806+00:00
instance: kb-cron
parent: actor-analysis-20260505-0
summary:
Actor analysis can be seen as an approach to environmental management. Environmental issues are often very complex, because many parties are involved. All parties have their own interests, goals and strategies. Actor analysis provides a structured inventory of the parties and their interests to get an overview. Instead of parties, we speak of actors which comprise both individuals and groups like organizations, administrative authorities or consumer organisations. All these actors can change an existing situation by their priorities or value systems. There have been many changes of environmental behaviour that can be described via actor analysis. For example, all cars are now equipped with catalytic converters. Environmental organisations, governments, companies, legislators, and customers have all been actors in this process. == See also == Actor–network theory Stakeholder analysis == References == == External links == Communication: a meeting ground for sustainable development


id: adventive-plant-20260505-0
file: data/en.wikipedia.org/wiki/Adventive_plant-0.md
category: reference
title: Adventive plant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Adventive_plant
date_saved: 2026-05-05T07:17:09.478421+00:00
instance: kb-cron
parent: adventive-plant-20260505-0
summary:
Adventive plants, also known as alien plants, foreign plants or casual plants are alien plant species appearing in a place that does not correspond to their area of origin, in contrast to the native species. These plants can arrive by natural means (such as wind or animal) or by human intervention (either intentional or accidental). Although some alien plants become naturalized, others do not become established, thereby distinguishing them from weeds or an invasive species. Many alien plants have been introduced to aesthetically improve public recreation areas or private properties, or for agricultural purposes. The term "adventive" is derived from the Latin advena, meaning a 'stranger', 'alien' or 'immigrant'. == Definitions == According to Dictionary.com, an adventive plant is "usually not yet well established". According to Collins Dictionary, adventive plants are "introduced to a new area and not yet established there". In the broadest sense, the term "adventive plants" is used to denote exotic plant species that are alien to the native flora. Though the word has different shades of meaning, as it is also used for species that settle into new environments, and are not self-sufficient or are rarely naturalized, but need an episodic population assistance from their homeland.


id: adventive-plant-20260505-1
file: data/en.wikipedia.org/wiki/Adventive_plant-1.md
category: reference
title: Adventive plant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Adventive_plant
date_saved: 2026-05-05T07:17:09.478421+00:00
instance: kb-cron
parent: adventive-plant-20260505-0
summary:
The introduced Norway maple occupies a prominent status in many of Canada's parks. The transport of ornamental plants for landscaping use has and continues to be a source of many introductions. Some of these species have escaped horticultural control and become invasive. Notable examples include water hyacinth, salt cedar, and purple loosestrife. Peaches originated in China, and have been carried to much of the populated world. Tomatoes are native to the Andes. Squash (pumpkins), maize (corn), and tobacco are native to the Americas, but were introduced to the Old World. Many alien species require continued human intervention to survive in the new environment. Others may become feral, but do not seriously compete with natives, but simply increase the biodiversity of the area. One example would be dandelions in North America, which have become an essential source of early season nectar for both native and introduced pollinators, and do not meaningfully compete with native grasses or flowers. Many alien plants have been introduced into new territories, initially as either ornamental plants or for erosion control, stock feed, or forestry. Whether an exotic will become an invasive species is seldom understood in the beginning, and many non-native ornamentals languish in the trade


id: afghanistanism-20260505-0
file: data/en.wikipedia.org/wiki/Afghanistanism-0.md
category: reference
title: Afghanistanism
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Afghanistanism
date_saved: 2026-05-05T07:17:10.749620+00:00
instance: kb-cron
parent: afghanistanism-20260505-0
summary:
Afghanistanism is a term, first recorded in the United States, for the practice of concentrating on problems in distant parts of the world while ignoring controversial local issues. In other contexts, the term has referred to "hopelessly arcane and irrelevant scholarship", "fascination with exotic, faraway lands", or "Railing and shaking your fist at an unseen foe who is quite unaware of your existence, much less your fury". == Origin == The Oxford English Dictionary lists Afghanistanism as a U.S. colloquialism; the first written citation it provides is from 1948: J. Lloyd Jones in Probl. Journalism (American Society of Newspaper Editors Convention) 73, "I don't wish to belabor this subject of Afghanistanism, this business of taking forthright stands on elections in Costa Rica, while the uncollected local garbage reeks beneath the editor's window." Robert H. Stopher and James S. Jackson, writing in their April 1948 column "Behind the Front Page", said the "new term" was coined by Jenkin Lloyd Jones of Oklahoma's Tulsa Tribune at that same convention, in Washington, D.C. They quoted Jones as saying: The tragic fact is that many an editorial writer can't hit a short-range target. He's hell on distance. He can pontificate about the situation in


id: astroecology-20260505-0
file: data/en.wikipedia.org/wiki/Astroecology-0.md
category: reference
title: Astroecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Astroecology
date_saved: 2026-05-05T07:17:12.052454+00:00
instance: kb-cron
parent: astroecology-20260505-0
summary:
Astroecology concerns the interactions of biota with space environments. It studies resources for life on planets, asteroids and comets, around various stars, in galaxies, and in the universe. The results allow estimating the future prospects for life, from planetary to galactic and cosmological scales. Available energy, and microgravity, radiation, pressure and temperature are physical factors that affect astroecology. The ways by which life can reach space environments, including natural panspermia and directed panspermia are also considered. Further, for human expansion in space and directed panspermia, motivation by life-centered biotic ethics, panbiotic ethics and planetary bioethics are also relevant. == Overview == The term "astroecology" was first applied in the context of performing studies in actual meteorites to evaluate their potential resources favorable to sustaining life. Early results showed that meteorite/asteroid materials can support microorganisms, algae and plant cultures under Earth's atmosphere and supplemented with water. Several observations suggest that diverse planetary materials, similar to meteorites collected on Earth, could be used as agricultural soils, as they provide nutrients to support microscopic life when supplemented with water and an atmosphere. Experimental astroecology has been proposed to rate planetary materials as targets for astrobiology exploration and as potential biological in-situ resources. The


id: astroecology-20260505-1
file: data/en.wikipedia.org/wiki/Astroecology-1.md
category: reference
title: Astroecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Astroecology
date_saved: 2026-05-05T07:17:12.052454+00:00
instance: kb-cron
parent: astroecology-20260505-0
summary:
Equation 3: B I O T A = M b i o m a s s ( 0 ) k {\displaystyle BIOTA={\frac {M_{biomass}(0)}{k}}} For example, if 0.01% of the biomass is lost per year, then the time-integrated BIOTA will be 10,000 M b i o m a s s ( 0 ) {\displaystyle M_{biomass}(0)} . For the 6·1020 kg biomass constructed from asteroid resources, this yields 6·1024 kg-years of BIOTA in the Solar System. Even with this small rate of loss, life in the Solar System would disappear in a few hundred thousand years, and the potential total time-integrated BIOTA of 3·1030 kg-years under the main-sequence Sun would decrease by a factor of 5·105, although a still substantial population of 1.2·1012 biomass-supported humans could exist through the habitable lifespan of the Sun. The integrated biomass can be maximized by minimizing its rate of dissipation. If this rate can be reduced sufficiently, all the constructed biomass can last for the duration of the habitat and it pays to construct the biomass as fast as possible. However, if the rate of dissipation is significant, the construction rate of the biomass and its steady-state amounts may be reduced allowing a steady-state biomass and


id: biogeography-20260505-0
file: data/en.wikipedia.org/wiki/Biogeography-0.md
category: reference
title: Biogeography
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biogeography
date_saved: 2026-05-05T07:17:13.296244+00:00
instance: kb-cron
parent: biogeography-20260505-0
summary:
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area. Phytogeography is the branch of biogeography that studies the distribution of plants, Zoogeography is the branch that studies distribution of animals, while Mycogeography is the branch that studies distribution of fungi, such as mushrooms. Knowledge of spatial variation in the numbers and types of organisms is as vital to us today as it was to our early human ancestors, as we adapt to heterogeneous but geographically predictable environments. Biogeography is an integrative field of inquiry that unites concepts and information from ecology, evolutionary biology, taxonomy, geology, physical geography, palaeontology, and climatology. Modern biogeographic research combines information and ideas from many fields, from the physiological and ecological constraints on organismal dispersal to geological and climatological phenomena operating at global spatial scales and evolutionary time frames. The short-term interactions within a habitat and species of organisms describe the ecological application of biogeography. Historical biogeography describes the long-term, evolutionary periods of time for broader classifications of organisms. Early scientists, beginning with Carl Linnaeus, contributed to


id: biogeography-20260505-1
file: data/en.wikipedia.org/wiki/Biogeography-1.md
category: reference
title: Biogeography
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biogeography
date_saved: 2026-05-05T07:17:13.296244+00:00
instance: kb-cron
parent: biogeography-20260505-0
summary:
=== 19th century === Following the period of exploration came the Age of Enlightenment in Europe, which attempted to explain the patterns of biodiversity observed by Buffon and Linnaeus. At the birth of the 19th century, Alexander von Humboldt, known as the "founder of plant geography", developed the concept of "physique generale" to demonstrate the unity of science and how species fit together. As one of the first to contribute empirical data to the science of biogeography through his travel as an explorer, he observed differences in climate and vegetation. The Earth was divided into regions which he defined as tropical, temperate, and arctic and within these regions there were similar forms of vegetation. This ultimately enabled him to create the isotherm (temperature lines on a map), which allowed scientists to see patterns of life within different climates. He contributed his observations to findings of botanical geography by previous scientists, and sketched this description of both the biotic and abiotic features of the Earth in his book, Cosmos. Augustin de Candolle contributed to the field of biogeography as he observed species competition and the several differences that influenced the discovery of the diversity of life. He was a Swiss botanist


id: biogeography-20260505-2
file: data/en.wikipedia.org/wiki/Biogeography-2.md
category: reference
title: Biogeography
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biogeography
date_saved: 2026-05-05T07:17:13.296244+00:00
instance: kb-cron
parent: biogeography-20260505-0
summary:
The publication of The Theory of Island Biogeography by Robert MacArthur and E.O. Wilson in 1967 showed that the species richness of an area could be predicted in terms of such factors as habitat area, immigration rate and extinction rate. This added to the long-standing interest in island biogeography. The application of island biogeography theory to habitat fragments spurred the development of the fields of conservation biology and landscape ecology. Classic biogeography has been expanded by the development of molecular systematics, creating a new discipline known as phylogeography. This development allowed scientists to test theories about the origin and dispersal of populations, such as island endemics. For example, while classic biogeographers were able to speculate about the origins of species in the Hawaiian Islands, phylogeography allows them to test theories of relatedness between these populations and putative source populations on various continents, notably in Asia and North America. Biogeography continues as a point of study for many life sciences and geography students worldwide, however it may be under different broader titles within institutions such as ecology or evolutionary biology. In recent years, one of the most important and consequential developments in biogeography has been to show how multiple organisms, including


id: biogeography-20260505-3
file: data/en.wikipedia.org/wiki/Biogeography-3.md
category: reference
title: Biogeography
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biogeography
date_saved: 2026-05-05T07:17:13.296244+00:00
instance: kb-cron
parent: biogeography-20260505-0
summary:
Paleobiogeography goes one step further to include paleogeographic data and considerations of plate tectonics. Using molecular analyses and corroborated by fossils, it has been possible to demonstrate that perching birds evolved first in the region of Australia or the adjacent Antarctic (which at that time lay somewhat further north and had a temperate climate). From there, they spread to the other Gondwanan continents and Southeast Asia – the part of Laurasia then closest to their origin of dispersal – in the late Paleogene, before achieving a global distribution in the early Neogene. Not knowing that at the time of dispersal, the Indian Ocean was much narrower than it is today, and that South America was closer to the Antarctic, one would be hard pressed to explain the presence of many "ancient" lineages of perching birds in Africa, as well as the mainly South American distribution of the suboscines. Paleobiogeography also helps constrain hypotheses on the timing of biogeographic events such as vicariance and geodispersal, and provides unique information on the formation of regional biotas. For example, data from species-level phylogenetic and biogeographic studies tell us that the Amazonian teleost fauna accumulated in increments over a period of tens of millions


id: biological-pollution-20260505-0
file: data/en.wikipedia.org/wiki/Biological_pollution-0.md
category: reference
title: Biological pollution
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biological_pollution
date_saved: 2026-05-05T07:17:14.514866+00:00
instance: kb-cron
parent: biological-pollution-20260505-0
summary:
Biological pollution (impacts or bio pollution) is the impact of humanity's actions on the quality of aquatic and terrestrial environment. Specifically, biological pollution is the introduction of non-indigenous and invasive species, otherwise known as Invasive Alien Species (IAS). When the biological pollution is introduced to an aquatic environment, it contributes to water pollution. Biopollution may cause adverse effects at several levels of biological organization: an individual organism (internal pollution by parasites or pathogens), a population (by genetic change, i.e. hybridization of IAS with a native species), a community or biocoenosis (by structural shifts, i.e. dominance of IAS, replacement or elimination of native species), a habitat (by modification of physical-chemical conditions), an ecosystem (by alteration of energy and organic material flow). Biopollution may also cause decline in naturalness of nature conservation areas, adverse economic consequences and impacts on human health. The notion of "biological pollution" and "biological pollutants" described by Elliott (2000) is generally accepted in invasion biology; it was used to develop the concept of biopollution level assessment (Olenin et al., 2007) and criteria for a Good Ecological Status descriptor in the European Marine Strategy Framework Directive (Olenin et al., 2010) The magnitude of the bioinvasion impact or biopollution level


id: biomass-ecology-20260505-0
file: data/en.wikipedia.org/wiki/Biomass_(ecology)-0.md
category: reference
title: Biomass (ecology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biomass_(ecology)
date_saved: 2026-05-05T07:17:15.767962+00:00
instance: kb-cron
parent: biomass-ecology-20260505-0
summary:
Biomass is the total mass of living biological organisms in a given area or ecosystem at a specific time. Biomass may refer to the species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It encompasses microorganisms, plants, and animals, and is typically expressed as total mass or average mass per unit area. The method used to measure biomass depends on the context. In some cases, biomass refers to the wet weight of organisms as they exist in nature. For example, in a salmon fishery, the salmon biomass might be regarded as the total wet weight the salmon would have if they were taken out of the water. In other contexts, biomass can be measured in terms of the dried organic mass, so perhaps only 30% of the actual weight might count, the rest being water. In other contexts, it may refer to dry weight (excluding water content), or to the mass of organic carbon, excluding inorganic components such as bones, shells, or teeth. In 2018, Bar-On et al. estimated Earth's total live biomass at approximately 550 billion tonnes of carbon, the majority of which


id: biomass-ecology-20260505-1
file: data/en.wikipedia.org/wiki/Biomass_(ecology)-1.md
category: reference
title: Biomass (ecology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biomass_(ecology)
date_saved: 2026-05-05T07:17:15.767962+00:00
instance: kb-cron
parent: biomass-ecology-20260505-0
summary:
Phytoplankton are the main primary producers at the bottom of the marine food chain. Phytoplankton use photosynthesis to convert inorganic carbon into protoplasm. They are then consumed by zooplankton that range in size from a few micrometers in diameter in the case of protistan microzooplankton to macroscopic gelatinous and crustacean zooplankton. Zooplankton comprise the second level in the food chain, and includes small crustaceans, such as copepods and krill, and the larva of fish, squid, lobsters and crabs. In turn, small zooplankton are consumed by both larger predatory zooplankters, such as krill, and by forage fish, which are small, schooling, filter-feeding fish. This makes up the third level in the food chain. A fourth trophic level can consist of predatory fish, marine mammals and seabirds that consume forage fish. Examples are swordfish, seals and gannets. Apex predators, such as orcas, which can consume seals, and shortfin mako sharks, which can consume swordfish, make up a fifth trophic level. Baleen whales can consume zooplankton and krill directly, leading to a food chain with only three or four trophic levels. Marine environments can have inverted biomass pyramids. In particular, the biomass of consumers (copepods, krill, shrimp, forage fish) is larger than the


id: biomass-ecology-20260505-2
file: data/en.wikipedia.org/wiki/Biomass_(ecology)-2.md
category: reference
title: Biomass (ecology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biomass_(ecology)
date_saved: 2026-05-05T07:17:15.767962+00:00
instance: kb-cron
parent: biomass-ecology-20260505-0
summary:
Animals represent less than 0.5% of the total biomass on Earth, with about 2 billion tonnes C in total. Most animal biomass is found in the oceans, where arthropods, such as copepods, account for about 1 billion tonnes C and fish for another 0.7 billion tonnes C. Roughly half of the biomass of fish in the world are mesopelagic, such as lanternfish, spending most of the day in the deep, dark waters. Marine mammals such as whales and dolphins account for about 0.006 billion tonnes C. Land animals account for about 500 million tonnes C, or about 20% of the biomass of animals on Earth. Terrestrial arthropods account for about 150 million tonnes C, most of which is found in the topsoil. Land mammals account for about 180 million tonnes C, most of which are humans (about 80 million tonnes C) and domesticated mammals (about 90 million tonnes C). Wild terrestrial mammals account for only about 3 million tonnes C, less than 2% of the total mammalian biomass on land. Most of the global biomass is found on land, with only 5 to 10 billion tonnes C found in the oceans. On land, there is about 1,000 times more plant


id: bioremediation-20260505-0
file: data/en.wikipedia.org/wiki/Bioremediation-0.md
category: reference
title: Bioremediation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bioremediation
date_saved: 2026-05-05T07:17:17.028374+00:00
instance: kb-cron
parent: bioremediation-20260505-0
summary:
Bioremediation broadly refers to any process wherein a biological system (typically bacteria, microalgae, fungi in mycoremediation, and plants in phytoremediation), living or dead, is employed for removing environmental pollutants from air, water, soil, fuel gasses, industrial effluents etc., in natural or artificial settings. The natural ability of organisms to adsorb, accumulate, and degrade common and emerging pollutants has attracted the use of biological resources in treatment of contaminated environment. In comparison to conventional physicochemical treatment methods bioremediation may offer advantages as it aims to be sustainable, eco-friendly, cheap, and scalable. Most bioremediation is inadvertent, involving native organisms. Research on bioremediation is heavily focused on stimulating the process by inoculation of a polluted site with organisms or supplying nutrients to promote their growth. Environmental remediation is an alternative to bioremediation. While organic pollutants are susceptible to biodegradation, heavy metals cannot be degraded, but rather oxidized or reduced. Typical bioremediations involves oxidations. Oxidations enhance the water-solubility of organic compounds and their susceptibility to further degradation by further oxidation and hydrolysis. Ultimately biodegradation converts hydrocarbons to carbon dioxide and water. For heavy metals, bioremediation offers few solutions. Metal-containing pollutant can be removed, at least partially, with varying bioremediation techniques. The main challenge to


id: bioremediation-20260505-1
file: data/en.wikipedia.org/wiki/Bioremediation-1.md
category: reference
title: Bioremediation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bioremediation
date_saved: 2026-05-05T07:17:17.028374+00:00
instance: kb-cron
parent: bioremediation-20260505-0
summary:
Bioremediation can be carried out by bacteria that are naturally present. In biostimulation, the population of these helpful bacteria can be increased by adding nutrients. Bacteria can in principle be used to degrade hydrocarbons. Specific to marine oil spills, nitrogen and phosphorus have been key nutrients in biodegradation. The bioremediation of hydrocarbons suffers from low rates. Bioremediation can involve the action of microbial consortium. Within the consortium, the product of one species could be the substrate for another species. Anaerobic bioremediation can in principle be employed to treat a range of oxidized contaminants including PCE, TCE, DCE, VC), chlorinated ethanes (TCA, DCA), chloromethanes (CT, CF), chlorinated cyclic hydrocarbons, various energetics (e.g., perchlorate, RDX, TNT), and nitrate. This process involves the addition of an electron donor to: 1) deplete background electron acceptors including oxygen, nitrate, oxidized iron and manganese and sulfate; and 2) stimulate the biological and/or chemical reduction of the oxidized pollutants. The choice of substrate and the method of injection depend on the contaminant type and distribution in the aquifer, hydrogeology, and remediation objectives. Substrate can be added using conventional well installations, by direct-push technology, or by excavation and backfill such as permeable reactive barriers (PRB) or biowalls. Slow-release


id: bioremediation-20260505-2
file: data/en.wikipedia.org/wiki/Bioremediation-2.md
category: reference
title: Bioremediation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Bioremediation
date_saved: 2026-05-05T07:17:17.028374+00:00
instance: kb-cron
parent: bioremediation-20260505-0
summary:
=== Pesticides === Of the many ways to deal with pesticide contamination, bioremediation promises to be more effective. Many sites around the world are contaminated with agrichemicals. These agrichemicals often resist biodegradation, by design. Harming all manners of organic life with long term health issues such as cancer, rashes, blindness, paralysis, and mental illness. An example is Lindane which was a commonly used insecticide in the 20th century. Long time exposure poses a serious threat to humans and the surrounding ecosystem. Lindane reduces the potential of beneficial bacteria in the soil such as nitrogen fixation cyanobacteria. As well as causing central nervous system issues in smaller mammals such as seizures, dizziness, and even death. What makes it so harmful to these organisms is how quickly distributed it gets through the brain and fatty tissues. While Lindane has been mostly limited to specific use, it is still produced and used around the world. Actinobacteria has been a promising candidate in situ technique specifically for removing pesticides. When certain strains of Actinobacteria have been grouped together, their efficiency in degrading pesticides has enhanced. As well as being a reusable technique that strengthens through further use by limiting the migration space of these


id: biosurfactant-20260505-0
file: data/en.wikipedia.org/wiki/Biosurfactant-0.md
category: reference
title: Biosurfactant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Biosurfactant
date_saved: 2026-05-05T07:17:28.527624+00:00
instance: kb-cron
parent: biosurfactant-20260505-0
summary:
Biosurfactant usually refers to surfactants of microbial origin. Most of the biosurfactants produced by microbes are synthesized extracellularly and many microbes are known to produce biosurfactants in large relative quantities. Some are of commercial interest. As a secondary metabolite of microorganisms, biosurfactants can be processed by the cultivation of biosurfactant producing microorganisms in the stationary phase on many sorts of low-priced substrates like biochar, plant oils, carbohydrates, wastes, etc. High-level production of biosurfactants can be controlled by regulation of environmental factors and growth circumstances. == Classification == Biosurfactants are usually categorized by their molecular structure. Like synthetic surfactants, they are composed of a hydrophilic moiety made up of amino acids, peptides, (poly)saccharides, or sugar alcohols and a hydrophobic moiety consisting of fatty acids. Correspondingly, the significant classes of biosurfactants include glycolipids, lipopeptides and lipoproteins, and polymeric surfactants as well as particulate surfactants. == Examples == Common biosurfactants include: Bile salts are mixtures of micelle-forming compounds that encapsulate food, enabling absorption through the small intestine. Lecithin, which can be obtained either from soybean or from egg yolk, is a common food ingredient. Rhamnolipids, which can be produced by some species of Pseudomonas, e.g., Pseudomonas aeruginosa. Sophorolipids are produced by various nonpathogenic


id: carbon-footprint-20260505-0
file: data/en.wikipedia.org/wiki/Carbon_footprint-0.md
category: reference
title: Carbon footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carbon_footprint
date_saved: 2026-05-05T07:17:29.854297+00:00
instance: kb-cron
parent: carbon-footprint-20260505-0
summary:
A carbon footprint (or greenhouse gas footprint) is a calculated value or index that makes it possible to compare the total amount of greenhouse gases that an activity, product, company or country adds to the atmosphere. Carbon footprints are usually reported in tonnes of emissions (CO2-equivalent) per unit of comparison. Such units can be, for example, tonnes CO2-eq per year, per kilogram of protein for consumption, per kilometer travelled, per piece of clothing and so forth. A product's carbon footprint includes the emissions for the entire life cycle. These run from the production along the supply chain to its final consumption and disposal. Similarly, an organization's carbon footprint includes the direct as well as the indirect emissions that it causes. The Greenhouse Gas Protocol (for carbon accounting of organizations) calls these Scope 1, 2 and 3 emissions. There are several methodologies and online tools to calculate the carbon footprint. They depend on whether the focus is on a country, organization, product or individual person. For example, the carbon footprint of a product could help consumers decide which product to buy if they want to be climate aware. For climate change mitigation activities, the carbon footprint can help distinguish those economic


id: carbon-footprint-20260505-1
file: data/en.wikipedia.org/wiki/Carbon_footprint-1.md
category: reference
title: Carbon footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carbon_footprint
date_saved: 2026-05-05T07:17:29.854297+00:00
instance: kb-cron
parent: carbon-footprint-20260505-0
summary:
The greenhouse gas protocol is a set of standards for tracking greenhouse gas emissions. The standards divide emissions into three scopes (Scope 1, 2 and 3) within the value chain. Greenhouse gas emissions caused directly by the organization such as by burning fossil fuels are referred to as Scope 1. Emissions caused indirectly by an organization, such as by purchasing secondary energy sources like electricity, heat, cooling or steam are called Scope 2. Lastly, indirect emissions associated with upstream or downstream processes are called Scope 3. === Direct carbon emissions (Scope 1) === Direct or Scope 1 carbon emissions come from sources on the site that is producing a product or delivering a service. An example for industry would be the emissions from burning a fuel on site. On the individual level, emissions from personal vehicles or gas-burning stoves are Scope 1. === Indirect carbon emissions (Scope 2) === Indirect carbon emissions are emissions from sources upstream or downstream from the process being studied. They are also known as Scope 2 or Scope 3 emissions. Scope 2 emissions are the indirect emissions related to purchasing electricity, heat, or steam used on site. Examples of upstream carbon emissions include transportation of


id: carbon-footprint-20260505-2
file: data/en.wikipedia.org/wiki/Carbon_footprint-2.md
category: reference
title: Carbon footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carbon_footprint
date_saved: 2026-05-05T07:17:29.854297+00:00
instance: kb-cron
parent: carbon-footprint-20260505-0
summary:
== Underlying concepts for calculations == The calculation of the carbon footprint of a product, service or sector requires expert knowledge and careful examination of what is to be included. Carbon footprints can be calculated at different scales. They can apply to whole countries, cities, neighborhoods and also sectors, companies and products. Several free online carbon footprint calculators exist to calculate personal carbon footprints. Software such as the "Scope 3 Evaluator" can help companies report emissions throughout their value chain. The software tools can help consultants and researchers to model global sustainability footprints. In each situation there are a number of questions that need to be answered. These include which activities are linked to which emissions, and which proportion should be attributed to which company. Software is essential for company management. But there is a need for new ways of enterprise resource planning to improve corporate sustainability performance. To achieve 95% carbon footprint coverage, it would be necessary to assess 12 million individual supply-chain contributions. This is based on analyzing 12 sectoral case studies. The Scope 3 calculations can be made easier using input-output analysis. This is a technique originally developed by Nobel Prize-winning economist Wassily Leontief. === Consumption-based emission


id: carbon-footprint-20260505-3
file: data/en.wikipedia.org/wiki/Carbon_footprint-3.md
category: reference
title: Carbon footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carbon_footprint
date_saved: 2026-05-05T07:17:29.854297+00:00
instance: kb-cron
parent: carbon-footprint-20260505-0
summary:
=== Relationship with other environmental impacts === A focus on carbon footprints can lead people to ignore or even exacerbate other related environmental issues of concern. These include biodiversity loss, ecotoxicity, and habitat destruction. It may not be easy to measure these other human impacts on the environment with a single indicator like the carbon footprint. Consumers may think that the carbon footprint is a proxy for environmental impact. In many cases this is not correct. There can be trade-offs between reducing carbon footprint and environmental protection goals. One example is the use of biofuel, a renewable energy source that can reduce the carbon footprint of the energy supply but can also pose ecological challenges during its production. This is because it is often produced in monocultures with ample use of fertilizers and pesticides. Another example is offshore wind parks, which could have unintended impacts on marine ecosystems. The carbon footprint analysis solely focuses on greenhouse gas emissions, unlike a life-cycle assessment which is much broader and looks at all environmental impacts. Therefore, it is useful to stress in communication activities that the carbon footprint is just one in a family of indicators (e.g. ecological footprint, water footprint, land footprint,


id: carbon-footprint-20260505-4
file: data/en.wikipedia.org/wiki/Carbon_footprint-4.md
category: reference
title: Carbon footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carbon_footprint
date_saved: 2026-05-05T07:17:29.854297+00:00
instance: kb-cron
parent: carbon-footprint-20260505-0
summary:
CO2 emissions of countries are typically measured on the basis of production. This accounting method is sometimes referred to as territorial emissions. Countries use it when they report their emissions, and set domestic and international targets such as Nationally Determined Contributions. Consumption-based emissions on the other hand are adjusted for trade. To calculate consumption-based emissions analysts have to track which goods are traded across the world. Whenever a product is imported, all CO2 emissions that were emitted in the production of that product are included. Consumption-based emissions reflect the lifestyle choices of a country's citizens. According to the World Bank, the global average carbon footprint in 2014 was about 5 tonnes of CO2 per person, measured on a production basis. The EU average for 2007 was about 13.8 tonnes CO2e per person. For the USA, Luxembourg and Australia it was over 25 tonnes CO2e per person. In 2017, the average for the USA was about 20 metric tonnes CO2e per person. This is one of the highest per capita figures in the world. The footprints per capita of countries in Africa and India were well below average. Assuming a global population of around 9–10 billion by 2050, a carbon footprint


id: carbon-rift-20260505-0
file: data/en.wikipedia.org/wiki/Carbon_rift-0.md
category: reference
title: Carbon rift
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carbon_rift
date_saved: 2026-05-05T07:17:31.133510+00:00
instance: kb-cron
parent: carbon-rift-20260505-0
summary:
Carbon rift is a theory attributing the input and output of carbon into the environment to human capitalistic systems. This is a derivative of Karl Marx's concept of metabolic rift. In practical terms, increased commodity production demands that greater levels of carbon dioxide (or CO2) be emitted into the biosphere via fossil fuel consumption. Carbon rift theory states that this ultimately disrupts the natural carbon cycle and that this "rift" has adverse effects on nearly every aspect of life. Many of the specifics regarding how this metabolic carbon rift interacts with capitalism are proposed by Brett Clark and Richard York in a 2005 article titled "Carbon Metabolism: Global capitalism, climate change, and the biospheric rift" in the journal Theory and Society. Researchers such as Jean P. Sapinski of the University of Oregon claim that, despite increased interest in closing the carbon rift, it is projected that as long as capitalism continues, there is little hope of reducing the rift. Both deforestation and the emission of greenhouse gases have been linked to increased atmospheric CO2 levels. Carbon rift theory states that these are the result of human production through capitalistic systems. There are proposed solutions to climate change such as geoengineering


id: carrying-capacity-20260505-0
file: data/en.wikipedia.org/wiki/Carrying_capacity-0.md
category: reference
title: Carrying capacity
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carrying_capacity
date_saved: 2026-05-05T07:17:32.393840+00:00
instance: kb-cron
parent: carrying-capacity-20260505-0
summary:
The carrying capacity of an ecosystem is the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available. The carrying capacity is defined as the environment's maximal load, which in population ecology corresponds to the population equilibrium, when the number of deaths in a population equals the number of births (as well as immigration and emigration). Carrying capacity of the environment implies that the resources extraction is not above the rate of regeneration of the resources and the wastes generated are within the assimilating capacity of the environment. The effect of carrying capacity on population dynamics is modelled with a logistic function. Carrying capacity is applied to the maximum population an environment can support in ecology, agriculture and fisheries. The term carrying capacity had been applied to a few different processes in the past before finally being applied to human population limits in the 1950s. The notion of carrying capacity for humans is covered by the notion of sustainable population. An early detailed examination of global limits on human population was published in the 1972 book Limits to Growth, which has prompted follow-up commentary and analysis,


id: carrying-capacity-20260505-1
file: data/en.wikipedia.org/wiki/Carrying_capacity-1.md
category: reference
title: Carrying capacity
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carrying_capacity
date_saved: 2026-05-05T07:17:32.393840+00:00
instance: kb-cron
parent: carrying-capacity-20260505-0
summary:
e is Euler's number, A is a constant determined by the initial population N 0 {\displaystyle N_{0}} via A = K N 0 − 1 {\displaystyle A={K \over N_{0}}-1} . When the initial population is below the carrying capacity, A {\displaystyle A} is positive; when it is above, A {\displaystyle A} is negative. r is the initial exponential growth rate, and K is the carrying capacity. The logistic growth curve depicts how population growth rate and carrying capacity are inter-connected. As illustrated in the logistic growth curve model, when the population size is small, the population increases exponentially. However, as population size nears carrying capacity, the growth decreases and reaches zero at K. What determines a specific system's carrying capacity involves a limiting factor; this may be available supplies of food or water, nesting areas, space, or the amount of waste that can be absorbed without degrading the environment and decreasing carrying capacity. == Population ecology == Carrying capacity is a commonly used concept for biologists when trying to better understand biological populations and the factors which affect them. When addressing biological populations, carrying capacity can be seen as a stable dynamic equilibrium, taking into account extinction and colonization rates.


id: carrying-capacity-20260505-2
file: data/en.wikipedia.org/wiki/Carrying_capacity-2.md
category: reference
title: Carrying capacity
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carrying_capacity
date_saved: 2026-05-05T07:17:32.393840+00:00
instance: kb-cron
parent: carrying-capacity-20260505-0
summary:
In fisheries, carrying capacity is used in the formulae to calculate sustainable yields for fisheries management. The maximum sustainable yield (MSY) is defined as "the highest average catch that can be continuously taken from an exploited population (=stock) under average environmental conditions". MSY was originally calculated as half of the carrying capacity, but has been refined over the years, now being seen as roughly 30% of the population, depending on the species or population. Because the population of a species which is brought below its carrying capacity due to fishing will find itself in the exponential phase of growth, as seen in the Verhulst model, the harvesting of an amount of fish at or below MSY is a surplus yield which can be sustainably harvested without reducing population size at equilibrium, keeping the population at its maximum recruitment. However, annual fishing can be seen as a modification of r in the equation -i.e. the environment has been modified, which means that the population size at equilibrium with annual fishing is slightly below what K would be without it. Note that mathematically and in practical terms, MSY is problematic. If mistakes are made and even a tiny amount of fish are


id: carrying-capacity-20260505-3
file: data/en.wikipedia.org/wiki/Carrying_capacity-3.md
category: reference
title: Carrying capacity
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carrying_capacity
date_saved: 2026-05-05T07:17:32.393840+00:00
instance: kb-cron
parent: carrying-capacity-20260505-0
summary:
Another issue to consider when applying carrying capacity, especially to humans, is that measuring food resources is arbitrary. This is due to choosing what to consider (e.g., whether or not to include plants that are not available every year), how to classify what is considered (e.g., classifying edible plants that are not usually eaten as food resources or not), and determining if caloric values or nutritional values are privileged. Additional layers to this for humans are their cultural differences in culinary preferences (e.g., some consume flying termites) and individual choices on what to invest their labor into (e.g., fishing vs. farming), both of which vary over time. This leads to the need to determine whether or not to include all food resources or only those the population considered will actually consume. Measuring water resources carrying capacity is likewise highly arbitrary: choices in temporal resolution (e.g., monthly versus annual), spatial resolution (e.g., how subbasins are delineated), and whether to include human activities such as inter-basin water transfers and reservoir storage in the assessment can all lead to vastly different WRCC results. Carrying capacity measurements over large areas also assumes homogeneity in the resources available but this does not account for how


id: carrying-capacity-20260505-4
file: data/en.wikipedia.org/wiki/Carrying_capacity-4.md
category: reference
title: Carrying capacity
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Carrying_capacity
date_saved: 2026-05-05T07:17:32.393840+00:00
instance: kb-cron
parent: carrying-capacity-20260505-0
summary:
=== Ecological footprint accounting === Ecological footprint accounting measures the demands people make on nature and compares them to available supplies, for both individual countries and the world as a whole. Developed originally by Mathis Wackernagel and William Rees, it has been refined and applied in a variety of contexts over the years by Global Footprint Network (GFN). On the demand side, the ecological footprint measures how fast a population uses resources and generates wastes, with a focus on five main areas: carbon emissions (or carbon footprint); land devoted to direct settlement; timber and paper use; food and fiber use; and seafood consumption. It converts these into per capita or total hectares used. On the supply side, national or global biocapacity represents the productivity of ecological assets in a particular nation or the world as a whole; this includes "cropland, grazing land, forest land, fishing grounds, and built-up land." Again the various metrics to capture biocapacity are translated into the single term of hectares of available land. As Global Footprint Network (GFN) states:Each city, state or nation's Ecological Footprint can be compared to its biocapacity, or that of the world. If a population's Ecological Footprint exceeds the region's biocapacity, that


id: climate-restoration-20260505-0
file: data/en.wikipedia.org/wiki/Climate_restoration-0.md
category: reference
title: Climate restoration
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Climate_restoration
date_saved: 2026-05-05T07:17:33.592291+00:00
instance: kb-cron
parent: climate-restoration-20260505-0
summary:
Climate restoration refers to intentionally restoring preindustrial levels of greenhouse gases by 2050, thereby ending the climate crisis and enabling future generations of humanity and nature to flourish. The climate restoration movement is committed to lowering carbon dioxide (CO2) levels below 300 parts per million (ppm)—the levels at which humans evolved and have thrived. Climate-restoration solutions include large-scale carbon dioxide removal (CDR)) to pull down the excess atmospheric CO2 built up in the air since the industrial revolution. Climate-restoration actions also include restoring pre-industrial atmospheric methane levels by accelerating natural methane oxidation. Climate restoration expands on the legacy climate goal of stabilizing Earth's climate by achieving "net-zero emissions." The movement calls for the transition to clean energy as well as for restoring preindustrial CO2 levels. These levels allowed humanity to develop agriculture and civilizations, so they are considered historically safe. == Mitigation and restoration == Advocates of climate restoration point out that continuing on our current climate trajectory threatens the long-term survival of society, current biodiversity, and humanity itself. They cite a moral imperative to leave a safe climate to our children and future generations. But the current mitigation pathway carries the risk that climatic conditions will worsen beyond our


id: climate-restoration-20260505-1
file: data/en.wikipedia.org/wiki/Climate_restoration-1.md
category: reference
title: Climate restoration
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Climate_restoration
date_saved: 2026-05-05T07:17:33.592291+00:00
instance: kb-cron
parent: climate-restoration-20260505-0
summary:
levels of climate forcing agents in the atmosphere, especially CO2 and methane for positive forcing and SO2 aerosol for negative forcing; global mean surface temperature (compared to some baseline) and its rate of increase; sea level and the rate that sea level is rising; pH and rate of ocean acidification. Ice levels of the polar ice caps. One of the principal goals for climate restoration is to bring the CO2 level down from current level of ~420 ppm (2022) towards its pre-industrial level of ~280 ppm. Not only will this reduce CO2's global warming effect but also its effect on ocean acidification. The removed carbon would be sequestered or used as a construction material. == Climate restoration open letter == On November 13, 2020, an open letter, put together by the youth organisation Worldward, calling for climate restoration was published in the Guardian newspaper. The letter was signed by prominent scientists and activists, including: Michael E Mann, Dr James Hansen, George Monbiot, Hindou Oumarou Ibrahim, Dr Rowan Williams, Bella Lack, Will Attenborough, Mark Lynas, Chloe Ardijis, Dr Shahrar Ali, and many more. After its publication, the letter was opened up to general signatories, and the signatories published on Worldward's website.


id: climax-community-20260505-0
file: data/en.wikipedia.org/wiki/Climax_community-0.md
category: reference
title: Climax community
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Climax_community
date_saved: 2026-05-05T07:17:34.903771+00:00
instance: kb-cron
parent: climax-community-20260505-0
summary:
In scientific ecology, climax community or climatic climax community is a historic term for a community of plants, animals, and fungi which, through the process of ecological succession in the development of vegetation in an area over time, have reached a steady state. This equilibrium was thought to occur because the climax community is composed of species best adapted to average conditions in that area. The term is sometimes also applied in soil development. Nevertheless, it has been found that a "steady state" is more apparent than real, particularly across long timescales. The idea of a single climax, which is defined in relation to regional climate, originated with Frederic Clements in the early 1900s. The first analysis of succession as leading to something like a climax was written by Henry Cowles in 1899, but it was Clements who used the term "climax" to describe the idealized endpoint of succession. == Frederic Clements' use of "climax" == Clements described the successional development of an ecological community comparable to the ontogenetic development of individual organisms. Clements suggested only comparisons to very simple organisms. Later ecologists developed this idea that the ecological community is a "superorganism" and even sometimes claimed that communities could


id: climax-species-20260505-0
file: data/en.wikipedia.org/wiki/Climax_species-0.md
category: reference
title: Climax species
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Climax_species
date_saved: 2026-05-05T07:17:36.067235+00:00
instance: kb-cron
parent: climax-species-20260505-0
summary:
Climax species, also called late seral, late-successional, K-selected or equilibrium species, are plant species that can germinate and grow with limited resources; e.g., they need heat exposure or low water availability. They are the species within forest succession that are more adapted to stable and predictable environments, and will remain essentially unchanged in terms of species composition for as long as a site remains undisturbed. The seedlings of climax species can grow in the shade of the parent trees, ensuring their dominance indefinitely. The presence of climax species can also reduce the prevalence of other species within an ecosystem. However, a disturbance, such as fire, may kill the climax species, allowing pioneer or earlier successional species to re-establish for a time. They are the opposite of pioneer species, also known as ruderal, fugitive, opportunistic or R-selected species, in the sense that climax species are good competitors but poor colonizers, whereas pioneer species are good colonizers but poor competitors. Given the prevailing ecological conditions, climax species dominate the climax community. When the pace of succession slows down as the result of ecological homeostasis, the maximum permitted biodiversity is reached. Their reproductive strategies and other adaptive characteristics can be considered more sophisticated


id: coevolution-20260505-0
file: data/en.wikipedia.org/wiki/Coevolution-0.md
category: reference
title: Coevolution
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Coevolution
date_saved: 2026-05-05T07:17:37.344867+00:00
instance: kb-cron
parent: coevolution-20260505-0
summary:
In biology, coevolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection. The term sometimes is used for two traits in the same species affecting each other's evolution, as well as gene-culture coevolution. Charles Darwin mentioned evolutionary interactions between flowering plants and insects in On the Origin of Species (1859). He used use the similar word coadaptation and suggested how plants and insects could evolve through reciprocal evolutionary changes. Naturalists in the late 1800s studied other examples of how interactions among species could result in reciprocal evolutionary change. Beginning in the 1940s, plant pathologists developed breeding programs that were examples of human-induced coevolution. Development of new crop plant varieties that were resistant to some diseases favored rapid evolution in pathogen populations to overcome those plant defenses. That, in turn, required the development of yet new resistant crop plant varieties, producing an ongoing cycle of reciprocal evolution in crop plants and diseases that continues to this day. Coevolution as a major topic for study in nature expanded rapidly from the 1960s, when Daniel H. Janzen showed coevolution between acacias and ants (see below) and Paul R. Ehrlich and Peter H. Raven suggested how


id: coevolution-20260505-1
file: data/en.wikipedia.org/wiki/Coevolution-1.md
category: reference
title: Coevolution
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Coevolution
date_saved: 2026-05-05T07:17:37.344867+00:00
instance: kb-cron
parent: coevolution-20260505-0
summary:
Hummingbirds and ornithophilous (bird-pollinated) flowers have evolved a mutualistic relationship. The flowers have nectar suited to the birds' diet, their color suits the birds' vision and their shape fits that of the birds' bills. The blooming times of the flowers have also been found to coincide with hummingbirds' breeding seasons. The floral characteristics of ornithophilous plants vary greatly among each other compared to closely related insect-pollinated species. These flowers also tend to be more ornate, complex, and showy than their insect pollinated counterparts. It is generally agreed that plants formed coevolutionary relationships with insects first, and ornithophilous species diverged at a later time. There is not much scientific support for instances of the reverse of this divergence: from ornithophily to insect pollination. The diversity in floral phenotype in ornithophilous species, and the relative consistency observed in bee-pollinated species can be attributed to the direction of the shift in pollinator preference. Flowers have converged to take advantage of similar birds. Flowers compete for pollinators, and adaptations reduce unfavourable effects of this competition. The fact that birds can fly during inclement weather makes them more efficient pollinators where bees and other insects would be inactive. Ornithophily may have arisen for this reason


id: coevolution-20260505-2
file: data/en.wikipedia.org/wiki/Coevolution-2.md
category: reference
title: Coevolution
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Coevolution
date_saved: 2026-05-05T07:17:37.344867+00:00
instance: kb-cron
parent: coevolution-20260505-0
summary:
Brood parasitism demonstrates close coevolution of host and parasite, for example in some cuckoos. These birds do not make their own nests, but lay their eggs in nests of other species, ejecting or killing the eggs and young of the host and thus having a strong negative impact on the host's reproductive fitness. Their eggs are camouflaged as eggs of their hosts, implying that hosts can distinguish their own eggs from those of intruders and are in an evolutionary arms race with the cuckoo between camouflage and recognition. Cuckoos are counter-adapted to host defences with features such as thickened eggshells, shorter incubation (so their young hatch first), and flat backs adapted to lift eggs out of the nest. === Antagonistic coevolution === Antagonistic coevolution is seen in the harvester ant species Pogonomyrmex barbatus and Pogonomyrmex rugosus, in a relationship both parasitic and mutualistic. The queens are unable to produce worker ants by mating with their own species. Only by crossbreeding can they produce workers. The winged females act as parasites for the males of the other species as their sperm will only produce sterile hybrids. But because the colonies are fully dependent on these hybrids to survive, it is also


id: coevolution-20260505-3
file: data/en.wikipedia.org/wiki/Coevolution-3.md
category: reference
title: Coevolution
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Coevolution
date_saved: 2026-05-05T07:17:37.344867+00:00
instance: kb-cron
parent: coevolution-20260505-0
summary:
=== In management and organisation studies === Since 2000, coevolution has been explored in management and organisation studies, for example in the business ecosystem of partners of the Intel corporation, where Intel both shapes and is shaped by its partners. However, the processes that characterise coevolution in these fields remain unclear, and its applicability is undefined. It has been suggested that when an organisation seeks ideas from external partners, it tends to select and retain partners whose ideas align with its own. This means that far from passively receiving ideas during a search, organisations actively shape the nature of the contributions they can receive in a two-way "coevolutionary lock-in" process. === In political economy === Some scholars have applied coevolution to propose non-linear theories in political economy. The Emergence of Organizations and Markets, by John Padgett and Walter Powell, presents case studies of social networks coevolving with institutions, mainly based on early European history (e.g., commercial networks in 13th century Tuscany). A more contemporary application is How China Escaped the Poverty Trap, by Yuen Yuen Ang, which traces the mutual adaptation of the economy and institution, first in China's development under Deng Xiaoping, and also in Nigeria's film industry and


id: colony-biology-20260505-0
file: data/en.wikipedia.org/wiki/Colony_(biology)-0.md
category: reference
title: Colony (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Colony_(biology)
date_saved: 2026-05-05T07:17:38.621004+00:00
instance: kb-cron
parent: colony-biology-20260505-0
summary:
In biology, a colony is composed of two or more conspecific individuals living in close association with, or connected to, one another. This association is usually for mutual benefit such as stronger defense or the ability to attack bigger prey. Colonies can form in various shapes and ways depending on the organism involved. For instance, the bacterial colony is a cluster of identical cells (clones). These colonies often form and grow on the surface of (or within) a solid medium, usually derived from a single parent cell. Colonies, in the context of development, may be composed of two or more unitary (or solitary) organisms or be modular organisms. Unitary organisms have determinate development (set life stages) from zygote to adult form and individuals or groups of individuals (colonies) are visually distinct. Modular organisms have indeterminate growth forms (life stages not set) through repeated iteration of genetically identical modules (or individuals), and it can be difficult to distinguish between the colony as a whole and the modules within. In the latter case, modules may have specific functions within the colony. In contrast, solitary organisms – such as jaguars – do not associate with colonies; they are ones in which all individuals


id: colony-biology-20260505-1
file: data/en.wikipedia.org/wiki/Colony_(biology)-1.md
category: reference
title: Colony (biology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Colony_(biology)
date_saved: 2026-05-05T07:17:38.621004+00:00
instance: kb-cron
parent: colony-biology-20260505-0
summary:
=== Worker emergence === This is also known as the ergonomic stage. As the eggs laid by the foundresses develop, they give rise to the first generation of workers. These workers can assume various tasks, such as foraging, brood care, and nest maintenance. Initially, the worker population is relatively small, and their tasks are not as specialised. As the colony grows, more workers emerge, and the division of labor becomes more pronounced. Some individuals may specialise in tasks like foraging, defense, or tending to the brood, while others may take on general tasks within the nest. These specialised tasks can change throughout the life of a worker. === Reproductive phase === At a certain point in the colony ontogeny, usually after a period of growth and maturation, the colony produces reproductives, including new virgin queens (princesses) and males. These individuals have the potential to leave the nest and start new colonies, ensuring the transmission of the gene pool of its natal colony. === Colony death === Over time, colonies may go through a senescence phase where the reproductive output declines, and the colony's overall vitality diminishes. Eventually, the colony may die off or be replaced by a new generation of


id: common-species-20260505-0
file: data/en.wikipedia.org/wiki/Common_species-0.md
category: reference
title: Common species
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Common_species
date_saved: 2026-05-05T07:17:40.304201+00:00
instance: kb-cron
parent: common-species-20260505-0
summary:
Common species and uncommon species are designations used in ecology to describe the population status of a species. Commonness is closely related to abundance. Abundance refers to the frequency with which a species is found in controlled samples; in contrast, species are defined as common or uncommon based on their overall presence in the environment. A species may be locally abundant without being common. However, "common" and "uncommon" are also sometimes used to describe levels of abundance, with a common species being less abundant than an abundant species, while an uncommon species is more abundant than a rare species. Common species are frequently regarded as being at low risk of extinction simply because they exist in large numbers, and hence their conservation status is often overlooked. While this is broadly logical, there are several cases of once common species being driven to extinction such as the passenger pigeon and the Rocky Mountain locust, which numbered in the billions and trillions respectively before their demise. Moreover, a small proportional decline in a common species results in the loss of a large number of individuals, and the contribution to ecosystem function that those individuals represented. A recent paper argued that because common


id: conservation-status-20260505-0
file: data/en.wikipedia.org/wiki/Conservation_status-0.md
category: reference
title: Conservation status
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Conservation_status
date_saved: 2026-05-05T07:17:42.109211+00:00
instance: kb-cron
parent: conservation-status-20260505-0
summary:
The conservation status of a group of organisms (for example, a species) indicates whether the group still exists and how likely it is to become extinct in the near future. Many factors are taken into account when assessing conservation status—not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. Various systems of conservation status are in use at international, multi-country, national and local levels, as well as for consumer use such as sustainable seafood advisory lists and certification. The two international systems are by the International Union for Conservation of Nature (IUCN) and The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). == International systems == === IUCN Red List of Threatened Species === The IUCN Red List of Threatened Species by the International Union for Conservation of Nature is the best known worldwide conservation status listing and ranking system. Species are classified by the IUCN Red List into nine groups set through criteria such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmentation. Also included are species that have gone extinct since


id: conservation-status-20260505-1
file: data/en.wikipedia.org/wiki/Conservation_status-1.md
category: reference
title: Conservation status
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Conservation_status
date_saved: 2026-05-05T07:17:42.109211+00:00
instance: kb-cron
parent: conservation-status-20260505-0
summary:
== National systems == In Australia, the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) describes lists of threatened species, ecological communities and threatening processes. The categories resemble those of the 1994 IUCN Red List Categories & Criteria (version 2.3). Prior to the EPBC Act, a simpler classification system was used by the Endangered Species Protection Act 1992. Some state and territory governments also have their own systems for conservation status. The codes for the Western Australian conservation system are given at Declared Rare and Priority Flora List (abbreviated to DECF when using in a taxobox). In Belgium, the Flemish Research Institute for Nature and Forest publishes an online set of more than 150 nature indicators in Dutch. In Canada, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is a group of experts that assesses and designates which wild species are in some danger of disappearing from Canada. Under the Species at Risk Act (SARA), it is up to the federal government, which is politically accountable, to legally protect species assessed by COSEWIC. In China, the State, provinces and some counties have determined their key protected wildlife species. There is the China red data book. In


id: constructed-wetland-20260505-0
file: data/en.wikipedia.org/wiki/Constructed_wetland-0.md
category: reference
title: Constructed wetland
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Constructed_wetland
date_saved: 2026-05-05T07:17:43.561117+00:00
instance: kb-cron
parent: constructed-wetland-20260505-0
summary:
A constructed wetland is an artificial wetland to treat sewage, greywater, stormwater runoff or industrial wastewater. It may also be designed for land reclamation after mining, or as a mitigation step for natural areas lost to land development. Constructed wetlands are engineered systems that use the natural functions of vegetation, soil, and organisms to provide secondary treatment to wastewater. The design of the constructed wetland has to be adjusted according to the type of wastewater to be treated. Constructed wetlands have been used in both centralized and decentralized wastewater systems. Primary treatment is recommended when there is a large amount of suspended solids or soluble organic matter (measured as biochemical oxygen demand and chemical oxygen demand). Similar to natural wetlands, constructed wetlands also act as a biofilter and/or can remove a range of pollutants (such as organic matter, nutrients, pathogens, heavy metals) from the water. Constructed wetlands are designed to remove water pollutants such as suspended solids, organic matter and nutrients (nitrogen and phosphorus). All types of pathogens (i.e., bacteria, viruses, protozoans and helminths) are expected to be removed to some extent in a constructed wetland. Subsurface wetlands provide greater pathogen removal than surface wetlands. There are two main types


id: constructed-wetland-20260505-1
file: data/en.wikipedia.org/wiki/Constructed_wetland-1.md
category: reference
title: Constructed wetland
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Constructed_wetland
date_saved: 2026-05-05T07:17:43.561117+00:00
instance: kb-cron
parent: constructed-wetland-20260505-0
summary:
Nitrification is the biological conversion of organic and inorganic nitrogenous compounds from a reduced state to a more oxidized state, based on the action of two different bacteria types. Nitrification is strictly an aerobic process in which the end product is nitrate (NO−3). The process of nitrification oxidizes ammonium (from the wastewater) to nitrite (NO−2), and then nitrite is oxidized to nitrate (NO−3). ==== Denitrification ==== Denitrification is the biochemical reduction of oxidized nitrogen anions, nitrate and nitrite to produce the gaseous products nitric oxide (NO), nitrous oxide (N2O) and nitrogen gas (N2), with concomitant oxidation of organic matter. The end product, N2, and to a lesser extent the intermediary by product, N2O, are gases that re-enter the atmosphere. ==== Ammonia removal from mine water ==== Constructed wetlands have been used to remove ammonia and other nitrogenous compounds from contaminated mine water, including cyanide and nitrate. === Phosphorus removal === Phosphorus occurs naturally in both organic and inorganic forms. The analytical measure of biologically available orthophosphates is referred to as soluble reactive phosphorus (SR-P). Dissolved organic phosphorus and insoluble forms of organic and inorganic phosphorus are generally not biologically available until transformed into soluble inorganic forms. In freshwater aquatic ecosystems,


id: constructed-wetland-20260505-2
file: data/en.wikipedia.org/wiki/Constructed_wetland-2.md
category: reference
title: Constructed wetland
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Constructed_wetland
date_saved: 2026-05-05T07:17:43.561117+00:00
instance: kb-cron
parent: constructed-wetland-20260505-0
summary:
Subsurface flow constructed wetland – this wetland can be either with vertical flow (the effluent moves vertically, from the planted layer down through the substrate and out) or with horizontal flow (the effluent moves horizontally, parallel to the surface) Surface flow constructed wetland (this wetland has horizontal flow) Floating treatment wetland The former types are placed in a basin with a substrate to provide a surface area upon which large amounts of waste degrading biofilms form, while the latter relies on a flooded treatment basin upon which aquatic plants are held in flotation till they develop a thick mat of roots and rhizomes upon which biofilms form. In most cases, the bottom is lined with either a polymer geomembrane, concrete or clay (when there is appropriate clay type) in order to protect the water table and surrounding grounds. The substrate can be either gravel—generally limestone or pumice/volcanic rock, depending on local availability, sand or a mixture of various sizes of media (for vertical flow constructed wetlands). Constructed wetlands can be used after a septic tank for primary treatment (or other types of systems) in order to separate the solids from the liquid effluent. Some constructed wetland designs however do not


id: constructed-wetland-20260505-3
file: data/en.wikipedia.org/wiki/Constructed_wetland-3.md
category: reference
title: Constructed wetland
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Constructed_wetland
date_saved: 2026-05-05T07:17:43.561117+00:00
instance: kb-cron
parent: constructed-wetland-20260505-0
summary:
==== Comparisons with other types ==== Subsurface wetlands are less hospitable to mosquitoes compared to surface flow wetlands, as there is no water exposed to the surface. Mosquitos can be a problem in surface flow constructed wetlands. Subsurface flow systems have the advantage of requiring less land area for water treatment than surface flow. However, surface flow wetlands can be more suitable for wildlife habitat. For urban applications the area requirement of a subsurface flow constructed wetland might be a limiting factor compared to conventional municipal wastewater treatment plants. High rate aerobic treatment processes like activated sludge plants, trickling filters, rotating discs, submerged aerated filters or membrane bioreactor plants require less space. The advantage of subsurface flow constructed wetlands compared to those technologies is their operational robustness which is particularly important in developing countries. The fact that constructed wetlands do not produce secondary sludge (sewage sludge) is another advantage as there is no need for sewage sludge treatment. However, primary sludge from primary settling tanks does get produced and needs to be removed and treated. ==== Costs ==== The costs of subsurface flow constructed wetlands mainly depend on the costs of sand with which the bed has to be filled.


id: constructed-wetland-20260505-4
file: data/en.wikipedia.org/wiki/Constructed_wetland-4.md
category: reference
title: Constructed wetland
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Constructed_wetland
date_saved: 2026-05-05T07:17:43.561117+00:00
instance: kb-cron
parent: constructed-wetland-20260505-0
summary:
== History == Primary clarifier effluent was discharged directly to natural wetlands for decades before environmental regulations discouraged the practice. Subsurface flow constructed wetlands with sand filter beds have their origin in China and are now used in Asia in small cities. == Examples == === Austria === The total number of constructed wetlands in Austria is 5,450 (in 2015). Due to legal requirements (nitrification), only vertical flow constructed wetlands are implemented in Austria as they achieve better nitrification performance than horizontal flow constructed wetlands. Only about 100 of these constructed wetlands have a design size of 50 population equivalents or more. The remaining 5,350 treatment plants are smaller than that. === Canada === As part of the remediation efforts to remove contamination from CFB Goose Bay, one of the waste dumps was transformed into an engineered wetland. In 2023, Clearwater County implemented the first biofilter-based wetland wastewater treatment system in the province. The system uses 2 types of subsurface constructed wetlands to conduct both aerobic and anaerobic wastewater treatment. == See also == == References == == External links == Constructed Wetlands – US Environmental Protection Agency — Handbook, studies and related resources Publications on constructed wetlands in the


id: convergence-sustainability-science-20260505-0
file: data/en.wikipedia.org/wiki/Convergence_(sustainability_science)-0.md
category: reference
title: Convergence (sustainability science)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Convergence_(sustainability_science)
date_saved: 2026-05-05T07:17:44.793521+00:00
instance: kb-cron
parent: convergence-sustainability-science-20260505-0
summary:
Convergence in sustainability sciences refers to mechanisms and pathways that lead towards sustainability with a specific focus on 'Equity within biological planetary limits'. These pathways and mechanisms explicitly advocate equity and recognise the need for redistribution of the Earth's resources in order for human society to operate enduringly within the Earth's biophysical limits. The term was first introduced by Phillip A. Sharp and Robert Langer in 2011 in the context of biomedical science. They called for a problem-solving approach that integrated knowledge from the fields of engineering, the physical sciences, computer science, and the life sciences to find solutions to human problems. The idea has since been applied in areas including climate change, environmental health, public health, systemic inequities. and sustainability. One strategy is to add “friction” to undesirable practices and make them harder to do, while making the desired practices “frictionless” or easy to do. This use of the term 'convergence' harkens from the concept of contraction and convergence (C&C), taking its core principles of Equity and Survival and applying them beyond the frame of greenhouse gas emissions to the wider sustainability agenda. == References ==


id: critical-habitat-20260505-0
file: data/en.wikipedia.org/wiki/Critical_habitat-0.md
category: reference
title: Critical habitat
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Critical_habitat
date_saved: 2026-05-05T07:17:45.990677+00:00
instance: kb-cron
parent: critical-habitat-20260505-0
summary:
Critical habitat refers to specific geographic areas essential to the conservation of a listed endangered species, though the area need not actually be occupied by the species at the time it is designated. Critical habitat is a legal designation of land use defined within the U.S. Endangered Species Act-ESA. Contrary to common belief, designating an area as critical habitat does not preclude that area from development. A critical habitat designation only affects federal agency actions. Such actions include federally funded activities or activities requiring a federal permit that may negatively affect the quality of habitat for a listed species. This law also defines that there may be no "take" of a listed species from the designated area. This land designation aims to protect vital habitat for endangered species by preserving areas that are able to meet the identified needs for the target species. This is a key feature of conservation as outlined in the ESA. == Designation process == Critical habitat must be designated for all threatened species and endangered species under the Endangered Species Act, with certain specified exceptions. Designations of critical habitats must be based on the best scientific information available and follow the procedure as outlined in


id: cumulative-effects-environment-20260505-0
file: data/en.wikipedia.org/wiki/Cumulative_effects_(environment)-0.md
category: reference
title: Cumulative effects (environment)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cumulative_effects_(environment)
date_saved: 2026-05-05T07:17:47.221717+00:00
instance: kb-cron
parent: cumulative-effects-environment-20260505-0
summary:
Cumulative effects, also referred to as cumulative environmental effects and cumulative impacts, can be defined as changes to the environment caused by the combined impact of past, present and future human activities and natural processes. Cumulative effects to the environment are the result of multiple activities whose individual direct impacts may be relatively minor but in combination with others result are significant environmental effects. The multiple impacts of different activities may have an additive, synergistic or antagonistic effect on one another and with natural processes. Cumulative effects can be difficult to predict and manage due to inadequate environmental baseline data, complex ecological processes, and the large scale at which human development occurs. The emergence of cumulative effects in environmental regulations began in the 1970s and has since been increasingly seen as a consideration in environmental impact assessments and land management. However, despite its growing relevance, there are no generally accepted methodologies for cumulative effects assessments and there remains debate surrounding the issue. Many human activities result in direct and indirect impacts that collectively impact the environment. The impacts of activities in combination with natural processes can result in cascading responses in ecosystems that can become unpredictable. Some activities known to


id: cumulative-effects-environment-20260505-1
file: data/en.wikipedia.org/wiki/Cumulative_effects_(environment)-1.md
category: reference
title: Cumulative effects (environment)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cumulative_effects_(environment)
date_saved: 2026-05-05T07:17:47.221717+00:00
instance: kb-cron
parent: cumulative-effects-environment-20260505-0
summary:
=== Land use change === Land use changes can have a range of direct and indirect impacts on the environment. Individual changes to land uses (e.g., clearing vegetation to build a home) may result in negligible impacts, but the accumulation of these changes across a region or landscape may result in major impacts. Land use changes can cause dramatic losses to high quality and intact wildlife habitat. Residential development and road construction, for example, directly result in fragmenting and reducing the quality of wildlife habitat. Other direct impacts on the ecosystem include noise, light, and air pollution from increased human and vehicle traffic and construction. During construction of new projects, native vegetation is often removed, which can result in changes to the composition of wildlife in the surrounding areas. Additionally, the amount of fencing typically increases with more development, which prevents many species from moving freely. Wildlife will change their behaviour as a result of changed land uses; for example, deer have been found to avoid developed areas as far as 1 kilometre. Indirectly, changes to land uses can result in urban growth, increased deforestation as a result of more accessibility, and degradation of soil stability as a result of


id: cumulative-effects-environment-20260505-2
file: data/en.wikipedia.org/wiki/Cumulative_effects_(environment)-2.md
category: reference
title: Cumulative effects (environment)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cumulative_effects_(environment)
date_saved: 2026-05-05T07:17:47.221717+00:00
instance: kb-cron
parent: cumulative-effects-environment-20260505-0
summary:
Move away from project-specific environmental assessments: Cumulative effects are best understood and managed at a policy, program or sector level because of the need for long-term planning. Develop national environmental baseline databases: Agencies and organizations conducting research within nations share their data in a standardized approach that allows for information to be merged and used in various studies. Many practitioners use computer simulations to predict potential impacts of activities and land use change; therefore, an inventory of national environmental baseline data will strengthen the predictive ability of these models. Coordination among jurisdictional agencies: The fragmentation of environmental assessments between jurisdiction inadequately addresses cumulative effects problems. Coordination between agencies at various levels (national, regional, local) can help set environmental objectives, anticipate and plan for future development, and share best practices. Regional Environmental Assessment (REA): Cumulative effects of human activities on the environment are better understood at a regional scale. Because REAs study the effects of developments occurring within a region, they are more capable than conventional environmental assessments at analyzing cumulative effects. They can also help make more strategic decisions for future development by helping strengthen the understanding the environmental state at a regional scale. Considering cumulative effects early: It is


id: deltaic-lobe-20260505-0
file: data/en.wikipedia.org/wiki/Deltaic_lobe-0.md
category: reference
title: Deltaic lobe
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Deltaic_lobe
date_saved: 2026-05-05T07:17:48.539575+00:00
instance: kb-cron
parent: deltaic-lobe-20260505-0
summary:
A deltaic lobe is a wetland formation that forms as a river empties water and sediment into other bodies of water. As the sediment builds up from this delta, the river will break away from its single channel and the mouth will be pushed outwards, forming a deltaic lobe. When the rate of water discharge and lobe progradation are sufficiently high, a river can form a deltaic lobe. A single deltaic lobe includes a network of shallow channels called distributaries that make up a distributary network that branches off from the mainstream of the river. These networks can be the blueprint for a future progradational deltaic lobe when the initial deltaic lobe is abandoned. As the deltaic lobe progresses, heavier and coarser sediments settle first. As heavier sediments are deposited at the top of the deltaic lobe, smaller and finer sediments get deposited out, creating the beginning of a deltaic fan. When the alluvium, the smallest sediment carried by the deltaic lobe, is deposited and new land is formed, the resulting formation is considered a delta. Lobes are important in forming river deltas over time by amalgamation of channel avulsions. When a lobe is prograded the frequency of avulsion decreases,


id: desakota-20260505-0
file: data/en.wikipedia.org/wiki/Desakota-0.md
category: reference
title: Desakota
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Desakota
date_saved: 2026-05-05T07:17:49.837611+00:00
instance: kb-cron
parent: desakota-20260505-0
summary:
Desakota is a term used in urban geography to describe areas in the extended surroundings of large cities, in which urban and agricultural forms of land use and settlement coexist and are intensively intermingled. == Etymology == The term was coined by the urban researcher Terry McGee of the University of British Columbia around 1990. It comes from Indonesian desa "village" and kota "city". Desakota areas typically occur in Asia, especially South East Asia. Examples can be found in the urbanised regions of Java, the densely populated, delta-shaped areas on the peripheries of the Jakarta agglomeration ("Jabodetabek"), but also the extended metropolitan regions of Bangkok or Manila. Outside South East Asia, areas with comparable features have been described in mainland China, India, Nepal, Japan, Taiwan, and South Korea. == Characteristics == Desakota areas are situated outside the periurban zones, from which daily commuting is easily possible, i.e. more than 30 to 50 km (19 to 31 mi) off the city centre. They often sprawl alongside arterial and communication roads, sometimes from one agglomeration to the next. They are characterised by high population density and intensive agricultural use (especially wet-rice cultivation), but differ from densely populated rural areas by more urban-like


id: disturbance-ecology-20260505-0
file: data/en.wikipedia.org/wiki/Disturbance_(ecology)-0.md
category: reference
title: Disturbance (ecology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Disturbance_(ecology)
date_saved: 2026-05-05T07:17:51.127287+00:00
instance: kb-cron
parent: disturbance-ecology-20260505-0
summary:
In ecology, a disturbance is a change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements. A disturbance can also occur over a long period of time and can impact the biodiversity within an ecosystem. Ecological disturbances include fires, flooding, storms, insect outbreaks, trampling, human presence, earthquakes, plant diseases, infestations, volcanic eruptions, impact events, etc. Not only invasive species can have a profound effect on an ecosystem, native species can also cause disturbance by their behavior. Disturbance forces can have profound immediate effects on ecosystems and can, accordingly, greatly alter the natural community’s population size or species richness. Because of these and the impacts on populations, disturbance determines the future shifts in dominance, various species successively becoming dominant as their life history characteristics, and associated life-forms, are exhibited over time. == Definition and types == The scale of disturbance ranges from events as small as a single tree falling, to as large as a mass extinction. Many natural ecosystems experience periodic disturbance that may broadly fall into a cyclical pattern. Ecosystems that form under these conditions are often


id: disturbance-ecology-20260505-1
file: data/en.wikipedia.org/wiki/Disturbance_(ecology)-1.md
category: reference
title: Disturbance (ecology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Disturbance_(ecology)
date_saved: 2026-05-05T07:17:51.127287+00:00
instance: kb-cron
parent: disturbance-ecology-20260505-0
summary:
Often, when disturbances occur naturally, they provide conditions that favor the success of different species over pre-disturbance organisms. This can be attributed to physical changes in the biotic and abiotic conditions of an ecosystem. Because of this, a disturbance force can change an ecosystem for significantly longer than the period over which the immediate effects persist. With the passage of time following a disturbance, shifts in dominance may occur with ephemeral herbaceous life-forms progressively becoming over topped by taller perennials herbs, shrubs and trees. However, in the absence of further disturbance forces, many ecosystems trend back toward pre-disturbance conditions. Long lived species and those that can regenerate in the presence of their own adults finally become dominant. Such alteration, accompanied by changes in the abundance of different species over time, is called ecological succession. Succession often leads to conditions that will once again predispose an ecosystem to disturbance. Pine forests in western North America provide a good example of such a cycle involving insect outbreaks. The mountain pine beetle (Dendroctonus ponderosae) plays an important role in limiting pine trees like lodgepole pine in forests of western North America. In 2004 the beetles affected more than 90,000 square kilometres. The beetles


id: disturbance-ecology-20260505-2
file: data/en.wikipedia.org/wiki/Disturbance_(ecology)-2.md
category: reference
title: Disturbance (ecology)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Disturbance_(ecology)
date_saved: 2026-05-05T07:17:51.127287+00:00
instance: kb-cron
parent: disturbance-ecology-20260505-0
summary:
== Importance == Biological diversity is dependent on natural disturbance. The success of a wide range of species from all taxonomic groups is closely tied to natural disturbance events such as fire, flooding, and windstorm. As an example, many shade-intolerant plant species rely on disturbances for successful establishment and to limit competition. Without this perpetual thinning, diversity of forest flora can decline, affecting animals dependent on those plants as well. A good example of this role of disturbance is in ponderosa pine (Pinus ponderosa) forests in the western United States, where surface fires frequently thin existing vegetation allowing for new growth. If fire is suppressed, douglas fir (Pesudotsuga menziesii), a shade tolerant species, eventually replaces the pines. Douglas firs, having dense crowns, severely limit the amount of sunlight reaching the forest floor. Without sufficient light new growth is severely limited. As the diversity of surface plants decreases, animal species that rely on them diminish as well. Fire, in this case, is important not only to the species directly affected but also to many other organisms whose survival depends on those key plants. Diversity is low in harsh environments because of the intolerance of all but opportunistic and highly resistant species


id: dpsir-20260505-0
file: data/en.wikipedia.org/wiki/DPSIR-0.md
category: reference
title: DPSIR
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/DPSIR
date_saved: 2026-05-05T07:17:52.516306+00:00
instance: kb-cron
parent: dpsir-20260505-0
summary:
DPSIR (drivers, pressures, state, impact, and response model of intervention) is a causal framework used to describe the interactions between society and the environment. It seeks to analyze and assess environmental problems by bringing together various scientific disciplines, environmental managers, and stakeholders, and solve them by incorporating sustainable development. First, the indicators are categorized into "drivers" which put "pressures" in the "state" of the system, which in turn results in certain "impacts" that will lead to various "responses" to maintain or recover the system under consideration. It is followed by the organization of available data, and suggestion of procedures to collect missing data for future analysis. Since its formulation in the late 1990s, it has been widely adopted by international organizations for ecosystem-based study in various fields like biodiversity, soil erosion, and groundwater depletion and contamination. In recent times, the framework has been used in combination with other analytical methods and models, to compensate for its shortcomings. It is employed to evaluate environmental changes in ecosystems, identify the social and economic pressures on a system, predict potential challenges and improve management practices. The flexibility and general applicability of the framework make it a resilient tool that can be applied in


id: dpsir-20260505-1
file: data/en.wikipedia.org/wiki/DPSIR-1.md
category: reference
title: DPSIR
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/DPSIR
date_saved: 2026-05-05T07:17:52.516306+00:00
instance: kb-cron
parent: dpsir-20260505-0
summary:
=== Impact === Impact refers to how changes in the state of the system affect human well-being. It is often measured in terms of damages to the environment or human health, like migration, poverty, and increased vulnerability to diseases, but can also be identified and quantified without any positive or negative connotation, by simply indicating a change in the environmental parameters. Impact can be ecologic (e.g.: reduction of wetlands, biodiversity loss), socio-economic (e.g.: reduced tourism), or a combination of both. Its definition may vary depending on the discipline and methodology applied. For instance, it refers to the effect on living beings and non-living domains of ecosystems in biosciences (e.g.: modifications in the chemical composition of air or water), whereas it is associated with the effects on human systems related to changes in the environmental functions in socio-economic sciences (e.g.: physical and mental health). === Response === Response refers to actions taken to correct the problems of the previous stages, by adjusting the drivers, reducing the pressure on the system, bringing the system back to its initial state, and mitigating the impacts. It can be associated uniquely with policy action, or to different levels of the society, including groups and/or individuals


id: dpsir-20260505-2
file: data/en.wikipedia.org/wiki/DPSIR-2.md
category: reference
title: DPSIR
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/DPSIR
date_saved: 2026-05-05T07:17:52.516306+00:00
instance: kb-cron
parent: dpsir-20260505-0
summary:
== Applications == Despite its criticisms, DPSIR continues to be widely used to frame and assess environmental problems to identify appropriate responses. Its main objective is to support sustainable management of natural resources. DPSIR structures indicators related to the environmental problem addressed with reference to the political objectives and focuses on supposed causal relationships effectively, such that it appeals to policy actors. Some examples include the assessment of the pressure of alien species, evaluation of impacts of developmental activities on the coastal environment and society, identification of economic elements affecting global wildfire activities, and cost-benefit analysis (CBA) and gross domestic product (GDP) correction. To compensate for its shortcomings, DPSIR is also used in conjunction with several analytical methods and models. It has been used in conjunction with Multiple-Criteria Decision Making (MCDM) for desertification risk management, with Analytic Hierarchy Process (AHP) to study urban green electricity power, and with Tobit model to assess freshwater ecosystems. The framework itself has also been modified to assess specific systems, like DPSWR, which focuses on the impacts on human welfare alone, by shifting ecological impact to the state category. Another approach is a differential DPSIR (ΔDPSIR), which evaluates the changes in drivers, pressures and state


id: ecological-design-20260505-0
file: data/en.wikipedia.org/wiki/Ecological_design-0.md
category: reference
title: Ecological design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_design
date_saved: 2026-05-05T07:17:53.698459+00:00
instance: kb-cron
parent: ecological-design-20260505-0
summary:
Ecological design or ecodesign is an approach to designing products and services that gives special consideration to the environmental impacts of a product over its entire lifecycle. Sim Van der Ryn and Stuart Cowan define it as "any form of design that minimizes environmentally destructive impacts by integrating itself with living processes." Ecological design can also be defined as the process of integrating environmental considerations into design and development with the aim of reducing environmental impacts of products through their life cycle. The idea helps connect scattered efforts to address environmental issues in architecture, agriculture, engineering, and ecological restoration, among others. The term was first used by Sim Van der Ryn and Stuart Cowan in 1996. Ecological design was originally conceptualized as the "adding in "of environmental factor to the design process, but later turned to the details of eco-design practice, such as product system or individual product or industry as a whole. With the inclusion of life cycle modeling techniques, ecological design was related to the new interdisciplinary subject of industrial ecology. == Overview == As the whole product's life cycle should be regarded in an integrated perspective, representatives from advanced product design, production, marketing, purchasing, and project management


id: ecological-design-20260505-1
file: data/en.wikipedia.org/wiki/Ecological_design-1.md
category: reference
title: Ecological design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_design
date_saved: 2026-05-05T07:17:53.698459+00:00
instance: kb-cron
parent: ecological-design-20260505-0
summary:
=== The rise and conceptualization of ecological design === Since the Industrial Revolution, design fields have been criticized for employing unsustainable practices. The architect-designer Victor Papanek (1923–1998) suggested that industrial design has murdered by creating new species of permanent garbage and by choosing materials and processes that pollute the air. Papanek states that the designer-planner shares responsibility for nearly all of our products and tools, and hence, nearly all of our environmental mistakes. To address these issues, R. Buckminster Fuller (1895–1983) demonstrated how design could play a central role in identifying and addressing major world problems. Fuller was concerned with the Earth's finite energy resources and natural resources, and how to integrate machine tools into efficient systems of industrial production. He promoted the principle of "ephemeralization", a term he coined himself to do "more with less" and increase technological efficiency. This concept is key in ecological design that works towards sustainability. In 1986, the design theorist Clive Dilnot argued that design must once again become a means of ordering the world rather than merely of shaping products. Despite rising ecological awareness in the 20th century, unsustainable design practices continued. The 1992 conference "The Agenda 21: The Earth Summit Strategy to


id: ecological-design-20260505-2
file: data/en.wikipedia.org/wiki/Ecological_design-2.md
category: reference
title: Ecological design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_design
date_saved: 2026-05-05T07:17:53.698459+00:00
instance: kb-cron
parent: ecological-design-20260505-0
summary:
== Urban Ecological Design == Related to ecological urbanism, Urban Ecological Design integrates aesthetic, social, and ecological concerns into an urban design framework that seeks to increase ecological functioning, sustainably generate and consume resources, and create resilient built environments and the infrastructure to maintain them. Urban ecological design is inherently interdisciplinary: it integrates multiple academic and professional fields including environmental studies, sociology, justice studies, urban ecology, landscape ecology, urban planning, architecture, and landscape architecture. Urban ecological design aims to solve issues related to multiple large-scale trends including the growth of urban areas, climate change, and biodiversity loss. Urban ecological design has been described as a "process model" contrasted to a normative approach that outlines principles of design. Urban ecological design blends a multitude of frameworks and approaches to create solutions to these issues by improving Urban resilience, sustainable use and management of resources, and integrating ecological processes into the urban landscape. == Applications in design == EcoMaterials, such as the use of local raw materials, are less costly and reduce the environmental costs of shipping, fuel consumption, and CO2 emissions generated from transportation. Certified green building materials, such as wood from sustainably managed forest plantations, with accreditations from companies such


id: ecological-design-20260505-3
file: data/en.wikipedia.org/wiki/Ecological_design-3.md
category: reference
title: Ecological design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_design
date_saved: 2026-05-05T07:17:53.698459+00:00
instance: kb-cron
parent: ecological-design-20260505-0
summary:
== Active systems == These systems use the principle of harnessing the power generated from renewable and inexhaustible sources of energy, for example; solar, wind, thermal, biomass, geothermal, and hydropower energy. Solar power is a widely known and used renewable energy source. An increase in technology has allowed solar power to be used in a wide variety of applications. Two types of solar panels generate heat into electricity. Thermal solar panels reduce or eliminate the consumption of gas and diesel, and reduce CO2 emissions. Photovoltaic panels convert solar radiation into an electric current which can power any appliance. This is a more complex technology and is generally more expensive to manufacture than thermal panels. Biomass is the energy source created from organic materials generated through a forced or spontaneous biological process. Geothermal energy is obtained by harnessing heat from the ground. This type of energy can be used to heat and cool homes. It eliminates dependence on external energy and generates minimum waste. It is also hidden from view as it is placed underground, making it more aesthetically pleasing and easier to incorporate in a design. Wind turbines are a useful application for areas without immediate conventional power sources, e.g.,


id: ecological-engineering-20260505-0
file: data/en.wikipedia.org/wiki/Ecological_engineering-0.md
category: reference
title: Ecological engineering
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_engineering
date_saved: 2026-05-05T07:17:54.933512+00:00
instance: kb-cron
parent: ecological-engineering-20260505-0
summary:
Ecological engineering uses ecology and engineering to predict, design, construct or restore, and manage ecosystems that integrate "human society with its natural environment for the benefit of both". == Origins, key concepts, definitions, and applications == Ecological engineering emerged as a new idea in the early 1960s, but its definition has taken several decades to refine. Its implementation is still undergoing adjustment, and its broader recognition as a new paradigm is relatively recent. Ecological engineering was introduced by Howard Odum and others as utilizing natural energy sources as the predominant input to manipulate and control environmental systems. The origins of ecological engineering are in Odum's work with ecological modeling and ecosystem simulation to capture holistic macro-patterns of energy and material flows affecting the efficient use of resources. Mitsch and Jorgensen summarized five basic concepts that differentiate ecological engineering from other approaches to addressing problems to benefit society and nature: 1) it is based on the self-designing capacity of ecosystems; 2) it can be the field (or acid) test of ecological theories; 3) it relies on system approaches; 4) it conserves non-renewable energy sources; and 5) it supports ecosystem and biological conservation. Mitsch and Jorgensen were the first to define ecological


id: ecological-engineering-20260505-1
file: data/en.wikipedia.org/wiki/Ecological_engineering-1.md
category: reference
title: Ecological engineering
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_engineering
date_saved: 2026-05-05T07:17:54.933512+00:00
instance: kb-cron
parent: ecological-engineering-20260505-0
summary:
Ecosystem structure & function are determined by forcing functions of the system; Energy inputs to the ecosystems and available storage of the ecosystem is limited; Ecosystems are open and dissipative systems (not thermodynamic balance of energy, matter, entropy, but spontaneous appearance of complex, chaotic structure); Attention to a limited number of governing/controlling factors is most strategic in preventing pollution or restoring ecosystems; Ecosystem have some homeostatic capability that results in smoothing out and depressing the effects of strongly variable inputs; Match recycling pathways to the rates of ecosystems and reduce pollution effects; Design for pulsing systems wherever possible; Ecosystems are self-designing systems; Processes of ecosystems have characteristic time and space scales that should be accounted for in environmental management; Biodiversity should be championed to maintain an ecosystem's self design capacity; Ecotones, transition zones, are as important for ecosystems as membranes for cells; Coupling between ecosystems should be utilized wherever possible; The components of an ecosystem are interconnected, interrelated, and form a network; consider direct as well as indirect efforts of ecosystem development; An ecosystem has a history of development; Ecosystems and species are most vulnerable at their geographical edges; Ecosystems are hierarchical systems and are parts of a larger landscape;


id: ecological-footprint-20260505-0
file: data/en.wikipedia.org/wiki/Ecological_footprint-0.md
category: reference
title: Ecological footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_footprint
date_saved: 2026-05-05T07:17:56.107504+00:00
instance: kb-cron
parent: ecological-footprint-20260505-0
summary:
The ecological footprint measures human demand on natural capital, i.e. the quantity of nature it takes to support people and their economies. It tracks human demand on nature through an ecological accounting system. The accounts contrast the biologically productive area people use to satisfy their consumption to the biologically productive area available within a region, nation, or the world (biocapacity). Biocapacity is the productive area that can regenerate what people demand from nature. Therefore, the metric is a measure of human impact on the environment. As Ecological Footprint accounts measure to what extent human activities operate within the means of our planet, they are a central metric for sustainability. The metric is promoted by the Global Footprint Network which has developed standards to make results comparable. FoDaFo, supported by Global Footprint Network and York University are now providing the national assessments of Footprints and biocapacity. Footprint and biocapacity can be compared at the individual, regional, national or global scale. Both footprint and demands on biocapacity change every year with number of people, per person consumption, efficiency of production, and productivity of ecosystems. At a global scale, footprint assessments show how big humanity's demand is compared to what Earth can renew.


id: ecological-footprint-20260505-1
file: data/en.wikipedia.org/wiki/Ecological_footprint-1.md
category: reference
title: Ecological footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_footprint
date_saved: 2026-05-05T07:17:56.107504+00:00
instance: kb-cron
parent: ecological-footprint-20260505-0
summary:
Ecological footprint accounting is built on the recognition that regenerative resources are the physically most limiting resources of all. Even fossil fuel use is far more limited by the amount of sequestration the biosphere can provide rather than by the amounts left underground. The same is true for ores and minerals, where the limiting factor is how much damage to the biosphere we are willing to accept to extract and concentrate those materials, rather than by how much of them is still left underground. Therefore, the focus of ecological footprint accounting is human competition for regenerative resources. The amount of the planet's regeneration, including how many resources are renewed and how much waste the planet can absorb, is dubbed biocapacity. Ecological footprints therefore track how much biocapacity is needed to provide for all the inputs that human activities demand. It can be calculated at any scale: for an activity, a person, a community, a city, a region, a nation, or humanity as a whole. Footprints can be split into consumption categories: food, housing, and goods and services. Or it can be organized by area types occupied: cropland, pasture, forests for forest products, forests for carbon sequestration, marine areas, etc. When


id: ecological-footprint-20260505-2
file: data/en.wikipedia.org/wiki/Ecological_footprint-2.md
category: reference
title: Ecological footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_footprint
date_saved: 2026-05-05T07:17:56.107504+00:00
instance: kb-cron
parent: ecological-footprint-20260505-0
summary:
According to Wackernagel and the organisation he has founded, the Earth has been in "overshoot", where humanity is using more resources and generating waste at a pace that the ecosystem cannot renew, since the 1970s. According to the Global Footprint Network's calculations, currently people use Earth's resources at approximately 171% of capacity. This implies that humanity is well over Earth's human carrying capacity at current levels of affluence. In 2025, Earth Overshoot Day advanced to 24 July. Earth Overshoot Day marks the date when humanity has exhausted nature's budget for the year. For the rest of the year, we are maintaining our ecological deficit by drawing down local resource stocks and accumulating carbon dioxide in the atmosphere. Currently, more than 85% of humanity lives in countries that run an ecological deficit. This means their citizens use more resources and generate more waste and pollution than can be sustained by the biocapacity found within their national boundaries. In some cases, countries are running an ecological deficit because their per capita ecological footprints are higher than the hectares of bioproductive land available on average globally (this was estimated at <1.7 hectares per person in 2019). Examples include France, Germany and Saudi Arabia.


id: ecological-footprint-20260505-3
file: data/en.wikipedia.org/wiki/Ecological_footprint-3.md
category: reference
title: Ecological footprint
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_footprint
date_saved: 2026-05-05T07:17:56.107504+00:00
instance: kb-cron
parent: ecological-footprint-20260505-0
summary:
In a 2012 study of consumers acting 'green' vs. 'brown' (where green people are "expected to have significantly lower ecological impact than 'brown' consumers"), "the research found no significant difference between the carbon footprints of green and brown consumers". A 2013 study concluded the same. == Reviews and critiques == Early criticism was published by van den Bergh and Verbruggen in 1999, which was updated in 2014. Their colleague Fiala published similar criticism in 2008. A comprehensive review commissioned by the Directorate-General for the Environment (European Commission) was published in June 2008. The European Commission's review found the concept unique and useful for assessing progress on the EU's Resource Strategy. They also recommended further improvements in data quality, methodologies and assumptions. Blomqvist et al.. published a critical paper in 2013. It led to a reply from Rees and Wackernagel (2013), and a rejoinder by Blomqvist et al. (2013). An additional strand of critique is from Giampietro and Saltelli (2014), with a reply from Goldfinger et al., 2014, and a rejoinder by Giampietro and Saltelli (2014). A joint paper authored by the critical researchers (Giampietro and Saltelli) and proponents (various Global Footprint Network researchers) summarized the terms of the controversy in


id: ecological-classification-20260505-0
file: data/en.wikipedia.org/wiki/Ecological_classification-0.md
category: reference
title: Ecological classification
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_classification
date_saved: 2026-05-05T07:17:57.302627+00:00
instance: kb-cron
parent: ecological-classification-20260505-0
summary:
Ecological classification or ecological typology is the classification of land or water into geographical units that represent variation in one or more ecological features. Traditional approaches focus on geology, topography, biogeography, soils, vegetation, climate conditions, living species, habitats, water resources, and sometimes also anthropic factors. Most approaches pursue the cartographical delineation or regionalisation of distinct areas for mapping and planning. == Approaches to classifications == Different approaches to ecological classifications have been developed in terrestrial, freshwater and marine disciplines. Traditionally these approaches have focused on biotic components (vegetation classification), abiotic components (environmental approaches) or implied ecological and evolutionary processes (biogeographical approaches). Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems: a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy (ecotope). === Vegetation classification === Vegetation is often used to classify terrestrial ecological units. Vegetation classification can be based on vegetation structure and floristic composition. Classifications based entirely on vegetation structure overlap with land cover mapping categories. Many schemes of vegetation classification are in use by the land, resource and environmental management agencies of different national and state jurisdictions. The International Vegetation Classification


id: ecological-succession-20260505-0
file: data/en.wikipedia.org/wiki/Ecological_succession-0.md
category: reference
title: Ecological succession
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_succession
date_saved: 2026-05-05T07:17:58.613092+00:00
instance: kb-cron
parent: ecological-succession-20260505-0
summary:
Ecological succession is the process of how species compositions change in an ecological community over time. The two main categories of ecological succession are primary succession and secondary succession. Primary succession occurs after the initial colonization of a newly created habitat with no living organisms. Secondary succession occurs after a disturbance such as fire, habitat destruction, or a natural disaster destroys a pre-existing community. Both consistent patterns and variability are observed in ecological succession. Theories of ecological succession identify different factors that help explain why plant communities change the way they do. Succession was among the first theories advanced in ecology. Ecological succession was first documented in the Indiana Dunes of Northwest Indiana by Henry Chandler Cowles during the late 19th century and remains a main ecological topic of study. Over time, the understanding of succession has changed to include a more complex cyclical model that argues organisms do not have fixed roles or relationships. Ecologists and conservationists have since used the theory of succession to aid in developing ecological restoration strategies. == Stages of succession == === Mechanisms === In 1916, Frederic Clements published a descriptive theory of succession and advanced it as a general ecological concept. The process


id: ecological-succession-20260505-1
file: data/en.wikipedia.org/wiki/Ecological_succession-1.md
category: reference
title: Ecological succession
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_succession
date_saved: 2026-05-05T07:17:58.613092+00:00
instance: kb-cron
parent: ecological-succession-20260505-0
summary:
Monoclimax or Climatic Climax Theory was advanced by Clements (1916) and recognizes only one climax whose characteristics are determined solely by climate (climatic climax). The processes of succession and modification of environment overcome the effects of differences in topography, parent material of the soil, and other factors. The whole area would be covered with uniform plant community. Communities other than the climax are related to it, and are recognized as subclimax, postclimax and disclimax. Polyclimax Theory was advanced by Tansley (1935). It proposes that the climax vegetation of a region consists of more than one vegetation climaxes controlled by soil moisture, soil nutrients, topography, slope exposure, fire, and animal activity. Climax Pattern Theory was proposed by Whittaker (1953). The climax pattern theory recognizes a variety of climaxes governed by responses of species populations to biotic and abiotic conditions. According to this theory the total environment of the ecosystem determines the composition, species structure, and balance of a climax community. The environment includes the species' responses to moisture, temperature, and nutrients, their biotic relationships, availability of flora and fauna to colonize the area, chance dispersal of seeds and animals, soils, climate, and disturbance such as fire and wind. The nature of


id: ecological-succession-20260505-2
file: data/en.wikipedia.org/wiki/Ecological_succession-2.md
category: reference
title: Ecological succession
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_succession
date_saved: 2026-05-05T07:17:58.613092+00:00
instance: kb-cron
parent: ecological-succession-20260505-0
summary:
=== Disruptions === Two important perturbation factors today are human actions and climatic change. Additions to available species pools through range expansions and introductions can also continually reshape communities. == Types of succession == === Primary succession === The successional dynamics beginning with colonization of an area with little to no biotic factors is referred to as primary succession. This includes newly exposed rock or sand surfaces, lava flows, and newly exposed glacial tills. The stages of primary succession include pioneer species such as microorganisms, plants (lichens and mosses), grasses, smaller shrubs, and trees. Small animals move into the area when enough suitable habitat has been established. When it is a fully functioning ecosystem, it has reached the climax community stage. === Secondary succession === Secondary succession follows severe disturbance or removal of a preexisting community that has remnants of the previous ecosystem. Secondary succession is strongly influenced by pre-disturbance conditions such as soil development, seed banks, remaining organic matter, and residual living organisms. Because of residual fertility and preexisting organisms, community change in early stages of secondary succession can be relatively rapid. Secondary succession is much more commonly observed and studied than primary succession. Particularly common types of secondary


id: ecological-succession-20260505-3
file: data/en.wikipedia.org/wiki/Ecological_succession-3.md
category: reference
title: Ecological succession
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_succession
date_saved: 2026-05-05T07:17:58.613092+00:00
instance: kb-cron
parent: ecological-succession-20260505-0
summary:
Succession of micro-organisms including fungi and bacteria occurring within a microhabitat is known as microsuccession or serule. In artificial bacterial meta-communities of motile strains on-chip it has been shown that ecological succession is based on a trade-off between colonization and competition abilities. To exploit locations or explore the landscape? Escherichia coli is a fugitive species, whereas Pseudomonas aeruginosa is a slower colonizer but superior competitor. Like in plants, microbial succession can occur in newly available habitats (primary succession) such as surfaces of plant leaves, recently exposed rock surfaces (i.e., glacial till) or animal infant guts, and also on disturbed communities (secondary succession) like those growing in recently dead trees, decaying fruits, or animal droppings. Microbial communities may also change due to products secreted by the bacteria present. Changes of pH in a habitat could provide ideal conditions for a new species to inhabit the area. In some cases the new species may outcompete the present ones for nutrients leading to the primary species demise. Changes can also occur by microbial succession with variations in water availability and temperature. Theories of macroecology have only recently been applied to microbiology and so much remains to be understood about this growing field. A


id: ecological-succession-20260505-4
file: data/en.wikipedia.org/wiki/Ecological_succession-4.md
category: reference
title: Ecological succession
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_succession
date_saved: 2026-05-05T07:17:58.613092+00:00
instance: kb-cron
parent: ecological-succession-20260505-0
summary:
=== Grassland succession === For a long time, grasslands were thought to be early stages of succession, dominated by weedy species and with little conservation value. However, comparing grasslands that form after recovery from long-term disruptions like agricultural tillage with ancient or "old-growth" grasslands has shown that grasslands are not inherently early-successional communities. Rather, grasslands undergo a centuries-long process of succession, and a grassland that is tilled up for agriculture or otherwise destroyed is estimated to take a minimum of 100 years, and potentially on average 1,400 years, to recover to its previous level of biodiversity. However, planting a high diversity of late-successional grassland species in a disturbed environment can accelerate the recovery of the soil's ability to sequester carbon, resulting in twice as much carbon storage as a naturally recovering grassland over the same period of time. Many grassland ecosystems are maintained by disturbance, such as fire and grazing by large animals, or else the process of succession will change them to forest or shrubland. In fact, it is debated whether fire should be considered disturbance at all for the North American prairie ecosystems, since it maintains, rather than disrupts, an equilibrium state. Many late-successional grassland species have adaptations


id: ecological-succession-20260505-5
file: data/en.wikipedia.org/wiki/Ecological_succession-5.md
category: reference
title: Ecological succession
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_succession
date_saved: 2026-05-05T07:17:58.613092+00:00
instance: kb-cron
parent: ecological-succession-20260505-0
summary:
An association is not an organism, scarcely even a vegetational unit, but merely a coincidence. Gleason's ideas were, in fact, more consistent with Cowles' original thinking about succession. About Clements' distinction between primary succession and secondary succession, Cowles wrote (1911): This classification seems not to be of fundamental value, since it separates such closely related phenomena as those of erosion and deposition, and it places together such unlike things as human agencies and the subsidence of land. === Eugene Odum === In 1969, Eugene Odum published The Strategy of Ecosystem Development, a paper that was highly influential to conservation and environmental restoration. Odum argued that ecological succession was an orderly progression toward a climax state where "maximum biomass and symbiotic function between organisms are maintained per unit energy flow." Odum highlighted how succession was not merely a change in the species composition of an ecosystem, but also created change in more complex attributes of the ecosystem, such as structure and nutrient cycling. === Modern era === A more rigorous, data-driven testing of successional models and community theory generally began with the work of Robert Whittaker and John Curtis in the 1950s and 1960s. Succession theory has since become less monolithic


id: ecological-thinning-20260505-0
file: data/en.wikipedia.org/wiki/Ecological_thinning-0.md
category: reference
title: Ecological thinning
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_thinning
date_saved: 2026-05-05T07:18:00.005531+00:00
instance: kb-cron
parent: ecological-thinning-20260505-0
summary:
Ecological thinning is a silvicultural technique used in forest management that involves cutting trees to improve functions of a forest other than timber production. Although thinning originated as a man-made forest management tool, aimed at increasing timber yields, the shift from production forests to multifunctional forests brought with it the cutting of trees to manipulate an ecosystem for various reasons, ranging from removing non-native species from a plot to removing poplars growing on a riverside beach aimed at recreational use. Since the 1970s, leaving the thinned trees on the forest floor has become an increasingly common policy: wood can be decomposed in a more natural fashion, playing an important role in increasing biodiversity by providing habitat to various invertebrates, birds and small mammals. Many fungi (e.g. Calocera viscosa) and mosses are saproxylic or epixylic as well (e.g. Marchantiophyta) – some moss species completing their entire life-cycle on a single log. Where trees are managed under a commercial regime, competition is reduced by removing adjacent stems that exhibit less favourable timber quality potential. When left in a natural state trees will "self-thin", but this process can be unreliable in some circumstances. Examples of this can be found in the Buxus–Ironbark forests


id: ecological-trap-20260505-0
file: data/en.wikipedia.org/wiki/Ecological_trap-0.md
category: reference
title: Ecological trap
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecological_trap
date_saved: 2026-05-05T07:18:01.305123+00:00
instance: kb-cron
parent: ecological-trap-20260505-0
summary:
Ecological traps are scenarios in which rapid environmental change leads organisms to prefer to settle in poor-quality habitats. The concept stems from the idea that organisms that are actively selecting habitat must rely on environmental cues to help them identify high-quality habitat. If either the habitat quality or the cue changes so that one does not reliably indicate the other, organisms may be lured into poor-quality habitat. == Overview == Ecological traps are thought to occur when the attractiveness of a habitat increases disproportionately in relation to its value for survival and reproduction. The result is preference of falsely attractive habitat and a general avoidance of high-quality but less-attractive habitats. For example, indigo buntings typically nest in shrubby habitat or broken forest transitions between closed canopy forest and open field. Human activity can create 'sharper', more abrupt forest edges and buntings prefer to nest along these edges. However, these artificial sharp forest edges also concentrate the movement of predators which predate their nests. In this way, Buntings prefer to nest in highly altered habitats where their nest success is lowest. While the demographic consequences of this type of maladaptive habitat selection behavior have been explored in the context of the


id: ecosystem-model-20260505-0
file: data/en.wikipedia.org/wiki/Ecosystem_model-0.md
category: reference
title: Ecosystem model
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecosystem_model
date_saved: 2026-05-05T07:18:02.620003+00:00
instance: kb-cron
parent: ecosystem-model-20260505-0
summary:
An ecosystem model is an abstract, usually mathematical, representation of an ecological system (ranging in scale from an individual population, to an ecological community, or even an entire biome), which is studied to better understand the real system. Using data gathered from the field, ecological relationships—such as the relation of sunlight and water availability to photosynthetic rate, or that between predator and prey populations—are derived, and these are combined to form ecosystem models. These model systems are then studied in order to make predictions about the dynamics of the real system. Often, the study of inaccuracies in the model (when compared to empirical observations) will lead to the generation of hypotheses about possible ecological relations that are not yet known or well understood. Models enable researchers to simulate large-scale experiments that would be too costly or unethical to perform on a real ecosystem. They also enable the simulation of ecological processes over very long periods of time (i.e. simulating a process that takes centuries in reality, can be done in a matter of minutes in a computer model). Ecosystem models have applications in a wide variety of disciplines, such as natural resource management, ecotoxicology and environmental health, agriculture, and wildlife


id: ecosystem-model-20260505-1
file: data/en.wikipedia.org/wiki/Ecosystem_model-1.md
category: reference
title: Ecosystem model
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ecosystem_model
date_saved: 2026-05-05T07:18:02.620003+00:00
instance: kb-cron
parent: ecosystem-model-20260505-0
summary:
=== Others === The theoretical ecologist Robert Ulanowicz has used information theory tools to describe the structure of ecosystems, emphasizing mutual information (correlations) in studied systems. Drawing on this methodology and prior observations of complex ecosystems, Ulanowicz depicts approaches to determining the stress levels on ecosystems and predicting system reactions to defined types of alteration in their settings (such as increased or reduced energy flow, and eutrophication. Conway's Game of Life and its variations model ecosystems where proximity of the members of a population are factors in population growth. == See also == == References == == Further reading == Khan, M. F.; Preetha, P.; Sharma, A. P. (2015). "Modelling the food web for assessment of the impact of stock supplementation in a reservoir ecosystem in India". Fisheries Management and Ecology. 22 (5): 359–370. Bibcode:2015FisME..22..359K. doi:10.1111/fme.12134. Panikkar, Preetha; Khan, M. Feroz; Desai, V. R.; Shrivastava, N. P.; Sharma, A. P. (2014). "Characterizing trophic interactions of a catfish dominated tropical reservoir ecosystem to assess the effects of management practices". Environmental Biology of Fishes. 98: 237–247. doi:10.1007/s10641-014-0255-6. S2CID 16992082. Panikkar, Preetha; Khan, M. Feroz (2008). "Comparative mass-balanced trophic models to assess the impact of environmental management measures in a tropical reservoir ecosystem".


id: edge-effects-20260505-0
file: data/en.wikipedia.org/wiki/Edge_effects-0.md
category: reference
title: Edge effects
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Edge_effects
date_saved: 2026-05-05T07:18:03.896436+00:00
instance: kb-cron
parent: edge-effects-20260505-0
summary:
== Definition == In ecology, edge effects are changes in population or community structures that occur at the boundary of two or more habitats. These effects transpire since environmental conditions near habitat boundaries differ from those in the interior areas. Habitat boundaries experience conditions like increased wind exposure, light, and temperature fluctuations. Areas with small habitat fragments exhibit especially pronounced edge effects that may extend throughout the range. As the edge effects increase, the boundary habitat can support higher levels of biodiversity than adjacent ecosystems with increased habitat fragmentation because they serve as transitional zones for overlapping environmental conditions. In this way species from each of these two separate ecosystems are able to co-exist in the same general area along with species which have developed adaptations specific to the edge environment. == Biodiversity == Environmental conditions enable certain species of plants and animals to colonize habitat borders. Plants that colonize forest edges tend to be shade-intolerant. These plants also tend to be tolerant of dry conditions, such as shrubs and vines. Animals that colonize tend to be those that require two or more habitats, such as white-tailed and mule deer, elk, cottontail rabbits, blue jays, and robins. Some animals travel


id: edge-effects-20260505-1
file: data/en.wikipedia.org/wiki/Edge_effects-1.md
category: reference
title: Edge effects
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Edge_effects
date_saved: 2026-05-05T07:18:03.896436+00:00
instance: kb-cron
parent: edge-effects-20260505-0
summary:
Introduction of invasives/exotics Agriculture Higher severity and frequency of fires Companion animals (pets) acting as predators and competitors Trails Pollution, erosion Loss of foraging habitats Habitat fragmentation Deforestation and land use == Examples == When edges divide any natural ecosystem and the area outside the boundary is a disturbed or unnatural system, the natural ecosystem can be seriously affected for some distance in from the edge. In 1971, Odum wrote, 'The tendency for increased variety and diversity at community junctions is known as the edge effect... It is common knowledge that the density of songbirds is greater on estates, campuses and similar settings...as compared with tracts of uniform forest'. In a forest where the adjacent land has been cut, creating an open/forest boundary, sunlight and wind penetrate to a much greater extent, drying out the interior of the forest close to the edge and encouraging growth of opportunistic species there. Air temperature, vapor pressure deficit, soil moisture, light intensity and levels of photosynthetically active radiation (PAR) all change at edges. === Amazon rainforest === One study estimated that the amount of Amazon Basin area modified by edge effects exceeded the area that had been cleared. "In studies of Amazon forest


id: environmental-data-20260505-0
file: data/en.wikipedia.org/wiki/Environmental_data-0.md
category: reference
title: Environmental data
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Environmental_data
date_saved: 2026-05-05T07:18:05.191093+00:00
instance: kb-cron
parent: environmental-data-20260505-0
summary:
Environmental data is that which is based on the measurement of environmental pressures, the state of the environment and the impacts on ecosystems. This is usually the "P", "S" and "I" of the DPSIR model where D = Drivers, P = Pressures, S = State, I = Impact, R = Response. Environmental data is typically generated by institutions executing environmental law or doing environmental research. Environment statistics are usually generated by statistical offices and are considered as environmental data, too. Socio-economic data and other statistical data (often the "D" and the "R" of the DPSIR model) are not considered as environmental data. However, they are to be integrated into comprehensive environmental assessments. Usually this kind of data is held by other institutions than the environmental administration (e.g. National Statistical Offices). The same is true for geo-basisdata, which are not considered as environmental data, but have to be available for environmental policies and environmental information. In recent years, environmental data has become increasingly important to investors, prompting Bloomberg L.P. to begin providing Environmental, Social and Governance (ESG) data through their terminals. All data generated by the execution of environmental law are to be considered as environmental data. == Environmental Data Management


id: environmental-engineering-20260505-0
file: data/en.wikipedia.org/wiki/Environmental_engineering-0.md
category: reference
title: Environmental engineering
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Environmental_engineering
date_saved: 2026-05-05T07:18:06.373158+00:00
instance: kb-cron
parent: environmental-engineering-20260505-0
summary:
Environmental engineering is a professional engineering discipline related to environmental science. It encompasses broad scientific topics like chemistry, biology, ecology, geology, hydraulics, hydrology, microbiology, and mathematics to create solutions that will protect and also improve the health of living organisms and improve the quality of the environment. Environmental engineering is a sub-discipline of civil engineering and chemical engineering. While on the part of civil engineering, the Environmental Engineering is focused mainly on Sanitary Engineering. Environmental engineering applies scientific and engineering principles to improve and maintain the environment to protect human health, protect nature's beneficial ecosystems, and improve environmental-related enhancement of the quality of human life. Environmental engineers devise solutions for wastewater management, water and air pollution control, recycling, waste disposal, and public health. They design municipal water supply and industrial wastewater treatment systems, and design plans to prevent waterborne diseases and improve sanitation in urban, rural and recreational areas. They evaluate hazardous-waste management systems to evaluate the severity of such hazards, advise on treatment and containment, and develop regulations to prevent mishaps. They implement environmental engineering law, as in assessing the environmental impact of proposed construction projects. Environmental engineers study the effect of technological advances on the environment, addressing local


id: environmental-engineering-20260505-1
file: data/en.wikipedia.org/wiki/Environmental_engineering-1.md
category: reference
title: Environmental engineering
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Environmental_engineering
date_saved: 2026-05-05T07:18:06.373158+00:00
instance: kb-cron
parent: environmental-engineering-20260505-0
summary:
Many universities offer environmental engineering programs through either the department of civil engineering or chemical engineering and also including electronic projects to develop and balance the environmental conditions. Environmental engineers in a civil engineering program often focus on hydrology, water resources management, bioremediation, and water and wastewater treatment plant design. Environmental engineers in a chemical engineering program tend to focus on environmental chemistry, advanced air and water treatment technologies, and separation processes. Some subdivisions of environmental engineering include natural resources engineering and agricultural engineering. Courses for students fall into a few broad classes: Mechanical engineering courses oriented towards designing machines and mechanical systems for environmental use such as water and wastewater treatment facilities, pumping stations, garbage segregation plants, and other mechanical facilities. Environmental engineering or environmental systems courses oriented towards a civil engineering approach in which structures and the landscape are constructed to blend with or protect the environment. Environmental chemistry, sustainable chemistry or environmental chemical engineering courses oriented towards understanding the effects of chemicals in the environment, including any mining processes, pollutants, and also biochemical processes. Environmental technology courses oriented towards producing electronic or electrical graduates capable of developing devices and artifacts able to monitor, measure, model and control


id: environmental-impact-design-20260505-0
file: data/en.wikipedia.org/wiki/Environmental_impact_design-0.md
category: reference
title: Environmental impact design
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Environmental_impact_design
date_saved: 2026-05-05T07:18:07.741869+00:00
instance: kb-cron
parent: environmental-impact-design-20260505-0
summary:
Environmental impact design (EID) is the design of development projects so as to achieve positive environmental objectives that benefit the environment and raise the stock of public goods. == Examples == Examples of EID include: Habitat creation as a result of afforestation projects that can "expand forest resources and reduce the gap between timber production and consumption." An example is the China Afforestation Project. Coastal management projects that strengthens biodiversity and promotes sustainable use of biological resources. Flood defense projects that improve livability in flood-prone areas by reducing future losses. Flood preparedness and mitigation systems can aid in handling periodic flooding. Bridge designs such as concrete bridges that are sustainable, recyclable, durable and can be built quickly, reducing greenhouse gas emissions caused by traffic delays and construction equipment. == Types == Environmental impact design impacts can be broken down into three types: Direct impacts: caused by the project and building process, such as land consumption, erosion and loss of vegetation. Indirect impacts: side-effects of a project such as degradation of surface water quality from erosion of land cleared as a result of a project. Over time, indirect impacts can affect larger geographical areas. Cumulative impacts: synergistic effects such as the


id: escaped-plant-20260505-0
file: data/en.wikipedia.org/wiki/Escaped_plant-0.md
category: reference
title: Escaped plant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Escaped_plant
date_saved: 2026-05-05T07:18:08.970480+00:00
instance: kb-cron
parent: escaped-plant-20260505-0
summary:
An escaped plant is a cultivated plant that has escaped from agriculture, forestry or garden cultivation and has become naturalized in the wild. Usually not native to an area, escaped plants may become invasive. Therefore, escaped plants are the subject of research in invasion biology. All escaped plants belong to the so-called hemerochoric plants. This term is used across the board for plants that have been introduced directly or indirectly by humans. The term also includes the unintentionally introduced plants that were introduced through seed pollution (speirochoric) or through unintentional transport (agochoric). Some ornamental plants have characteristics which allow them to escape cultivation and become weedy in alien ecosystems with far-reaching ecological and economic consequences. Escaped garden plants may be called garden escapes or escaped ornamentals. Sometimes, their origins can even be traced back to botanical gardens. == Dispersal == Plants may escape from cultivation in various ways, including the dumping of green waste in bushland and road reserves and by birds or other animals eating the fruits or seeds and dispersing them. Others are accidental hitchhikers that escape on ships, vehicles, and equipment. Plants can also escape through sending stolons (runners), as stolons are capable of independent growth in


id: escaped-plant-20260505-1
file: data/en.wikipedia.org/wiki/Escaped_plant-1.md
category: reference
title: Escaped plant
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Escaped_plant
date_saved: 2026-05-05T07:18:08.970480+00:00
instance: kb-cron
parent: escaped-plant-20260505-0
summary:
Agriophyte: Refers to plant species that have invaded natural or near-natural vegetation and can survive there without human intervention. Established in their new natural habitats, they remain part of natural vegetation even after human influence has ceased, and are independent of humans in their continued existence. Examples in Central Europe are waterweed, Douglas fir and Japanese knotweed Alien: A non native species introduced by man. Archaeophyte: An alien species introduced by human activity long ago, such as the sweet chestnuts introduced by the Romans in Germany and now part of natural vegetation, and the opium and field poppies. Epecophyte: Species of recent appearance, usually numerous and constant in the country, but confined to artificial habitats, such as meadows and ruderal vegetation. They are dependent on humans for existence that their habitats require constant renewal. Ephemerophyte: Species that are only introduced inconsistently, that die briefly from culture or that would disappear again without constant replenishment of seeds. In other words, they can establish themselves temporarily, but they are not in a position to meet all the conditions relating to the territory. A cold winter, or an unusual drought, can lead to the death of these plants; most of the time, they


id: fire-ecology-20260505-0
file: data/en.wikipedia.org/wiki/Fire_ecology-0.md
category: reference
title: Fire ecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fire_ecology
date_saved: 2026-05-05T07:18:10.171501+00:00
instance: kb-cron
parent: fire-ecology-20260505-0
summary:
Fire ecology is a scientific discipline concerned with the effects of fire on natural ecosystems. Many ecosystems, particularly prairie, savanna, chaparral and coniferous forests, have evolved with fire as an essential contributor to habitat vitality and renewal. Many plant species in fire-affected environments use fire to germinate, establish, or to reproduce. Wildfire suppression not only endangers these species, but also the animals that depend upon them. Wildfire suppression campaigns in the United States have historically molded public opinion to believe that wildfires are harmful to nature. Ecological research has shown, however, that fire is an integral component in the function and biodiversity of many natural habitats, and that the organisms within these communities have adapted to withstand, and even to exploit, natural wildfire. More generally, fire is now regarded as a 'natural disturbance', similar to flooding, windstorms, and landslides, that has driven the evolution of species and controls the characteristics of ecosystems. Fire suppression, in combination with other human-caused environmental changes, may have resulted in unforeseen consequences for natural ecosystems. Some large wildfires in the United States have been blamed on years of fire suppression and the continuing expansion of people into fire-adapted ecosystems as well as climate change. Land


id: fire-ecology-20260505-1
file: data/en.wikipedia.org/wiki/Fire_ecology-1.md
category: reference
title: Fire ecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fire_ecology
date_saved: 2026-05-05T07:18:10.171501+00:00
instance: kb-cron
parent: fire-ecology-20260505-0
summary:
Plants have evolved many adaptations to cope with fire. Of these adaptations, one of the best-known is likely pyriscence, where maturation and release of seeds is triggered, in whole or in part, by fire or smoke; this behaviour is often erroneously called serotiny, although this term truly denotes the much broader category of seed release activated by any stimulus. All pyriscent plants are serotinous, but not all serotinous plants are pyriscent (some are necriscent, hygriscent, xeriscent, soliscent, or some combination thereof). On the other hand, germination of seed activated by trigger is not to be confused with pyriscence; it is known as physiological dormancy. In chaparral communities in Southern California, for example, some plants have leaves coated in flammable oils that encourage an intense fire. This heat causes their fire-activated seeds to germinate (an example of dormancy) and the young plants can then capitalize on the lack of competition in a burnt landscape. Other plants have smoke-activated seeds, or fire-activated buds. The cones of the Lodgepole pine (Pinus contorta) are, conversely, pyriscent: they are sealed with a resin that a fire melts away, releasing the seeds. Many plant species, including the shade-intolerant giant sequoia (Sequoiadendron giganteum), require fire to make


id: fire-ecology-20260505-2
file: data/en.wikipedia.org/wiki/Fire_ecology-2.md
category: reference
title: Fire ecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fire_ecology
date_saved: 2026-05-05T07:18:10.171501+00:00
instance: kb-cron
parent: fire-ecology-20260505-0
summary:
== Fire and ecological succession == Fire behavior is different in every ecosystem and the organisms in those ecosystems have adapted accordingly. One sweeping generality is that in all ecosystems, fire creates a mosaic of different habitat patches, with areas ranging from those having just been burned to those that have been untouched by fire for many years. This is a form of ecological succession in which a freshly burned site will progress through continuous and directional phases of colonization following the destruction caused by the fire. Ecologists usually characterize succession through the changes in vegetation that successively arise. After a fire, the first species to re-colonize will be those with seeds are already present in the soil, or those with seeds are able to travel into the burned area quickly. These are generally fast-growing herbaceous plants that require light and are intolerant of shading. As time passes, more slowly growing, shade-tolerant woody species will suppress some of the herbaceous plants. Conifers are often early successional species, while broad leaf trees frequently replace them in the absence of fire. Hence, many conifer forests are themselves dependent upon recurring fire. Both natural and human fires affect all ecosystems from peatlands to


id: fire-ecology-20260505-3
file: data/en.wikipedia.org/wiki/Fire_ecology-3.md
category: reference
title: Fire ecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fire_ecology
date_saved: 2026-05-05T07:18:10.171501+00:00
instance: kb-cron
parent: fire-ecology-20260505-0
summary:
== Species Richness == Species richness is at its peak post-fire but steadily declines over time. Post-fire endurance for certain species allows for a variety of different life histories to exist at the same time. Fires result in a change of biodiversity by reducing the population for the promotion of growth for species. Disturbances due to fire allow for an alternative recovery process for certain animal populations, which can result in recolonization and population growth. Post-fire has decreased the abundance of species and the result of extinction. The effects of burning depend on the size, timing, and severity of the burn. The increased frequency and the size of a fire can impact how a population recovers between other fire events, which causes a patch between population distributions . Fires have been used to alter species composition, such as suppressing species that are invasive. == Examples of fire in different ecosystems == === Forests === Mild to moderate fires burn in the forest understory, removing small trees and herbaceous groundcover. High-severity fires will burn into the crowns of the trees and kill most of the dominant vegetation. Crown fires may require support from ground fuels to maintain the fire in the


id: fire-ecology-20260505-4
file: data/en.wikipedia.org/wiki/Fire_ecology-4.md
category: reference
title: Fire ecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fire_ecology
date_saved: 2026-05-05T07:18:10.171501+00:00
instance: kb-cron
parent: fire-ecology-20260505-0
summary:
=== Grasslands === Grasslands burn more readily than forest and shrub ecosystems, with the fire moving through the stems and leaves of herbaceous plants and only lightly heating the underlying soil, even in cases of high intensity. In most grassland ecosystems, fire is the primary mode of decomposition, making it crucial in the recycling of nutrients. In some grassland systems, fire only became the primary mode of decomposition after the disappearance of large migratory herds of browsing or grazing megafauna driven by predator pressure. In the absence of functional communities of large migratory herds of herbivorous megafauna and attendant predators, overuse of fire to maintain grassland ecosystems may lead to excessive oxidation, loss of carbon, and desertification in susceptible climates. Some grassland ecosystems respond poorly to fire. ==== North American grasslands ==== In North America fire-adapted invasive grasses such as Bromus tectorum contribute to increased fire frequency which exerts selective pressure against native species. This is a concern for grasslands in the Western United States. In less arid grassland presettlement fires worked in concert with grazing to create a healthy grassland ecosystem as indicated by the accumulation of soil organic matter significantly altered by fire. The tallgrass prairie ecosystem in


id: fire-ecology-20260505-5
file: data/en.wikipedia.org/wiki/Fire_ecology-5.md
category: reference
title: Fire ecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fire_ecology
date_saved: 2026-05-05T07:18:10.171501+00:00
instance: kb-cron
parent: fire-ecology-20260505-0
summary:
Restoration ecology is the name given to an attempt to reverse or mitigate some of the changes that humans have caused to an ecosystem. Controlled burning is one tool that is currently receiving considerable attention as a means of restoration and management. Applying fire to an ecosystem may create habitats for species that have been negatively impacted by fire suppression, or fire may be used as a way of controlling invasive species without resorting to herbicides or pesticides. However, there is debate as to what land managers should aim to restore their ecosystems to, especially as to whether it be pre-human or pre-European conditions. Native American use of fire, along with natural fire, historically maintained the diversity of the savannas of North America. === U.S. Oak Savannas and Oak Woodlands === Oak savannas and oak woodlands historically expanded across the Midwest, creating a transitional zone between the eastern deciduous forested United States and the Great Plains tall grass prairie region. However, due to human impact, these ecosystems are now some of the most degraded ecosystems in the world. Roughly around <1% of original savanna habitats remain in the United States, making conservation and preservation of these habitats extremely important. Management


id: fire-ecology-20260505-6
file: data/en.wikipedia.org/wiki/Fire_ecology-6.md
category: reference
title: Fire ecology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fire_ecology
date_saved: 2026-05-05T07:18:10.171501+00:00
instance: kb-cron
parent: fire-ecology-20260505-0
summary:
=== Finnish boreal forests === The decline of habitat area and quality has caused many species populations to be red-listed by the International Union for Conservation of Nature. According to a study on forest management of Finnish boreal forests, improving the habitat quality of areas outside reserves can help in conservation efforts of endangered deadwood-dependent beetles. These beetles and various types of fungi both need dead trees in order to survive. Old growth forests can provide this particular habitat. However, most Fennoscandian boreal forested areas are used for timber and therefore are unprotected. The use of controlled burning and tree retention of a forested area with deadwood was studied and its effect on the endangered beetles. The study found that after the first year of management the number of species increased in abundance and richness compared to pre-fire treatment. The abundance of beetles continued to increase the following year in sites where tree retention was high and deadwood was abundant. The correlation between forest fire management and increased beetle populations shows a key to conserving these red-listed species. === Australian eucalypt forests === Much of the old growth eucalypt forest in Australia is designated for conservation. Management of these forests


id: flexible-mechanisms-20260505-0
file: data/en.wikipedia.org/wiki/Flexible_mechanisms-0.md
category: reference
title: Flexible mechanisms
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Flexible_mechanisms
date_saved: 2026-05-05T07:18:11.435428+00:00
instance: kb-cron
parent: flexible-mechanisms-20260505-0
summary:
Flexible mechanisms, also sometimes known as Flexibility Mechanisms or Kyoto Mechanisms, refers to emissions trading, the Clean Development Mechanism and Joint Implementation. These are mechanisms defined under the Kyoto Protocol intended to lower the overall costs of achieving its emissions targets. These mechanisms enable Parties to achieve emission reductions or to remove carbon from the atmosphere cost-effectively in other countries. While the cost of limiting emissions varies from region to region, the benefit for the atmosphere is in principle the same, wherever the action is taken. Much of the negotiations on the mechanisms has been concerned with ensuring their integrity. There was concern that the mechanisms do not confer a "right to emit" on Annex 1 Parties or lead to exchanges of fictitious credits which would undermine the Protocol's environmental goals. The negotiators of the Protocol and the Marrakesh Accords therefore sought to design a system that fulfilled the cost-effectiveness promise of the mechanisms, while addressing concerns about environmental integrity and equity. To participate in the mechanisms, Annex 1 Parties must meet the following eligibility requirements: They must have ratified the Kyoto Protocol. They must have calculated their assigned amount, as referred to in Articles 3.7 and 3.8 and Annex


