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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Biogeography | 4/4 | https://en.wikipedia.org/wiki/Biogeography | reference | science, encyclopedia | 2026-05-05T07:17:13.296244+00:00 | kb-cron |
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 of years, principally by means of allopatric speciation, and in an arena extending over most of the area of tropical South America. In other words, unlike some of the well-known insular faunas (Galapagos finches, Hawaiian drosophilid flies, African rift lake cichlids), the species-rich Amazonian ichthyofauna is not the result of recent adaptive radiations. For freshwater organisms, landscapes are divided naturally into discrete drainage basins by watersheds, episodically isolated and reunited by erosional processes. In regions like the Amazon Basin (or more generally Greater Amazonia, the Amazon basin, Orinoco basin, and Guianas) with an exceptionally low (flat) topographic relief, the many waterways have had a highly reticulated history over geological time. In such a context, stream capture is an important factor affecting the evolution and distribution of freshwater organisms. Stream capture occurs when an upstream portion of one river drainage is diverted to the downstream portion of an adjacent basin. This can happen as a result of tectonic uplift (or subsidence), natural damming created by a landslide, or headward or lateral erosion of the watershed between adjacent basins.
== Concepts and fields == Biogeography is a synthetic science, related to geography, biology, soil science, geology, climatology, ecology and evolution. Some fundamental concepts in biogeography include:
allopatric speciation – the splitting of a species by evolution of geographically isolated populations evolution – change in genetic composition of a population extinction – disappearance of a species dispersal – movement of populations away from their point of origin, related to migration endemic areas geodispersal – the erosion of barriers to biotic dispersal and gene flow, that permit range expansion and the merging of previously isolated biotas range and distribution vicariance – the formation of barriers to biotic dispersal and gene flow, that tend to subdivide species and biotas, leading to speciation and extinction; vicariance biogeography is the field that studies these patterns
=== Comparative biogeography === The study of comparative biogeography can follow two main lines of investigation:
Systematic biogeography, the study of biotic area relationships, their distribution, and hierarchical classification Evolutionary biogeography, the proposal of evolutionary mechanisms responsible for organismal distributions. Possible mechanisms include widespread taxa disrupted by continental break-up or individual episodes of long-distance movement.
== Biogeographic units ==
There are many types of biogeographic units used in biogeographic regionalisation schemes, as there are many criteria (species composition, physiognomy, ecological aspects) and hierarchization schemes: biogeographic realms (ecozones), bioregions (sensu stricto), ecoregions, zoogeographical regions, floristic regions, vegetation types, biomes, etc. The terms biogeographic unit or biogeographic area can be used for these regions, regardless of where they fall in any hierarchy. In 2008, an International Code of Area Nomenclature was proposed for biogeography. It achieved limited success; some studies commented favorably on it, but others were much more critical, and it "has not yet gained a significant following". Similarly, a set of rules for paleobiogeography has achieved limited success. In 2000, Westermann suggested that the difficulties in getting formal nomenclatural rules established in this field might be related to "the curious fact that neither paleo- nor neobiogeographers are organized in any formal groupings or societies, nationally (so far as I know) or internationally — an exception among active disciplines."
== See also ==
== Notes and references ==
== Further reading == Albert, J.S.; Crampton, W.G.R. (2010). "The geography and ecology of diversification in Neotropical freshwaters". Nature Education. 1 (10): 3. Cox, CB (2001). "The biogeographic regions reconsidered" (PDF). Journal of Biogeography. 28 (4): 511–523. Bibcode:2001JBiog..28..511B. doi:10.1046/j.1365-2699.2001.00566.x. Archived from the original (PDF) on 4 March 2016. Ebach, MC (2015). Origins of biogeography. The role of biological classification in early plant and animal geography. Dordrecht: Springer. ISBN 978-94-017-9999-7. Lieberman, BS (2001). Paleobiogeography: using fossils to study global change, plate tectonics, and evolution. Kluwer Academic, Plenum Publishing. ISBN 978-0-306-46277-1. Lomolino, MV; Brown, JH (2004). Foundations of biogeography: classic papers with commentaries. University of Chicago Press. ISBN 978-0-226-49236-0. MacArthur, Robert H. (1972). Geographic Ecology. New York: Harper & Row. McCarthy, Dennis (2009). Here be dragons: how the study of animal and plant distributions revolutionized our views of life and Earth. Oxford & New York: Oxford University Press. ISBN 978-0-19-954246-8. Millington, A; Blumler, M; Schickhoff, eds. (2011). The SAGE handbook of biogeography. London: Sage. ISBN 978-1-4462-5445-5. Nelson, GJ (1978). "From Candolle to Croizat: Comments on the history of biogeography" (PDF). Journal of the History of Biology. 11 (2): 269–305. doi:10.1007/BF00389302. PMID 11610435. Udvardy, MDF (1975). "A classification of the biogeographical provinces of the world" (PDF). IUCN Occasional Paper (18). Morges, Switzerland: IUCN. Archived from the original (PDF) on 11 August 2011.
== External links ==
The International Biogeography Society Systematic & Evolutionary Biogeographical Society (archived 5 December 2008) Early Classics in Biogeography, Distribution, and Diversity Studies: To 1950 Early Classics in Biogeography, Distribution, and Diversity Studies: 1951–1975 Some Biogeographers, Evolutionists and Ecologists: Chrono-Biographical Sketches Major journals
Journal of Biogeography homepage (archived 15 December 2004) Global Ecology and Biogeography homepage. Archived 2012-07-28 at the Wayback Machine. Ecography homepage.