5.7 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| History of paleontology | 8/10 | https://en.wikipedia.org/wiki/History_of_paleontology | reference | science, encyclopedia | 2026-05-05T04:00:05.779726+00:00 | kb-cron |
Charles Darwin's publication of the On the Origin of Species in 1859 was a watershed event in all the life sciences, especially paleontology. Fossils had played a role in the development of Darwin's theory. In particular he had been impressed by fossils he had collected in South America during the voyage of the Beagle of giant armadillos, giant sloths, and what at the time he thought were giant llamas that seemed to be related to species still living on the continent in modern times. The scientific debate that started immediately after the publication of Origin led to a concerted effort to look for transitional fossils and other evidence of evolution in the fossil record. There were two areas where early success attracted considerable public attention, the transition between reptiles and birds, and the evolution of the modern single-toed horse. In 1861 the first specimen of Archaeopteryx, an animal with both teeth and feathers and a mix of other reptilian and avian features, was discovered in a limestone quarry in Bavaria and described by Richard Owen. Another would be found in the late 1870s and put on display at the Natural History Museum, Berlin in 1881. Other primitive toothed birds were found by Othniel Marsh in Kansas in 1872. Marsh also discovered fossils of several primitive horses in the Western United States that helped trace the evolution of the horse from the small 5-toed Hyracotherium of the Eocene to the much larger single-toed modern horses of the genus Equus. Thomas Huxley would make extensive use of both the horse and bird fossils in his advocacy of evolution. Acceptance of evolution occurred rapidly in scientific circles, but acceptance of Darwin's proposed mechanism of natural selection as the driving force behind it was much less universal. In particular some paleontologists such as Edward Drinker Cope and Henry Fairfield Osborn preferred alternatives such as neo-Lamarckism, the inheritance of characteristics acquired during life, and orthogenesis, an innate drive to change in a particular direction, to explain what they perceived as linear trends in evolution.
There was also great interest in human evolution. Neanderthal fossils were discovered in 1856, but at the time it was not clear that they represented a different species from modern humans. Eugene Dubois created a sensation with his discovery of Java Man, the first fossil evidence of a species that seemed clearly intermediate between humans and apes, in 1891.
=== Developments in North America ===
A major development in the second half of the 19th century was a rapid expansion of paleontology in North America. In 1858 Joseph Leidy described a Hadrosaurus skeleton, which was the first North American dinosaur to be described from good remains. However, it was the massive westward expansion of railroads, military bases, and settlements into Kansas and other parts of the Western United States following the American Civil War that really fueled the expansion of fossil collection. The result was an increased understanding of the natural history of North America, including the discovery of the Western Interior Sea that had covered Kansas and much of the rest of the Midwestern United States during parts of the Cretaceous, the discovery of several important fossils of primitive birds and horses, and the discovery of a number of new dinosaur genera including Allosaurus, Stegosaurus, and Triceratops. Much of this activity was part of a fierce personal and professional rivalry between two men, Othniel Marsh, and Edward Cope, which has become known as the Bone Wars.
== Overview of developments in the 20th century ==
=== Developments in geology === Two 20th-century developments in geology had a big effect on paleontology. The first was the development of radiometric dating, which allowed absolute dates to be assigned to the geologic timescale. The second was the theory of plate tectonics, which helped make sense of the geographical distribution of ancient life.
=== Geographical expansion of paleontology === During the 20th century, paleontological exploration intensified everywhere and ceased to be a largely European and North American activity. In the 135 years between Buckland's first discovery and 1969 a total of 170 dinosaur genera were described. In the 25 years after 1969 that number increased to 315. Much of this increase was due to the examination of new rock exposures, particularly in previously little-explored areas in South America and Africa. Near the end of the 20th century, the opening of China to systematic exploration for fossils has yielded a wealth of material on dinosaurs and the origin of birds and mammals. Also study of the Chengjiang fauna, a Cambrian fossil site in China, during the 1990s has provided important clues to the origin of vertebrates.
=== Mass extinctions === The 20th century saw a major renewal of interest in mass extinction events and their effect on the course of the history of life. This was particularly true after 1980 when Luis and Walter Alvarez put forward the Alvarez hypothesis claiming that an impact event caused the Cretaceous–Paleogene extinction event, which killed off the non-avian dinosaurs along with many other living things. Also in the early 1980s Jack Sepkoski and David M. Raup published papers with statistical analysis of the fossil record of marine invertebrates that revealed a pattern (possibly cyclical) of repeated mass extinctions with significant implications for the evolutionary history of life.
=== Evolutionary paths and theory ===