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[[Scientific evidence]] for evolution comes from many aspects of biology and includes [[fossil]]s, [[Homology (biology)|homologous]] structures, and molecular similarities between species' DNA.
=== Fossil record ===
Research in the field of [[palaeontology]], the study of fossils, supports the idea that all living organisms are related. Fossils provide evidence that accumulated changes in organisms over long periods of time have led to the diverse forms of life we see today. A fossil itself reveals the organism's structure and the relationships between present and extinct species, allowing palaeontologists to construct a family tree for all of the life forms on Earth.<ref name="Virtual">{{cite web |url=http://www.fossilmuseum.net/fossilrecord.htm |title=The Fossil Record – Life's Epic |work=The Virtual Fossil Museum |publisher=Roger Perkins |access-date=2007-08-31}}</ref>
Modern palaeontology began with the work of [[Georges Cuvier]]. Cuvier noted that, in [[sedimentary rock]], each layer contained a specific group of fossils. The deeper layers, which he proposed to be older, contained simpler life forms. He noted that many forms of life from the past are no longer present today. One of Cuvier's successful contributions to the understanding of the fossil record was establishing extinction as a fact. In an attempt to explain extinction, Cuvier proposed the idea of "revolutions" or [[catastrophism]] in which he speculated that geological catastrophes had occurred throughout the Earth's history, wiping out large numbers of species.<ref>{{harvnb|Tattersall|1995|pp=5–6}}</ref> Cuvier's theory of revolutions was later replaced by uniformitarian theories, notably those of [[James Hutton]] and [[Charles Lyell]] who proposed that the Earth's geological changes were gradual and consistent.<ref>{{harvnb|Lyell|1830|p=76}}</ref> However, current evidence in the fossil record supports the concept of mass extinctions. As a result, the general idea of catastrophism has re-emerged as a valid hypothesis for at least some of the rapid changes in life forms that appear in the fossil records.
A very large number of fossils have now been discovered and identified. These fossils serve as a chronological record of evolution. The fossil record provides examples of [[Transitional fossil|transitional species]] that demonstrate ancestral links between past and present life forms.<ref>[[#NAS 2008|NAS 2008]], [http://books.nap.edu/openbook.php?record_id=11876&page=22 p. 22]</ref> One such transitional fossil is ''[[Archaeopteryx]]'', an ancient organism that had the distinct characteristics of a [[reptile]] (such as a long, bony [[tail]] and conical [[Tooth|teeth]]) yet also had characteristics of birds (such as [[feather]]s and a [[Furcula|wishbone]]). The implication from such a find is that modern reptiles and birds arose from a common ancestor.<ref>{{harvnb|Gould|1995|p=360}}</ref>
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=== Comparative anatomy ===
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