Editing Neo-Darwinism (section)

==Original use==
[[File:Modern Synthesis.svg|thumb|upright=1.75|Several major ideas about [[evolution]] came together in the [[population genetics]] of the early 20th century to form the so-called [[Modern synthesis (20th century)|modern synthesis]], including [[genetic variation]], [[natural selection]], and particulate ([[Mendelian genetics|Mendelian]]) inheritance. This was at the time called neo-Darwinism.]]
[[Darwinism|Darwin's theory of evolution]] by natural selection, as published in 1859, provided a selection mechanism for evolution, but not a trait transfer mechanism. [[Lamarckism]] was still a very popular candidate for this. [[August Weismann]] and [[Alfred Russel Wallace]] rejected the Lamarckian idea of [[inheritance of acquired characteristics]] that Darwin had accepted and later expanded upon in [[The Variation of Animals and Plants Under Domestication|his writings on heredity]].<ref name=Darwin1872/>{{rp|page=[http://darwin-online.org.uk/Variorum/1872/1872-108-dns.html 108]}}<ref name=Darwin1868/><ref name="Kutschera1"/> The basis for the complete rejection of Lamarckism was Weismann's [[germ plasm]] theory. Weismann realised that the cells that produce the germ plasm, or [[gamete]]s (such as [[sperm]] and [[Egg cell|eggs]] in [[animal]]s), separate from the [[Somatic (biology)|somatic]] cells that go on to make other body tissues at an early stage in development. Since he could see no obvious means of communication between the two, he asserted that the inheritance of acquired characteristics was therefore impossible; a conclusion now known as the [[Weismann barrier]].<ref name="Barbieri"/>

It is, however, usually [[George Romanes]] who is credited with the first use of the word in a scientific context. Romanes used the term to describe the combination of [[natural selection]] and Weismann's germ plasm theory that evolution occurs solely through natural selection, and not by the inheritance of acquired characteristics resulting from use or disuse, thus using the word to mean "Darwinism without Lamarckism."<ref name="Gould1"/><ref name = "wallacefund1"/><ref name="Reif"/>

Following the development, from about 1918 to 1947, of the [[Modern synthesis (20th century)|modern synthesis]] of [[evolutionary biology]], the term neo-Darwinian started to be used to refer to that contemporary evolutionary theory.<ref name="talkorigins1"/><ref name = "Walter1"/>