Editing Modern synthesis (20th century) (section)

==After the synthesis==

After the synthesis, evolutionary biology continued to develop with major contributions from workers including W. D. Hamilton,<ref name=Hamilton>{{cite journal |author=Hamilton, W. D. |date=1964 |title=The Genetical Evolution of Social Behaviour I  |journal=[[Journal of Theoretical Biology]] |volume=7 |issue=1 |pages=1–52 |url=http://www.uvm.edu/pdodds/files/papers/others/1964/hamilton1964a.pdf |archive-url=https://web.archive.org/web/20161218171138/http://www.uvm.edu/pdodds/files/papers/others/1964/hamilton1964a.pdf |archive-date=2016-12-18 |url-status=live |doi=10.1016/0022-5193(64)90038-4|pmid=5875341 |bibcode=1964JThBi...7....1H }}</ref> George C. Williams,<ref name=Williams/> E. O. Wilson,<ref name=YudellDesalle2000/> Edward B. Lewis<ref name=Gilbert2000/> and others.

===Hamilton's inclusive fitness, 1964===
{{further|Inclusive fitness|Kin selection}}

In 1964, [[W. D. Hamilton]] published two papers on "The Genetical Evolution of Social Behaviour". These defined [[inclusive fitness]] as the number of offspring equivalents an individual rears, rescues or otherwise supports through its behaviour. This was contrasted with personal reproductive fitness, the number of offspring that the individual directly begets. Hamilton, and others such as [[John Maynard Smith]], argued that a gene's success consisted in maximising the number of copies of itself, either by begetting them or by indirectly encouraging begetting by related individuals who shared the gene, the theory of [[kin selection]].<ref name=Hamilton/><ref>{{cite journal |last=Maynard Smith |first=John |author-link=John Maynard Smith |year=1964 |title=Group Selection and Kin Selection |journal=[[Nature (journal)|Nature]] |volume=201 |issue=4924 |pages=1145–1147 |doi=10.1038/2011145a0|bibcode=1964Natur.201.1145S |s2cid=4177102 }}</ref>

===Williams's gene-centred evolution, 1966===
{{further|Gene-centered view of evolution|Adaptation and Natural Selection}}

In 1966, [[George C. Williams (biologist)|George C. Williams]] published ''[[Adaptation and Natural Selection]]'', outlined a [[gene-centered view of evolution|gene-centred view of evolution]] following Hamilton's concepts, disputing the idea of [[evolutionary progress]], and attacking the then widespread theory of [[group selection]]. Williams argued that natural selection worked by changing the frequency of alleles, and could not work at the level of groups.<ref>{{cite book |last=Pinker |first=Steven |author-link=Steven Pinker |year=1994 |title=The Language Instinct |publisher=Harper Perennial Modern Classics |page=294}}</ref><ref name=Williams>{{cite book |last=Williams |first=George C. |title=Adaptation and Natural Selection |publisher=[[Princeton University Press]] |year=1966 |pages=307 |url=http://www.librarything.com/work/192870 |isbn=978-0-691-02615-2}}</ref> Gene-centred evolution was popularised by [[Richard Dawkins]] in his 1976 book ''[[The Selfish Gene]]'' and developed in his more technical writings.<ref>{{cite web |url=https://plato.stanford.edu/archives/fall2015/entries/population-genetics/ |title=Population Genetics |first=Samir |last=Okasha |date=September 22, 2006 |via=plato.stanford.edu}}</ref><ref name="extendedphenotype">{{cite book |last=Dawkins| first=Richard |author-link=Richard Dawkins |year=1982 |title=The Extended Phenotype |publisher=[[Oxford University Press]] |isbn=978-0-19-288051-2 |title-link=The Extended Phenotype}}</ref>

===Wilson's sociobiology, 1975===
[[File:Atta.cephalotes.gamut.selection.jpg|thumb|[[Ant]] [[sociobiology|societies have evolved]] elaborate [[caste (biology)|caste]] structures, widely different in size and function.]]
{{main|Sociobiology}}

In 1975, [[E. O. Wilson]] published his controversial<ref name=Fisher1994>{{cite web |last=Fisher |first=Helen |title='Wilson,' They Said, 'Your All Wet!' |url=https://www.nytimes.com/books/98/12/06/specials/wilson-naturalist.html |work=New York Times |access-date=21 July 2015 |date=16 October 1994}}</ref> book ''[[Sociobiology: The New Synthesis]]'', the subtitle alluding to the modern synthesis<ref name=YudellDesalle2000>{{cite journal |last1=Yudell |first1=Michael |last2=Desalle |first2=Rob |year=2000 |title=Sociobiology. The New Synthesis. by Edward O. Wilson |journal=[[Journal of the History of Biology]] |volume=33 |issue=3 |pages=577–584 |jstor=4331614 |doi=10.1023/a:1004845822189 |s2cid=88047081 }}</ref> as he attempted to bring the study of animal society into the evolutionary fold. This appeared radically new, although Wilson was following Darwin, Fisher, Dawkins and others.<ref name=YudellDesalle2000/> Critics such as [[Gerhard Lenski]] noted that he was following Huxley, Simpson and Dobzhansky's approach, which Lenski considered needlessly reductive as far as human society was concerned.<ref name=Lenski1976>{{cite journal| last=Lenski |first=Gerhard |year=1976 |title=Sociobiology. The New Synthesis. by Edward O. Wilson |journal=[[Social Forces]] |volume=55 |issue=2 |pages=530–531 |jstor=2576242 |doi=10.2307/2576242}}</ref> By 2000, the proposed discipline of [[sociobiology]] had morphed into the relatively well-accepted discipline of [[evolutionary psychology]].<ref name=YudellDesalle2000/>

===Lewis's homeotic genes, 1978===

[[File:Genes hox.jpeg|thumb|upright=1.<!--format to make text labels legible-->75|[[Evolutionary developmental biology]] has formed a synthesis of evolutionary and [[developmental biology]], discovering [[deep homology]] between the [[embryogenesis]] of such different animals as [[insect]]s and [[vertebrate]]s.]]

{{main|Evolutionary developmental biology}}

In 1977, [[recombinant DNA]] technology enabled biologists to start to explore the genetic control of development. The growth of [[evolutionary developmental biology]] from 1978, when [[Edward B. Lewis]] discovered [[homeotic]] genes, showed that many so-called [[toolkit gene]]s act to regulate development, influencing the expression of other genes. It also revealed that some of the regulatory genes are extremely ancient, so that animals as different as insects and mammals share control mechanisms; for example, the ''[[Pax6]]'' gene is involved in forming the [[eye]]s of mice and of fruit flies. Such [[deep homology]] provided strong evidence for evolution and indicated the paths that evolution had taken.<ref name=Gilbert2000>{{cite book |last=Gilbert |first=Scott F. |author-link=Scott F. Gilbert |chapter=A New Evolutionary Synthesis |title=Developmental Biology |date=2000 |publisher=[[Sinauer Associates]] |url=https://www.ncbi.nlm.nih.gov/books/NBK10128/}}</ref>