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|religion = |signature = |footnotes = }} George Christopher Williams (May 12, 1926 – September 8, 2010) was an American evolutionary biologist.〔http://chronicle.com/blogPost/George-C-Williams-1926-2010/26821/〕 Williams was a professor of biology at the State University of New York at Stony Brook who was best known for his vigorous critique of group selection. The work of Williams in this area, along with W. D. Hamilton, John Maynard Smith and others led to the development of a gene-centric view of evolution in the 1960s. ==Academic work== Williams' 1957 paper ''Pleiotropy, Natural Selection, and the Evolution of Senescence'' is one of the most influential in 20th century evolutionary biology, and contains at least 3 foundational ideas. The central hypothesis of antagonistic pleiotropy remains the prevailing evolutionary explanation of senescence. In this paper Williams was also the first to propose that senescence should be generally synchronized by natural selection. According to this original formulation
This important concept of synchrony of senescence was taken up a short time later by John Maynard Smith, and the origin of the idea is often misattributed to him, including in his obituary in the journal, Nature. This paper also contains the first basic outline of the so-called "grandmother hypothesis", which states that natural selection might select for menopause and post-reproductive life in females, although Williams does not explicitly mention grandchildren or the inclusive fitness contribution of grandparenting. In his first book, ''Adaptation and Natural Selection'', Williams advocated a "ground rule - or perhaps ''doctrine'' would be a better term - ... that adaptation is a special and onerous concept that should only be used where it is really necessary",〔(Adaptation and Natural Selection ) p4〕 and, that, when it is necessary, selection among genes or individuals would in general be the preferable explanation for it. He elaborated this view in later books and papers, which contributed to the development of a gene-centered view of evolution; Richard Dawkins built on Williams' ideas in this area in the book ''The Selfish Gene''. Williams was also well known for his work on the evolution of sex, and was an advocate of evolutionary medicine. In later books, including ''Natural Selection: Domains, Levels and Challenges'', Williams softened his views on group selection, recognizing that clade selection, trait group selection and multilevel selection did sometimes occur in nature, something he had earlier thought to be so unlikely it could be safely ignored.〔George C. Williams, Natural Selection: Domains, Levels and Challenges, (Oxford University Press, 1992), 23-55〕 Williams became convinced that the genic neo-Darwinism of his earlier years, while essentially correct as a theory of microevolutionary change, could not account for evolutionary phenomena over longer time scales, and was thus an "utterly inadequate account of the evolution of the Earth’s biota" (1992, p. 31). In particular, he became a staunch advocate of clade selection – a generalisation of species selection to monophyletic clades of any rank – which could potentially explain phenomena such as adaptive radiations, long-term phylogenetic trends, and biases in rates of speciation/extinction. In Natural Selection (1992), Williams argued that these phenomena cannot be explained by selectively-driven allele substitutions within populations, the evolutionary mechanism he had originally championed over all others. This book thus represents a substantial departure from the position of Adaptation and Natural Selection. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「George C. Williams」の詳細全文を読む スポンサード リンク
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