George C. Williams (biologist) should only be used where it is really necessary", 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
Adaptation and Natural Selection point, e.g. populations don't take any measures to avoid impending extinction. Finally he evaluates various ideas about progress in evolution, denying that selection will bring about the kind of progress that some have suggested. The author concludes that his view on the topic is similar to that of most of his colleagues, but worries that it is misrepresented to the public "when biologists become self-consciously philosophical". Adaptation and Natural Selection Adaptation and Natural Selection: A Critique of Some Current Evolutionary Thought is a 1966 book by the American evolutionary biologist George C. Williams. Williams, in what is now considered a