The Evolution of Cooperation insects, where the workers – which are sterile, and therefore incapable of passing on their genes – benefit the queen, who is essentially passing on copies of "their" genes. This is further elaborated in the "selfish gene" theory of Richard Dawkins, that the unit of evolution is not the individual organism, but the gene. (As stated by Wilson: "the organism is only DNA's way of making more DNA.") However, kinship selection works only where the individuals involved are closely related; it fails to explain the presence of altruism and cooperation between unrelated individuals, particularly across species. In a 1971 paper
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