History of evolutionary thought theory were particularly controversial, spawning the neutralist-selectionist debate over the relative importance of mutation, drift and selection, which continued into the 1980s without a clear resolution. In the mid-1960s, George C. Williams strongly critiqued explanations of adaptations worded in terms of "survival of the species" (group selection arguments). Such explanations were largely replaced by a gene-centered view of evolution, epitomized by the kin selection arguments of W. D. Hamilton, George R. Price and John Maynard Smith. This viewpoint would be summarized and popularized in the influential 1976 book "The Selfish Gene" by Richard Dawkins. Models of the period seemed to
Introduction to evolution that is, that natural selection operates as an evolutionary mechanism on genes as well as organisms. In his 1976 book, "The Selfish Gene", he explains: Others view selection working on many levels, not just at a single level of organism or gene; for example, Stephen Jay Gould called for a hierarchical perspective on selection. Introduction to evolution Evolution is the process of change in all forms of life over generations, and evolutionary biology is the study of how evolution occurs. Biological populations evolve through genetic changes that correspond to changes in the organisms' observable traits. Genetic changes include mutations, which