Unit of selection and Confirmation of Evolutionary Theory" provides a basic "philosophical" introduction to the debate. Below, cases of selection at the genic, cellular, individual and group level from within the multi-level selection perspective are presented and discussed. George C. Williams in his influential book "Adaptation and Natural Selection" was one of the first to present a gene-centered view of evolution with the gene as the unit of selection, arguing that a unit of selection should exhibit a high degree of permanence. Richard Dawkins has written several books popularizing and expanding the idea. According to Dawkins, genes cause phenotypes and a gene is
The Selfish Gene in which Dawkins describes the continued relevance of the gene's eye view of evolution and states that it, along with coalescence analysis "illuminates the deep past in ways of which I had no inkling when I first wrote "The Selfish Gene"..." In April 2016, "The Selfish Gene" was listed as number 10 on "The Guardian"'s list of the 100 best nonfiction books, by Robert McCrum. In July 2017, the book was listed as the most influential science book of all time in a poll to celebrate the 30th anniversary of the Royal Society science book prize, ahead of Charles Darwin's