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 "nature", providing an excuse for behavior with bad consequences for future human society. Dawkins' major concluding theme, that humanity is finally gaining power over the "selfish replicators" by virtue of their intelligence, is criticized also by primatologist Frans de Waal, who refers to it as an example of a "veneer theory" (the idea that morality is not fundamental, but is laid over a brutal foundation). Dawkins claims he merely describes how things are under evolution, and makes no moral arguments. On BBC-2 TV, Dawkins pointed to evidence for a "Tit-for-Tat" strategy (shown to be successful in game theory) as the