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
The Selfish Genius evolutionary theory that portrays natural selection as acting at the level of the individual gene to the exclusion of group selection models which state that it could also act at the level of organisms or species. The book also claims Dawkins embraces an outdated and prescriptive conception of evolution that actually restricts debate rather than promoting it. The book has provoked controversy with some online commentary claiming it is another 'flea', a term used by Dawkins to describe people who have published books about him or his ideas. An article by Fern Elsdon-Baker in "New Scientist" of 19 July 2009