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
Alternatives to evolution by natural selection Alternatives to evolution by natural selection Alternatives to evolution by natural selection, also described as non-Darwinian mechanisms of evolution, have been proposed by scholars investigating biology since classical times to explain signs of evolution and the relatedness of different groups of living things. The alternatives in question do not encompass religious points of view such as young or old earth creationism or intelligent design, but are limited to explanations proposed by biologists, though one was confusingly named 'theistic evolution' by Asa Gray. Where the fact of evolutionary change was accepted but the mechanism proposed by Charles Darwin, natural selection, was