In sexually reproducing species, the individual is too large and too temporary a genetic unit to qualify as a significant unit of natural selection.* The group of individuals is an even larger unit. Genetically speaking, individuals and groups are like clouds in the sky or dust-storms in the desert. They are temporary aggregations or federations. They are not stable through evolutionary time. Populations may last a long while, but they are constantly blending with other populations and so losing their identity.
