Sex, Mate Selection, and Evolution

Simulations of the evolution of populations of diploid organisms showed that mate selection strategies which selected for “good genes” and strategies based on assortative mating, confer a much higher average fitness and higher evolutionary stability to populations than random mating. This advantage was more conspicuous the more genes per organism were simulated and the more genes were involved in the phenotype screened for mate selection. The results suggest that the evolutionary advantage of mate selection becomes evident only when the simultaneous adaptation of several genes are simulated. A cautionary lesson from the model is that mating is not likely to be random in nature and that mate selection may direct evolution by accelerating the exposure to natural selection of relevant traits. That is, models assuming random mating may not reflect what is happening in nature as sexual reproduction is probably associated with mate or gamete selection in most living organisms.