Article,
Sexual Selection and the Evolution of Female Choice
Evolution, 36 (1): 1--12 (1982)
Abstract
The evolution of sexual selection is studied using a two-locus model of a polygynous population that follows both a male trait causing loss of viability and a female mating preference for that trait. The major conclusion is that such a mating preference is selected neither for nor against, but the mating advantage it confers on its preferred male type can maintain the less viable trait in the population. The equilibrium frequency of the preference is not uniquely determined by the forces of sexual selection, but this frequency determines the prevalence of the male trait in the population. If a mutant showing a mating preference for a male trait with reduced viability reaches high frequency, the trait can be taken to high frequency and consequently cause average male survivorship to deteriorate severely. Because the frequencies of the preference and hence the trait are indeterminate, it is possible that weak forces such as pleiotropy or genetic drift may control the direction and rate of their evolution. These conclusions still hold if a second, competing female mating preference that favors a more viable male type is introduced: neither that preference nor the more viable male trait will necessarily spread through the population.
