Selection for increased mutation rates with fertility difference between matings

Abstract

Previous studies of mutation modification have considered models in which selection is a result of viability difference that are sex symmetric. The results of a numerical study of a model in which selection is a result of fertility differences between mated pairs demonstrate that the type of selection to which population is subject can have a significant impact on the evolution of various parameters of the genetic system. When the fertility of mating between individuals with different genotypes exceeds the fertility at least some of the matings between individuals with the same genotype, selection may favor increased rates of mutation, in contrast to the results from all existing constant viability models with random mating and infinite population size. Increased mutation rates are most frequently favored when forward and back mutation occur at approximately equal rates and when the modifying locus is loosely linked to the selected locus. We present one example in which selection favors increased rates of mutation even though the selection scheme is reducible to one of differential viability between the sexes.