title: The evolution and consequences of sex-specific reproductive variance.
abstract: Natural selection favors alleles that increase the number of offspring produced by their carriers. But in a world that is inherently uncertain within generations, selection also favors alleles that reduce the variance in the number of offspring produced. If previous studies have established this principle, they have largely ignored fundamental aspects of sexual reproduction and therefore how selection on sex-specific reproductive variance operates. To study the evolution and consequences of sex-specific reproductive variance, we present a population-genetic model of phenotypic evolution in a dioecious population that incorporates previously neglected components of reproductive variance. First, we derive the probability of fixation for mutations that affect male and/or female reproductive phenotypes under sex-specific selection. We find that even in the simplest scenarios, the direction of selection is altered when reproductive variance is taken into account. In particular, previously unaccounted for covariances between the reproductive outputs of different individuals are expected to play a significant role in determining the direction of selection. Then, the probability of fixation is used to develop a stochastic model of joint male and female phenotypic evolution. We find that sex-specific reproductive variance can be responsible for changes in the course of long-term evolution. Finally, the model is applied to an example of parental-care evolution. Overall, our model allows for the evolutionary analysis of social traits in finite and dioecious populations, where interactions can occur within and between sexes under a realistic scenario of reproduction.
authors.affiliation: Centre of Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, London WC1E 6BT, United Kingdom.
authors.forename: Charles
authors.initials: C
authors.lastname: Mullon
authors.forename: Max
authors.initials: M
authors.lastname: Reuter
authors.forename: Laurent
authors.initials: L
authors.lastname: Lehmann
mesh_terms: D000483:Alleles; D000818:Animals; D005075:Biological Evolution; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D008297:Male; D008957:Models, Genetic; D010641:Phenotype; D012098:Reproduction; D012641:Selection, Genetic; D012723:Sex
keywords: Within-generation variance; convergent stable strategies; dioecious population, probability of fixation; sex-specific evolution