title: Fixation probability in a two-locus intersexual selection model.
abstract: We study a two-locus model of intersexual selection in a finite haploid population reproducing according to a discrete-time Moran model with a trait locus expressed in males and a preference locus expressed in females. We show that the probability of ultimate fixation of a single mutant allele for a male ornament introduced at random at the trait locus given any initial frequency state at the preference locus is increased by weak intersexual selection and recombination, weak or strong. Moreover, this probability exceeds the initial frequency of the mutant allele even in the case of a costly male ornament if intersexual selection is not too weak. On the other hand, the probability of ultimate fixation of a single mutant allele for a female preference towards a male ornament introduced at random at the preference locus is increased by weak intersexual selection and weak recombination if the female preference is not costly, and is strong enough in the case of a costly male ornament. The analysis relies on an extension of the ancestral recombination-selection graph for samples of haplotypes to take into account events of intersexual selection, while the symbolic calculation of the fixation probabilities is made possible in a reasonable time by an optimizing algorithm.
authors.affiliation: Laboratoire de Probabilités et Modèles Aléatoires, Université Pierre et Marie Curie, 4 place Jussieu, 75252 Paris cedex 05, France.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Durand
authors.affiliation: Département de mathématiques et de statistique, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal (Québec) H3C 3J7, Canada. Electronic address: lessards@dms.umontreal.ca.
authors.forename: Sabin
authors.initials: S
authors.lastname: Lessard
mesh_terms: D000465:Algorithms; D000483:Alleles; D000818:Animals; D005260:Female; D056426:Genetic Loci; D005828:Genetics, Population; D008297:Male; D008957:Models, Genetic; D009154:Mutation; D010641:Phenotype; D011336:Probability; D011995:Recombination, Genetic; D012641:Selection, Genetic; D012747:Sexual Partners
keywords: Ancestral recombination–selection graph; Fixation probability; Sexual selection