Abstracts (first author)
Homage to Bateman: sex roles predict sex differences in sexual selection
Classic sex role theory predicts that sexual selection should be stronger in males in taxa showing conventional sex roles and stronger in females in role reversed mating systems. I present the results of a study that tested this very central prediction and assessed the utility of different measures of sexual selection. We estimated sexual selection in both sexes in four seed beetle species with divergent sex roles using a novel experimental design. We found that sexual selection was sizeable in females, and that the strength of sexual selection in females and males varied with mating system and species. Residual selection formed a substantial component of net selection in both species. Further, we compared variance-based measures of sexual selection (the Bateman gradient and selection opportunities) with trait-based measures (selection differentials) in their ability to predict sexual dimorphism in reproductive behavior and morphology across species. Our results 1) highlight the importance of using assays that incorporate components of fitness manifested after mating, and 2) allow us to identify the generally most informative measure of the strength of sexual selection in comparisons across sexes and/or species.