Linking mating preferences to sexually selected traits and offspring viability: good versus complementary genes hypotheses

Indirect fitness benefits hypotheses suggest that offspring of preferred mates should exhibit greater survival or reproductive success. For example, good genes hypotheses propose that female mating preferences are mediated by secondary sexual traits because they honestly reflect the ability to pass on genes that will enhance offspring survival or reproduction. Conversely, complementary genes hypotheses propose that mating preferences are mediated by complementary genes because they enhance offspring viability. While these two research traditions are not strict alternatives and both may operate simultaneously, they have never been tested together. Here we explore the multiple potential underlying factors influencing mating preference ev

Choosy males in Jamaican field crickets

Male mate choice is an often neglected aspect of sexual selection studies. While theory predicts that females should exhibit mate choice due to their comparatively greater investment in gametes, males may also exhibit mate choice for a variety of reasons, including seeking mates with greater fecundity. Furthermore, males may exhibit discriminant or indiscriminate mate choice as a function of their own intrinsic characteristics, such as body size or condition. Here we experimentally evaluated male Jamaican field cricket, Gryllus assimilis, mating preferences using randomly selected females and determined how both male and female morphology (body size and residual mass) and male signalling behaviour influence male mate preference. Results show that male crickets exhibit mating preferences, with larger males tending to exhibit more consistent mate preferences than smaller males. Contrary to predictions, males did not prefer larger or relatively heavier females, suggesting that males may not be basing their choosiness on these proxy measures of female fecundity. Our findings highlight the need for continued research on male mate ch

What is driving male mate preference evolution in Jamaican field crickets?

Male mating preferences are often a neglected aspect of studies on sexual selection. Male mating preferences may evolve if they provide males with direct-fitness benefits such as increased opportunity to fertilize more eggs or indirect-fitness benefits such as enhanced offspring survival. We tested these ideas using Jamaican field crickets, Gryllus assimilis, previously shown to exhibit male mating preferences. We randomly mated males to either their preferred or non-preferred potential mates and then asked whether mating treatment influenced egg oviposition or offspring viability. Preferred females were not significantly more fecund and did not produce more viable eggs or offspring than non-preferred females. Male mate preferences were therefore inconsistent with both the direct- and indirect-fitness benefits hypotheses under the conditions of our experiment. Our null results leave us with an open question about what is driving the evolution of m