Female mating bias results in conflicting sex-specific offspring fitness

Abstract

Indirect-benefit models of sexual selection assert that females gain heritable offspring advantages through a mating bias for males of superior genetic quality. This has generally been tested by associating a simple morphological quality indicator (for example, bird tail length) with offspring viability¹. However, selection acts simultaneously on many characters, limiting the ability to detect significant associations, especially if the simple indicator is weakly correlated to male fitness^2,3. Furthermore, recent conceptual developments suggest that the benefits gained from such mating biases may be sex-specific because of sexually antagonistic genes that differentially influence male and female reproductive ability⁴. A more suitable test of the indirect-benefit model would examine associations between an aggregate quality indicator^1,3 (such as male mating success) and gender-specific adult fitness components, under the expectation that these components may trade off¹. Here, we show that a father's mating success in the cricket, Allonemobius socius, is positively genetically correlated with his son's mating success but negatively with his daughter's reproductive success. This provides empirical evidence that a female mating bias can result in sexually antagonistic offspring fitness.