How does female-specific selection affect male fertility?

Understanding how male and female fitness evolve requires an understanding of how they are linked. Males and females share most of their genome, so selection on one sex is likely to have consequences for the other. If selection acts upon sexually dimorphic traits with a shared developmental/genetic basis (e.g.

gonadal function), these consequences may be substantial both at the genotypic and phenotypic level (Rogers et al. 2020). In birds, selection for egg production induces large changes to the oviduct. Male and female gonads differentiate from the same tissue, so correlated responses in the testes are likely.

Pick et al. (2017) recently demonstrated that artificial selection for female reproductive investment affects reproductive success in males . It is not yet known whether sex-specific selection influences ejaculate traits (e.g. sperm function), or how this is linked to testis morphology.