Fig 1. Partitioning signals of sex differences in selection among fitness components.

A pair of autosomal alleles are represented by white and black dots, representing female- and male-beneficial alleles, respectively; ${\widehat{p}}_f,{\widehat{p}}_m,{\widehat{p}}_f^{\prime }$, and ${\widehat{p}}_m^{\prime }$ depict sex-specific frequency estimates for a given allele at different stages of the life cycle (see main text for details). Autosomal allele frequencies are equalised between sexes at fertilisation (left box; females, top; males, bottom), resulting in negligible allele frequency differentiation at this stage of the life cycle. Differentiation between sexes can arise in the sample of adults (middle box) due to sex differences in viability selection among juveniles (orange arrow) and in the projected gametes (right box) due to sex differences in LRS among adults (green arrow). Data on sex-specific allele frequencies and LRS thus allow the estimation of sex-differential effects of genetic variants on each fitness component (including overall fitness; purple arrow), despite the absence of allele frequency data among zygotes (left box) and gametes (right box), which are inferred and not directly observed. LRS, lifetime reproductive success.