Data from: Correlated divergence of female and male genitalia in replicated lineages with ongoing ecological speciation

Divergence of genital traits among lineages has the potential to serve as
a reproductive isolating barrier when copulation, insemination, or
fertilization are inhibited by incompatibilities between female and male
genitalia. Despite widespread evidence for genital trait diversity among
closely related lineages and coevolution of female and male genitalia
within lineages, few studies have investigated genital evolution during
the early stages of speciation. We quantified genital variation in
replicated population pairs of Poecilia mexicana with ongoing ecological
speciation between sulfidic (H2S-containing) and nearby non-sulfidic
habitats. These analyses revealed rapid and correlated divergence of
female and male genitalia across evolutionarily independent population
pairs exposed to divergent selection regimes. Both sexes exhibited
convergent evolution of genital traits among populations inhabiting
similar habitat types. Our results demonstrate that genital evolution can
occur during the early stages of speciation-with-gene-flow, potentially as
a result of variation in the intensity of sexual conflict among
populations. Our results suggest genitalia may contribute to early stages
of divergence, and challenge the generality of previously suggested
mechanisms of genital evolution in poeciliids.