Figure 2.

Traits included in our analysis of phenotypic divergence. As a proxy for divergent selection associated with ecological and sexual selection, phenotypic differences were quantified in (a) the mandibles, and (b) the male genitalia (specifically, the C-sclerite, which is inserted into the female reproductive tract during copulation), respectively. Shape divergence among populations of Amphiacusta sanctaecrucis in the genitalia and mandibles were quantified using geometric morphometric techniques (see §2).