Data from: Carnivory maintains cranial dimorphism between males and females: evidence for niche divergence in extant Musteloidea

The evolution and maintenance of sexual dimorphism has long been
attributed to sexual selection. Niche divergence, however, serves as an
alternative but rarely tested selective pressure also hypothesized to
drive phenotypic disparity between males and females. We reconstructed
ancestral social systems and diet and used Ornstein-Uhlenbeck (OU)
modeling approaches to test whether niche divergence is stronger than
sexual selection in driving the evolution of sexual dimorphism in cranial
size and bite force across extant Musteloidea. We found that multi-peak OU
models favored different dietary regimes over social behavior and that the
greatest degree of cranial size and bite force dimorphism were found in
terrestrial carnivores. Because competition for terrestrial vertebrate
prey is greater than other dietary groups, increased cranial size and bite
force dimorphism reduces dietary competition between the sexes. In
contrast, neither dietary regime nor social system influenced the
evolution of sexual dimorphism in cranial shape. Furthermore, we found
that the evolution of sexual dimorphism in bite force is influenced by the
evolution of sexual dimorphism in cranial size rather than cranial shape.
Overall, our results highlight niche divergence as an important mechanism
that maintains the evolution of sexual dimorphism in musteloids.