Research Project

The adaptive radiation of Musteloidea gathers high taxonomic and ecomorphological diversities. Unlike other carnivorans, hypercarnivours musteloids are the smallest and have high intensities of sexual dimorphism; females invest substantially in offspring development, while males allocate more energy to their own growth. Although the patterns of intersexual divergence may differ between species with similar levels of sexual dimorphism, the comparative study of shape sexual dimorphism in musteloids have been limited to quantifying its intensity. In this project, we will investigate how sexual dimorphism evolved in the mandible of Musteloidea, considering the indirect effects of size in the intensity and the patterns of shape dimorphism. Functioning as a tool for defense, predation, and combat, the mandible is essential to musteloids reproductive success. To describe the multidimensional patterns of sexual dimorphism in musteloids for the first time, the mandible shape and size will be quantified in male and female specimens from 73 species. Variations in adaptive and non-adaptive evolutionary models will be used to understand how sexual dimorphism evolves in complex morphological structures. We will test the hypothesis that sexual dimorphism evolves as a byproduct of differential ecomorphological evolution between the sexes. We do not expect distinct modes of evolution between the sexes, as they will likely follow the same selection regimes observed in Carnivora ecomorphology. However, it is possible that sexual differences in the rate of morphological modification contributed for the emergence of sexual dimorphism in musteloids. With sexual dimorphism only comparable to that of felids, Musteloidea is an indispensable taxon for studying the interaction between sexual selection and ecological niche divergence in the hypercarnivorous phenotype.