Meeting Abstract
Because lifetime reproductive success is often dependent upon the ability to compete for mates, males tend to be more specialized for physical competition than females. Among mammals, polygyny enforced by male-male competition is the most common mating system. However, variation in social structure may lead to differences in the relative importance of intraspecific aggression. Here we present a large comparative data set on sexual dimorphism in skeletal shape in Carnivora in order to test the hypothesis that male carnivorans are more specialized for physical aggression than females. We tested this hypothesis using a set of functional indices predicted to improve aggressive performance. Results from comparative analyses on 26 carnivoran species indicate that sexual dimorphism in skeletal shape is widespread. Phylogenetic model selection on a variety of life history traits suggests that the evolution of this dimorphism is best explained by sexual selection. Functional traits that are predicted to enhance aggressive performance are more pronounced in males. Importantly, these traits may entail functional trade-offs with locomotor performance, signifying the importance of aggression in the life history of carnivorans and perhaps mammals in general.
