Evolutionary relationships among life-history traits in Caninae (Mammalia: Carnivora)

Over the last few years, a debate about the relative roles of distinct factors on the evolution of lineages has gained prominence. The family Canidae is an excellent group for exploring this idea, owing to its rich fossil history. One of the most intriguing traits in canids is social organization, which varies from highly social to solitary species. However, we do not have a complete understanding of how sociality evolved in this clade. Here, we use a combination of phylogenetic analyses, ancestral character reconstructions and comparative methods on the only extant subfamily, Caninae, to understand how traits expressing ecological features evolved over the last 12.6 Myr. Our findings suggest that the evolution of low, medium and high sociality forms was abrupt and highly correlated with the evolution of hypo-, meso- and hypercarnivorous forms, respectively. In addition, our results suggest that the evolution of phenotypic traits in Caninae occurred through a sequential cause-effect relationship, where changes in habitat use and body size probably triggered changes in social behaviour, which in turn drove the evolution of diet.