115.4 Saturday, Jan. 7 The evolutionary relationship between social mating system and sex-biased dispersal in mammals MABRY, Karen *; BLUMSTEIN, Daniel ; VAN VUREN, Dirk; SHELLEY, Erin; New Mexico State University; University of California, Los Angeles; University of California, Davis; University of California, Los Angeles email@example.com
In vertebrate animals, natal dispersal is often sex-biased (one sex disperses farther, or more frequently, than the other). Birds are often socially monogamous and have female-biased dispersal, while mammals are typically socially polygynous and have male-biased dispersal. A hypothesized evolutionary relationship between social mating system and sex-biased dispersal in vertebrates is widely accepted, but has never been subjected to a phylogenetic analysis. To elucidate the evolutionary relationship between mating system and dispersal in mammals, we applied modern comparative methods to a phylogenetic tree of 52 species for which both social mating system and degree of sex-biased dispersal are known. Our results indicate that the most likely path from the ancestral state of non-monogamy and male-biased dispersal to the derived state of monogamy and female-biased dispersal is a change in social mating system followed by a change in the direction of sex-bias in dispersal. However, our analyses also suggest that the relationship between these two traits is more complex than previously thought.