Iliana Medina, Caroline Dong, Roberto Marquez, Daniela Perez, Ian J. Wang, Devi Stuart-Fox

Predator-prey interactions have been suggested as drivers of diversity in different lineages, and the presence of anti-predator defences in some clades is linked to higher rates of diversification. Warning signals are some of the most widespread defenses in the animal world, and there is evidence of higher diversification rates in aposematic lineages. The mechanisms behind such species richness, however, are still unclear. Here, we test whether lineages that use aposematism as anti-predator defense exhibit higher levels of genetic differentiation between populations, leading to increased opportunities for divergence. We collated from the literature > 3,000 pairwise genetic differentiation values across more than 700 populations from over 60 amphibian species. We find evidence that, given the same geographic distance, populations of species of aposematic lineages exhibit greater genetic divergence relative to species that are not aposematic. Our results support a scenario where the use of warning signals could restrict dispersal of individuals, and suggest that anti-predator defences could impact gene flow levels between populations and potentially have effects at a macro-evolutionary scale.