The distribution of traits within communities is thought to provide information on the evolutionary and ecological forces that structure community composition. Evidence for community-wide character displacement within sympatric populations of interacting species is widespread, and has been interpreted as evidence of interspecific competition. However, species’ traits are determined by a large number of factors, including their evolutionary history, as well as competition and the environment. Here, I illustrate how the expected distribution of traits varies with phylogenetic tree shape, and how deviation from simple phylogenetic expectations can offer new insights into species’ ecological histories. Using species lists from over 800 national parks in 107 countries, I compare the distribution of traits within regional carnivore communities against null phylogenetic expectation assuming a Brownian motion model of evolution in which lineages evolve independently in a manner analogous to a random walk.
Results/Conclusions
I demonstrate that the distribution of traits among species can be largely explained by their phylogenetic affinities. However, key ecological traits within regional carnivore communities are more evenly dispersed than phylogenetic expectations, providing strong evidence for competition. Either species are sorted into regional communities based upon their morphology, or ecological character displacement is common, and species traits evolve rapidly to minimize resource use overlap.
