Effects of phylogeny on coexistence in model communities

Abstract

A species traits influence the way in which it interacts with the environment. Thus, we expect traits to play a role in determining whether a given set of species coexists. Traits are, in turn, the outcome of an eco-evolutionary process summarized by a phylogenetic tree. Therefore, the phylogenetic tree associated with a set of species should encode information about the assembly properties of the community. Many studies have high-lighted the potentially complex ways in which phylogenetic information is translated into species ecological properties. However, much less emphasis has been placed on developing expectations for community properties under a particular hypothesis. In this work, we couple a simple model of trait evolution on a phylogenetic tree with local community dynamics governed by Lotka-Volterra equations. This allows us to derive properties of the community of coexisting species as a function of the number of traits, tree topology and the size of the species pool. Our results highlight how phylogenies and traits, in concert, affect the coexistence of a set of species. In this way, our work provides new baseline expectations for the ways in which phylogenetic information is reflected in the structure of and coexistence within local communities.