University of Lausanne
The evolution of inter-species interactions under limited dispersal
Laurent Lehmann, Charles Mullon
Understanding selection on traits that influence multi-species community dynamics in metapopulations is a long-standing problem in ecology and evolution. When dispersal is limited, eco-evolutionary stochastic dynamics are generally too complicated to make mathematically tractable inferences about natural selection on traits that influence local interactions within and between species. Here, we propose an approximate expression for the selection gradient on such a trait, which allows for the tractable search of singular and convergence stable trait values and hence for the study of community evolution under limited dispersal. Our approximation treats ecological dynamics as deterministic but takes into account the kin selection effects that arise from demographic stochasticity. We show that selection on a trait depends on the effects of the trait on the local population dynamics of all interacting species, weighted by relatedness coefficients, and how these effects feedback on future generations determines multi-species community coevolution. We use our approximation to study the co-evolution of two species-specific traits that mediate interactions between two species. We find that when interacting is optional, inter-species interactions only evolve when both species are dispersal limited. In particular, we show that limited dispersal and local competition between species favour the evolution of spiteful behaviours among individuals of different species.
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