Life history evolution facilitates trophic diversification

To what extent is biodiversity shaped by environmental conditions, and to what extent is it the result of self-organization? Both natural processes and structural features may contribute to promoting diversity. Here, we show that one such process, namely natural selection, and a structural feature, namely organismal life history, interact in a feedback mechanism that promotes the emergence of diversity. We illustrate how this mechanism operates using various models of ecological diversification driven by intraspecific resource competition, in which both a niche trait that determines resource use and a life history trait can evolve. We find that natural selection that acts on life history traits leads to increased competition, which, in the presence of ecological opportunity, facilitates niche diversification. As a consequence, the environmental conditions (e.g. productivity) for diversification are more restrictive in the absence of life history evolution than in its presence. Our findings indicate a strong influence of life history evolution on ecological processes that in turn shape the origin of biodiversity. Our results call for a better integration of life history evolution and ecological diversification in theoretical and empirical research.