Complex network eco-evolutionary dynamics in a disturbed world

Nicolas LOEUILLE
Institut d’écologie et des sciences de l’environnement de Paris, Université Pierre et Marie Curie, nicolas.loeuille@upmc.fr

(Seminar in English)

The structure of ecological networks depends on both ecological (eg, community assembly, species population dynamics) and evolutionary dynamics (eg, evolution of specialization, defense and attack traits). Current global changes happen by definition on large scales and often have large impacts on various fitness components for a large number of species. As such, they act as potent selective pressures and may largely alter eco-evolutionary dynamics in ecological networks in ways that are yet difficult to predict. In this presentation, I propose to study this question based on size-structured foodwebs assembled through eco-evolutionary dynamics. I will particularly focus on two aspects of global changes: current changes in temperature (climate warming) and species harvesting (eg, fisheries). Concerning climate warming, results suggest that the evolution of species body size largely depends on variations of species attack rate with temperature. Variations in selected body sizes are larger at higher trophic levels while lower trophic levels exhibit higher levels of stabilizing selection. I will also discuss whether species coevolutionary dynamics is such complex networks help to maintain local species diversity under warming scenarios. Concerning species harvesting, I will investigate when species co-evolutionary dynamics lead to the extinction of some species in the network. I will then compare various harvesting scenarios, to investigate their consequences in terms of biodiversity loss and economic yield.