Speaker
Description
Global environmental change threatens both the persistence of species and the stability of ecosystems, often demanding rapid evolutionary adaptation. While traditional perspectives have focused on evolutionary change within threatened species, this approach overlooks the crucial influence of evolutionary responses in interacting species. The likelihood and consequences of such indirect evolutionary effects remain poorly understood. In this talk, I discuss the concept of Indirect Evolutionary Facilitation (IEF), a process in which non-evolving populations benefit from the evolutionary adaptations of their interaction partners in response to environmental disturbances. Using a planktonic predator-prey system consisting of six strains of the green alga Chlamydomonas reinhardtii and the rotifer Brachionus calyciflorus, we combine experimental and modeling approaches to investigate how prey evolution affects predator populations under microplastic pollution as a disturbance. Our findings reveal that environmental disturbances can suppress predator growth by limiting ingestion rates, which in turn can drive evolutionary shifts in prey towards increased edibility. Depending on the degree of prey trait variation (as a proxy for evolutionary potential) and the intensity of disturbance, we identify two key processes: Indirect Evolutionary Facilitation, where prey evolution enhances predator density, and Indirect Evolutionary Rescue, where prey evolution prevents predator extinction. These results underscore the pivotal role of indirect eco-evolutionary processes in shaping ecological dynamics. Understanding how trait variation influences ecosystem responses to environmental stressors is essential for predicting species persistence in a rapidly changing world.