"Eco-evolutionary feedbacks," the interplay between rapid contemporary evolution and ecological processes, are now recognized as the latest synthesis in ecology and evolutionary biology. Previous studies have mainly investigated eco-evolutionary feedbacks driven by interspecific interactions (e.g., predation). On the other hand, little is known about how eco-evolutionary processes interact with abiotic environmental forcing, although daily, seasonal, and inter-annual environmental fluctuations are a major driver of natural ecosystem dynamics. By using numerical simulations and transfer function analyses of mathematical models, we demonstrate how environmental forcing on top-down (i.e., predator mortality rate) and bottom-up (i.e., nutrient supply) processes affects eco-evolutionary dynamics in an otherwise stable predator-prey plankton microcosm.
Results/Conclusions
We found that "phase-locking" of predator density and the prey defense trait is possible in bottom-up forcing with intermediate frequencies. This occurs because of the time lag of prey evolution in response to environmental changes. In addition, by using the Geber method, we demonstrate that the ratio of the evolutionary to ecological contribution to the predator growth is maximized in bottom-up forcing with intermediate frequencies. The results provide experimentally testable predictions, and suggest that the interaction between environmental forcing, interspecific interactions (in this case, predation), and rapid evolution can create interestingly complicated eco-evolutionary dynamics in natural ecosystems.