Invading predators can strongly affect populations of naïve prey due to the lack of evolved defenses. Many prey populations are therefore at risk of extinction due to overexploitation by exotic predators. Yet the strong selective effect of predation might drive evolution of imperiled prey toward more resistant forms, potentially allowing imperiled prey to persist. This evolutionary rescue, however, may be limited by heritable trait variation and the time frame of evolution. We evaluate the potential for evolutionary rescue in an imperiled prey using Gillespie eco-evolutionary models (GEMs). We focused on the roles of trait variance, carrying capacity, and the functional consequences of evolving traits in determining the increase in probability of persistence for prey populations.
Results/Conclusions
Using a standard predator-prey model solved with GEMs that characterize the evolution of prey body size, we show that 1) the requisite amount of heritable trait variation may exist in some populations, 2) rescue may be more likely for traits that show ecological pleiotropy in its effects on the species interactions, and 3) evolutionary rescue is most likely to play a role in systems with intermediate stability. Our findings suggest that evolutionary rescue is indeed possible, but from a probabilistic point of view, some populations may be only slightly more likely to persist given prey trait evolution.