Speaker
Description
Across the last decade, emergent pathogens have been identified as a common threat to the conservation of charismatic species. Outbreaks of Bd fungus, devil facial tumor disease, and abalone withering syndrome have contributed to considerable population declines of amphibians, Tasmanian devils, and abalone, respectively. In these same populations, there might be evolution of disease resistance and tolerance that can promote evolutionary rescue. However, it is unclear under what general conditions evolutionary rescue might occur in host-pathogen systems. Here, We use a population genetics model to describe evolutionary rescue in host-pathogen systems. We test our model across different dimensions of disease ecology (transmission, compartment structure) and evolution (disease tolerance/resistance/clearance and evolution cost/benefit). We find that evolutionary rescue is more likely to occur in host-pathogen systems when hosts develop strong tolerance (decreased mortality when infected) or clearance (increased speed of recovery). While evolutionary rescue in host-pathogen systems is possible, we also find that evolution of weak or costly disease-robustness can also lead to increased extinction risk. The combined results of our work help conservation managers in identifying populations which are more likely to undergo evolutionary rescue and suggest that conservation supporting population persistence can help promote evolutionary rescue.