BEE: Evolutionary rescue in response to infectious disease: when will populations be rescued from pathogens?

Purdue University, West Lafayette IN

Investigators

Abstract

Many species and populations are threatened by rapidly changing environmental conditions, including the introduction of novel infectious diseases. As outbreaks of infectious diseases get more common and severe, understanding how populations can survive when faced with deadly pathogens is increasingly important. Evolutionary rescue, which happens when a population evolves to survive environmental change that would otherwise cause extinction, may provide a way for some populations to persist in a changing world. Most studies of evolutionary rescue have focused on non-living drivers of environmental change (e.g., pollution, extreme temperatures), with little known regarding the role that evolutionary rescue plays in response to disease. In this project researchers will study a species of water flea (Daphnia) whose populations' challenges due to both non-living environmental change and pathogen infection are well known. By identifying the conditions that allow a population of water fleas to experience evolutionary rescue in response to disease the researchers will gain knowledge that will help in management and control of infectious diseases in many other systems. This project will also train graduate and undergraduate students with a focus on those from underrepresented groups. Additionally, the investigators will develop interactive classroom activities for undergraduate biology courses and organize a workshop to train early-career scientists in methods of modeling infectious disease. The investigators will combine experimental manipulations, genotyping, transcriptomics, and modeling to study evolutionary rescue in response to the introduction of a pathogen. They will address the following complementary questions: (1) How does evolutionary rescue in response to a pathogen differ from evolutionary rescue in response to an abiotic stressor? (2) Can abiotic stress facilitate evolutionary rescue from disease? and (3) What are the effects of community diversity on a population's evolutionary response to a pathogen? The proposed work will address these questions by utilizing a highly tractable Daphnia-pathogen system to perform experimental manipulations of populations at multiple scales (laboratory to outdoor mesocosm) while tracking demographic and genetic changes through time. Experimental manipulations will be paired with modeling efforts to identify mechanisms and generalize the results to additional host-pathogen systems. This approach will provide novel insight into how populations can respond and recover from outbreaks of infectious disease. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.