CAREER: Experimental evaluation of dispersal as a parasite avoidance strategy

Infectious diseases are widespread and reduce the health of their hosts. Hosts thus experience strong selection to avoid contracting an infection. This research will advance our understanding of the evolution of host strategies to avoid contact with parasites. Researchers for this project propose that hosts avoid their parasites through dispersal, the permanent movement between sites. This idea is important because it asserts that dispersal, a widespread behavior, drives rates of contact with parasites and evolves as part of hosts’ defense against infection. The proposed work will use experiments and field surveys to test parasites as drivers of dispersal evolution. The project will also create educational programs that engage community college transfer students in scientific research. The main idea of this work is that dispersal strategies evolve to be sensitive to infection risk. The researchers predict that hosts evolve to disperse early in an epidemic, when infection risk is low. The work will conduct experiments with a free-living nematode and its natural parasites. The researchers will track the evolution of dispersal strategies under parasite selection and identify the genetics and mechanisms of adaptation. They will also test if dispersal limits selection for other defenses. Finally, they will assess whether dispersal reduces infection risk in the wild, by observing the natural distribution of parasites. Community college students will contribute to this work through a research course at the local community college and a summer research experience for incoming transfer students. A bridge course will connect transfer students with research and provide academic support. Community college transfer students are more likely to identify as low-income and first-generation, and this work will promote their success in STEM while advancing fundamental knowledge of parasites as selective agents. 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.