CAREER: Integrating Field Experiments, Mathematical Models, and Inclusive Education To Understand Ecological Consequences of Variation in Host-Pathogen Interactions

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).

In nature, both disease-causing pathogens and their animal hosts exhibit tremendous variation. For example, hosts vary in their ability to resist disease, their history of disease exposure and immunity, and their general physical condition, while pathogens vary in their abilities to infect hosts, persist in the environment, and spread over long distances.

This variation has important consequences for how diseases spread in populations, and for the evolution of both pathogen and host species. This project will investigate sources and consequences of variation in a virus that infects the Gulf fritillary butterfly (Agraulis vanillae). Field and lab experiments will be used to investigate three main sources of variation: pathogen genetic variation, host variation, and environmental variation due to human impacts such as urbanization and a warming climate.

This CAREER project will be strengthened by education efforts to bring new viewpoints into ecology through support of inclusive quantitative biology research and teaching. Despite a widely recognized national need for graduates with the quantitative skills sought by industry, many undergraduate students struggle with quantitative content and leave science degree programs in unacceptably high numbers.

The educational components of this work are founded in biology education research on effective strategies for retaining underrepresented students in science, including individualized mentoring through research experiences, course-based programs, and building a sense of belonging in science.

This project is well-poised to take advantage of recent advances in theory and computational tools for studying host and pathogen variation, in order to understand how genetic and ecological sources of intraspecific variation affect host-pathogen population dynamics. Working in an insect-baculovirus system, this research will produce the following outcomes: 1.

Use field and lab experiments to determine how intraspecific variation in pathogen life history traits affects outcomes of competition between pathogen strains and long-term population dynamics of hosts and pathogens; 2. Quantify how host-pathogen interactions are affected by continuous variation in host susceptibility to infection and key environmental sources of variation; 3.Apply the above findings to larger scales and long-term population consequences using mathematical models that incorporate the above sources of variation into distributions of host and pathogen traits.

The integrated educational component of this CAREER project will produce the following core outcomes: 1. Establish the foundation for a long-term collaborative program with pairs of University of San Diego and University of Puerto Rico undergraduates working together on projects across both sites; 2. Develop a program for sustained undergraduate-student-led bilingual outreach in our local San Diego community, working with local partners and schools; 3.

Create, pilot, and refine a course-based program to recruit and support underrepresented students in quantitative undergraduate biology research at the University of San Diego.

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.