Description:

Speaker:

Mercedes Pascual, Professor, Department of Ecology and Evolution, University of Chicago

Title:

From eco-evolutionary assembly to network structure in a hyper-diverse host-pathogen system

Abstract:

How important are specific ecological interactions to the assembly of a diverse community of species? Can coexistence reflect instead neutral assembly, simply resulting from stochastic birth-death processes? What signatures of diversity patterns can help us distinguish among these two explanations? These long-standing questions from Ecology and its interplay with Evolution, can be similarly asked at a different level of organization for strain diversity within a pathogen population. I do so here for the malaria parasite P. falciparum in high-transmission regions. Strains compete for hosts in a frequency-dependent manner as hosts acquire specific immune memory against their variable surface antigens. Such competitive interactions result in negative frequency-dependent selection. I show that networks describing patterns of limiting similarity can help us identify the importance of this non-neutral process to coexistence.  Implications for pathogen persistence and responses to perturbations are discussed, as well as similar questions in another eco-evolutionary system.

Speaker Bio:

Mercedes Pascual is a Professor in the Department of Ecology and Evolution at the University of Chicago, and an external faculty of the Santa Fe Institute. Dr. Pascual is a theoretical ecologist interested in the population dynamics of infectious diseases, their response to changing environments and their interplay with pathogen diversity. She is also interested in the structure and dynamics of large interaction networks in ecology and epidemiology. Dr. Pascual received her Ph.D. degree from the joint program of the Woods Hole Oceanographic Institution and the Massachusetts Institute of Technology.  She was awarded a U.S. Department of Energy Alexander Hollaender Distinguished Postdoctoral Fellowship for studies at Princeton University, and a Centennial Fellowship in the area of Global and Complex Systems by the James S. McDonnell Foundation for her research at the University of Michigan.  She received the Robert H. MacArthur award from the Ecological Society of America. She is a fellow of the American Association for the Advancement of Science and a member of the American Academy of Arts and Sciences.

Webinar:

https://northwestern.zoom.us/j/95743710812
Passcode: NICO2022

About the Speaker Series:

Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems and data science. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.