Williams-Led Research Team Awarded $1.6M Grant to Study the Impact of Ecological and Evolutionary Changes on Species Coexistence

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WILLIAMSTOWN, Mass., July 14, 2021—Ron Bassar, assistant professor of biology at Williams College, has been awarded a prestigious grant from the National Science Foundation (NSF). The three-year, $1.6 million dollar grant will support research aimed at understanding how temporal variation in ecological and evolutionary processes allow similar species to coexist.

The project, titled “The Evolution of Fluctuation-dependent Species Coexistence,” integrates theoretical and empirical research in four experimental communities of Trinidadian guppies and killifish on the Caribbean island of Trinidad.

Image of Ron Bassar
Ron Bassar, assistant professor of biology at Williams College

“Understanding the processes that allow similar species to coexist has been a longstanding question in ecology and evolution,” Bassar said. “It is important because diversity is a defining characteristic of natural ecosystems. Traditional explanations for coexistence have focused on static differences between species. This research will be among the first to explore the possibility that differences in species responses to intra-annual environmental variation can allow species to coexist.”

This NSF-supported project is in collaboration with professors David Reznick (University of California, Riverside), Joe Travis (Florida State University), and Tim Coulson (University of Oxford). In collaboration with Bassar, the researchers run The Guppy Project, a long-term experimental study of community evolution in replicated streams of Trinidad’s Northern Range Mountains.

For the past 13 years, this group of researchers has been studying how evolution unfolds in real time and how this evolution influences the ecology of the streams. The majority of the research on the project has focused on short-term ecological and evolutionary change. Now with long-term monthly data on the populations of guppies and killifish the researchers are moving to address questions that require longer term data. Importantly, the overwhelming majority of long-term studies of species coexistence are with plants and are from the Northern Hemisphere. This research will be one of the first to address such questions in animals from tropical regions.

Another primary goal of the project is to provide research opportunities and training for recent college graduates. The project engages 38 Young Research Scientists each year to participate in the work in Trinidad. This diverse group of researchers are comprised of early-stage trainees from around the globe. Researchers participate in the monthly census of guppies and killifish and assist with other targeted projects run by postdoctoral scholars and graduate students in artificial and natural streams.

Williams College students have the opportunity to participate while at Williams through the college’s Summer Science Program and honors projects, which are funded by a supplementary grant awarded to Bassar by the NSF’s Research Experiences for Undergraduates program.

Bassar joined the faculty at Williams College in 2017. His area of expertise is evolutionary ecology and population biology. He teaches courses in ecology and evolution, and his research has been published in The Proceedings of the National Academy of Sciences, Ecology Letters, Global Change Biology, The American Naturalist, Ecology, and Evolution, among others. He has served as an associate editor for the Journal of Animal Ecology since 2015. He received his B.A. from Prescott College in 2001, his Ph.D. from the University of California in 2011, and did his postdoctoral research at the University of Oxford.


Founded in 1793, Williams College is the second-oldest institution of higher learning in Massachusetts. The college’s approximately 2,000 undergraduate students are taught by a faculty noted for the quality of their teaching and research, and the achievement of academic goals includes active participation of students with faculty in their research. The college is also home to roughly 100 master’s students enrolled in its renowned graduate programs in Development Economics and the History of Art (the latter offered in collaboration with the Clark Art Institute). Students’ educational experience is enriched by the residential campus environment in Williamstown, Mass., which provides a host of opportunities for interaction with one another and with faculty beyond the classroom. Admission decisions on U.S. applicants are made regardless of a student’s financial ability, and the college provides grants and other assistance to meet the demonstrated needs of all who are admitted.






Published July 14, 2021