COSAM News Articles 2023 February Auburn evolutionary ecologist explores the impact of environmental changes on species with $1.6 million NSF award # Auburn evolutionary ecologist explores the impact of environmental changes on species with$1.6 million NSF award

Published: 03/14/2023

How do changes in our environment such as weather and temperature impact how species coexist?

Ronald Bassar, an assistant professor in the Department of Biological Sciences, is the recipient of a \$1,616,701 award from the National Science Foundation, Division of Environmental Biology. The evolution of fluctuation-dependent species coexistence examines the role our changing environment plays using two species of fish, Trinidadian guppies and Hart’s Killifish.

“The traditional model of species coexistence relies on the environment being a constant factor,” Bassar said. “This is known as character displacement and is how most researchers have looked at this for decades. But what if the environment is not a constant factor and it fluctuates?”

Variation in environmental conditions can be regular, periodic changes fluctuations or irregular and random. Variation in conditions can favor coexistence, and hence diversity, when different species respond to the variation in contrasting ways. Changing climate can significantly increase the wet or dry seasons, which then can impact growth and breeding.

His research through the Guppy Project dives into three different areas: math models, streams and systems to further analyze their coexistence.

First, Bassar uses mathematical theory to model the data. Once he has a numerical viewpoint, he goes into the field.

“We rely on artificial streams to mock wet or dry seasons in controlled environments,” he explained. “This gives us the ability to change the environment and study the results.”

Finally, he uses a long-term study of Trinidadian guppies to understand how these communities of fish evolve.

“We travel monthly to Trinidad to mark fish for identification, measure their life span, take scale samples and compare traits,” Bassar shared. “We are seeking to build a genetic pedigree that unlocks a genetic map of forebears.”

As an evolutionary ecologist, his research in the Bassar Lab focuses on natural selection in natural populations. He studies similar species and how they coexist in their habitats. He is seeking to ask questions not using traditional models to provide insight with the array of changing environmental factors the world is facing. His work will provide insight and aim to help us understand these fluctuations.

Bassar earned his doctorate degree from the University of California, Riverside and his bachelor's degree from Prescott College. He was a postdoctoral scholar at the University of Massachusetts Amherst and the University of Oxford in the United Kingdom. Before joining Auburn University, Bassar was an assistant professor at Williams College.