prestigious NSF grant to further research into ecological drivers of eye and brain size evolution in fish

The University of Texas at Arlington News Releases



Shannon Beston, a third-year Ph.D. student in biology at UTA

Shannon Beston, a third-year Ph.D. student in biology at the University of Texas at Arlington, was selected to receive funds from the National Science Foundation’s Doctoral Dissertation Improvement Grants program to further her research into how brains and eyes evolved in response to predation.
The award will fund Beston’s dissertation project, titled “The evolution of complexity: tests of the ecological drivers of eye size and brain size evolution in nature”, which examines the evolution of complex traits in natural populations. Specifically, the work addresses how eyes and brains among populations of killifish, Rivulus hartii, found in the waters of the Caribbean off the island of Trinidad.
“Understanding how complex traits have evolved is a long-standing goal in evolutionary biology and the complex structure of the eye is frequently presented as an example of evolution that challenges the understanding of evolution by natural selection,” Beston said.
While eye size varies extensively across species, there are very few studies that have evaluated how eyes evolve within a single species, she explained. Increases in eye size are associated with improved vision. As a result, shifts in eye size are likely connected, and potentially driven, by a variety of ecological factors, such as foraging, avoiding predators, and identifying mates. Rivulus are found in fish communities on the island that vary in predation intensity, ranging from sites where they are preyed upon by large fish to sites where they are the only species present.
“My most recent work, and the basis of the research I have proposed in the DDIG, has shown that increases in predation are associated with genetically based decreases in eye size,” Beston said. “This work provides a clear link between an ecological driver of eye size evolution, but it does not establish causation. We still do not ...

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