Meeting Abstract

73.4  Tuesday, Jan. 6 08:45  Population genomics of rapid adaptation in Fundulus heteroclitus exposed to power station thermal effluents DAYAN, D I*; CRAWFORD, D L; OLEKSIAK, M F; University of Miami – Rosenstiel School of Marine and Atmospheric Science; University of Miami – Rosenstiel School of Marine and Atmospheric Science; University of Miami – Rosenstiel School of Marine and Atmospheric Science ddayan@rsmas.miami.edu

Temperature is one of the most important environmental parameters affecting an organism’s physiology, yet our understanding of evolutionary adaptation to rapidly changing environmental temperature is still incomplete. This study utilizes genotyping-by-sequencing derived genetic markers to examine genetic structure and adaptation among natural fish populations exposed to thermal effluents near power generating stations. Thermal effluents impact nearby estuaries and can raise mean water temperature by 1-3°C. Using a combination of outlier scan and population genetic structure clustering approaches, this study reveals substantial population structure among exposed and unexposed populations of the estuarine fish, Fundulus heteroclitus, that is most parsimoniously explained by evolution by natural selection. Replicate populations across different thermal effluents demonstrate both unique and shared adaptive responses. Further analysis provides insight into whether selection has acted on de novo mutation or the standing genetic variation among the populations recently adapted to increased temperature.