[All-postdocs] Bioseminar (Carriage House) - Andrew Whitehead

[Ana Velez]

Woods Hole Oceanographic Institution
Biology Department Seminar

Thursday, November 6, 2025 - 12:00 pm
Carriage House

Andrew Whitehead
Chair - Professor, University of California, Davis

Evolution in the Anthropocene: Mechanisms of Rapid Repeated Adaptation to Extreme Pollution in Urban Killifish
A hallmark of biological systems is their ability to evolve and adapt to changing environmental conditions, but the key challenge in the anthropocene is that the pace and severity of environmental change may limit evolutionary solutions. Declining population size coupled with immediate threats to fitness may constrain the sources of genetic variation that enable evolutionary rescue; new mutations arise slowly, standing variation may be insufficient, habitat fragmentation may limit migration, and hybridization may be rare and deleterious. The genetic complexity of adaptive traits may also limit the likelihood of evolutionary rescue. We use Fundulus killifish as a model system to explore the genetic basis of evolutionary rescue in rapidly changing environments. Resistance to the normally lethal effects of extreme environmental pollution has rapidly and repeatedly evolved in Fundulus killifish populations resident in urban estuaries across North America. We have discovered that the mechanism of resistance repeatedly involves profound desensitization of the aryl hydrocarbon receptor (AHR) signaling pathway. Genome scans reveal a complex suite of genotypes that are important for fitness in urban estuaries, yet quantitative genetics studies show that resistance to at least one important toxicant is underpinned by few mutations of large effect. Some adaptive mutations appear to arise from standing genetic variation, yet others have arrived through introgression between sister species. Ongoing studies in killifish and other species including Pacific herring are further exploring the complexity of pollution adaptation, and the circumstances which limit adaptive outcomes.

Biology Seminar Web Page<https://www.whoi.edu/what-we-do/understand/departments-centers-labs/bio/bio-highlights-events/>

For questions, contact:

Ana Maria Velez
Biology Pre-Award Administrative Associate
Ph: 508-289-2334
[signature_1005462319]

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