Evolution of Extreme Pollution Tolerance in Killifish
Developing a deep understanding of how natural selection shapes genetic variation is a central goal of evolutionary biology. Because genome science is in its infancy, we still have a relatively rudimentary understanding of the connections between genotype and phenotype, and how they mediate the effects of selection.
For my postdoctoral work, I am studying the evolution of extreme pollution tolerance in Killifish (Fundulus heteroclitus). In the last half century, several populations of these fish have independently evolved extraordinary tolerance to some industrial pollutants (dioxin-like compounds, or DLCs). Tolerant populations thrive in habitats with concentrations of DLCs in excess of 3 orders of magnitude higher than the lethal concentration for fish from clean habitats.
We aim to uncover the genomic basis of this adaptation by whole genome resequencing of tolerant and sensitive populations from across F. heteroclitus’s range. We are modeling the distribution of genetic variation among populations in order to look for signatures of selection, and genetic variants associated with tolerance. Developing methods to make these kinds of connections is of critical importance, not just to improve our fundamental understanding of the evolutionary process, but because they can help inform approaches to conservation in a world of rapidly proliferating threats to earth’s biota.