We are excited to welcome two new lab members this fall.

Linyi Zhang is a new postdoc in the lab. She completed her PhD with Scott Egan at Rice. She is broadly interested in adaptation and speciation, and her past work focused on how divergent host use promotes reproductive isolation among sympatric populations of gall wasps. She is currently combing genome-wide association mapping and whole genome sequencing of natural butterfly populations to determine the causes and consequences of (potentially) fluctuating selection on polygenic traits.

Brian Kissmer began his PhD in the lab this fall. He is interested how the nature and repeatability of adaptation depends on the degree to which a population is maladapted to a novel environment. He is initially addressing this question using experimental evolution in Callosobruchus maculatus seed beetles.

Theory indicates that non-linear selection (e.g., stabilizing, disruptive, or correlational selection) on traits can result in epsitasis for fitness even when alleles have additive affects on traits. In a paper recently published in Nature Ecology and Evolution, we demonstrate this in a field experiment with Timema stick insects. In particular, we show that color is determined mostly by alleles with additive effects, but that selection for crypsis favors color combinations resulting in epistasis for fitness. This in turn results in a rugged fitness landscape with respect to the color loci.

See our blog post for more thoughts and background on the paper.