GELIFES Seminars - James Lewis

Link to seminar

James Lewis (Clemson University)

Two modes of polygenic trait adaptation in Lepidoptera

One of the primary goals of evolutionary genetics is to identify how organisms generate an optimal phenotype for their local environment. While this process is somewhat understood for Mendelian traits, much less is known about polygenic trait adaptation. Classic models of selection on quantitative or polygenic traits rely on soft selective sweeps from standing genetic variation. Here I consider two modes of polygenic trait adaptation as alternatives to this canonical model. First, I will show how a large-effect Mendelian adaptation can trigger a polygenic refinement process to optimize trait fitness in aposematic Heliconius butterflies. Second, I will present evidence of polygenic climate adaptation from both soft and hard selective sweeps in a widespread boreal moth species.

Biosketch:
James J. Lewis is a assistant professor in Genetics and Biochemistry at Clemson University. His research combines new functional tools with comparative population genomics to understand butterfly evolution and diversification. His work focuses heavily on mimicry-related wing color patterns as a model for adaptation.