Towards an Integrative View of Adaptation: Bridging Population and Quantitative Genetics
Coordinators: Alison Etheridge, Kavita Jain, Christian Schlötterer, and Naomi Wray
The study of adaptive evolution in molecular population genetics and quantitative genetics have remained rather isolated disciplines despite the shared research theme. While quantitative genetics describes adaptation of quantitative traits as a collective effect due to small shifts in the allele frequencies of a large number of underlying genetic loci (polygenic adaptation), molecular population genetics has focused on adaptation due to a small number of favorable loci in which the allele frequencies sweep to fixation. The connection between these two areas became possible when molecular markers were introduced. Since then Quantitative Trait Locus (QTL) mapping and, more recently, Genome-Wide Association Studies (GWAS) developed into powerful approaches to link phenotypes of interest with their genetic basis. Furthermore, stochastic models of evolution that borrow techniques from statistical physics provided a link between the bottom-up and top- down approaches in understanding adaptive dynamics. As a result, it is now becoming increasingly clear that both “sweeps” and “small shifts” are rather the endpoints of a scale than exclusive alternatives. This program will bring together theoreticians and empiricists to develop the basis for a unified framework of adaptive genetic architectures. The new framework will integrate molecular population genetics and quantitative genetics, addressing three main questions: 1. What are the different adaptive scenarios that need to be distinguished and what are their defining characteristics? 2. What are the key factors that determine these scenarios? 3. How can we develop powerful statistical tests to detect polygenic adaptation from empirical data?