Mechanisms of adaptation in rapidly changing environments.

Abstract

Adaptation in rapidly changing environments entails rapid shifts in phenotypic distributions or allele frequencies. This process hinges on the amount of genetic variation. Recent empirical work suggests that balancing selection can potentiate such adaptation, while theoretical studies highlight storage effects as plausible mechanisms underlying balanced polymorphism. Polygenic theory recently proposed that genome-wide shifts in allelic frequency distributions occur in response to sudden environmental changes. However, balanced polymorphism across numerous loci remains largely unexplored in polygenic models, despite being observed in nature. Bridging the gap between population genetics of balancing selection and polygenic models remains a critical challenge and is essential for uncovering mechanisms of adaptation in an increasingly variable world.