title: Soft Selective Sweeps in Evolutionary Rescue.
abstract: Evolutionary rescue occurs when a population that is declining in size because of an environmental change is rescued from extinction by genetic adaptation. Evolutionary rescue is an important phenomenon at the intersection of ecology and population genetics, and the study of evolutionary rescue is critical to understanding processes ranging from species conservation to the evolution of drug and pesticide resistance. While most population-genetic models of evolutionary rescue focus on estimating the probability of rescue, we focus on whether one or more adaptive lineages contribute to evolutionary rescue. We find that when evolutionary rescue is likely, it is often driven by soft selective sweeps where multiple adaptive mutations spread through the population simultaneously. We give full analytic results for the probability of evolutionary rescue and the probability that evolutionary rescue occurs via soft selective sweeps. We expect that these results will find utility in understanding the genetic signatures associated with various evolutionary rescue scenarios in large populations, such as the evolution of drug resistance in viral, bacterial, or eukaryotic pathogens.
authors.affiliation: Department of Biology, Stanford University, California 94305 bawilson@alumni.stanford.edu.
authors.forename: Benjamin A
authors.identifier: 0000-0002-3992-2876
authors.initials: BA
authors.lastname: Wilson
authors.affiliation: Department of Biology, San Francisco State University, California 94132.
authors.forename: Pleuni S
authors.identifier: 0000-0001-8704-6578
authors.initials: PS
authors.lastname: Pennings
authors.affiliation: Department of Biology, Stanford University, California 94305.
authors.forename: Dmitri A
authors.identifier: 0000-0002-3664-9130
authors.initials: DA
authors.lastname: Petrov
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D019143:Evolution, Molecular; D056084:Genetic Fitness; D008957:Models, Genetic; D009154:Mutation; D012641:Selection, Genetic
keywords: adaptation; extinction; genetic diversity; population density; resistance evolution