title: Stress-induced mutagenesis and complex adaptation.
abstract: Because mutations are mostly deleterious, mutation rates should be reduced by natural selection. However, mutations also provide the raw material for adaptation. Therefore, evolutionary theory suggests that the mutation rate must balance between adaptability-the ability to adapt-and adaptedness-the ability to remain adapted. We model an asexual population crossing a fitness valley and analyse the rate of complex adaptation with and without stress-induced mutagenesis (SIM)-the increase of mutation rates in response to stress or maladaptation. We show that SIM increases the rate of complex adaptation without reducing the population mean fitness, thus breaking the evolutionary trade-off between adaptability and adaptedness. Our theoretical results support the hypothesis that SIM promotes adaptation and provide quantitative predictions of the rate of complex adaptation with different mutational strategies.
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Yoav
authors.identifier: http://orcid.org/0000-0002-9653-4458
authors.initials: Y
authors.lastname: Ram
authors.affiliation: Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel Aviv, Israel lilach.hadany@gmail.com.
authors.forename: Lilach
authors.initials: L
authors.lastname: Hadany
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D056084:Genetic Fitness; D008957:Models, Genetic; D016296:Mutagenesis / Q000502:physiology*; D059645:Mutation Rate; D013312:Stress, Physiological / Q000235:genetics*
keywords: adaptive peak shifts; evolvability; mathematical model; mutation rate; stress-induced variation; trade-off