title: How competition affects evolutionary rescue.
abstract: Populations facing novel environments can persist by adapting. In nature, the ability to adapt and persist will depend on interactions between coexisting individuals. Here we use an adaptive dynamic model to assess how the potential for evolutionary rescue is affected by intra- and interspecific competition. Intraspecific competition (negative density-dependence) lowers abundance, which decreases the supply rate of beneficial mutations, hindering evolutionary rescue. On the other hand, interspecific competition can aid evolutionary rescue when it speeds adaptation by increasing the strength of selection. Our results clarify this point and give an additional requirement: competition must increase selection pressure enough to overcome the negative effect of reduced abundance. We therefore expect evolutionary rescue to be most likely in communities which facilitate rapid niche displacement. Our model, which aligns to previous quantitative and population genetic models in the absence of competition, provides a first analysis of when competitors should help or hinder evolutionary rescue.
authors.affiliation: Redpath Museum, McGill University, 859 Sherbrooke Street West, Montreal, Quebec, Canada. matthew.osmond@mail.mcgill.ca
authors.forename: Matthew Miles
authors.initials: MM
authors.lastname: Osmond
authors.forename: Claire
authors.initials: C
authors.lastname: de Mazancourt
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D005075:Biological Evolution; D049628:Body Size; D003163:Competitive Behavior / Q000502:physiology*; D003198:Computer Simulation; D053476:Extinction, Biological; D046369:Finches / Q000502:physiology; D005828:Genetics, Population / Q000379:methods; D008954:Models, Biological; D009154:Mutation; D010641:Phenotype; D011156:Population Density; D011157:Population Dynamics; D012307:Risk Factors; D012641:Selection, Genetic