title: Extensive behavioural divergence following colonisation of the freshwater environment in threespine sticklebacks.
abstract: Colonisation of novel environments means facing new ecological challenges often resulting in the evolution of striking divergence in phenotypes. However, little is known about behavioural divergence following colonisation, despite the predicted importance of the role of behavioural phenotype-environment associations in adaptive divergence. We studied the threespine stickleback (Gasterosteus aculeatus), a model system for postglacial colonisation of freshwater habitats largely differing in ecological conditions from the ones faced by the descendants of the marine ancestor. We found that common-environment reared freshwater juveniles were less social, more active and more aggressive than their marine counterparts. This behavioural divergence could represent the result of natural selection that acted on individuals following freshwater colonisation, with predation as a key selection agent. Alternatively, the behavioural profile of freshwater juveniles could represent the characteristics of individuals that preferentially invaded freshwater after the glacial retreat, drawn from the standing variation present in the marine population.
authors.affiliation: Département de Biologie & Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada.
authors.forename: Carole
authors.initials: C
authors.lastname: Di-Poi
authors.affiliation: Département de Biologie & Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada.
authors.forename: Jennyfer
authors.initials: J
authors.lastname: Lacasse
authors.affiliation: Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Rogers
authors.affiliation: Département de Biologie & Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada.
authors.forename: Nadia
authors.initials: N
authors.lastname: Aubin-Horth
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D017753:Ecosystem; D005618:Fresh Water; D016014:Linear Models; D023701:Smegmamorpha / Q000254:growth & development* / Q000502:physiology*