title: Ecological opportunities and specializations shaped genetic divergence in a highly mobile marine top predator.
abstract: Environmental conditions can shape genetic and morphological divergence. Release of new habitats during historical environmental changes was a major driver of evolutionary diversification. Here, forces shaping population structure and ecotype differentiation ('pelagic' and 'coastal') of bottlenose dolphins in the North-east Atlantic were investigated using complementary evolutionary and ecological approaches. Inference of population demographic history using approximate Bayesian computation indicated that coastal populations were likely founded by the Atlantic pelagic population after the Last Glacial Maxima probably as a result of newly available coastal ecological niches. Pelagic dolphins from the Atlantic and the Mediterranean Sea likely diverged during a period of high productivity in the Mediterranean Sea. Genetic differentiation between coastal and pelagic ecotypes may be maintained by niche specializations, as indicated by stable isotope and stomach content analyses, and social behaviour. The two ecotypes were only weakly morphologically segregated in contrast to other parts of the World Ocean. This may be linked to weak contrasts between coastal and pelagic habitats and/or a relatively recent divergence. We suggest that ecological opportunity to specialize is a major driver of genetic and morphological divergence. Combining genetic, ecological and morphological approaches is essential to understanding the population structure of mobile and cryptic species.
authors.affiliation: Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-Université de La Rochelle, La Rochelle, France Littoral Environnement et Sociétés, UMR 7266 CNRS-Université de La Rochelle, La Rochelle, France Groupe d'Etude des Cétacés du Cotentin, Cherbourg-Octeville, France marielouis17@hotmail.com.
authors.forename: Marie
authors.initials: M
authors.lastname: Louis
authors.affiliation: Marine Evolution and Conservation, Centre of Evolutionary and Ecological Studies, University of Groningen, Groningen, The Netherlands Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Fontaine
authors.affiliation: Observatoire PELAGIS, UMS 3462 CNRS-Université La Rochelle, La Rochelle, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Spitz
authors.affiliation: Littoral Environnement et Sociétés, UMR 7266 CNRS-Université de La Rochelle, La Rochelle, France Observatoire PELAGIS, UMS 3462 CNRS-Université La Rochelle, La Rochelle, France.
authors.forename: Erika
authors.initials: E
authors.lastname: Schlund
authors.affiliation: Observatoire PELAGIS, UMS 3462 CNRS-Université La Rochelle, La Rochelle, France.
authors.forename: Willy
authors.initials: W
authors.lastname: Dabin
authors.affiliation: Institute of Zoology, Zoological Society of London, London, UK.
authors.forename: Rob
authors.initials: R
authors.lastname: Deaville
authors.affiliation: Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-Université de La Rochelle, La Rochelle, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Caurant
authors.affiliation: Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-Université de La Rochelle, La Rochelle, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Cherel
authors.affiliation: Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-Université de La Rochelle, La Rochelle, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Guinet
authors.affiliation: Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-Université de La Rochelle, La Rochelle, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Simon-Bouhet
mesh_terms: D063147:Animal Distribution; D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000033:anatomy & histology* / Q000235:genetics / Q000502:physiology*; D004272:DNA, Mitochondrial / Q000235:genetics; D004032:Diet; D017753:Ecosystem; D005060:Europe; D014644:Genetic Variation; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial
keywords: bottlenose dolphins; demographic history; ecological niches; morphology; population genetics