Killer whale genomes reveal a complex history of recurrent admixture and vicariance

• Published in: Molecular Ecology
• Main Authors: Foote, Andrew, Martin, Michael, Louis, Marie, Pacheco, George, Robertson, Kelly, Sinding, Mikkel‐Holger, Amaral, Ana, Baird, Robin, Baker, Charles Scott, Ballance, Lisa, Barlow, Jay, Collins, Tim, Constantine, Rochelle, Dabin, Rochelle, Dalla Rosa, Luciano, Davison, Nicholas, Durban, John, Esteban, Ruth, Ferguson, Steven, Gerrodette, Tim, Guinet, Christophe, Hanson, M. Bradley, Hoggard, Wayne, Matthews, Cory, Samarra, Filipa, De Stephanis, Renaud, Tavares, Andrew, Tixier, Paul, Totterdell, John, Wade, Paul, Excoffier, Laurent, Gilbert, M. Thomas P., Martin, Jochen, Morin, Phillip
• Other Authors: Computational and Molecular Population Genetics (CMPG), Institute of Ecology and Evolution, University of Bern, NTNU University Museum Trondheim, Norwegian University of Science and Technology Trondheim (NTNU), Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology (NTNU), Department of Biology Copenhagen, Faculty of Science Copenhagen, University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Scottish Oceans Institute, University of St Andrews Scotland, Marine Mammal and Turtle Division (MMTD), Southwest Fisheries Science Center (SWFSC), NOAA National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)-NOAA National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA), American Museum of Natural History (AMNH), Cascadia Research Washington, USA, Department of Fisheries and Wildlife, Marine Mammal Institute Oregon, USA, Oregon State University (OSU), Wildlife Conservation Society (WCS), School of Biological Sciences Auckland, New Zealand, University of Auckland Auckland, Observatoire PELAGIS UMS 3462 (PELAGIS), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS)-Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Laboratório de Ecologia e Conservação da Megafauna Marinha Rio Grande, Brazil, Universidade Federal do Rio Grande do Sul (UFRGS), Animal Health and Veterinary Laboratories Agency, CIRCE (Conservation, Information and Research on Cetaceans), Fisheries & Oceans Canada Canada, Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), National Oceanic and Atmospheric Administration (NOAA), National Marine Fisheries Service Mississippi, USA, Southeast Fisheries Science Center USA
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: drift; admixture; genomics; population structure; secondary contact; [SDE]Environmental Sciences; Antarctic; Antarc*; Killer Whale; Killer whale
• Online Access: https://hal.archives-ouvertes.fr/hal-02263580; https://doi.org/10.1111/mec.15099

International audience Reconstruction of the demographic and evolutionary history of populations assuminga consensus tree‐like relationship can mask more complex scenarios, which areprevalent in nature. An emerging genomic toolset, which has been most comprehensivelyharnessed in the reconstruction of human evolutionary history, enablesmolecular ecologists to elucidate complex population histories. Killer whales havelimited extrinsic barriers to dispersal and have radiated globally, and are thereforea good candidate model for the application of such tools. Here, we analyse a globaldata set of killer whale genomes in a rare attempt to elucidate global populationstructure in a nonhuman species. We identify a pattern of genetic homogenisationat lower latitudes and the greatest differentiation at high latitudes, even betweencurrently sympatric lineages. The processes underlying the major axis of structureinclude high drift at the edge of species' range, likely associated with founder effectsand allelic surfing during postglacial range expansion. Divergence between Antarcticand non‐Antarctic lineages is further driven by ancestry segments with up to fourfoldolder coalescence time than the genome‐wide average; relicts of a previousvicariance during an earlier glacial cycle. Our study further underpins that episodicgene flow is ubiquitous in natural populations, and can occur across great distancesand after substantial periods of isolation between populations. Thus, understandingthe evolutionary history of a species requires comprehensive geographic samplingand genome‐wide data to sample the variation in ancestry within individuals.