title: Geographic and temporal dynamics of a global radiation and diversification in the killer whale.
abstract: Global climate change during the Late Pleistocene periodically encroached and then released habitat during the glacial cycles, causing range expansions and contractions in some species. These dynamics have played a major role in geographic radiations, diversification and speciation. We investigate these dynamics in the most widely distributed of marine mammals, the killer whale (Orcinus orca), using a global data set of over 450 samples. This marine top predator inhabits coastal and pelagic ecosystems ranging from the ice edge to the tropics, often exhibiting ecological, behavioural and morphological variation suggestive of local adaptation accompanied by reproductive isolation. Results suggest a rapid global radiation occurred over the last 350 000 years. Based on habitat models, we estimated there was only a 15% global contraction of core suitable habitat during the last glacial maximum, and the resources appeared to sustain a constant global effective female population size throughout the Late Pleistocene. Reconstruction of the ancestral phylogeography highlighted the high mobility of this species, identifying 22 strongly supported long-range dispersal events including interoceanic and interhemispheric movement. Despite this propensity for geographic dispersal, the increased sampling of this study uncovered very few potential examples of ancestral dispersal among ecotypes. Concordance of nuclear and mitochondrial data further confirms genetic cohesiveness, with little or no current gene flow among sympatric ecotypes. Taken as a whole, our data suggest that the glacial cycles influenced local populations in different ways, with no clear global pattern, but with secondary contact among lineages following long-range dispersal as a potential mechanism driving ecological diversification.
authors.affiliation: Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 8901 La Jolla Shores Dr., La Jolla, CA, 92037, USA.
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Morin
authors.affiliation: Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, 7600 Sand Point Way NE, Seattle, WA, 98115, USA.
authors.forename: Kim M
authors.initials: KM
authors.lastname: Parsons
authors.affiliation: Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 8901 La Jolla Shores Dr., La Jolla, CA, 92037, USA.
authors.forename: Frederick I
authors.initials: FI
authors.lastname: Archer
authors.affiliation: Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350, Copenhagen, Denmark.
authors.forename: María C
authors.initials: MC
authors.lastname: Ávila-Arcos
authors.affiliation: Vancouver Aquarium Marine Science Centre, 845 Avison Way, Vancouver, British Columbia, V6G 3E2, Canada.
authors.forename: Lance G
authors.initials: LG
authors.lastname: Barrett-Lennard
authors.affiliation: Laboratório de Ecologia e Conservação da Megafauna Marinha, Instituto de Oceanografia, Universidade Federal do Rio Grande, Av. Itália km. 8 s/n, Campus Carreiros, Rio Grande, RS, 96201-900, Brazil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Dalla Rosa
authors.affiliation: School of Biological Sciences, University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Duchêne
authors.affiliation: Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 8901 La Jolla Shores Dr., La Jolla, CA, 92037, USA.|Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, 7600 Sand Point Way NE, Seattle, WA, 98115, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Durban
authors.affiliation: Fisheries and Oceans Canada, Pacific Biological Station, 3190 Hammond Bay Rd, Nanaimo, British Columbia, Canada.
authors.forename: Graeme M
authors.initials: GM
authors.lastname: Ellis
authors.affiliation: Fisheries & Oceans Canada, 501 University Crescent, Winnipeg, Manitoba, R3T 2N6, Canada.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Ferguson
authors.affiliation: Fisheries and Oceans Canada, Pacific Biological Station, 3190 Hammond Bay Rd, Nanaimo, British Columbia, Canada.
authors.forename: John K
authors.initials: JK
authors.lastname: Ford
authors.affiliation: Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA 2725 Montlake Blvd E, Seattle, WA, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ford
authors.affiliation: GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel Düsternbrooker Weg 2, 24105, Kiel, Germany.
authors.forename: Cristina
authors.initials: C
authors.lastname: Garilao
authors.affiliation: Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350, Copenhagen, Denmark.|Trace and Environmental DNA laboratory, Department of Environment and Agriculture, Curtin University, Perth, Western Australia, 6845, Australia.
authors.forename: M Thomas P
authors.initials: MT
authors.lastname: Gilbert
authors.affiliation: Department of Biometry and Environmental System Analysis, Albert-Ludwigs-University of Freiburg, Tennenbacher Strasse 4, 79106, Freiburg, Germany.
authors.forename: Kristin
authors.initials: K
authors.lastname: Kaschner
authors.affiliation: North Gulf Oceanic Society, 3430 Main St. Ste. B1, Homer, AK, 99603, USA.
authors.forename: Craig O
authors.initials: CO
authors.lastname: Matkin
authors.affiliation: Assiniboine Park Zoo, 2595 Roblin Blvd, Winnipeg, Manitoba, R3P 2N7, Canada.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Petersen
authors.affiliation: Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 8901 La Jolla Shores Dr., La Jolla, CA, 92037, USA.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Robertson
authors.affiliation: Orca Research Trust, P.O. Box 402043, Tutukaka, Northland, 0153, New Zealand.
authors.forename: Ingrid N
authors.initials: IN
authors.lastname: Visser
authors.affiliation: Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, 7600 Sand Point Way NE, Seattle, WA, 98115, USA.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Wade
authors.affiliation: School of Biological Sciences, University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Simon Y W
authors.initials: SY
authors.lastname: Ho
authors.affiliation: Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Øster Voldgade 5-7, 1350, Copenhagen, Denmark.|Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36, Uppsala, Sweden.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Foote
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D002467:Cell Nucleus / Q000235:genetics; D057231:Climate Change; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D060146:Ecotype; D014644:Genetic Variation; D008962:Models, Theoretical; D008969:Molecular Sequence Data; D010802:Phylogeny; D058974:Phylogeography; D020641:Polymorphism, Single Nucleotide; D011157:Population Dynamics; D017422:Sequence Analysis, DNA; D050685:Whale, Killer / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial
keywords: cetacean; habitat models; mitogenomics; phylogeography; single nucleotide polymorphism; speciation