Genetic structure of the world’s polar bear populations

Authors

  • D. Paetkau,

    Corresponding author
    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • S. C. Amstrup,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • E. W. Born,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • W. Calvert,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • A. E. Derocher,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • G. W. Garner,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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    • §§

      Sadly, Dr Garner died while this manuscript was being prepared.

  • F. Messier,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • I. Stirling,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • M. K. Taylor,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • Ø. Wiig,

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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  • C. Strobeck

    1. *Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada, †Biological Resource Division, USGS, 1011 E. Tudor Rd., Anchorage, AK 99503, USA, ‡Greenland Institute of Natural Resources c/o National Environmental Research Institute, Department of Arctic Environment, Tagensvej 135, 4th floor, DK-2200 Copenhagen, Denmark, §Canadian Wildlife Service, 5320–122 St., Edmonton, AB, T6H 3S5, Canada, ¶Norwegian Polar Institute, N-9296 Tromsø, Norway, **Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada, †† DRWED, Government of the Northwest Territories, PO Box 1870, Iqaluit, NT, X0 A 0H0, Canada,‡‡Zoological Museum, University of Oslo, Sarsgate 1, N-0562 Oslo, Norway
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D. Paetkau. Department of Zoology, University of Queensland, St. Lucia, Qld. 4072, Australia. Fax: + 61 7-3365 1655; E-mail:dpaetkau@zoology.uq.edu.au

Abstract

We studied genetic structure in polar bear (Ursus maritimus) populations by typing a sample of 473 individuals spanning the species distribution at 16 highly variable microsatellite loci. No genetic discontinuities were found that would be consistent with evolutionarily significant periods of isolation between groups. Direct comparison of movement data and genetic data from the Canadian Arctic revealed a highly significant correlation. Genetic data generally supported existing population (management unit) designations, although there were two cases where genetic data failed to differentiate between pairs of populations previously resolved by movement data. A sharp contrast was found between the minimal genetic structure observed among populations surrounding the polar basin and the presence of several marked genetic discontinuities in the Canadian Arctic. The discontinuities in the Canadian Arctic caused the appearance of four genetic clusters of polar bear populations. These clusters vary in total estimated population size from 100 to over 10 000, and the smallest may merit a relatively conservative management strategy in consideration of its apparent isolation. We suggest that the observed pattern of genetic discontinuities has developed in response to differences in the seasonal distribution and pattern of sea ice habitat and the effects of these differences on the distribution and abundance of seals.

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