| Ancient Hybridization and an Irish Origin for the Modern Polar Bear Matriline. | |
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MedLine Citation:
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PMID: 21737280 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
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BACKGROUND: Polar bears (Ursus maritimus) are among those species most susceptible to the rapidly changing arctic climate, and their survival is of global concern. Despite this, little is known about polar bear species history. Future conservation strategies would significantly benefit from an understanding of basic evolutionary information, such as the timing and conditions of their initial divergence from brown bears (U. arctos) or their response to previous environmental change. RESULTS: We used a spatially explicit phylogeographic model to estimate the dynamics of 242 brown bear and polar bear matrilines sampled throughout the last 120,000 years and across their present and past geographic ranges. Our results show that the present distribution of these matrilines was shaped by a combination of regional stability and rapid, long-distance dispersal from ice-age refugia. In addition, hybridization between polar bears and brown bears may have occurred multiple times throughout the Late Pleistocene. CONCLUSIONS: The reconstructed matrilineal history of brown and polar bears has two striking features. First, it is punctuated by dramatic and discrete climate-driven dispersal events. Second, opportunistic mating between these two species as their ranges overlapped has left a strong genetic imprint. In particular, a likely genetic exchange with extinct Irish brown bears forms the origin of the modern polar bear matriline. This suggests that interspecific hybridization not only may be more common than previously considered but may be a mechanism by which species deal with marginal habitats during periods of environmental deterioration. |
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Authors:
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Ceiridwen J Edwards; Marc A Suchard; Philippe Lemey; John J Welch; Ian Barnes; Tara L Fulton; Ross Barnett; Tamsin C O'Connell; Peter Coxon; Nigel Monaghan; Cristina E Valdiosera; Eline D Lorenzen; Eske Willerslev; Gennady F Baryshnikov; Andrew Rambaut; Mark G Thomas; Daniel G Bradley; Beth Shapiro |
Publication Detail:
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Type: JOURNAL ARTICLE Date: 2011-7-5 |
Journal Detail:
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Title: Current biology : CB Volume: - ISSN: 1879-0445 ISO Abbreviation: - Publication Date: 2011 Jul |
Date Detail:
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Created Date: 2011-7-8 Completed Date: - Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 9107782 Medline TA: Curr Biol Country: - |
Other Details:
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Languages: ENG Pagination: - Citation Subset: - |
Copyright Information:
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Copyright © 2011 Elsevier Ltd. All rights reserved. |
Affiliation:
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Smurfit Institute of Genetics, Trinity College, University of Dublin, Dublin, Ireland. |
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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