Insights into bear evolution from a Pleistocene polar bear genome
The polar bear (Ursus maritimus) has become a symbol of the threat to biodiversity from climate change. Understanding polar bear evolutionary history may provide insights into apex carnivore responses and prospects during periods of extreme environmental perturbations. In recent years, genomic studi...
Published in: | Proceedings of the National Academy of Sciences |
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Online Access: | http://hdl.handle.net/10852/98172 https://doi.org/10.1073/pnas.2200016119 |
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ftoslouniv:oai:www.duo.uio.no:10852/98172 2023-05-15T14:18:08+02:00 Insights into bear evolution from a Pleistocene polar bear genome ENEngelskEnglishInsights into bear evolution from a Pleistocene polar bear genome Lan, Tianying Leppälä, Kalle Tomlin, Crystal Talbot, Sandra L Sage, George K. Farley, Sean Shideler, Richard T. Bachmann, Lutz Wiig, Øystein Albert, Victor A Salojärvi, Jarkko Mailund, Thomas Drautz-Moses, Daniela I. Herrera-Estrella, Luis Lindqvist, Charlotte 2022-12-11T14:25:08Z http://hdl.handle.net/10852/98172 https://doi.org/10.1073/pnas.2200016119 EN eng The National Academy of Sciences Lan, Tianying Leppälä, Kalle Tomlin, Crystal Talbot, Sandra L Sage, George K. Farley, Sean Shideler, Richard T. Bachmann, Lutz Wiig, Øystein Albert, Victor A Salojärvi, Jarkko Mailund, Thomas Drautz-Moses, Daniela I. Herrera-Estrella, Luis Lindqvist, Charlotte . Insights into bear evolution from a Pleistocene polar bear genome. Proceedings of the National Academy of Sciences of the United States of America. 2022, 119 http://hdl.handle.net/10852/98172 2091585 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Proceedings of the National Academy of Sciences of the United States of America&rft.volume=119&rft.spage=&rft.date=2022 Proceedings of the National Academy of Sciences of the United States of America 119 24 https://doi.org/10.1073/pnas.2200016119 Attribution-NonCommercial-NoDerivatives 4.0 International https://creativecommons.org/licenses/by-nc-nd/4.0/ CC-BY-NC-ND 0027-8424 Journal article Tidsskriftartikkel Peer reviewed PublishedVersion 2022 ftoslouniv https://doi.org/10.1073/pnas.2200016119 2022-12-14T23:36:16Z The polar bear (Ursus maritimus) has become a symbol of the threat to biodiversity from climate change. Understanding polar bear evolutionary history may provide insights into apex carnivore responses and prospects during periods of extreme environmental perturbations. In recent years, genomic studies have examined bear speciation and population history, including evidence for ancient admixture between polar bears and brown bears (Ursus arctos). Here, we extend our earlier studies of a 130,000- to 115,000-y-old polar bear from the Svalbard Archipelago using a 10× coverage genome sequence and 10 new genomes of polar and brown bears from contemporary zones of overlap in northern Alaska. We demonstrate a dramatic decline in effective population size for this ancient polar bear’s lineage, followed by a modest increase just before its demise. A slightly higher genetic diversity in the ancient polar bear suggests a severe genetic erosion over a prolonged bottleneck in modern polar bears. Statistical fitting of data to alternative admixture graph scenarios favors at least one ancient introgression event from brown bears into the ancestor of polar bears, possibly dating back over 150,000 y. Gene flow was likely bidirectional, but allelic transfer from brown into polar bear is the strongest detected signal, which contrasts with other published work. These findings may have implications for our understanding of climate change impacts: Polar bears, a specialist Arctic lineage, may not only have undergone severe genetic bottlenecks but also been the recipient of generalist, boreal genetic variants from brown bears during critical phases of Northern Hemisphere glacial oscillations. Article in Journal/Newspaper Archipelago Arctic Climate change Svalbard Ursus arctos Ursus maritimus Alaska Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Arctic Svalbard Svalbard Archipelago Proceedings of the National Academy of Sciences 119 24 |
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Open Polar |
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Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
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ftoslouniv |
language |
English |
description |
The polar bear (Ursus maritimus) has become a symbol of the threat to biodiversity from climate change. Understanding polar bear evolutionary history may provide insights into apex carnivore responses and prospects during periods of extreme environmental perturbations. In recent years, genomic studies have examined bear speciation and population history, including evidence for ancient admixture between polar bears and brown bears (Ursus arctos). Here, we extend our earlier studies of a 130,000- to 115,000-y-old polar bear from the Svalbard Archipelago using a 10× coverage genome sequence and 10 new genomes of polar and brown bears from contemporary zones of overlap in northern Alaska. We demonstrate a dramatic decline in effective population size for this ancient polar bear’s lineage, followed by a modest increase just before its demise. A slightly higher genetic diversity in the ancient polar bear suggests a severe genetic erosion over a prolonged bottleneck in modern polar bears. Statistical fitting of data to alternative admixture graph scenarios favors at least one ancient introgression event from brown bears into the ancestor of polar bears, possibly dating back over 150,000 y. Gene flow was likely bidirectional, but allelic transfer from brown into polar bear is the strongest detected signal, which contrasts with other published work. These findings may have implications for our understanding of climate change impacts: Polar bears, a specialist Arctic lineage, may not only have undergone severe genetic bottlenecks but also been the recipient of generalist, boreal genetic variants from brown bears during critical phases of Northern Hemisphere glacial oscillations. |
format |
Article in Journal/Newspaper |
author |
Lan, Tianying Leppälä, Kalle Tomlin, Crystal Talbot, Sandra L Sage, George K. Farley, Sean Shideler, Richard T. Bachmann, Lutz Wiig, Øystein Albert, Victor A Salojärvi, Jarkko Mailund, Thomas Drautz-Moses, Daniela I. Herrera-Estrella, Luis Lindqvist, Charlotte |
spellingShingle |
Lan, Tianying Leppälä, Kalle Tomlin, Crystal Talbot, Sandra L Sage, George K. Farley, Sean Shideler, Richard T. Bachmann, Lutz Wiig, Øystein Albert, Victor A Salojärvi, Jarkko Mailund, Thomas Drautz-Moses, Daniela I. Herrera-Estrella, Luis Lindqvist, Charlotte Insights into bear evolution from a Pleistocene polar bear genome |
author_facet |
Lan, Tianying Leppälä, Kalle Tomlin, Crystal Talbot, Sandra L Sage, George K. Farley, Sean Shideler, Richard T. Bachmann, Lutz Wiig, Øystein Albert, Victor A Salojärvi, Jarkko Mailund, Thomas Drautz-Moses, Daniela I. Herrera-Estrella, Luis Lindqvist, Charlotte |
author_sort |
Lan, Tianying |
title |
Insights into bear evolution from a Pleistocene polar bear genome |
title_short |
Insights into bear evolution from a Pleistocene polar bear genome |
title_full |
Insights into bear evolution from a Pleistocene polar bear genome |
title_fullStr |
Insights into bear evolution from a Pleistocene polar bear genome |
title_full_unstemmed |
Insights into bear evolution from a Pleistocene polar bear genome |
title_sort |
insights into bear evolution from a pleistocene polar bear genome |
publisher |
The National Academy of Sciences |
publishDate |
2022 |
url |
http://hdl.handle.net/10852/98172 https://doi.org/10.1073/pnas.2200016119 |
geographic |
Arctic Svalbard Svalbard Archipelago |
geographic_facet |
Arctic Svalbard Svalbard Archipelago |
genre |
Archipelago Arctic Climate change Svalbard Ursus arctos Ursus maritimus Alaska |
genre_facet |
Archipelago Arctic Climate change Svalbard Ursus arctos Ursus maritimus Alaska |
op_source |
0027-8424 |
op_relation |
Lan, Tianying Leppälä, Kalle Tomlin, Crystal Talbot, Sandra L Sage, George K. Farley, Sean Shideler, Richard T. Bachmann, Lutz Wiig, Øystein Albert, Victor A Salojärvi, Jarkko Mailund, Thomas Drautz-Moses, Daniela I. Herrera-Estrella, Luis Lindqvist, Charlotte . Insights into bear evolution from a Pleistocene polar bear genome. Proceedings of the National Academy of Sciences of the United States of America. 2022, 119 http://hdl.handle.net/10852/98172 2091585 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Proceedings of the National Academy of Sciences of the United States of America&rft.volume=119&rft.spage=&rft.date=2022 Proceedings of the National Academy of Sciences of the United States of America 119 24 https://doi.org/10.1073/pnas.2200016119 |
op_rights |
Attribution-NonCommercial-NoDerivatives 4.0 International https://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1073/pnas.2200016119 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
119 |
container_issue |
24 |
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1766289846697984000 |