Ancient bears provide insights into Pleistocene ice age refugia in Southeast Alaska
During the Late Pleistocene, major parts of North America were periodically covered by ice sheets. However, there are still questions about whether ice-free refugia were present in the Alexander Archipelago along the Southeast (SE) Alaska coast during the last glacial maximum (LGM). Numerous subfoss...
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ftunivnebraskali:oai:digitalcommons.unl.edu:ncfwrustaff-1323 2023-11-12T04:08:56+01:00 Ancient bears provide insights into Pleistocene ice age refugia in Southeast Alaska da Silva Coelho, Flavio Augusto Gill, Stephanie Tomlin, Crystal M. Papavassiliou, Marilena Farley, Sean D. Cook, Joseph A. Sonsthagen, Sarah A. Sage, George K. Heaton, Timothy H. Talbot, Sandra L. Lindqvist, Charlotte 2023-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/ncfwrustaff/321 https://digitalcommons.unl.edu/context/ncfwrustaff/article/1323/viewcontent/Coelho_ME_2023_Ancient_bears_provide_insights_into_Pleistocene.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/ncfwrustaff/321 https://digitalcommons.unl.edu/context/ncfwrustaff/article/1323/viewcontent/Coelho_ME_2023_Ancient_bears_provide_insights_into_Pleistocene.pdf Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications last glacial maximum paleogenetics refugia Southeast Alaska Ursus americanus Ursus arctos Animal Sciences Aquaculture and Fisheries Environmental Indicators and Impact Assessment Environmental Monitoring Environmental Sciences Natural Resource Economics Natural Resources and Conservation Water Resource Management text 2023 ftunivnebraskali 2023-10-30T12:14:11Z During the Late Pleistocene, major parts of North America were periodically covered by ice sheets. However, there are still questions about whether ice-free refugia were present in the Alexander Archipelago along the Southeast (SE) Alaska coast during the last glacial maximum (LGM). Numerous subfossils have been recovered from caves in SE Alaska, including American black (Ursus americanus) and brown (U. arctos) bears, which today are found in the Alexander Archipelago but are genetically distinct from mainland bear populations. Hence, these bear species offer an ideal system to investigate long-term occupation, potential refugial survival and lineage turnover. Here, we present genetic analyses based on 99 new complete mitochondrial genomes from ancient and modern brown and black bears spanning the last ~45,000 years. Black bears form two SE Alaskan subclades, one preglacial and another postglacial, that diverged >100,000 years ago. All postglacial ancient brown bears are closely related to modern brown bears in the archipelago, while a single preglacial brown bear is found in a distantly related clade. A hiatus in the bear subfossil record around the LGM and the deep split of their pre-and postglacial subclades fail to support a hypothesis of continuous occupancy in SE Alaska throughout the LGM for either species. Our results are consistent with an absence of refugia along the SE Alaska coast, but indicate that vegetation quickly expanded after deglaciation, allowing bears to recolonize the area after a short-lived LGM peak. Text Archipelago Ursus arctos Alaska University of Nebraska-Lincoln: DigitalCommons@UNL |
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Open Polar |
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University of Nebraska-Lincoln: DigitalCommons@UNL |
op_collection_id |
ftunivnebraskali |
language |
unknown |
topic |
last glacial maximum paleogenetics refugia Southeast Alaska Ursus americanus Ursus arctos Animal Sciences Aquaculture and Fisheries Environmental Indicators and Impact Assessment Environmental Monitoring Environmental Sciences Natural Resource Economics Natural Resources and Conservation Water Resource Management |
spellingShingle |
last glacial maximum paleogenetics refugia Southeast Alaska Ursus americanus Ursus arctos Animal Sciences Aquaculture and Fisheries Environmental Indicators and Impact Assessment Environmental Monitoring Environmental Sciences Natural Resource Economics Natural Resources and Conservation Water Resource Management da Silva Coelho, Flavio Augusto Gill, Stephanie Tomlin, Crystal M. Papavassiliou, Marilena Farley, Sean D. Cook, Joseph A. Sonsthagen, Sarah A. Sage, George K. Heaton, Timothy H. Talbot, Sandra L. Lindqvist, Charlotte Ancient bears provide insights into Pleistocene ice age refugia in Southeast Alaska |
topic_facet |
last glacial maximum paleogenetics refugia Southeast Alaska Ursus americanus Ursus arctos Animal Sciences Aquaculture and Fisheries Environmental Indicators and Impact Assessment Environmental Monitoring Environmental Sciences Natural Resource Economics Natural Resources and Conservation Water Resource Management |
description |
During the Late Pleistocene, major parts of North America were periodically covered by ice sheets. However, there are still questions about whether ice-free refugia were present in the Alexander Archipelago along the Southeast (SE) Alaska coast during the last glacial maximum (LGM). Numerous subfossils have been recovered from caves in SE Alaska, including American black (Ursus americanus) and brown (U. arctos) bears, which today are found in the Alexander Archipelago but are genetically distinct from mainland bear populations. Hence, these bear species offer an ideal system to investigate long-term occupation, potential refugial survival and lineage turnover. Here, we present genetic analyses based on 99 new complete mitochondrial genomes from ancient and modern brown and black bears spanning the last ~45,000 years. Black bears form two SE Alaskan subclades, one preglacial and another postglacial, that diverged >100,000 years ago. All postglacial ancient brown bears are closely related to modern brown bears in the archipelago, while a single preglacial brown bear is found in a distantly related clade. A hiatus in the bear subfossil record around the LGM and the deep split of their pre-and postglacial subclades fail to support a hypothesis of continuous occupancy in SE Alaska throughout the LGM for either species. Our results are consistent with an absence of refugia along the SE Alaska coast, but indicate that vegetation quickly expanded after deglaciation, allowing bears to recolonize the area after a short-lived LGM peak. |
format |
Text |
author |
da Silva Coelho, Flavio Augusto Gill, Stephanie Tomlin, Crystal M. Papavassiliou, Marilena Farley, Sean D. Cook, Joseph A. Sonsthagen, Sarah A. Sage, George K. Heaton, Timothy H. Talbot, Sandra L. Lindqvist, Charlotte |
author_facet |
da Silva Coelho, Flavio Augusto Gill, Stephanie Tomlin, Crystal M. Papavassiliou, Marilena Farley, Sean D. Cook, Joseph A. Sonsthagen, Sarah A. Sage, George K. Heaton, Timothy H. Talbot, Sandra L. Lindqvist, Charlotte |
author_sort |
da Silva Coelho, Flavio Augusto |
title |
Ancient bears provide insights into Pleistocene ice age refugia in Southeast Alaska |
title_short |
Ancient bears provide insights into Pleistocene ice age refugia in Southeast Alaska |
title_full |
Ancient bears provide insights into Pleistocene ice age refugia in Southeast Alaska |
title_fullStr |
Ancient bears provide insights into Pleistocene ice age refugia in Southeast Alaska |
title_full_unstemmed |
Ancient bears provide insights into Pleistocene ice age refugia in Southeast Alaska |
title_sort |
ancient bears provide insights into pleistocene ice age refugia in southeast alaska |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2023 |
url |
https://digitalcommons.unl.edu/ncfwrustaff/321 https://digitalcommons.unl.edu/context/ncfwrustaff/article/1323/viewcontent/Coelho_ME_2023_Ancient_bears_provide_insights_into_Pleistocene.pdf |
genre |
Archipelago Ursus arctos Alaska |
genre_facet |
Archipelago Ursus arctos Alaska |
op_source |
Nebraska Cooperative Fish & Wildlife Research Unit -- Staff Publications |
op_relation |
https://digitalcommons.unl.edu/ncfwrustaff/321 https://digitalcommons.unl.edu/context/ncfwrustaff/article/1323/viewcontent/Coelho_ME_2023_Ancient_bears_provide_insights_into_Pleistocene.pdf |
_version_ |
1782329125595250688 |