Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age
Recent genomic analyses have provided substantial evidence for past periods of gene flow from polar bears (Ursus maritimus) into Alaskan brown bears (Ursus arctos), with some analyses suggesting a link between climate change and genomic introgression. However, because it has mainly been possible to...
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Language: | English |
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ftcdlib:qt0p7239rx 2023-05-15T18:42:10+02:00 Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age Cahill, JA Heintzman, PD Harris, K Teasdale, MD Kapp, J Soares, AER Stirling, I Bradley, D Edwards, CJ Graim, K Kisleika, AA Malev, AV Monaghan, N Green, RE Shapiro, B 1120 - 1129 2018-05-01 application/pdf http://www.escholarship.org/uc/item/0p7239rx english eng eScholarship, University of California qt0p7239rx http://www.escholarship.org/uc/item/0p7239rx public Cahill, JA; Heintzman, PD; Harris, K; Teasdale, MD; Kapp, J; Soares, AER; et al.(2018). Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age. MOLECULAR BIOLOGY AND EVOLUTION, 35(5), 1120 - 1129. doi:10.1093/molbev/msy018. UC Santa Cruz: Retrieved from: http://www.escholarship.org/uc/item/0p7239rx genomics hybridization ancient DNA ursus paleogenomics admixture article 2018 ftcdlib https://doi.org/10.1093/molbev/msy018 2018-09-28T22:53:01Z Recent genomic analyses have provided substantial evidence for past periods of gene flow from polar bears (Ursus maritimus) into Alaskan brown bears (Ursus arctos), with some analyses suggesting a link between climate change and genomic introgression. However, because it has mainly been possible to sample bears from the present day, the timing, frequency, and evolutionary significance of this admixture remains unknown. Here, we analyze genomic DNA from three additional and geographically distinct brown bear populations, including two that lived temporally close to the peak of the last ice age. We find evidence of admixture in all three populations, suggesting that admixture between these species has been common in their recent evolutionary history. In addition, analyses of ten fossil bears from the now-extinct Irish population indicate that admixture peaked during the last ice age, whereas brown bear and polar bear ranges overlapped. Following this peak, the proportion of polar bear ancestry in Irish brown bears declined rapidly until their extinction. Our results support a model in which ice age climate change created geographically widespread conditions conducive to admixture between polar bears and brown bears, as is again occurring today. We postulate that this model will be informative for many admixing species pairs impacted by climate change. Our results highlight the power of paleogenomics to reveal patterns of evolutionary change that are otherwise masked in contemporary data. Article in Journal/Newspaper Ursus arctos Ursus maritimus University of California: eScholarship Molecular Biology and Evolution 35 5 1120 1129 |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
genomics hybridization ancient DNA ursus paleogenomics admixture |
spellingShingle |
genomics hybridization ancient DNA ursus paleogenomics admixture Cahill, JA Heintzman, PD Harris, K Teasdale, MD Kapp, J Soares, AER Stirling, I Bradley, D Edwards, CJ Graim, K Kisleika, AA Malev, AV Monaghan, N Green, RE Shapiro, B Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age |
topic_facet |
genomics hybridization ancient DNA ursus paleogenomics admixture |
description |
Recent genomic analyses have provided substantial evidence for past periods of gene flow from polar bears (Ursus maritimus) into Alaskan brown bears (Ursus arctos), with some analyses suggesting a link between climate change and genomic introgression. However, because it has mainly been possible to sample bears from the present day, the timing, frequency, and evolutionary significance of this admixture remains unknown. Here, we analyze genomic DNA from three additional and geographically distinct brown bear populations, including two that lived temporally close to the peak of the last ice age. We find evidence of admixture in all three populations, suggesting that admixture between these species has been common in their recent evolutionary history. In addition, analyses of ten fossil bears from the now-extinct Irish population indicate that admixture peaked during the last ice age, whereas brown bear and polar bear ranges overlapped. Following this peak, the proportion of polar bear ancestry in Irish brown bears declined rapidly until their extinction. Our results support a model in which ice age climate change created geographically widespread conditions conducive to admixture between polar bears and brown bears, as is again occurring today. We postulate that this model will be informative for many admixing species pairs impacted by climate change. Our results highlight the power of paleogenomics to reveal patterns of evolutionary change that are otherwise masked in contemporary data. |
format |
Article in Journal/Newspaper |
author |
Cahill, JA Heintzman, PD Harris, K Teasdale, MD Kapp, J Soares, AER Stirling, I Bradley, D Edwards, CJ Graim, K Kisleika, AA Malev, AV Monaghan, N Green, RE Shapiro, B |
author_facet |
Cahill, JA Heintzman, PD Harris, K Teasdale, MD Kapp, J Soares, AER Stirling, I Bradley, D Edwards, CJ Graim, K Kisleika, AA Malev, AV Monaghan, N Green, RE Shapiro, B |
author_sort |
Cahill, JA |
title |
Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age |
title_short |
Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age |
title_full |
Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age |
title_fullStr |
Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age |
title_full_unstemmed |
Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age |
title_sort |
genomic evidence of widespread admixture from polar bears into brown bears during the last ice age |
publisher |
eScholarship, University of California |
publishDate |
2018 |
url |
http://www.escholarship.org/uc/item/0p7239rx |
op_coverage |
1120 - 1129 |
genre |
Ursus arctos Ursus maritimus |
genre_facet |
Ursus arctos Ursus maritimus |
op_source |
Cahill, JA; Heintzman, PD; Harris, K; Teasdale, MD; Kapp, J; Soares, AER; et al.(2018). Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age. MOLECULAR BIOLOGY AND EVOLUTION, 35(5), 1120 - 1129. doi:10.1093/molbev/msy018. UC Santa Cruz: Retrieved from: http://www.escholarship.org/uc/item/0p7239rx |
op_relation |
qt0p7239rx http://www.escholarship.org/uc/item/0p7239rx |
op_rights |
public |
op_doi |
https://doi.org/10.1093/molbev/msy018 |
container_title |
Molecular Biology and Evolution |
container_volume |
35 |
container_issue |
5 |
container_start_page |
1120 |
op_container_end_page |
1129 |
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1766231775726534656 |