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Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age
- Source :
- Molecular biology and evolution, vol 35, iss 5, 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
- Publication Year :
- 2018
- Publisher :
- Oxford University Press (OUP), 2018.
-
Abstract
- This article has been accepted for publication in Molecular Biology and Evolution. Published by Oxford University Press. Submitted manuscript version. Published version available at https://doi.org/10.1093/molbev/msy018. 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.
- Subjects :
- Gene Flow
0106 biological sciences
0301 basic medicine
VDP::Matematikk og naturvitenskap: 400::Zoologiske og botaniske fag: 480::Økologi: 488
Ursus maritimus
Climate Change
Population
Climate change
010603 evolutionary biology
01 natural sciences
Gene flow
03 medical and health sciences
Genetic
biology.animal
genomics
Genetics
Ice age
Animals
Ice Cover
Ursus
education
hybridization
ancient DNA
Molecular Biology
Ecology, Evolution, Behavior and Systematics
Evolutionary Biology
education.field_of_study
Extinction
VDP::Mathematics and natural scienses: 400::Zoology and botany: 480::Ecology: 488
biology
Fossils
Ecology
Human Genome
biology.organism_classification
VDP::Matematikk og naturvitenskap: 400::Zoologiske og botaniske fag: 480::Zoogeografi: 486
paleogenomics
030104 developmental biology
Ancient DNA
VDP::Mathematics and natural scienses: 400::Zoology and botany: 480::Zoogeography: 486
Hybridization, Genetic
admixture
Biochemistry and Cell Biology
Ursidae
ursus
Subjects
Details
- ISSN :
- 15371719 and 07374038
- Volume :
- 35
- Database :
- OpenAIRE
- Journal :
- Molecular Biology and Evolution
- Accession number :
- edsair.doi.dedup.....007090bc9352909bc3e20a74f4658a10