Abstract

Recent studies have shown that the polar bear matriline (mitochondrial DNA) evolved from a brown bear lineage since the late Pleistocene, potentially indicating rapid speciation and adaption to arctic conditions. Here, we present a high-resolution data set from multiple independent loci across the nuclear genomes of a broad sample of polar, brown, and black bears. Bayesian coalescent analyses place polar bears outside the brown bear clade and date the divergence much earlier, in the middle Pleistocene, about 600 (338 to 934) thousand years ago. This provides more time for polar bear evolution and confirms previous suggestions that polar bears carry introgressed brown bear mitochondrial DNA due to past hybridization. Our results highlight that multilocus genomic analyses are crucial for an accurate understanding of evolutionary history.

Links

Publisher Full Text

Authors

Hailer F, Kutschera VE, Hallström BM, Klassert D, Fain SR, Leonard JA, Arnason U, Janke A

Institution

Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325 Frankfurt am Main, Germany. frashai@gmx.net

Source

Science (New York, N.Y.) 336:6079 2012 Apr 20 pg 344-7

MeSH

Animals
Bayes Theorem
Biological Evolution
Cell Nucleus
DNA, Mitochondrial
Gene Flow
Genetic Speciation
Genetic Variation
Genome
Haplotypes
Hybridization, Genetic
Molecular Sequence Data
Multilocus Sequence Typing
Phylogeny
Ursidae

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22517859