Nuclear Genomic Sequences Reveal that Polar Bears Are an Old and Distinct Bear Lineage

Research output: Contribution to journalArticle


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.


  • Frank Hailer
  • Verena E. Kutschera
  • Bjoern M. Hallstroem
  • Denise Klassert
  • Steven R. Fain
  • Jennifer A. Leonard
  • Ulfur Arnason
  • Axel Janke
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Neurology
  • Surgery
Original languageEnglish
Pages (from-to)344-347
Issue number6079
Publication statusPublished - 2012
Publication categoryResearch