2012/04/19 by Frank Hailer, Verena E. Kutschera, Björn M. Hallström +5 · 3 citations
Environmental Science · Biochemistry, Genetics and Molecular Biology · #Marine animal studies overview #Genetic diversity and population structure #Genomics and Phylogenetic Studies
paper · doi:10.1126/science.1216424
openalex publication_date 2012/04/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
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.