Inter- and intraspecific mitochondrial DNA variation in North American bears (Ursus)

Canadian Journal of Zoology
By: , and 



We assessed mitochondrial DNA variation in North American black bears (Ursus americanus), brown bears (Ursus arctos), and polar bears (Ursus maritimus). Divergent mitochondrial DNA haplotypes (0.05 base substitutions per nucleotide) were identified in populations of black bears from Montana and Oregon. In contrast, very similar haplotypes occur in black bears across North America. This discordance of haplotype phylogeny and geographic distribution indicates that there has been maintenance of polymorphism and considerable gene flow throughout the history of the species. Intraspecific mitochondrial DNA sequence divergence in brown bears and polar bears is lower than in black bears. The two morphological forms of U. arctos, grizzly and coastal brown bears, are not in distinct mtDNA lineages. Interspecific comparisons indicate that brown bears and polar bears share similar mitochondrial DNA (0.023 base substitutions per nucleotide) which is quite divergent (0.078 base substitutions per nucleotide) from that of black bears. High mitochondrial DNA divergence within black bears and paraphyletic relationships of brown and polar bear mitochondrial DNA indicate that intraspecific variation across species' ranges should be considered in phylogenetic analyses of mitochondrial DNA.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Inter- and intraspecific mitochondrial DNA variation in North American bears (Ursus)
Series title Canadian Journal of Zoology
DOI 10.1139/z91-421
Volume 69
Issue 12
Year Published 1991
Language English
Publisher NRC Research Press
Contributing office(s) Alaska Biological Science Center
Description pp. 2985-2992
First page 2985
Last page 2992