The DNA analyses of the polar bear jaw found in Svalbard a few years ago confirm beyond doubt that polar bear is a young specie and it has an evolution history reaching ancestor in brown bear.

These two species share the same evolutionary branch until 150 000 years ago when the polar bear separated from it and has developed a set of new skills and evolutionary "adjustments" to live in a quite a different environment. The polar bear is a very young specie in terms of evolution.

The DNA study of a polar bear jaw fossil was compared with results from polar bears from Alaska and brown bears living in south eastern Alaska and Kodiak Island. It was also established through stable isotope analyses and molecular dating that polar bears were inhabitants of the Arctic sea ice very early in their evolution history. They have adapted to new conditions very rapidly too. Therefore they represent an excellent example of evolutionary opportunism within mammals.

The next stage will be to study the whole genom in order to reconstruct the whole history of polar bear evolution path.

Source: 130.000 år gammel fossilt DNA fra Svalbard avklarer isbjørnens aner (NPI news, in Norwegian only)

Read the full article: Lindqvist, C. and others: Complete mitochondrial genome of a Pleistocene jawbone unveils the origin of polar bear (Open Access article at www.PNAS.org)

Contact: Charlotte Lindqvist, university at Buffalo (cl243@buffalo.edu) or Jon Aars, NPI (aars@npolar.no)

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Brown bear, Ursus arctos (photo: The Animal files.com)

Polar bear, Ursus maritimus (photo: Jürgen Holtford)