March 3rd, 2010 | By Nora Sawyer | Filed in Arctic Animals, Conservation, Global Warming, SCIENCE

The jawbone of a fully grown male polar bear, believed to be somewhere between 110,000 and 130,000 years old, is giving scientists a rare glimpse into polar bear evolution.

Polar Bears: Younger than they look

DNA from the jawbone, which was discovered in Svalbard by researcher Olafur Ingolfsson of the University of Iceland in 2004, shows that polar bears are a relatively young species, having split from brown bears approximately 150,000 years ago and evolved rapidly during the climate changes that took place during the late Pleistocene. As Ingolfsson notes, in an email quoted on the New York Times’ Dot Earth blog,

I think our find shows that polar bears have been around for a while, and they probably have survived situations in the past where the Arctic was warmer and there was less seasonal sea ice than today. . .

I want to stress that we should be concerned about the polar bears’ future. There are other risks out there, mainly from chemical pollution of the Arctic (heavy metals, pcbs, etc). Also, increased traffic (oil tankers) when/if ship lanes open up across the Arctic Ocean could constitute a major threat.

Polar bear fossils are rare, as the animals spend most of their lives on the sea ice, which means that their remains rarely end up on land. The DNA taken from the jawbone gives researchers a rare glimpse into the lives of ancient polar bears. It is also the oldest mitochondrial sample from a mammal sequenced to date.

Read more:

Science Daily: Ancient DNA from rare fossil reveals that polar bears evolved recently and adapted quickly

Arctic Update: Resilient Bears, Shrinking Ice — Dot Earth Blog, NY Times.com

Unis: Oldest remains of a polar bear ever discovered.

Tags: arctic science, dna, polar bear, polar bears, svalbard