Prehistoric Fossil Shows Polar Bears Lived During Last Global Warming Period

Until the oldest known remains of a polar bear were uncovered on the Svalbard archipelago in the Arctic, polar bears we thought to be a relatively new species, with one study claiming they evolved less than 100,000 years ago. The previous oldest recovered remains are about 70,000 years old. The specimen was found at Poolepynten on Prins Karls Forland, a narrow strip of land on the far west of the archipelago.

The well-preserved 23cm-long bone jawbone was pulled from sediments that suggest the specimen is perhaps 110,000 or 130,000 years old. Professor Olafur Ingolfsson from the University of Iceland says tests show it was an adult, possibly a female.

What's so fascinating about the discovery is that it places the polar bear remnant living in the Eeemian - the last interglacial - which was much warmer than our current Holocene epoch and might portend goods news for today's polar bear population numbering 20-25,000 animals.

This discovery has the potential to throw into doubt the New York Times report on September 7th that announced that two-thirds of the world’s polar bears will disappear by 2050, even under moderate projections for shrinking summer sea ice caused by greenhouse gases in the atmosphere, government scientists have reported. The finding is part of a yearlong review of the effects of climate and ice changes on polar bears to help determine whether they should be protected under the Endangered Species Act. Scientists estimate the current polar bear population at 22,000.

The polar bear has assumed an iconic status in the current global warming debate because of its dependence on ice to provide a hunting platform for seals.

"The polar bear," says Ingolfsson, "is basically a brown bear that decided some time ago that it would be easier to feed on seals on the ice. So long as there are seals, there are going to be polar bears. I think the threat to the polar bears is much more to do with pollution, the build up of heavy metals in the Arctic."

Posted by Casey Kazan.

Story Link:

http://news.bbc.co.uk/2/hi/science/nature/7132220.stm