Skooter reporting 04/20/12
Basing on the new genetic evidence, the polar bear is much older than previously believed. DNA studies show the Arctic marauder broke up from its forerunner, the brown bear, about 600,000 years ago.
Earlier approximation put the polar bear at about 150,000 years old, signifying the mammal adapted very speedily to Arctic life.
Conservationists say the new study, published in Science, has allegation for bear conservation. Under the US Endangered Species, Polar bears are listed as threatened. Because of the loss of the Arctic sea ice on which this mammal spends much of their lives, their survival is at peril.
The genetic information brought new light on conservation issues, said Dr Frank Hailer who led the international study at the German Biodiversity and Climate Research Centre in Frankfurt. He explained that it basically changes the understanding of polar bears and their conservation today. Polar bears have survived previous warm places but they carry marks from these times, they must have been close to annihilation at times.
DNA from modern bears were investigated by researchers to study the history of the species, evaluating genetic information from the cell nucleus of more than 40 brown, black and polar bears.
Previous study has depended mainly on mitochondrial DNA, the remains of genetic material contained within tiny cell mechanism call mitochondria. The latest results prove the polar bear evolved in the mid Pleistocene, about 600,000 years ago. This scene paints a new picture of the bear's evolutionary history. The mammal would have had more time to inhabit and get used to life in the high Arctic, and lived through various rounds of warming and cooling.
Due to polar bear's short of genetic multiplicity proves that changes in the environment, such as warm phases, led to dramatic falls in numbers at times.
It is said that polar bears’ survival today is at risk, such as habitat destruction, hunting and the effects of environmental pollutants could magnify the impact of current climate change, posing a novel and possibly a deep threat to polar bear survival.