Survivor: A fossil has been found that indicates polar bears evolved from brown bears during an ice ageA fossil find suggests that polar bears may only have come into existence during an ice age 150,000 years ago as part of the brown bears' battle for survival against climate change.
Scientists discovered the jawbone of an animal that died up to 130,000 years ago at Poolepynten on the Arctic island of Svalbard. It is oldest polar bear fossil ever found and has given an intriguing insight into the origins of the planet's largest predator.
Professors Olafur Ingolfsson, of the University of Iceland, and Oystein Wiig, of the University of Oslo, who made the discovery believe it reveals polar bears may have survived at least one long period of global warming.
The research paper, as reported in The Sunday Times newspaper, concluded: 'The Poolepynten subfossil mandible, which we argue is from a fully grown male, is probably the oldest polar bear find discovered so far. Its true age is interpreted to be 110,000-130,000 years old.'
Academics have long been divided over the evolution of the the great animal, with some believing they first appeared 50,000 years ago, and others suggesting it was closer to one million years ago.
Anatomical and DNA evidence from the fossil suggests polar bears might have emerged when the brown bear was being forced to adapt to cold and ice an ice age in the northern hemisphere that lasted from 190,000 to 130,000 years ago.
Furthermore, in a paper published by a research group connected to the University of Alaska Fairbanks. said: 'Brown bears found on the Alaskan islands of Admiralty, Baranof and Chichagof may be descendants of ancient ursids [bears] that diverged from other lineages of brown bears and subsequently founded the polar bear lineage
Evolution: Brown bears that became trapped on islands during an ice age some 150,000 years ago were forced to adapt It means polar bears have already survived a global warming that affected the northern hemisphere from 130,000 to 115,000 years ago, when the Greenland ice sheet and the Arctic ice cap were smaller than now.
But Professor Chris Stringer, of the Natural History Museum in London, said: 'Living through a warm period back then does not mean polar bears are resilient to climate change now.'
source: dailymail