Polar bears are no new kids on the block

Thu, 26th April 2012

Research published today in the journal Science, shows the Arctic's top predators split off from brown bears, their closest relatives, around 600,000 years ago - five times earlier than scientists had generally assumed.The finding suggests polar bears took a long time to adapt to their icy world and may therefore struggle to adjust as the Arctic gets warmer and the sea ice melts, depriving them of vital hunting platforms.

ABC online has more.