Polar bears. [File photo]
A new genetic study showed that polar bears have evolved as a separate species far earlier than previously thought, Reuters reported.
Research published on Thursday found the Arctic's top predators split off from brown bears, their closest relatives, around 600,000 years ago - five times earlier than scientists generally assumed.
The findings suggest that polar bears took a long time to adapt to their icy world and may therefore struggle to adjust as the Arctic is now warming up and sea ice is melting, which deprives them of their vital hunting platforms.