Polar bear origins revised – they’re older and more distinct than we thought | Not Exactly Rocket Science

Doesn’t look a day older than 602,000

It looked like we had the polar bear’s origin story nailed down. Genetic studies suggested that between 111 and 166 thousand years ago, a group of brown bears, possibly from Ireland, split off from their kin. In a blink of geological time, they adapted to the cold of the Arctic, and became the polar bears we know and worry about. Fossils supported this story: the oldest polar bear bone is between 110 and 130 thousand years old.

But according to Frank Hailer at the Biodiversity and Climate Research Centre in Frankfurt, this story is wrong in two important ways. First, the polar bear aren’t just a branch of the brown bear family tree. They’re a separate lineage in their own right. Second, they around four times older than anyone had thought, arising around 600 thousand years ago.

If this new vision is right, the bear’s journey to polar dominance wasn’t a speedy sprint, but a more leisurely stroll. As a species, polar bears have seen many ice ages. Rather than being a symbol of extraordinarily fast evolution, they’ve actually had plenty of ...

Source: http://feedproxy.google.com/~r/DiscoverMag/~3/HOhqY_zQ_IU/

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