North American Bear Program (sample photographs and notes)
First to arrive in North America 2.5 million years ago was the black bear.
Brown bears made their way to North America 300,000 years ago by way of the Aleutian land bridge.
DNA evidence confirms the polar bear evolved from the brown bear 150,000 years ago.
There are grizzly bear hybrids, where a polar bear and grizzly have produced offspring.
In North America there are an estimated 750,000 black bears, 60,000 brown bears and 25,000 polar bears.
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