Polar Bear/Grizzly Hybrids Reveal Species’ Mixed Ancestry
OutdoorHub Reporters 03.19.13
Scientists are hurriedly delving into the polar bear’s past in an attempt to help preserve the animals, but a recent discovery may turn the current belief of polar bear evolution on its head.
It is widely thought that the arctic bear developed from grizzlies and Irish brown bears. A hybrid grizzly/polar bear discovered in 2006 gave scientists a whole new avenue of research: whether brown bears and polar bears can mate in the wild.
One of the staging grounds of this new research were Alaska’s Admiralty, Baranof, and Chichagof (ABC) islands. Researchers previously believed that the islands’ brown bears were similar to the polar bear’s ancestors, an intermediary stage between the brown bear and polar bear. However, according to a new study led by James A. Cahill, the brown bears on the island are actually the decedents of polar bear mothers.
“It’s as if you were studying how humans are related to chimpanzees and were looking at DNA from some weird population of hybrid humans who had mated with chimps,” study co-author Ed Green told The LA Times. “The bears that are confusing everything are these ABC island bears.”
An early thesis that stated all polar bears in the world today diverge from female brown bears in Ireland is being challenged. Some now believe polar bear genetics have gone into brown bears, and contributed to the modern brown’s hereditary makeup as well. It could still be an isolated case however. Researchers are now studying to see if the situation on the ABC islands was unique, or if it is widespread across the globe.
So, the next grizzly you see might have a little bit of polar bear in them.
