Polar bears and brown bears don’t share many familial traits. They have different physical features, from body size and coat color to type of fur and tooth structure. Their lives are also very different. Polar bears are carnivores and expert swimmers, whereas brown bears live in the forest and subsist on an omnivorous diet. But a 2011 study of mitochondrial DNA indicates that the Arctic polar bear’s family tree goes back to now-extinct brown bears that roamed Ireland during the last ice age.
Climate's role in bear breeding:
- Scientists made the discovery after analyzing the teeth and bones of 17 bears found in Irish caves. Climate change is believed to have produced mating opportunities during the past 100,000 years.
- Environmental conditions have played a big role in the evolution of polar bears. Even today, scientists see modern polar bears encountering brown bears in places like Canada and Alaska.
- Before this discovery, scientists previously thought that polar bears were related to brown bears living on the Alaskan islands of Admiralty, Baranof, and Chichagof.
