Polar bears live far above the Arctic Circle and can be found at all points where land and the Arctic Ocean meet. Populations of polar bears are found in Alaska, Canada, Norway, Russia and Greenland. However, a Current Biology study points to polar bears having originated in Ireland.
The maternal ancestry of polar bears has been traced to a female brown bear who lived in what is now known as Ireland over 100,000 years ago during the peak of planet Earth's last Ice Age. The Current Biology study points to interbreeding between polar bears and brown bears as being quite common during that time, which is of interest because hybridizations in the wild have been discovered by animal biologists. It is believed that these hybridizations are a result of polar bear habitat becoming significantly diminished in recent years as the sea ice has melted and the bears have been forced south.