The maternal ancestors of modern polar bears were from Ireland, according to a DNA study of ancient brown bear bones

Scientists analyzed the teeth and skeletons of 17 brown bears that were found at eight cave sites across Ireland. Previously, it was believed that modern polar bears were most closely related to brown bears living on islands off the coast of Alaska. However, analysis of mitochondrial DNA - which is passed from mother to child - has shown that the extinct Irish brown bears are the ancestors of all modern polar bears.