The largest living bears are polar bears. Their impressive white coats help camouflage them and aid in stalking ringed and bearded seals, their main prey. Dense fur and thick body fat provide insulation from cold air and water in their circum-Arctic, coastal habitat.
Polar bears stemmed from brown bears (Ursus arctos) about 1 million years ago, according to DNA findings. Fossils are rare. The oldest fossil known is a well-preserved jaw from Svalbard (islands north of Norway). It is considered to be of the last interglacial age (about 130 000 years old). A skull from a Scottish cave dates to about 19 000 years ago—the cold peak of the last ice age.
Perhaps a painting of two tear-drop shaped bears on a wall in the Paleolithic cave of Ekain near the northern coast of Spain depicts young polar bears that landed on the coast some 17 000 to 12 000 years ago. Later fossils, between about 11 000 and 8 000 years old, are from Scandinavia and Russia. The early inhabitants of a Mesolithic site (approximately 9000 to 8000 years ago) on Zhokov Island in Siberia evidently relied heavily on polar bears for subsistence.
Learn about modern populations.