Which living bear is the polar bear’s closest relative?

The brown bear is the polar bear’s closest living relative.

Genetic studies show that polar bears and brown bears share a relatively recent common ancestor. Their evolutionary relationship is close enough that the two species can occasionally interbreed, producing fertile hybrids known as pizzly or grolar bears. Such hybrids are rare in the wild.

Polar bears evolved as specialists of Arctic sea ice, while brown bears occupy a much wider range of terrestrial habitats across Eurasia and North America. Polar bears have adaptations for marine hunting, including streamlined bodies, broad paws, dense insulation, and a diet dominated by seals.

The two species are still distinct. Differences in body shape, habitat, behavior, diet, and appearance reflect their separate evolutionary paths. A common mistake is to assume that the polar bear is most closely related to the American black bear simply because both are familiar North American species.