The Evolution of Bear Species

Wednesday, August 1, 2018

Divergent Evolution Polar Bear Brown Bear common ancestor

Where did the bear really come from? The evolution of bears as we know them today, started around 30 million years ago. Their ancestors evolved into a family of small mammals known as the Miacids (Miacidae). The bears, small bears and also the canines developed from the Miacids. Some of the canine species resembled bears, and we refer to them as bear dogs or Amphicyonidae. The size and appearance of the bear dog varied from small and dog-like to big and bear-like. Please see below diagram which represents this ‘evolutionary tree’.

 Bears family tree

The family of real bears can ultimately be traced back to the oldest genus, the Ursavus, which was roughly the size of a sheepdog and had evolved from a canine ancestor.

Slovak Wildlife Society Esther Tyson, Svetlana Beťková

The bears (Ursidae) form a separate family within the order of carnivora. The bear family can be divided into three subfamilies: the giant panda (Ailuropodinae), the spectacled bear (Tremarctinae), and the real bears (Ursinae). The family of Ursinae consists of six different species, all of which have similar external characteristics like strong claws and a robust body. They also have their diet in common. Although these bears are all omnivores, their diet is mainly vegetarian. Bears live in very different regions of the world, from the North Pole to the tropical rainforests around the equator. The projects which are run by Bears in Mind focus mainly on the brown bear, but also on the Asiatic black bear, the Malayan sun bear, the spectacled bear and the sloth bear.