Polar bears are shown in this undated photograph from UCLA released to Reuters Nov 23, 2010. Polar Bears are likely to lose out to grizzly bears in fierce competition for food as climate change drives the two species closer together into shared habitat, biologists concluded in a study by evolutionary biologists at the University of California, Los Angeles, released on Tuesday. The research was based on 3-D computer modeling that compared the skull and jaw strength of the two bruins and found polar bears are ill-suited to the tougher chewing demands posed by the largely vegetarian diet of their grizzly cousins.??