Polar Bear Evolution

Evolution is defined as a slow and steady change in the same species to help their survival. There were two theories on this type of evolution: Lamarck’s theory of acquired characteristics and Darwin theory on natural selection. Both scientists agree that evolution is caused by the need of survival. Natural selection is the process by which biological traits of an organism become less in common in a population over time. This process can even result in a different species. Polar bears have gone under a series of evolutionary changes over time to help them survive in conditions on the planet some such adaptations include larger paws, thicker white fur, extra fat to keep them warm and more recently they have developed polar bear type teeth. These
Under the polar bears thick, white fur they have black skin that reflects light of the freezing arctic landscape. Their fur is oily which helps them to be water repellent; the polar bear's solid fur and a remarkably thick layer of fat under its skin protect it against the cold temperatures of the ice .The fat is important when the bear is swimming, because the fur cannot keep the insulating air trapped in it. The hairs are hollow, so the black skin underneath can absorbed light from the UV rays; these genetic traits allow them to have a better chance of survival in temperatures below zero. The polar bear’s fur grows from 5 to 15 cm long. The growth of the fur is the same amount of insulation from the cold that the polar bear receives. The physical features that defined this species include longer neck and head; this trait allowed the polar bears to reach for their prey. During the day polar bears can locate seals from a long distance. The polar bears are patient when it comes to stalking their prey. They flatten their bodies on the icy surface, their forefront feet are under them and only their hind feet provide the force when moving closer. Sometimes they push a small blocks of ice in front of them to camouflage their dark noses, or cover their noses with their white paws to avoid their prey from seeing them. Polar bears spend a lot time in water; the use of the polar bear limbs in
The most recent change was the molar teeth. With this change the polar bear now has forty-two teeth that are much longer and larger than the regular brown bear which have flat rounded teeth. The interbreeding of grizzle bears and polar bears has created a new type of bear. Polar bears and grizzly bears are breading at an increased frequency due to global warming, which is slowly forcing the polar bears out their natural environment. This cross breading has been increasing as more brown bears have been spotted in polar bear territory and parts of Canada, the traits of this new hybrid bear consist of long dirty white fur, long claws, wider teeth, and a slightly larger head. In addition, this new hybrid demonstrates more similar behavior to polar bears than grizzle