Polar Bear, Essay Example

Evolutionary Change of the Polar Bear

The animal I have chosen for this topic is the Arctic Polar Bear.

The polar bear is a unique species in that it is only found in the natural environment at latitudes above 66’33N.  The average temperature in the warm months is below 50’F.  The coldest recorded temperature in this region is -90’F.  Many animals inhabit this region, though the polar bear is one of the core predators.  However, the polar bear is unique in that it hunts mainly from the marine ice, hunting for seals, penguins, and other marine life.

The polar bear is a distinctive animal.  As a bear, its features that mark it as different from other bears of warmer climates include a striking white coat that does not change color year-round.  Also, the polar bear has enormous paws uniquely padded to tread the arctic landscape and swim in the oceans.  It has a dense layer of fat and a waterproof coat.  Additionally, it has a low profile head that is relatively smaller than other bear species, with an elongated neck, and very long legs.

The polar bear is the world’s largest land predator, sharing the top honors with a close cousin, the Kodiak Grizzly bear.  Interestingly, both of these species have evolved in a specific geographic location, to fill a specific ecological niche.  The Kodiak is confined to Kodiak Island of Alaska.  The polar bear is confined to the Arctic.  It is thought that the polar bears evolved from grizzly bears that traveled north, and stayed there.

The focus trait of this report on the polar bear is coat color. It is an inevitability that the greenhouse gases are warming the atmosphere.  Polar ice caps are melting, and the polar bear will lose its natural ecosystem.  Changes to the ecosystem of the Arctic, as a whole, will devastate many species, while some species will adapt.

The polar bear is primarily a land animal that hunts in the ocean.  Its coat is white, as a natural selection of the bears living in a geographic area dominated by snow and ice.  The white coat is an adaptation for this carnivore, so that the predatory needs could be met – camouflaging the bear from its prey.

When the icecaps melt, the bear will adapt.  It has the necessary attributes to once again move south to warmer climes of solid ground.  The trait that will change due to the selective pressure of climate change and loss of ecosystem, will be coat color.  The polar bear’s coat will get darker.  Other traits may also change, such as head size, feet size, fat storage, and peculiarities of its biology.  One striking peculiarity of interesting note is that the liver of a polar bear is toxic to humans.  Vitamin A toxicity will occur for a human attempting to consumer polar bear liver.  This interesting trait likely arose due to the polar bears diet and exposure to sun on the open ice.  This trait may change, and likely will, and until it does we should not eat polar bear liver.

The trait of the white coat of the polar bear will change color and grow darker in response to the selective pressure of climate change, which will destroy its natural habitat.  As the polar bear once again moves south, selective pressure will cause its coat to grow darker in order to allow it, as one of the world’s largest carnivores, to hunt effectively.