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Into the Future
Transcript of Into the Future
Physiologist from the Department of Nature and Development The polar bear, as we know it today, live in one of the planet's coldest environments and depend on a thick coat of insulated fur, which covers a warming layer of fat. Fur even grows on the bottom of their paws, which protects against cold surfaces and provides a good grip on ice. The bear's stark white coat provides camouflage in surrounding snow and ice. But under their fur, polar bears have black skin—the better to soak in the sun's warming rays.
These powerful predators typically prey on seals. In search of these seals, they frequently shift areas, cracking ice where seals may surface to breathe air. They also stalk ice edges and breathing holes. If the opportunity presents itself, polar bears will also consume carcasses, such as those of dead whales. These Arctic giants are the masters of their environment and have no natural enemies. (Klenzendorf, 2012) Polar bears roam the Arctic ice sheets and swim in that region's coastal waters. They are very strong swimmers, and their large front paws, which they use to paddle, are slightly webbed. Some polar bears have been seen swimming hundreds of miles from land—though they probably cover most of that distance by floating on sheets of ice. (Klenzendorf, 2012) However, due to the constant increase in the Earth's overall temperature, the arctic sea ice has been rapidly diminishing, affecting the entire arctic ecosystem. For polar bears, loss in sea ice means reduced access to food, shelter, migration, and hibernation patterns which ultimately lead to the decline in population. (McCall, 2012) Polar Bear Brunisca bear Similarities According to Darwin's theory of natural selection, those individuals with phenotypic traits best suited to their particular environmental conditions are more likely to survive and reproduce. Therefore, the individuals with the most favorable traits are able to pass these on to the next generation, resulting in the gradual change and adaptation of an organism to its environment, also known as microevolution. In the case of the polar bears, during the three million year period the changing environmental conditions resulted in natural selection acting on the entire species, which gradually made the whole species evolve into a new species. This is referred to as Allopatric speciation, which involves a geographic barrier, such as the melting ice, separating individuals from the initial population. When the polar bears were isolated in the new environments, many different factors affected the population. Over periods of time natural selection had occurred separately on the populations, eventually creating the new species. However, due to adaptive radiation many of the similar structures, such as fur, developed over time to do different jobs because of the change in environment. As the Earth's temperature increased significantly over the three million years, the population of the polar bears decreased dramatically. This form of genetic bottleneck resulted in a significant amount of genetic drift which is the change in allele frequency as a result of chance. This caused certain beneficial mutations that increased the individuals fitness overtime as the environment changed. This change in environment attributed to relatively rapid spurts of change followed by long periods of little or no change, also known as punctuated equilibrium. There are plenty of different mutations that had occurred during these periods of time which natural selection had favored as beneficial variations. To begin, temperatures are rising far more rapidly in the Arctic than in the rest of the world. Since 1978, sea ice cover has declined by approximately nine per cent per decade, and the rate of melting appears to be increasing each year. This loss of sea ice threatens the polar bear, which are wholly dependent on the Arctic sea ice habitat for survival. Without any ice to travel on, they are forced to swim long distances and eventually the polar bears die unable to swim to shore. (Chou, 2008) thick fur
bigger body sizes
thick layer of fat
white reflection of fur
small, round ears
short, compact tails
live in the arctic
food includes ringed seals,
walruses, fish, narwhals thick, sharp claws
layers of fat and fur
thin, hollow fur
basic structures such as eyes,
nose, sharp teeth
short compact tails thin fur
smaller body sizes
thin layer of fat
brown reflection of fur
large, pointy ears
live in terrestrial areas
food includes fish, rabbits, moose, geese, and other mammals In addition, as the Earth became warmer, the bears started to lose some of there thick layers of fur and skin since there was no need for insulation. The bears also developed keen senses of hearing and sight in order to avoid predators and to catch their prey. This resulted in large and pointy ears that enable them to capture more sound waves.
Brunisca bear silhouettes are distinct among bears. Their bodies are long and tapered—from their round posteriors to pointed, Roman noses. Their necks are also very long, which is helpful when they swim. A Brunisca bear's teeth are sharp so they can shear off chunks of meat. Their canine teeth are long, sharp, and widely spaced so they can seize and hold prey. The thick and hollow fur of polar bears are pigment free and transparent. These hairs scatter and reflect the color of the white snow and ice by absorbing the sun's ultraviolet rays. However, as the bear became more terrestrial, it began to reflect a dark brown color in order to camouflage with its environment to avoid being seen by predators and prey.
As the final evolutionary change, the bears grew large front and rear paws that have widely spread out toes. In between the toes are thick webbed areas that help them to swim longer distances at a faster rate. Although, the bears have adapted to more terrestrial environments, they still swim in large bodies of water to obtain food such as fish, ducks, and marine iguanas. Brunisca bears are omnivorous and will eat both vegetation and animals. Grasses, sedges, roots, berries, insects, fish, carrion and small and large mammals. In some areas Brunisca bears eat moose, caribou and elk, in others they eat salmon. Brunisca bear diet varies depending on what foods are available in that particular season.
Brunisca bears are found in a variety of habitats, from dense forests, to sub alpine meadows.
They are known to live solitary lives except during breeding, cub rearing, and in areas with an abundant food supply such as salmon streams. For this reason, after long periods of time away from the sea, the polar bears began to grow thicker papillae underneath there paws while living in terrestrial environments. The thick papillae helps the bears to walk on the hard ground and to avoid getting hurt by any sharp objects such as rocks or sticks. As an expert in the field of animal behavior and physiology, I was hired by the Department of Nature and Development to board the Futuristica, the very first time traveling spaceship. Being the only scientist on board, I was assigned to travel to Earth three million years into the future and write a documentary describing the appearance, lifestyle, and evolutionary story of the polar bear. In preparation for this assignment, I had gathered data about the polar bear at the zoo. After years of documenting observations, researching and analyzing, I give you the evolutionary story of the Brunisca bear. All of these evolutionary changes occurred to the polar bear over the course of three million years, creating a series of transition species. This large scale of evolutionary changes including the formation of the new species is defined as macroevolution. References Each day, you can help stop global warming by riding your biking or taking the public transport to work, buying products that have less packaging, replacing incandescent bulbs with energy-efficient ones to cut down on greenhouse gas emissions, and saving water by shutting off the faucet instead of letting the water run while brushing your teeth, shaving or washing dishes. It may seem like the affect of global warming on polar bears will have no detrimental affect in the future since the empty ecological niche will eventually be replaced by the Brunisca bear. However, a small shift in climate can affect living ecosystems. Some plants and animals would adapt to the change or move, but many species would be killed off. Since ecosystems are connected, changes in climate could cause a chain reaction, killing off species that depend on each other. Changes in average temperatures could also affect growing seasons and precipitation amounts, depending on whether the area is more or less temperate.(Cook, 2012) Klenzendorf, Sybille. "Polar Bear." Learn about Saving the Polar Bear. N.p., Aug. 2012. Web. 07 May 2013.
McCall, Alysa. "About Polar Bears." Polar Bears International. N.p., Feb. 2012. Web. 07 May 2013.
Cox, Daniel J. N.d. Photograph. Natural Exposures. Natural Exposures Inc., Sept. 2007. Web. 07 May 2013.
Chou, Ben. "The Consequences of Global Warming On Wildlife." Consequences of Global Warming. N.p., Apr. 2008. Web. 07 May 2013.
Cook, Anne-Marie. "Climate Science Glossary." Skeptical Science. N.p., 30 Sept. 2010. Web. 07 May 2013.
"Causes of Microevolution." Causes of Microevolution. N.p., n.d. Web. 07 May 2013.
"Blog Trek Express." : Global Warming Hourglass. N.p., 14 Oct. 2010. Web. 09 May 2013.