Friday, October 29, 2010

My Favorite Biome: Boreal Forest

Boreal Forests

             Boreal forests, also known as taiga, can be found about 50 degrees and 60 degrees north and are mostly made up of conifers. They lie south of the tundra and north of the deciduous foresets and grasslands. They are made up of slow growing plants due to the cold temperatures and short growing season. Prominent tree species found within boreal forests include: birch, hemlocks, maples, pines, spruce, alder and ceder.

Monday, October 25, 2010

Ecological Niche of My Favorite Organism

The Gray Wolf (canis lupus)

         Gray wolves can survive in many biomes as long as food is plentiful and the climate is relatively cold. However, they are best suited to a northern conifer rain forest or tiaga biome. Their coats are made up of woolly fur to provide insulation from the cold and long guard hairs to keep out moisture. Their diet consists solely of meat. They are known to eat moose, caribou, and rodents when food is scarce.  The gray wolf is also the largest wild canine. They are around 3 feet tall at the shoulder and are about 3 to 5 feet in length from nose to tail. Due to poaching the number of wild gray wolves in America is dwindling. Though the gray wolf has been accused of posing a threat to humans, no humans have ever been killed by healthy wolves in North America.
       In Canada and Alaska, the gray wolf population is stable. In most of North America, however, they are an endangered species. In Europe, Asia, and Africa, the remaining wolf populations are tiny. The largest wolf population in Europe and Asia can be found in Russia.

Friday, October 22, 2010

Mitochondrial Eve

       Using Mitochondrial DNA passed down from mother to child one can trace their ancestry back to our first matrilineal descendant. This individual is referred to as Mitochondrial Eve. Mitochondrial Eve is our earliest female ancestor whom all human beings are descended from. By using Mitochondrial DNA, it has been determined that she probably hailed from East Africa. 

 Man from Angola
Korean Woman 

Woman from Eygpt

Woman from the Native American Navajo Tribe

Man from Ireland

Indian Woman

        The wide range of diversity in the human species can be attributed to the migration of our ancestors.  As our ancestors migrated they developed characteristics that corresponded with their new environment.  People such as the man from Angola (pictured above) are related to ancestors who did not migrate out of Africa.  Others, such as the man shown above from Ireland, have lighter skin because their ancestors did migrate out of Africa. The amount of sun our ancestors were exposed to on a daily basis helps to determine skin tone. The amount of sun one is exposed to determines melanin production, which in turn determines skin tone.  The more sun a person’s ancestor was exposed to, the darker their skin tone will be.

       Given the global trends of the human species today, the general appearance of a person 1,000 years from now will most likely consist of these characteristics: dark hair and eyes, a medium skin complexion and a medium height.