Sunday, October 24, 2010

Mitochondrial Eve

Mitochondrial Eve is defined as the woman who is the matrilineal most recent common ancestor for all living humans. It is believed that most of the ancestors of Mitochondrial Eve originated from the region of East Africa. This idea further confirms that all humans have some type of Mitochondrial DNA in their body. Mitochondrial Eve is thought to be a woman that lived in eastern Africa about 140,000 years ago. The concept is distinct from most recent common ancestor because the number of ancestors one has goes up exponentially as one travels back into time, the most recent shared common ancestor of all humanity lived more recently, probably less than 100,000 years ago. But due to sexual recombination of nuclear DNA, every living person today has only a fraction of shared genetic material with that common ancestor.
Painting of Mitochondrial Eve about             
150,000 years ago.                                        
Dominican woman
Male from Cameroon
Nigerian Women

Wednesday, October 20, 2010

Ecological Niche


The organism I chose to do my ecological niche on is the beaver. In a beavers ecological niche, one might  find trees branches, ponds , and other organisms (foxes, coyotes, and wolves) near wetlands.  Beavers use the trees as a sources of nutrients while their dam building provides as a habit for other organisms in a niche; such as fish, frogs. and water plants. Overall, the ecological niche of a beaver is define as providing habitat for other animals through their dam building as well being prey for other animals.

Oregon St. Beaver and Oregon Duck

Favorite Biome!!!!!!!

The biome that I found to be the most interesting was the cold desert biome. The cold desert consist of species such as; jack rabbits, kangaroo rabbits, pocket mice, antelope, lizards, and coyotes. On average, the temperature for the cold desert  located in Antarctica is between -2 and 4 degrees Celsius. During the summer the temperature shows very little change with temperatures being between 21-26 degrees Celsius. This biome also receives a bit snow, in the winter there can be as much as 15-26 amount of snow. I chose this biome because the desert is an interesting place to me and I have never heard of a "cold" desert.
Cold Desert
kangrat.jpg (48155 bytes)
Kangaroo Rat