The Mitochondrial Eve theory discusses the idea that everyone in the world is descended from one woman.  Her name is "Mitochondrial" eve refers to her being our matrilineal most common ancestor.  Humans share Mitochondrial DNA with their mothers; this would mean that  everyone shares a small percentage of mitochondria with each other, which descended from Mitochondrial Eve.  Scientists believe that Mitochondrial Eve lived in the region of Northeast Africa.  From here, people dispersed to the now inhabited areas of the earth.   Over time, as the people dispersed, their physical features changed to better suit their new climates.

Ethiopians tend to have naturally straight hair, slender noses, lighter complexions, and overall slender body frames than people from other African nations.

 Nigerian people physical features are quite the opposite from Ethiopians.  They have stockier builds, broader noses, and tend to be of a darker complexion.

Filipino people tend to have rounder eyes than the Chinese; they also tend to have light to medium skin tones and medium body sizes, yet short heights.

Indian people tend to have medium to dark complexions, with straight black hair and average builds.

Mexican people tend to have medium to dark skin, with fuller bodies and short builds, as well as dark hair.

http://www.ornl.gov/sci/techresources/Human_Genome/project/about.shtml