I assume you mean President Barack Obama? Not sure what a barac is.
".According to James King, author of The Biology of Race, Physical characteristics such as hair color, eye color, height, skin color, build, etc., are the components that make up an individual. These are the observable characteristics that can be inferred as inborn qualities. From these qualities we assume that the traits are inherited from the parents. The genotype is the genes that are directly given to the offspring, and the phenotype is the consequence of those genes. For example, we can assume that an individual with blue eyes has received the blue eye color gene from both parents and no genes for brown eye color, because brown is a dominant gene and blue would not be observable. So the Genotype of blue eyes is two blue eye genes and the phenotype is the blue eyes that we can see (King 111-114).
People of European dissent tend to embody a variation of skin color. Variation within groups is as strong as the socially recognized variation between ethinicities. There seems to be a direct relation between parents and their offspring. When two parents of similar phenotypical pigmentation produce offspring. The offspring usually embody the sane color. However, unlike eye color, phenotypically dissimilar pigmentation produce offspring, that offspring tends to be intermediate. Oddly enough, when two of these intermediate parents produce offspring the result is often to the extreme of the original parents (King 212).
Pigmentation also has a key environmental factor, writes L.C. Dunn author of Heredity and Race (315). When individuals with pale skin color are exposed to long periods of direct sunlight the result is darker skin. As the original skin color gets darker the effect of exposure to the sun diminishes. The darker the skin the greater the resistance to the damage the sun can cause. Hence, the minimal need for darkly pigmented people to darken. In this instance it is difficult to infer genotype from phenotype (315)