Answers to your question can be a very complex yet hard to understand somewhat but these pieces of information seems to make it all clear some what,Hope this answer your question it is a bit long.THE ORIGIN OF MAN’S “COLORS”
Most people, when they speak of a “race,” refer to the racial characteristic of skin coloration. For the purpose of the present discussion, I will limit my discussion, for the most part, to the origin of such a characteristic (being careful to do so only in an accommodative sense). In humans, production of the skin coloring agent melanin is controlled by two pairs of genes. We can designate them Aa and Bb, the capital letters representing dominant genes and the small letters recessive genes. A and B, being dominant, produce melanin very well; being recessive, a and b produce melanin to a lesser degree.
Gary Parker, in his book, Creation: The Facts of Life (1980, pp. 77-81), has observed that if Adam and Eve were both AABB, they could have produced only children with the darkest coloration possible, and they themselves likewise would have been dark. That, barring genetic mutations (to be discussed later), would have produced a world composed only of dark-skinned people. But, as has been noted already, the Negroid race composes less than 10% of the world’s population, so by a process of elimination, this choice can be ruled out.
If Adam and Eve both had been aabb, they could have had only children that were aabb, that being the lightest coloration possible. Then, the world would contain no other groupings. But it does. So, this option also is ruled out by a process of elimination.
The real question is this: Is there a mechanism by which the racial characteristics which we see today could have originated with one human couple—in the short, few thousand year or so history of the Earth?
The answer is a resounding yes! If Adam and Eve had been “heterozygous” (AaBb; two dominant, two recessive genes), they would have been middle-brown in color. And, from them—in one generation—racial differences could have occurred quite easily. Figure 1 expresses the genetic possibilities that could result if Adam and Eve had been heterozygous. Note that in a single generation, one could expect (theoretically) these colorations to be produced: 1 darkest; 4 dark; 6 medium; 4 light; and 1 lightest.
A person born AABB carries genes for the darkest coloration possible, and since all genes are dominant, has no genes for lightness. If that person married another person who likewise carried all dominant genes, and moved to an area where no intermarriage with people of different colors occurred, the offspring resulting from this marriage then would carry the same dominant genes. These offspring will have “lost” the ability to be “white.” Conversely, if a person who is aabb, and thus the lightest possible, marries another person who likewise carries all recessive genes, and moves into an area where no intermarriage with people of other colors occurs, henceforth this union will produce only offspring of the lightest possible coloration. The offspring so produced will have “lost” the ability to be “black.” They no longer have the genes necessary to produce enough melanin for the black color.
Thus, starting with any two parents who were heterozygous (i.e., middle-brown in color), extreme racial colors (black and white, to name only two examples) could be produced in such a way that races would have permanently different colors. Of course, it also is possible to produce a middle-brown race that will have a fixed middle-brown color. If the original middle-brown parents produce offspring of either AAbb or aaBB, and these offspring marry only others their own color, avoiding intermarriage with those not of their own genetic makeup, their descendants will be a fixed middle-brown color.
Is it likely that people of various colorations intermarried? The preponderance of so many colorations in the world is evidence aplenty that they did. Interestingly, even the evolutionists agree on this point. Rensberger says:
Race mixing has not only been a fact of human history but is, in this day of unprecedented global mobility, taking place at a more rapid rate than ever. It is not farfetched to envision the day when, generations hence, the entire “complexion” of major population centers will be different. Meanwhile, we can see such changes taking place before our eyes, for they are a part of everyday reality (1981, p. 54, emp. added).
Dr. Francisco Ayala of the University of California has observed that if the process started out with a couple that had only a 6.7% heterozygosity (which is the average in modern humans), the different combinations possible would be 1x102,017 before the couple would have one child identical to another (1978, p 63)!
As Parker observed, it is likely that Adam and Eve were heterozygous. Otherwise, their descendants would have lacked variation. However, one might suggest that Adam and Eve began with all dominant (or all recessive) sets of genes, but that changes occurred after the Creation as the result of mutations. Indeed, many of the genetic differences, and many of the genetic disorders, no doubt have arisen since the first couple was removed from that original, pristine environment. Thus, the possibility that some heterozygosity is a product of mutations cannot be ruled out.
You can check out the link and finish read the whole article http://www.apologeticspress.org/defdocs/rr1990/r&r9008a.htm
Also there was An Albino Gorrilla named Snowflake who died of skin cancer in a Barcelona Zoo last November, The only Albino Gorrila I ever heard of, you can read the articlehttp://msnbc.msn.com/id/3541441/