What defines the human's skin color?

What are the possibilities of colors of the children's skin color from white mother and brown skin father?


The father's family are white and brown and they have black uncles,what is the effet of those black members in the color of the children of these couple mentioned before?

What defines the human's skin color?
Skin color is pretty complicated. There are at least two things going on (and probably more).





First off, Caucasians tend to have two copies of a certain gene version that makes them more pale than everyone else (see http://www.thetech.org/genetics/news.php... for the details). This gene, first found in Zebra fish, is one of the reasons you occasionally hear stories about couples having children much lighter or darker than themselves.





But this gene isn't the whole story. Part of the reason we know this is Africans and Asians share the same darker version. But clearly Africans are darker on average than Asians. And there are lighter and darker Africans and lighter and darker Caucasians as well.





This second layer of skin color is thought to act a lot like hair color (see http://www.thetech.org/genetics/ask.php?... for the details). These genes act more like an additive effect (instead of a dominant-recessive one).





Let's say we have 8 of these genes. They can be either on or off. If they're all off, you are very pale and if they're all on you're darker. Imagine two parents have 4 on and 4 off genes each.





The most likely result is that the kids will have the same 4 on and 4 off. But it is possible that each parent will contribute 4 off genes (and so the child will be much lighter) or 4 on genes (and so the child would be much darker).





These two sets of genes work together to give skin color. Well, it probably isn't as simple as that. As you can tell, it isn't really possible to predict what skin color will result.
Reply:The amount of pigmentation
Reply:melanocytes in the skin determine the skin color
Reply:Human skin color is more complicated genetically than some other characteristics (like eye color). Keep in mind that uncles/aunts/cousins do not play a part in determining someone's genotype (genetic makeup). Only parents and grandparents contribute (and only parents directly contribute). So the black uncles won't really influence the child's skin color. If a man has black brothers and his skin is lighter, all that means is that one of his parents probably has darker skin. A white mother and brown father can produce a wide range of skin colors. They could have children anywhere from white to some color of brown. Here's how it works:





Human skin color isn't determined by just two genes, like AA or aa or Aa. It's determined by a string of genes, like ABCDEFG. Dark skin is dominant (capital letter) over light skin (lowercase letter). So here's how a white mother's skin genes might look: aabbCcddeeFfgg. It doesn't matter which letters (genes) are capitalized (dominant); all of them add up equally to give you the result (skin color). Here's how the brown father's skin genes might look: AAbbCcDdEEffGg. (Notice how he has more capital letters.) When those two people have kids, each of them will contribute one a, b, c, and so on to the child's skin color genes. That's why there's such a huge range of possibilities. Here's the lightest possible skin color code that they could produce for a child: AabbccddEeffgg. There's only 2 dominant alleles (capital letters) there. That child's skin would be lighter than the mother's! And here's the darkest skin color code they could produce for a kid: AabbCCDdEeFfGg. There's 7 dominant alleles (capital letters) there--the same as the father (result: skin that's about the same color as the father's--brown).





Usually, a child's skin color will be somewhere in the middle of his/her parents (because that's what's most likely statistically), but you can see how a child's skin color could be much lighter or darker than one parent, just because of how genetics works. Cool, huh?





Hope that helps answer your question!
Reply:there is a 50% percent chance that the children will have brown skin, and a 50% chance of having white skin. The father's family has no effect on what genes the father can pass onto his children. The father's and mother's genome effects the color of the children's skin.