What defines the humans 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
