If adam and eve were white people,how did blacks originate?
First of all, what possible reason is there to believe Adam and Eve were white? I know of no reason to assume this. More likely, they may have been the color of people as we find them in Mesopotamia today, which is "olive colored." It seems more likely that they were black than white, but we really have no idea.
Let me reword your question. If Adam and Eve were of some particular color skin and had certain particular genetic "racial characteristics," how did the different races of human beings arise? The answer is that they evolved. We know for a fact that evolution happens based on genetic diversity and natural selection. It is a fact that those with darker pigmented skin have a higher survival rate in places near the equator, while dark pigment is actually disadvantageous in far northern or southern regions because the body receives insufficient UV light which is essential to make Vitamin D and other important coenzymes. The fact is that the different races of human beings are extemely similar in genetic information. There is far more diversity in dogs, chimpanzees or almost any higher species of life. Natural mutation followed by natural selection can probably account for the observed variety of racial characteristics of human beings.
John Oakes, PhD