How did there get to be so many different races?
First, we need to get past the idea of “races.” The Bible divides us into nations, kindreds, tribes, and tongues but never by race. Why? Because, genetically, there is only one race — the human race. Darwin’s theory of evolution is how we started categorizing man into races because he considered a white Englishmen were the most highly evolved of all humans, which he was, he began to degrade people from there to the darkest of skin. But, scientifically, the average DNA of any two people on the planet differs by only 0.2%. We are, in other words, 99.8% similar to any other person. And those color differences that have caused us so much angst, war, problems of racism, slavery, prejudices and division are just variations in melanin levels. Some have less, which makes one whiter; some have more which makes them darker. By contrast, the Bible teaches that all people are made in the image of God and that God “is no respecter of persons” (He doesn’t favor one group above another).
Now as the Bible is concerned, all the descendants today came from Noah, his wife, his sons and their wives. The Bible tells us that the flood greatly changed the environment. Afterward, the population that descended from Noah’s family had one language and by living in one place were disobeying God’s command to “fill the earth” (Genesis 9:1, 11:4). God confused their language, causing a break-up of the population into smaller groups which scattered over the earth (Genesis 11:8-9). Now, we do not know, but it is suggested that Noah and his family were of a mid brown color and when this family was separated at Babel, upon their moving to different and new climates zones, their melanin adapted, vitamin D and DNA changes took place. Modern genetics show how, following such a break-up of a population, variations in skin color, for example, can develop in only a few generations.
Of course, we are all still of one human race (acts 17:26). And, Scriptures often distinguish by tribal or national grouping, not by skin color or physical appearance.