The families that scattered from Babel brought different combinations of genes with them. But their physical differences were trivial. We all have the same basic brown pigment, and we belong to one race—the human race—descended from Adam.
Have you ever been “people watching” in a shopping mall and noticed how different people look? So many shapes, colors, and sizes! In family photos that include my adopted daughter from China, it’s easy to see some of those differences. They aren’t major but nonetheless visible. My daughter will tell you that my eyes are rounder than hers and my skin is lighter brown. If all people descended from Adam and Eve as the Bible makes clear (Genesis 3:20; 1 Corinthians 15:45), why do we look so different?
The Bible gives us the answers. Although Adam and Eve are often shown to be fair-skinned and blond, this was unlikely. To derive all the different skin shades from one couple, Adam and Eve likely were middle-brown in color. If Adam and Eve had a mixture of “light color” genes and “dark color” genes, then their descendants could have a wide range of skin color from very light to very dark, with most people somewhere between (as seen in the world today). Adam and Eve likely possessed genetic variation for eye shape and other distinguishing characteristics as well.
As people migrated from Babel, different groups became isolated from others and likely married only within their language group. Each group carried a set of physical characteristics as determined by their genes. As they intermarried, certain characteristics would begin to dominate due to the group’s small pool of genes. Over time, different people groups displayed distinct physical characteristics. For example, Asians typically have almond-shaped eyes, dark hair, and middle-brown skin, whereas Europeans have round eyes and fair-colored hair and skin.
The term race is often used to classify people based almost solely on physical characteristics. According to evolutionary ideas, these so-called races descended from different ancestors separated by location and time. However, based on biblical history, the term race must be incorrect. We are all one race (“one blood” in Acts 17:26), the human race, descended from two ancestors, Adam and Eve.
When we stand boldly and confidently on God’s Word, we can correctly understand the unity and diversity of the human race.
http://www.answersingenesis.org/articles/am/v5/n2/one-race