Noah’s descendants disobeyed the Creator’s command to spread out and fill the earth after the great Flood. They wanted to stay together and began to build a tall tower (Genesis 10, 11). So, God gave to each family group a different language. This made it difficult for the groups to understand each other, and so they split apart. Each extended family went its own way, and found a different place to live. Some of the families used the land bridges that were exposed during the Ice Age to travel to different continents. Others sailed to different parts of the world. As they went, each of these groups took with it its own special set of characteristics (for instance, for lighter skin and eye color, or for darker skin and eye color). These characteristics were passed through their DNA to their children, and so on. Because the groups no longer freely mixed with other groups, the characteristics of each became more and more prominent as new generations of children were born. Eventually, the many different people groups developed.
The Babel exhibit in the Creation Museum near Cincinnati depicts a city and tower that were abandoned in the very early stages of construction.