Races, Human. All human beings are descended from people who lived hundreds of thousands of years ago. Thus, we all share a common ancestry. This means that all people living today are related to one another. But even though we are all related, we do not all look alike. Our bodies have different sizes and shapes, our skins have varying shades, our eyes differ in color and shape, our lips and noses have different shapes, and our hair has different colors and textures.

Most anthropologists believe that human beings originated in Africa and gradually spread throughout the world. They have observed that groups of people who have lived in certain parts of the world for many thousands of years tend to differ from groups living in other parts of the world. Living in regions with differing environments is one reason human beings have developed different appearances. For example, people whose ancestors lived for many generations in northern parts of the world