One of the things that makes people so special is that we’re all different. Each person you meet has their own special talents, their own favorite food, and a different face looking back at them in the mirror. So why do people have different-colored skin? The answer goes back to your ancestors (AN-sess-ters). That means your parents, grandparents, great-grandparents, great-great-grandparents, and all your relatives all the way back through history. A lot of the way you look comes from your ancestors.
Your body is made of very small parts called cells. One kind of cell is a melanocyte (mell-ANN-o-site). Melanocytes make a chemical called melanin (MELL-uh-nin) that decides what color your skin will be. If you have a lot of melanin in your skin, your skin will be very dark. If you only have a little, your skin will be very light. How much melanin you have is like having brown eyes or being tall: You get it from your ancestors. The color of their skin depends on where they came from. Some families are all from one place, and others are from a mix of places.
The equator (ee-KWAY-ter) is an invisible line that wraps around Earth like a belt. Countries on the equator get more sunlight than countries near the North and South Poles. If you’ve ever gotten a sunburn, you know that too much sunlight can be dangerous. Melanin and dark skin are a way of protecting a person’s body from getting too much sunlight. So people whose families come from countries near the equator often have dark skin, while people with ancestors from farther north or south usually have light skin. There are many different skin colors in the world. We may all look different, but we're all the same on the inside.
To learn more about melanin, check out this article from Wonderopolis.