Why Do Humans Have Such Diverse Skin Colors?

Imagine your skin is like a sponge that can absorb or block sunlight. People with darker skin have more melanin, which acts like a stronger sponge and blocks more sunlight. People in regions where the sun is very strong, like Africa, often have more melanin to protect them from the heat of the sun. But if you move somewhere with less sun, like Europe or Asia, your body might make less melanin over time.