The darker the skin, the more melanin it contains. Melanin is how the body protects itself from the ultraviolet rays that the sun gives off. The rays can cause skin cancer, and melanin is the body���s defense. When ultraviolet rays attempt to penetrate the skin, cells known as melanocytes start producing melanin to protect the skin.
People with darker skin do not burn easily when exposed to ultraviolet rays because they produce more melanin. However, those with fairer skin are easily burnt due to smaller amounts of melanocytes in the skin. Severe sunburn can be dangerous because it can lead to infections of the skin and may even send the person into shock.
People from hotter places such as Africa and India tend to have darker skin, while Europeans have lighter skin. Researchers have theorized that the closer a person���s ancestors lived to the equator, the darker their skin is because the sun is hotter near the equator. If a person has lighter skin, then their ancestors are likely to have lived farther away from the equator.Learn more about Biology