Ultraviolet light is a mutagen, but humans need some exposure to it in order to synthesize vitamin D3. The amount of ultraviolet light that penetrates the skin depends on the skin's pigmentation: more melanin (skin pigment) means less penetration. Certain mutations result in decreased melanin production. Such mutations:

Question

Quizplus · Accepted Answer

Mutations that result in decreased melanin production may be harmful in environments with high levels of ultraviolet light, increasing the risk of skin cancer. However, in environments with lower ultraviolet light levels, these mutations may be beneficial as they allow for increased vitamin D synthesis. Therefore, the effect of these mutations depends on the environment in which they are present.

Ultraviolet Light Is a Mutagen, but Humans Need Some Exposure