How have the historic levels of melanin in human populations changed due to migration?

Question

1. Humans that produced less melanin became more common as populations migrated away from the equator.
2. Humans that produced more melanin became more common as populations migrated away from the equator.
3. Humans that produced more melanin became more common as populations migrated toward the equator.
4. Humans that produced less melanin became more common as populations migrated toward the equator.

Answer 1

The correct statement regarding how the historic levels of melanin in human populations changed due to migration is:

1. Humans that produced less melanin became more common as populations migrated away from the equator.

As humans migrated from equatorial regions, where there is high UV radiation, to higher latitudes with lower UV radiation, those with less melanin (which provides melanin protection from UV rays) had advantages in synthesizing vitamin D in conditions with less sunlight. This led to a gradual decrease in melanin levels in these populations. Conversely, in equatorial regions where UV radiation is intense, higher melanin levels are advantageous for protection against skin damage and skin cancers, leading to greater prevalence of individuals with higher melanin in those areas.