How have the historic levels of melanin in human populations changed due to migration? (1 point)
Humans that produced less melanin became more common as populations migrated away from the equator.
Humans that produced less melanin became more common as populations migrated toward the equator.
Humans that produced more melanin became more common as populations migrated away from the equator.
Humans that produced more melanin became more common as populations migrated toward the equator.
Humans that produced more melanin became more common as populations migrated toward the equator.
Humans that produced more melanin became more common as populations migrated toward the equator.
To answer this question, we need to understand the role of melanin in human populations and how it is influenced by migration.
Melanin is the pigment responsible for determining the color of our skin, hair, and eyes. It serves as a natural protection against harmful ultraviolet (UV) radiation from the sun. People living closer to the equator experience more intense sun exposure and higher levels of UV radiation compared to those living farther away.
Historically, as populations migrated away from the equator, they were exposed to less UV radiation. In these areas with lower levels of UV radiation, there was less selective pressure for darker skin, as melanin provides protection against the sun. Consequently, populations migrating away from the equator would generally experience a decrease in melanin production over time.
On the other hand, as populations migrated toward the equator, they encountered more intense sun exposure and higher levels of UV radiation. This increased UV radiation necessitated a higher level of melanin production in order to protect the skin from harmful effects. Therefore, populations migrating towards the equator would generally experience an increase in melanin production over time.
Thus, to answer the question, "How have the historic levels of melanin in human populations changed due to migration?", the correct answer would be:
Humans that produced more melanin became more common as populations migrated toward the equator.