The levels of melanin in human populations changed during migration as a consequence of adaptation. It is an evolutionary process.
Genetic variation can be defined as the raw material used for evolutionary processes to occur.
Evolution can be defined as descendence with modification, which mainly depends on natural selection.
Adaptation (in this case associated with melanin levels) is the evolutionary process by which organisms fit certain environmental conditions.
Learn more about adaptation here:
https://brainly.com/question/1213023
