Which factors were determined to directly cause the loss of skin pigmentation in humans as a result of natural selection?

a change in the diet of human populations as they settles in colder climates
the impact of UV radiation on folate and Vitamin D levels in human populations
the interaction of human populations with predators in colder climates
the clothing worn by humans in the early 8th century

1 answer

the impact of UV radiation on folate and Vitamin D levels in human populations.