PATHOLOGY

Detailed explanation-1: -Darker, eumelanin-rich skin endowed a crucial reproductive success by protecting the body’s folate stores from UV light, thereby preventing neural tube defects.

Detailed explanation-2: -Darker skin colors evolved because they provided increased fitness in early human populations living in equatorial Africa. Darker skin protects circulating folate from being broken down. Some human populations migrated out of Africa to places where UV radiation was less intense.

Detailed explanation-3: -Natural selection has, thus, affected varied genetic and physiological mechanisms in order to protect folate and 5-MTHF in the face of high UVR. The primary role of constitutive dark skin colour in hominin and modern human evolution is that of a natural sunscreen to conserve folate.