Answer:
Latitude
- high latitude
- low latitude
Step-by-step explanation:
Clinical variations takes about gradual change in a trait and this variations take place over the geographic space, In clinical variations in skin color the latitude plays a major role because the latitude determine the amount of UV rays one will be exposed to.
The two physiological effects of solar radiation are At
- High latitude: An individual is less exposed to UV rays hence the person tends to have a lighter skin while having a higher probability of Vitamin D synthesis
- low latitudes : An individual is more exposed to UV rays hence the person tends to have a darker skin and increased protection against folate deficiencies.