Final answer:
Darker skin offers more protection from UV rays due to higher melanin content, which absorbs harmful UV radiation and protects the skin's DNA. This evolutionary trait balances the need for UV protection with the production of vitamin D, vital for bone health.
Step-by-step explanation:
A person with darker skin is more protected from UV rays than a person with fair skin because of the presence of a pigment known as melanin. Melanin, which is found in greater quantities in dark-skinned individuals, acts as a natural sunscreen that absorbs harmful ultraviolet radiation. This helps protect the skin cells'/tissue's DNA from UV-related damage and also prevents the breakdown of important nutrients like folic acid.
In areas of high UV exposure, like near the equator, having more melanin provides an evolutionary advantage by offering better protection against sun damage. However, this benefit comes with a trade-off since excessive melanin can interfere with vitamin D production, which is vital for calcium absorption and bone health. Therefore, skin pigmentation across populations has adapted over thousands of years, balancing between UV protection and nutritional needs depending on their geographic location.