Question

• Why is it that variations in skin color are considered to be adaptive?

Answer 1

In this case, we are observing a trait that is considered an adaptive trait because there many variations of it around the world but why and where all of these variations came from?.The theory says that the first human populations around the world were light skin. But this started to change in some places where the sun radiation was too high. For example, in Africa the sun radiation is very high and a light skinned person could be in disadvantage. But why? Well, the answer is simple, melanin. Melanin is a biopolymer that is produced by melanocytes in our skin. Its main function is to absorb UV radiation and protect us. The melanin is what cause us the brown coloration in our skin.

Now, imagine that light skin people and dark skin people are living at the same place where UV radiation is very high. The light people wont be able to survive because they does not have the enough melanin in their skin and the dark skin people will survive and adapt. For this reason, we can observe that in some places (such as Africa) the dark skin color is more present than light skin color.

So, the variations of pigmentation are adaptive traits because the different pigments depends on the level of melanin and these levels of melanin determine if a person can ”survive” in a determined environment.