Why is there less melanin (which makes skin darker) in the palm of hands and soul of feet?

Question

Especially if someone has a darker skin the palm of his/her hands and the soul of the feet are quite fair due to the lack of melanin. One reason could be, that the sun most likely does not shine there. But this leads to the question, why for instance the armpits are not fair.
In evolution there was a reason for everything. Only the fittest could survive. So the question is, where is the advantage of having white palms?

Answer 1

I think that the genes that code for melanin or any body part aren't aware of the outside world and that there are body parts like arm pits and hands.
The palms and the soles have thicker skin than the rest of the body to begin with. So, the thickness of the skin on these parts is enough to block the radiation and melanin is not necessary there. I've never gotten a burning sensation on my palms or soles from the Suns direct radiation

Answer 2

Quoting Dr. Mabel Rodrigues:

"Melanin, the pigment that determines the color of skin, hair and eyes, is produced in cells called melanocytes, as you know. The amount of melanin is one of the factors that determine the races.If melanin is not formed by the melanocytes the skin becomes lighter or completely white and more melanin a skin has, darker it turns. The need of melanin is to protect the skin from the UV radiation that comes from the sun light. The species adapt themselves according to their needs. So the Africans skin during the millions of years of evolution become dark and darker to protect from the high temperatures and sunburn. But due to the same adaptation the body parts that are less exposed to the sun, as the palm hands and the soles feet got less melanin because it was lesser needed. As a consequence they are lighter. So is nature...very wise.."

Answer 3

because we works continiously with palm and sole region, so that shining takes place due to shining the melanin pigment is lowered. stratum germinatum divides mitotically and form so many cells this cell has the keratin protein and melanin pigment at the time of dividing but after dividing it was dead and it is pushed to stratum corneum layer of skin and this cells are exposed to sunlight and makes skin darker.

Answer 4

genetics
(double helix spiral code)