Have you ever wondered why you have hair on your feet, but not on the feet of your feet?
Or why do we have a lot of hair on the head, but not one hair on the hands of our hands?
The issue for years has been an ongoing problem for doctors, researchers and other scientists from the complex machinery of the human body.
For decades, science has been limited to just that it is evolutionary trait of some animals, but the physiological explanation of how it was produced until recently was any question.
Scientists from the University of Pennsylvania School of Medicine have been exploring this "mystery" for years and now claim to have come up with an answer.
The study, published in magazine magazine Cell Reports, shows that the "culprit" of no We get hair in certain areas of our body is a special kind of molecule, for more signal, protein.
According to researchers, it is about Dickkopf 2 (DKK2), which blocks the so-called "WNT signaling pathways", mobile channels that, among other things, are responsible for stimulating hair growth.
"In this study we show that skin in useless regions naturally produces an inhibitor that prevents WNT from doing its job," he told the magazine. Newsweek Sarah E. Millar, one of the authors of the investigation.
"We know that WNT signaling is essential for the development of hair follicles, blocking it causes skinless skin and triggering it causes the formation of multiple hair," he said.
But why do some animals have hair on most of the body, and others do not?
Works on evolution
The study suggests that, as is known for years, it is an evolutionary adaptation.
The research finds that some animals have developed to produce DKK2 in certain parts of their bodies to help them better survive their environments.
Thus, for example, a sleek hand will serve more to maintain instruments or other tasks, while the absence of toes on the feet of the feet will help to better go.
In cold climates, however, it would be better if they were coated, as in the case of polar bears.
To achieve these conclusions, the team analyzed the skin on the feet of the mouse (which, like humans, does not have fibers on their plants) and compared it to other animals that do such things as rabbits.
When comparing the levels of DKK2 between the two species, they found that the amount of protein was significantly lower in the skin of the animals having hair on the legs of the legs.
Meanwhile, the molecular level was much higher in areas where the hair does not grow, than in the outermost regions.
The study shows that not in these areas there are no WNT signaling pathways, hair generators, but the protein blocks them.
Now researchers hope this discovery can be used for new hair growth studies, treatment of some diseases or future treatments for people who have suffered serious burns or accidents.