Ever wondered why you have hair on your legs but not at the bottom of your feet?
Or why do we have enough hair at the head, but not single hair at the top of our hands?
The question for years is a matter that awaits doctors, researchers and other scholars of the human body's complex machines.
For decades, science was limited to thinking it was evolutionary feature of some animals, but the physiological explanation of how it was produced was a question until recently.
Scientists from the School of Medicine of Pennsylvania researched this "mystery" for years and now claimed that they had answered.
The study, published in the magazine magazine Cell Reports, stating that "the perpetrator" not We have hair in some areas of our body a special type of molecule, for more sign, protein.
According to the researchers, it's about Dickkopf 2 (DKK2), which blocked the "WNT signal paths", cellular channels that, among other things, are responsible for triggering hair growth.
"In this study, we show that the skin in hair regions naturally produces an inhibitor that prevents WNT from doing their job," he told the magazine. Newsweek Sarah E. Millar, one of the authors of the investigation.
"We know that WNT signs are essential for the development of hair follicles, preventing it from causing hair skin and its activation causes more hair formation," he said.
But why do some animals get hair on most of their body and others do not do that?
Things of evolution
The study suggests that, as is known for years, of evolutional adaptation.
The research considers that some animals evolve to produce DKK2 in some parts of their bodies help them to survive better their environments.
So, for example, a handbag would serve more to hold other instruments or tasks, while the absence of villi on the remains of the feet would help to walk better.
In cold climates, however, it would be better if they had been covered, as in the case of polar enemies.
To reach these conclusions, the team analyzed the mouse legs (which, as people, does not have a cat on their plants) and compared to other animals doing, such as rabbits.
When comparing DKK2 levels between the two species, the size of the protein was found to be much less in the skin of the animals that have only a leg on their legs.
Meanwhile, the molecule level was much higher in areas where hair does not grow than in the happiest areas.
The study shows that WNT signaling pathways, hair generators are not in these areas, but the protein is blocking them.
Now, researchers hope that the perception can be used for new hair growth research, to treat some illnesses or for future treatments for people who have suffered burns or serious accidents.