About a million years ago, humans lost most of their body hair, but the furry genes are still in our DNA.
Zoologist Desmond Morris titled his famous book on the peculiarities of the human species “The Naked Ape”, since of all the great apes, we are the only space that does not have fur covered with fur. About a million years ago, humans lost most of their body hair, a key moment in evolution that involved major changes.
in a study Published in eLife magazine our genetic patterns are compared with those of 62 other mammals, including elephants, manatees and armadillos, and we examine how hairlessness evolved in different species and at different times. The work also identified new genes and genetic regulators related to body hair, a discovery that may one day be used to treat baldness.
The same technique of comparing changes in the genetic codes of different mammals could also allow scientists to investigate other questions, such as the genes that protect mole rats from cancer, or those that allowed bowhead whales to live up to 200 years.
According to researchers at the University of Utah and the University of Pittsburgh who conducted the study, the loss of most of our body hair likely involved several hundred genes. Using computer tools, they found that body hair genes remain in our genetic code but have been silenced.
In the case of humans, there is a theory that the loss of body hair was advantageous for hunting in hot climates, coupled with the development of a system that allowed the body to cool itself through sweat. This allowed us exhaustion hunting, in which we were able to chase prey like antelopes, which don’t have efficient cooling mechanisms, until exhaustion.
The scientists compared more than 19,000 genes and nearly 350,000 regulatory regions and zeroed in on those related to maintaining or losing body hair. Many of the genes associated with hair growth contain instructions for making the protein keratin, which makes up hair, nails and the outer layer of skin.
Scientists looked at animals that lost all body hair along with others, such as bison, guinea pigs, anteaters, and bears, that retained all of their hair. They designed their study to rule out genetic regions that encode two confounding variables: living in water and large body size. A disproportionate number of fine-haired mammals are large, and those that live on land in hot climates would have difficulty dissipating heat. Among the animals that lost body hair, some may have experienced the evolutionary change much more recently.
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