(ORDO NEWS) — For a long time, scientists could not answer the question why people have much less body hair than their closest relatives.
But now, by comparing the genomes of 62 species of mammals, geneticists have unraveled the mystery of the appearance of the first “hairless monkey”.
Humans are the most famous mammals with little to no hair, but they are far from unique.
In different evolutionary lines – rodents, ungulates, seals – species have also arisen in which wool is either very rare or completely absent.
Hairless animals have their own advantages over hairy ones: for example, it is easier for elephants to cool their huge bodies in hot climates, and it is easier for walruses to glide in icy water, placing the function of thermal insulation on a thick skin and an impressive layer of subcutaneous fat.
However, the evolutionary ancestors of the same elephants and walruses diverged many millions of years ago, and genetically they are quite distant relatives to each other.
So how did their descendants, not being close relatives, get rid of their hairline?
To answer this question, researchers from the University of Pittsburgh (USA) analyzed the genomes of 62 mammalian species with sparse or no hair.
The sample included naked mole rats , armadillos, dolphins, manatees, and other species of land and sea animals.
They found that evolution is not prone to originality: during the course of their development, mammals became bald at least nine times, and each time mutations in the same genes were involved in this process.
These genes either directly affect hair growth (for example, they encode the keratin of which it is composed) or regulate the work of other genes.
In total, scientists analyzed 19,149 genes and 343,598 regulatory regions.
In addition to answering a fundamental question about the development of one of the most characteristic features of modern man, the results of the study may be useful in medicine.
In the future, knowing which genes are responsible for natural baldness in elephants and pigs, scientists will be able to develop ways to restore hair in humans.
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