Modern man has inherited allergies it about 40,000 years ago, as a result of interbreeding with Neanderthals and Dénisoviens, extinct relatives of modern humans.

This is the result of two studies, published last January 7 in the journal American Journal of Human Genetics . With these prehistoric couplings, all modern humans inherited from 1 to 6% of early hominid genes, Neanderthal and Denisova says Sciences et Avenir. These genes were shared with modern humans when the first groups left Africa to come to Europe. They then had sex with Neanderthals, already established in Eurasia.

Janet Kelso, lead author of both studies, scanned the genomes of modern humans to detect genes from Neanderthals or Denisoviens. Two of the three genes of the immune system corresponded to DNA and the third Néandertal than Denisova. The most common of them was found in most of the world population, especially in the second and the third Asian, similar to DNA Denisova and rare, in a small group of Asians.

This genetic inheritance plays a vital role in our immune system, according to two studies. This proves that inherited genes, even thousands of years old, can be an advantage for the adaptation and evolution of man, especially by boosting the immune system. “ Our study shows that interbreeding with archaic humans have had practical implications for modern people, the most obvious was our adaptation to the environment by improving our resistance to pathogens and our metabolism to digest new foods , “says Janet Kelso, the Max Planck Institute in Germany, lead author of a study. “ Neanderthals lived in Europe and western Asia for 200,000 years before the arrival of modern humans. They were probably well adapted to the climate, food and pathogens and mating with them, we modern humans inherited these beneficial adaptations “, she continues.

But these genes can also confer disadvantages and lead, according to studies, excessive sensitivity of the immune system. It is this phenomenon that is the basis of our allergies. People carrying these genes are more likely to have asthma, hay fever or other allergies.

(LO)