The genes inherited from Neanderthals by crosses with this extinct cousin of humans are linked to many diseases including depression, allergies or of disorders of metabolism, according to research published Thursday.
This research, published in the journal Science, has for the first time directly compared DNA of Neanderthal genomes in 28,000 adults of European descent with their medical records, confirming that this archaic genetic heritage has significant effects on the biology of modern humans.
“Our conclusion is that the DNA Neanderthals influences the clinical features of people today, “said John Capra assistant professor of biology at Vanderbilt University (Tennessee, southeast), lead author of the research.
” We discovered a relationship between the DNA of Neanderthals and a wide range of immunological, dermatological, neurological, psychiatric traits and with the reproductive system diseases, “he said.
these researchers established with a high degree of certainty that the DNA of modern humans contained more than 135,000 genetic variations from Neanderthals.
They then determined the relationship between these variants and disease and found that some of these Neanderthal genetic variations were closely linked to an increased risk of twelve diseases including depression, myocardial infarction and blood disorders.
Some relationships found between these inherited genetic variants of Neanderthal man confirms previous hypotheses like that of Neanderthal DNA affects keratinocyte cells lining the epidermis and help protect the skin from ultraviolet rays and pathogens.
the researchers were surprised to discover that some of these genes of Neanderthals increased the risk of nicotine addiction.
This discovery suggests that these traits transmitted by Neanderthals to humans could have conferred on them adapt to their new environment soon after their arrival from Africa to Eurasia 40,000 years ago.
But many of these genetic variants are no longer an advantage in a modern environment.
for example, a Neanderthal genetic variation that increases blood clotting, was useful to human survival modern arrived in Eurasia against pathogens encountered in the new environment.
This biological trait allowed to close more quickly from injury. Today it increases the risk of clot formation and stroke, pulmonary embolism or birth complications.
A previous study published in January in the American Journal of Human Genetics had revealed genes from Neandertalians which are responsible for excessive sensitivity of the immune system, causing allergies. Holders are thus more prone to asthma, hay fever and other allergies.
The 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 breeding with modern humans they have inherited these adaptations.