Two different studies published in the scientific journals Nature and Science confirm the number of Neanderthal genes that run through the veins of modern humans. According to research, the remains of Neanderthal DNA are associated with genes involved in diabetes, lupus, Crohn’s disease and even smoking. Furthermore, research suggests that the Neanderthal genome may have helped modern humans adapt to non-African environments.
Just four years ago anthropology surprised the world by pointing out that between 1 4% of the human genome (2% of its genes) come from Neanderthal man, a species that appeared about 400,000 years ago and became extinct 30,000 ago. At the end of 2013 an article published in Nature went further and after analyzing the genome of Homo Neanderthalensis, the researchers verified the four human species that lived around 50,000 years ago on the planet mated with each other. Now this new research takes a further step in understanding our family tree.
According to research carried out by a group of geneticists at Harvard Medical School (United States) and published in Nature , the remaining remains of Neanderthal DNA in modern humans are associated with genes that affect various diseases, traits and even behaviors. This is the case with Cronh’s disease, lupus, type 2 diabetes, some characteristics of the skin and hair of modern humans and even with the behavior of smokers.
As David Reich, a researcher at Harvard Medical School and co-author of the work published in Nature , explains, “ we can now estimate the probability that a certain genetic variant comes from Neanderthals . We can begin to understand how this inherited DNA has affected us. “
For their part, the University of Washington researchers sequenced the complete genome of 600 non-African people today and compared them with that of Neanderthals. As they explain in Science , this analysis has allowed them to verify that the percentage of Neanderthal genes in each individual is small, but that in total around 20% could have survived in modern humans if we put together all the small parts that we have inherited. the different populations of the world.
The investigations of both research teams show that there are large parts of our genome without any trace of Neanderthal DNA, but that in others there are more remains than expected. In the words of Sriram Sankararaman of the Department of Genetics, Harvard Medical School, Boston, Massachusetts, ” the introduction of some of these Neanderthal mutations were detrimental to the ancestors of non-Africans and were later eliminated by the action of selection. natural “. Likewise, those parts of the Neanderthal genome that had some adaptive advantage, were maintained over the years, such as the type of skin and hair.
“The history of early human evolution is fascinating in itself, yet it also has far-reaching implications for understanding the modern human genome,” explains Irene A. Eckstrand of the National Institute of General Medical Sciences, which has partially funded the research. . ” Each piece of this history that we discover tells us more about the genetic contributions of our ancestors to modern human health and disease,” says the researcher.
