Dman did not appear in the Holocene. This epoch in Earth's history, characterized by a largely stable warm period, only began around 12,000 years ago – our species had already existed for three hundred thousand years and had reached Europe no later than 40,000 years ago.
However, after the enormous climatic fluctuations of the preceding Pleistocene epoch, a fundamental and generally irreversible change occurred in the Holocene: By developing agriculture and animal husbandry in the Neolithic period, Homo sapiens began to subjugate the rest of nature – to put it more progressively – to emancipate yourself from it.
However, this also had consequences that had to remain hidden from researchers as long as they could only study the material evidence of prehistoric people – their ceramics, tools, settlement remains – or their constitution and state of health based on the bones in their burials.
For about two decades, remnants of these people's genetic material have also been isolated from skeletal material, and scientists have used them to reconstruct their genome with ever-increasing precision. The amazing insights that are possible as a result are shown once again by a bundle of four publications that have just been published published in Nature are.
MS is significantly more common in northern Europe than in the south
The publications present the results of a project led by Eske Willerslev from the Universities of Copenhagen and Cambridge, his Copenhagen colleague Thomas Werge and Rasmus Nielsen from the University of California at Berkeley. A total of 175 scientists from all over the world and from various disciplines were involved.
To do this, they evaluated paleogenetic material from more than 5,000 Eurasians from various epochs from the Paleolithic to the Vikings and the Middle Ages and compared it with genetic information from modern Europeans. The oldest DNA sample recorded comes from a human who lived 34,000 years ago – before the peak of the most recent ice age.
The most surprising of the findings now published concerns the neurodegenerative autoimmune disease multiple sclerosis, or MS for short. The immune system attacks the nerves in the brain and spinal cord. The first symptoms are often visual impairments, and as the disease progresses, those affected can no longer speak or walk. The disease begins in young adulthood; women suffer from MS more often than men.
Why MS is so common, especially in Europe, is still a mystery. Studies have recently shown that a latent infection with the herpes virus Epstein-Barr virus plays an important role as a trigger. But almost all people become infected with the pathogen that causes Pfeiffer's glandular fever over the course of their lives. So there must be more to MS than the virus.
MS is a complex disease in which genetic factors also play a role. A total of 233 genetic variants have been identified that increase the risk of developing MS. Up to a fifth of all northern Europeans carry a variant called HLA-DRB1*15:01 on the sixth chromosome, making them three times more likely to develop MS than people who lack it.
DNA variants that increase the risk of MS are found in all Homo sapiens populations on Earth, but are more common among people of northern or northwestern European descent. Accordingly, Northern Europe has the most MS patients. The incidence there today is approximately twice as high as in southern Europe.
#Paleomedicine #Multiple #sclerosis #legacy #steppe
