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A team of geneticists discovered the first known case of plague on the corpse of a 20-year-old farmer who was buried 5,000 years ago in Sweden. The bacterial strain Yersinia pestis found in the DNA extracted from its teeth exhibits the same genetic variants that currently make pulmonary plague fatal if it is not treated in time. Another body of a 20-year-old farmer, found in the same grave in Frälsegården in the south of the country, also bears traces of this pathogen. The authors of the discovery believe that they face the evidence of the first major pandemic of humanity.
5,000 years ago, Europe was going through a dark phase of which very little is known. It has been centuries since Asian immigrants had introduced agriculture and livestock to the continent. At that time, the first cities of up to 20,000 inhabitants had flourished, in which the inhabitants and cattle lived in a small unhygienic space. For unknown reasons, there was at that time a sharp reduction in the population, from 30% to 60%, similar to that occurred in the Middle Ages with the so-called Black Death. Some cities have been burned down and abandoned. It was the end of the stone age
According to his genetic badysis, the strain of plague that killed the Swede appeared 5,700 years ago, making it the most important ancestor close to all the variants of the plague since. Swedish, Danish and French geneticists have badyzed the genome of more than a thousand corpses from this time and from the Bronze Age. The results show that "in a very short time, about 600 years, many strains of plague spread throughout Eurasia, from the steppes of southeastern Russia to Sweden," says Nicholas Rascován, biologist at the University of Aix-Marseille (France). The main author of the study published Thursday in Cell . "We have also shown that there are no large human migrations that can explain this dispersal, because we do not see half-breeds among the different infected populations, just as we see the spread of the plague, major technological innovations are appeared, such as wheeled transport and animal traction, the ideal means of transporting this pathogen over large distances.This was the first time in human history that the conditions necessary for the emergence of diseases and at the same time they were spread at great distances at the same time, so we think it was probably the first big pandemic, "says the Argentinian researcher. 19659002] The study indicates that the common ancestor of all Y. pestis must have appeared somewhere in Eastern Europe. The team speculated that its origin could be at the heart of the enigmatic culture of the Cucuteni, which flourished 5,700 years ago in present-day Moldova, Romania, and Ukraine, and whose vast colonies were burned intentionally.
After the Neolithic crisis, 4,700 years ago, a new wave of immigration arrived: the yamnayas, a nomad of nomadic steppe herdsmen. Eurasia, which some experts claim has invaded Europe from blood and fire, has almost completely replaced the country's men. The possibility was mentioned that the yamnayas, who also introduced the Indo-European languages, brought the plague with them. But the new work shows that the disease has been present in Europe for several centuries before. "We believe that what these people have found is a Europe with ghost towns and a population decimated by plague and other causes," says Simon Rasmussen, a geneticist at the University of Copenhagen and co-author of the study. "The yamnayas had a completely different lifestyle, they did not build large settlements and they were perhaps less vulnerable to peasant disease."
Carles Lalueza-Fox, a geneticist at the Institute of Evolutionary Biology in Barcelona, studies the genetic markers of yamnaya and plague in the populations of the Iberian Peninsula. "It was a time of crisis, violence and abandoned settlements, which until now had been attributed to other causes, such as more arid conditions for crops, but this new explanation seems more plausible," he said. he declared. The expert points out that, thanks to the badysis of the ancient DNA found in the graves – which had been discarded but was accessible in a public database – the authors of the study were able to reveal a "pandemic for which he did not exist history. [19659010] It was the first time in the history of humanity that the conditions necessary for the emergence of the disease as well as its diffusion at great distances
