A plague that mysterious way spread from Europe 4000 years ago in Asia. Scientists now think that they might know how

For thousands of years, a disease repeatedly met old Eurasia and spread quickly wide and sides. The bite of infected fleas that lived on rats passed the plague in its most notorious form – the black death of the 14th century – to people, and remains the most common form of transfer today.

During the Bronze Age, the Pest Bacterium, Yersinia Pestis, had not yet developed the genetic tool kit that would make it possible for later strains to be spread through fleas. Scientists are stunned about how the disease could have existed at that time.

Now an international team of researchers has recovered the first old Yersinia-Pestis genome of a non-human host-a domesticated sheep of the Bronze Age that lived about 4000 years ago in what is now today’s Russia. The discovery has enabled scientists to better understand the transmission and ecology of the disease in the old past, so that they believe that cattle played a role in its spread in Eurasia. The findings were published on Monday in the Journal Cell.

“Yersinia Pestis is a zoosotic disease (transferred between people and animals) that originated during prehistory, but so far the way we have studied it with the help of ancient DNA is entirely of human remains that left us with many questions and few answers about how people were infected,” said the Max in Berlijn. There were almost 200 years. Pestis -taken have been found from old people, the researchers wrote.

Finding the old bacterium in an animal helps researchers not only understand how the bacterial descent has evolved, but it can also have implications for understanding modern diseases, Lichtmaka added via e-mail. “Evolution can sometimes be ‘lazy’, finding the same type of solution independent for a similar problem – the genetic tools that worked for Pestis to thrive over Erazia for more than 2000 years can be reused.”

The mystery of a scourge of a Bronze Age

The old bacterium that caused the plague of the Eurasia, which is nowadays known as the late Neolithic Bronze Age Line, spread all the way from Europe to Mongolia, with proof of the disease found over 6,000 kilometers (3,700 miles).

Recent evidence suggests that the majority of modern human diseases arose within the past 10,000 years and coincided with the domestication of animals such as cattle and pets, according to a release of the German research institute. Scientists suspected that animals other than rodents were part of the enormous puzzle of the teasing transmission of the Bronze Age, but without bacterial who were recovered from animal hosts, it was not clear which one.

To find the old bullying, the authors of the study have investigated the remains of the Bronze Age of an archaeological place in Russia that is known as Arkaim. The settlement was once associated with a culture called Sintashta-Petrovka, known for its innovations in cattle. There the researchers discovered the missing connection-the tooth of a 4000 year old sheep that was infected with the same bullying bacteria found in people from that area.

Finding infected cattle suggests that the domestic sheep served as a bridge between the people and infected wild animals, Dr. Taylor Hermes, co -author of a study and a assistant professor of anthropology at the University of Arkansas.

“We reveal this a bit in real time and try to get a feeling of how the nomadic shepherds of the Bronze Age in the Eurasian steppe were the scene for disease breakdown mission that may led to impacts elsewhere,” said Hermes, “not only in time, but also in a much more distant landscape.”

During this time within the Eurasian steppe, no less than 20% of the bodies are in some cemeteries who were infected with and probably died of the plague, making it an extremely profound disease, Hermes said. Although cattle apparently are part of what the disease has made so widespread, they are only one piece of the puzzle. The identification of the bacterial descent in an animal opens new ways for investigating the evolution of this disease, as well as the later origin caused in Europe and the plague that is still there today, he added.

“It is not surprising, but it is very cool to see (the DNA) isolated of an old animal. It is extremely difficult to find it in people and even more in animal residues, so this is really interesting and important,” wrote Hendrik Painar, evolutionary geneticist and director of the old DNA center in McMasteron, in In -MASTON, in Hallonon, in Hallonon, in Hallonon, in In -Masterton, in In -Masteron, in In -Masteronon, in In -Masterton’s University, e -mail. Painar was not involved in the study.

It is likely that people and animals passed the tensions back and forth, but it is not clear how they did – or how sheep were in the first place. It is possible that sheep picked up the bacteria through a food or water source and then transferred the disease to people through the animal’s contaminated meat, he added.

“I think it shows how extremely successful (if you want to label it that way) this specific pathogen has been,” Pointar added. He, like the authors of the study, said they hope that further research reveals other animals infected with the old tension to promote the understanding of the spread and evolution of the disease.

Old plague to modern plague

While the plague that persists during the Bronze Age is extinct, Yersinia Pestis is still in parts of Africa and Asia, as well as in the Western United States, Brazil and Peru. But it is rare to encounter the bacteria, with only 1,000 to 2,000 cases of plague worldwide.

There is no need for an alarm when it comes to dealing with cattle and pets, Hermes said. The findings remind that animals wear diseases that are exaggerating for people. Be careful when cooking meat, or to take care of when it is bitten by an animal, he added.

“The collection meal is that people are not only in illness, and this has been true for thousands of years.” And if you see a dead prairie dog, it might not be going. “

Taylor Nicioli is a freelance journalist based in New York.

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