With protruding teeth and fluffy skin, the groundhog may seem like a relatively harmless rodent, but new research suggests it may have been to blame for killing off half of Europe.
The origin of the Black Death has finally been pinpointed in the Tian Shan region of northern Kyrgyzstan, where a marmot spill event is likely to have seeded the plague in a community of Christian merchants, who then spread the disease to through the Silk Road.
Inscriptions on tombstones near Lake Issyk Kul had already shown that a “pestilence” epidemic ravaged the area in 1338 and 1339, nine years before the plague entered the Mediterranean via trading ships.
But now, DNA sequencing of teeth from the graves has shown that the dead were plagued by an early ancestral form of Yersinia pestis, the bacteria responsible for bubonic plague.
A similar strain of the same bacteria has also been found in living marmot populations around the lake, providing confirmatory evidence that the site is ground zero.
Dr Philip Slavin, historian at the University of Stirling, Scotland, said: “Our study puts to rest one of the biggest and most fascinating questions in history and determines when and where the most notorious and infamous killer of humans began.
“We studied specimens from two cemeteries near Lake Issyk Kul in what is now northern Kyrgyzstan after identifying a large increase in the number of burials there in 1338 and 1339.
“When you have one or two years with excess mortality, it means something strange was going on there, and it wasn’t just any year, it was just seven or eight years before the Black Death hit Europe.
“We later discovered that this site had been excavated in the late 1880s with around 30 skeletons removed from the graves.”
The research required complex and painstaking work, with Dr Slavin and his colleagues studying historical journals from original grave excavations to match individual skeletons to their tombstones, carefully translating the inscriptions, which were written in the Syriac language.
Despite the high risk of environmental contamination and no guarantee that the bacteria had been preserved, the team was able to obtain DNA from seven individuals unearthed from two of these cemeteries, Kara-Djigach and Burana in the Chu Valley, and found bacteria from the plague in Three.
“We were able to trace these skeletons and analyze the DNA taken from the teeth,” Dr. Salvin added.
“To my amazement, this confirmed the beginning of the second plague pandemic.”
The Black Death was first detected in the 1330s and in just a few decades had spread across Europe, the Middle East and North Africa, claiming up to 60 percent of the population and lasting 500 years. .
One of the largest infectious disease catastrophes in history.
It is considered one of the largest infectious disease catastrophes in human history, but despite intense multidisciplinary research, its geographic and chronological origins have never been identified, with many speculating that its origin was China.
The plague is not a disease of humans; the bacterium survives in wild rodent populations around the world, in so-called pest reservoirs, and spreads to humans via animal fleas.
The team believes the plague jumped to humans via groundhogs, triggering a “Big Bang” event that allowed the disease to branch out and evolve into new types of bacteria, many of which survive today.
“We found that the modern strains most closely related to the ancient strain are found today in pest reservoirs around the Tian Shan mountains, very close to where the ancient strain was found,” said Professor Johannes Krause, lead author of the study. study and director of the Max Planck Institute for Evolutionary Anthropology.
“Marmots still carry it and thousands of strains of plague have been analyzed around the world, but the closest ones are found in that particular place.
“We even take this one step further and suggest that marmots or other rodent populations had something to do with the indirect event that led to the epidemic we describe in 1338.”
Plague largely disappeared in the 18th century with improved hygiene and the disappearance of the “plague” black rat, which was replaced by the brown rat.
However, there are still some reservoirs, particularly in remote areas of the western US, and hunters are often infected with prairie dog outbreaks.
Although the disease is currently easily treatable with antibiotics, should antibiotic resistance emerge in the future, the Black Death may return.
“If there were antibiotic resistance to the strain, it would go back to the 60 per cent mortality rates of the past, which would be pretty horrific for the thousands of people who get infected every year,” Prof Krause added.
The research was published in the journal Nature.