Rats ... Black Death may have jumped into humans from marmots

‘When you have one or two years with excess mortality it means something funny was going on’

BUCK-TOOTHED and fluffy, the marmot might seem a harmless rodent, but research suggests it could have been to blame for killing half of Europe.

The origin of the Black Death has been traced back to the Tian Shan region of north Kyrgyzstan, where a marmot “spillover event” is believed to have seeded plague into a community of Christian traders, who then spread the disease via the Silk Road.

Inscriptions on gravestones near Lake Issyk Kul had already shown an epidemic of “pestilence” devastated the area in 1338-39, nine years before the plague entered the Mediterranean via trade ships.

Now, DNA sequencing on dental remains has shown the dead were riddled with an early ancestral form of Yersinia pestis, the bacterium responsible for bubonic plague.

A similar strain has been found in living marmot populations around the lake, providing evidence the site was ground zero for the Black Death.

Dr Philip Slavin, a historian from the University of Stirling, said: “Our study puts to rest one of the biggest and most fascinating questions in history, and determines when and where the single most notorious and infamous killer of humans began.

“We studied specimens from two cemeteries near Lake Issyk Kul after identifying a huge spike in the number of burials there in 1338 and 1339. When you have one or two years with excess mortality it means something funny was going on, and it wasn’t just any year. It was just seven or eight years before the Black Death came to Europe.

“We then discovered this site had been excavated in the 1880s, with around 30 skeletons taken from graves.”

The team was able to get DNA from seven individuals and found plague bacteria in three.

“We were able to trace these skeletons and analyse DNA taken from the teeth,” added Dr Slavin. “To my astonishment, this confirmed the beginning of the second plague pandemic.”

The Black Death was first detected in the 1330s and within just a few decades spread across Europe, the Middle East and northern Africa, claiming the lives of up to 60 per cent of the population.

Its geographic and chronological origin has never been identified, with many speculating it started in China.

Prof Johannes Krause, senior author of the study and director at the Max Planck Institute for Evolutionary Anthropology, said: “We found that modern strains most closely related to the ancient strain are today found in plague reservoirs around the Tian Shan mountains, so very close to where the ancient strain was found.

“We … suggest that marmots or other rodent populations had something to do with the spillover event that led to the epidemic we describe in 1338.”

The plague would today be easily treatable with medicine.

However, if antibiotic resistance were to arise, it is possible the Black Death could return.

“If there was antibiotic resistance to the strain then it would come back [with a] 60 per cent death rate of before, which would be quite horrible for the thousands of people who get infected every year,” added Prof Krause.

The research was published in the journal Nature.