A group of researchers from the Max Planck Institute for Human History Science conducted various analyses of the genomes of the remains of people who lived from the 14th to the 17th century to find out where the strain of Yersinia pestis appeared, which caused a severe and widespread plague epidemic that shook Europe in the 14th century, an epidemic nicknamed Black Death.
The epidemic killed more than 60% of Europe’s population and spread very widely from the Black Sea to Central Europe. According to historians, the first traces of the first symptoms of the disease can be found in time in 1346 and geographically in the territory connected with the Volga region in Russia.
However, it has not been possible to understand whether the pandemic was caused by a single bacterial source or was introduced into Europe from several sources, such as travelers. After a genomic analysis of 34 human remains buried in 10 different places in Europe, from Russia to France, researchers found that the first traces of the pandemic appeared in the city of Laishevo, Volga region of Russia.
The remains found in this area indicate the presence of a “generic” strain of Yersinia pestis compared to all other analyzed genomes, which differed only by a single mutation, allowing plague to spread throughout Europe.
It is not yet possible to understand whether this strain can be considered “zero” in absolute terms, since the same strain can be obtained from other regions, such as Asia.
However, once the plague had begun to spread in Europe, it was one strain that caused it to spread, and researchers believe that this was what was found in Laishevo, which then probably spread through rodents.
The researchers noted a certain lack of genetic diversity in the timing of plague spread and the low diversity of the epidemic itself after the first appearance of bacteria from Eastern Europe.