Scientists have studied 108 skeletons found in a stone grave constructed with massive stones, revealing that 17% of the skeletons showed evidence of plague infection.
Approximately 5,000 years ago, the population in Northern Europe experienced a significant decline, devastating Stone Age farming communities across the region. The cause of this event, referred to as the Neolithic decline, remains a topic of debate.
Plague may have led to the decline of the Neolithic era. (Illustration: CNN).
The new study is based on DNA obtained from the teeth and bones of individuals excavated from an ancient grave in the Scandinavia region, including seven samples from the Falbygden area in Sweden, one sample from the coastal region of Sweden near Gothenburg, and one sample from Denmark.
The results indicate that plague, specifically the bubonic plague, may have contributed to the decline of the Neolithic era.
Specifically, the scientists examined 108 skeletons in a stone grave built with gigantic stones, finding that 17% of the skeletons exhibited signs of plague infection.
From this, researchers were able to construct a family tree of 38 individuals from Falbygden spanning six generations over approximately 120 years, with 12 individuals (or 32%) infected with the plague. Genetic analysis revealed that their community had experienced three outbreaks of the plague.
The researchers reconstructed the full genomes of various strains of the Yersinia pestis bacteria responsible for these outbreaks. The findings suggest that the most recent strain had a higher virulence than others, and characteristics identified indicate that the disease could spread from person to person, leading to epidemics.
According to the researchers, the strain of the plague bacteria during the Neolithic era is considered the “ancestor” of all subsequent strains that caused the disease. One of these strains resulted in the Justinian plague pandemic in the 6th century CE and the “Black Death” in the 14th century, which swept across Europe, North Africa, and the Middle East.
Scientists emphasize that the widespread transmission of the plague demonstrates that this pandemic was a significant factor in the decline of the Neolithic period in this region.
This is plausible, as many other areas of Europe that experienced decline were also somewhat affected by the plague. Researchers also have evidence of plague in other stone graves across Northern Europe.
The population decline during the Neolithic period in Northern Europe occurred from around 3300 BCE to 2900 BCE.
The population in Scandinavia and Northwestern Europe eventually disappeared entirely, later replaced by migrants from the Yamnaya culture originating from the steppes covering much of present-day Ukraine. They are the ancestors of modern Northern Europeans.
To date, many scenarios have been proposed to explain the decline of the Neolithic era, including war, famine, and diseases (including the plague).
However, previously only one strain of plague bacteria had been identified, and it was unclear whether this disease could spread within a human population.
The study has recently been published in the journal Nature.
