TPO – A new study based on ancient DNA collected from 108 prehistoric individuals unearthed at nine burial sites in Sweden and Denmark shows that an ancient form of plague may have been widespread. among the first farmers in Europe and may explain why this population mysteriously declined over 400 years.

Excavated remains at the Neolithic tomb at Karleby in Falbygden, Sweden, yielded several ancient DNA samples used in research. (Photo: Frederik Seersholm)

The oldest known plague victims date back to about 5,000 years ago in Europe. But it remains unclear whether the two cases, one in Latvia and one in Sweden, are isolated cases or evidence of a wider outbreak.

This trend is fairly uniform across Northern Europe, including France and Sweden. Despite significant variations in the archaeology, we still observe the same patterns, although they eventually fade away.

This group, known as Neolithic farmers, migrated from the eastern Mediterranean, displacing small groups of hunter-gatherers and bringing agriculture and a settled lifestyle to Northwest Europe for the first time around 6,000 to 7,000 years ago. Their legacy lives on in many of the continent’s great stone tombs and monuments, the most famous of which is Stonehenge.

Archaeologists fiercely debate what caused the population to disappear between 5,300 and 4,900 years ago. Some believe their disappearance is due to the agricultural crisis brought on by climate change, while others suspect disease as the cause.

“Suddenly, burials ceased at these monuments. The builders of these large stone structures have also vanished,” Seersholm remarked.

The study found that forms of the plague-causing bacteria were present in one in six ancient specimens, suggesting that infection with the disease was not uncommon.

Transmission of the plague in prehistoric times

Because the remains were carefully buried in a grave, Seersholm said, it’s possible that the genetic data examined in the study captured the beginning of a plague epidemic.

It is also possible that the disease was less severe than the plague that caused the “Black Death”, the world’s most devastating plague outbreak which is estimated to have killed half of Europe’s population within seven years in the Middle Ages.

Furthermore, because the variants detected in the samples lacked a gene that geneticists know is important for the survival of bacteria in the fleas’ digestive tracts, the resulting disease was not the same. with the bubonic plague, which is spread by fleas on rodents.

The plague still exists today and symptoms include painful swollen lymph nodes, called lymph nodes, in the groin, armpit or neck area, as well as fever, chills and cough.