Archaeologists working near the small Croatian village of Potočani made a dismal discovery in 2007. In a shallow grave, only one meter deep and two meters wide, they found bones piled up by at least 41 people. Radiocarbon dating in several of the bones revealed that they were in the pit for about 6,200 years. Among the dead were men, women and children, from babies to the elderly, and it was clear that they died violently.
Thirteen of the 41 people in the ditch had taken lethal blows to the sides or the back of the neck with a mix of different weapons. Based on the shape of the wounds, they probably included stone hammers, wooden clubs and copper axes.
“The position and morphology (appearance) of the wounds strongly suggest that these people did not run away from their attackers,” said archaeologist Mario Novak of the Croatian Anthropological Research Institute, “but they were probably kneeling or lying with their hands on.” This evidence, along with the presence of so many women and children in the group, told archaeologists that they had not unearthed the consequences of a battle, but of a massacre.
Potočani is just one of several very similar massacre sites spread across Neolithic and Copper Age Europe. So far, archaeologists have unearthed the remains of about half a dozen similar cases across the continent, all dating from 7,500 to 6,000 years ago. Novak told Ars that there are probably more sites and are just waiting to be found and excavated.
In each of these locations, there is a clear pattern: large numbers of victims of both sexes and all age groups, killed with several different types of weapons and apparently without fighting, and hurriedly buried in a shallow grave or trench.
Novak and his colleagues recently sequenced the ancient DNA of 38 of the 41 people in the mass grave in Potočani, hoping to learn more about who the victims were, how they related to each other and, ultimately, why they died.
Identifying the victims
Some fragments of pottery in the moat linked the victims to the Lasinja culture, a group of people who lived in a strip of present-day Croatia, northern Bosnia, Slovenia, eastern Austria and western Hungary during the Copper Age, around 3,200 to 2300 BC. Archaeological evidence tells us that the Lasinja made their living mainly by herding cattle and mining and working copper. The 41 people in the mass grave were probably part of a larger group.
“It is very likely that these are the unlucky ones who have not managed to escape,” Novak told Ars. “It is also possible that in a few years we may find another mass cemetery nearby, containing the remains of other members of his community. You have to remember that the archaeological excavation was done in a very small area (basically this pit), so the neighboring plots may contain some similar, but not studied, archaeological features. “
The DNA of 38 of the Potočani victims showed that they all shared essentially the same ancestry, with their roots mainly aligned with Anatolian farmers who brought agriculture to southern and central Europe some 8,000 to 7,000 years ago. They also owe about nine percent of their ancestry to hunter-gatherer groups that lived in Europe before the arrival of farmers from Anatolia.
At the time of the massacre, these people were part of a population that appeared to be large and quite stable. No DNA from the victims showed any sign of inbreeding, which may suggest a small, isolated population. And mitochondrial DNA, which is passed directly from mother to child, showed at least 30 maternal strains in the group, which also suggests a large genetically diverse community.
The mass grave in Potočani may appear to be the result of a conflict over territory; when a group moves to an area, people who already live there may resort to violence to expel newcomers. And it is easy to imagine that people who raised livestock for a living may come into conflict with more sedentary farmers. But, as the victims’ DNA suggests a large, well-established population, it is unlikely that they were recent migrants to the area.
Despite their shared heritage, most victims were not closely related to each other. Twenty-seven of the victims had no relatives in the mass grave with them. Novak and his colleagues identified a few small family groups: a young man with his two daughters and nephew, two small sisters with a cousin or great-grandfather, a father and son and a boy with his aunt or stepsister. Since the victims of the massacre, for the most part, were not related, we can also rule out the possibility that their attackers would target specific families for some reason.
What happened in Neolithic Europe?
DNA analysis answered two of the four big questions about the old mass grave; archaeologists now know more about who the victims were and how they relate to each other. We are left with evidence that some group of people committed a terrible act of violence against others 6,200 years ago – but almost no evidence to tell us who or why.
“We also know almost nothing about the perpetrators of this horrible act because we have no cultural (material) and / or biological (skeletal) traces in this place that we can associate with them,” said Novak to Ars. “Then again, we can only speculate based on the available data from Potočani and some similar sites known across Europe.”
Another unanswered question is why these unexplained (at least for modern researchers) mass murders appear to have become more common in Neolithic Europe. “Why such a large number of nearly identical episodes / events occurred in continental Europe at that time is still unclear,” Novak told Ars. Some archaeologists have suggested that Europe’s population increased dramatically during the late Neolithic and early Copper Age, when agriculture would have made food more abundant and predictable – but at that time, changes in the ancient climate brought about drought, hunger and a struggle for resources. .
“At this point, we can’t say for sure,” Novak told Ars. “So far, we have had no evidence of adverse weather conditions in the region for about 6,200 years. But this is a topic that is completely under-researched, so we may get some new information in the near future. “
PLOS ONE, 2021 DOI: 10.1371 / journal.pone.0247332 (About DOIs).