The human population has faced ups and downs throughout history. One significant drop occurred during the Neolithic period, about 5,000 years ago, affecting communities across Europe. The reasons behind this decline have puzzled scientists for years, but new research is shedding light on the mystery.
A recent study led by researchers from the University of Copenhagen analyzed ancient DNA from a tomb in France. They looked at 132 individuals buried at two different times, separated by several centuries. What they found was striking. “We can see a clear genetic break between the two burial phases,” said geneticist Frederik Seersholm. The DNA from those buried before the decline was completely different from those buried afterward. This suggests a major disruption led to the decline and the arrival of a new population.
The Neolithic decline happened around 3000 BCE. Before this, populations were growing, technology was advancing, and farming was thriving. But suddenly, many farming communities, particularly in Scandinavia, vanished, replaced by newcomers from the Eurasian steppe.
In the Paris region, researchers studied a large megalithic tomb known as Bury, used for collective burials around the same time as this upheaval. Previous studies showed a gap in burials during the period of decline. The new DNA analysis revealed the same genetic pattern previously found in other parts of Europe—communities dramatically changed post-decline.
Interestingly, DNA from people buried during the first phase showed an unusually high number of young deaths. “This kind of mortality pattern is not what we expect in a normal, healthy population,” noted archaeologist Laure Salanova. This suggests that something catastrophic—like disease, famine, or conflict—may have occurred.
The second phase of burials came from a population genetically linked to southern France and Iberia, indicating a significant migration following the disruption. What caused the upheaval is still a question. Researchers found DNA from pathogenic bacteria in the remains, such as Yersinia pestis, the same microbe responsible for the Black Death much later. “The presence of pathogenic DNA shows infectious diseases were affecting human populations at this time,” said genomicist Martin Sikora.
Alongside health issues, environmental changes occurred. During the decline, forests regrew, taking over farmland. This suggests a reduction in human activity. Relationships among the buried individuals also tell a story. Before the decline, the deceased were closely related, indicating tight-knit communities. Afterward, the relationships became more distant, hinting at a more scattered population.
Overall, the findings suggest that these communities faced significant pressures, leading to a major population change. This local event is just one piece of the larger Neolithic decline puzzle, which was likely felt across Europe.
The research provides valuable insights into how populations can be affected by multiple factors, setting the stage for new narratives about ancient societies. Understanding these regional events helps create a clearer picture of life during the Late Neolithic period.
For more details on this research, check out the study published in Nature Ecology & Evolution.
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