neolithic
© Mark Cartwright/Creative CommonsNew research sheds light on a potential cause of a dramatic population decline in many parts of Europe around 3000 B.C.


A neolithic burial chamber in Carnac, France
Early humans experienced a rapid population collapse across large parts of Europe five thousand years ago, the cause of which has been heavily debated. A new study published in the journal Nature suggests an early form of the plague may have played an important role.

The early Neolithic period was marked by substantial population growth, as the shift from hunting and gathering to agriculture allowed for larger and more permanent settlements. Around 3000 B.C., however, Neolithic humans in many parts of Northern Europe are believed to have experienced a dramatic population decline, known as the Neolithic Decline. Several potential causes have been theorized, including the plague, but previous research has disagreed on whether early plague outbreaks could cause widespread epidemics.

A team of researchers led by Frederik Valeur Seersholm and Martin Sikora from the University of Copenhagen analyzed DNA from 108 individuals found in nine Neolithic grave sites in Sweden and Denmark. The researchers found plague in at least 17% of the sampled individuals from a variety of locales.

The researchers determined the plague moved through the population in three different waves over approximately 120 years. While the first two waves were small and isolated, the third was more widespread. In analyzing this early form of the plague, the researchers found it had the potential to be deadly.

"These results demonstrate that the Neolithic plague was prevalent and potentially lethal," the study's authors write. "Together with the fact that these plague cases are found in one of the last populations with Neolithic Farmer ancestry observed in Scandinavia, we believe that plague could have been a contributing factor to the Neolithic Decline."


Comment: It's interesting how plague is often not only associated with the decline of societies, but also a subsequent radically new way of living; in this instance it's farming, in more recent times it was the Renaissance.


The study also provides insight into the lives of Neolithic humans in the Falbygden area of Sweden, where seven of the nine sampled burial sites are located. The researchers identified four men with multiple reproductive partners, but there were no women with multiple partners, suggesting a patrilineal family structure. One woman was also found in a different tomb than her brothers, which suggests women would sometimes move to neighboring groups to start families.

"Taken together, the data presented here provide a highly detailed and intimate snapshot of what life was like in Neolithic Falbygden, Sweden," the authors write. "The social structure was organized along male kinship lines, and females generally came from other kin groups. Because plague was infecting a significant proportion of the population, excess mortality likely associated with the disease could have undermined the long-term viability of society, leading to the eventual collapse of this form of Neolithic society."