💀 Prehistoric graves: DNA analysis surprises researchers

The archaeological site of Ajvide in Sweden, dating back approximately 5,500 years, is renowned for its particularly well-preserved graves. At that time, while agriculture was becoming widespread in Europe, communities in the north maintained a lifestyle based on seal hunting and fishing.

Thanks to scientists from Uppsala University, the DNA of ten individuals from four collective graves has been analyzed. Their work, published in Proc Biol Sci, shows that people buried together were often distant relatives, such as cousins or uncles.


This is a surprise for the researchers. To illustrate this point, one burial contained a young woman accompanied by two children who were not hers, but probably her nephews or nieces. Another grave also held two children, a boy and a girl, identified as cousins by genetic analysis.

These burial configurations demonstrate that knowledge of family lineage extended beyond the immediate nuclear family. Thus, second- or third-degree relationships held an important place in the rites, a sign of social recognition of extended bonds.

To establish these kinships, the researchers compared the proportion of shared DNA. First-degree relatives, such as parents and children, share approximately 50% of their DNA, while cousins share about 12.5%.

This discovery thus provides a new angle on the social organization of hunter-gatherers. It indicates that communities placed importance on extended kinship networks, which could solidify group cohesion and chances of survival.

Going forward, this pilot project plans to examine more than 70 additional individuals from Ajvide. The objective is to refine the understanding of the life stories and burial traditions of these ancient populations.

The social life of Neolithic hunter-gatherers

Neolithic hunter-gatherers evolved in small, mobile groups, dependent on natural resources like hunting and fishing. Their sustainability relied on cooperation, the sharing of knowledge, and flexible organization according to the seasons. These communities regularly maintained links with other groups to exchange goods or partners.

Extended kinship networks played a central role in mutual aid and cultural transmission. Unions between different groups served to consolidate alliances and limited inbreeding. Such practices encouraged genetic diversity and better adaptation to environmental changes.

Burial rites, like those observed at Ajvide, materialize these social values. Burying distant relatives together could represent clan unity and the respect paid to ancestors. These gestures reinforced collective identity and shared memories within the community.