Ancient DNA from Ajvide graves shows Stone Age burials often grouped extended relatives, highlighting the importance of wider kinship networks.
One grave contained a young woman buried beside two small children who were not her own. In another burial, two children were placed together even though they were not siblings and were likely cousins.
A new study by researchers at Uppsala University examined family relationships in four graves belonging to a hunter-gatherer community that lived at Ajvide on the island of Gotland about 5,500 years ago. The genetic findings indicate that people at the site likely recognized and valued family lineage, including connections beyond the immediate household.
Ajvide is considered one of the most significant Stone Age archaeological locations in Scandinavia. The site is known for its well-preserved graves and numerous artifacts. Around 5,500 years ago, hunter-gatherers lived in the area and relied mainly on seal hunting and fishing for food. At that time, agriculture had already spread across much of Europe, but northern hunter-gatherer groups continued their traditional lifestyles and remained genetically different from farming populations.
The burial ground includes 85 known graves. Among them, eight graves contain two or more individuals. To better understand the relationships between those buried together, researchers from Uppsala University analyzed DNA taken from remains found in four of these shared graves.
DNA Study Reveals Extended Family Relationships in Burials
“Surprisingly enough, the analysis showed that many of those who were buried together were second- or third-degree relatives, rather than first-degree relatives – in other words, parent and child or siblings – as is often assumed. This suggests that these people had a good knowledge of their family lineages and that relationships beyond the immediate family played an important role,” says archaeogeneticist Helena Malmström, who was responsible for the design of the study.
In one grave, archaeologists discovered the remains of a 20-year-old woman lying on her back with two young children placed on either side of her. One child was about four years old and the other about one and a half years old. DNA results indicated that the boy and girl were full siblings, but the woman was not their mother. Genetic evidence indicates she was likely their father’s sister or possibly a half-sister.
Another burial contained the remains of a young individual alongside those of an adult man whose bones appear to have been moved into the grave from another location. Genetic analysis revealed that the young person was a girl and that the man was her father.
Surprising Burial Arrangements Among Children and Relatives
A third grave held two children, a boy and a girl, buried together. Their genetic connection was classified as third degree, which suggests they were probably cousins.
In a fourth grave, researchers found the remains of a girl and a young woman. DNA evidence showed that they were also third-degree relatives, meaning the older individual may have been the younger one’s great aunt or cousin.
“As it is unusual for these kinds of hunter-gatherer graves to be preserved, studies of kinship in archaeological hunter-gatherer cultures are scarce and typically limited in scale,” says population geneticist Tiina Mattila, who had lead responsibility for the genetic analyses.
New Genetic Insights Into Stone Age Social Organization
“The analyses provide insight into social organization in the Stone Age,” says Paul Wallin, professor of archaeology and an expert on the Ajvide burial ground.
The archaeogenetic study of the co-burials at Ajvide represents the first pilot project investigating family relationships among Scandinavian Neolithic hunter-gatherers. Researchers plan to expand the work by studying the remains of more than 70 individuals from the burial ground. This broader effort aims to reveal more about the social structures, life histories, and burial traditions of these ancient communities.
Scientists determined both sex and family relationships by examining DNA extracted from teeth and bones belonging to the ten individuals included in the study. The sex of the children cannot be identified from skeletal features alone, but genetic analysis can reveal whether the person had two X chromosomes (girl) or one X and one Y chromosome (boy).
Kinship can also be measured by comparing how much DNA two individuals share. First-degree relatives, such as parents and children or full siblings, share about half of their DNA. Second-degree relatives, including grandparents and grandchildren or half-siblings, share about a quarter. Third-degree relatives, such as cousins or great-grandparents and great-grandchildren, share roughly one-eighth of their DNA.
Reference: “Genetic relatedness mattered in the co-burial ritual of Neolithic hunter–gatherers” by Tiina Maria Mattila, Magdalena Fraser, Julian Koelman, Maja Krzewińska, Marieke Ivarsson-Aalders, Anders Götherström, Mattias Jakobsson, Jan Storå, Torsten Günther, Paul Wallin, Helena Malmström, 1 February 2026, Proc Biol Sci.
DOI: 10.1098/rspb.2025.0813
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