Earliest authentic molecular genetic evidence of the existence of a nuclear family in Late Stone Age society

In 2005, archaelogists discovered four closely grouped and well-preserved multiple burials near Eulau in Germany. The 4,600-year-old graves contained adults and children buried facing each other. DNA extracted from bones and teeth now scientifically proved a direct child-parent relationship in one of the four outstanding burials, thus providing the oldest molecular genetic evidence of a nuclear family. Skeletal and artifactual evidence and the simultaneous internment of the individuals suggest the supposed families fell victim to a violent event and were buried together. Results and findings of the joint project of the University of Bristol, the University of Adelaide, and the Johannes Gutenberg University Mainz in cooperation with the German Landesamt für Denkmalpflege und Archäologie Sachsen-Anhalt and the Landesmuseum für Vorgeschichte in Halle/Saale were now published in detail in the Proceedings of the National Academy of Sciences (PNAS).

Not all individuals found in the Eulau burials contained intact DNA. Thus, the researchers were only able to map out the genetic relationships among individuals in two of the four graves. Interestingly, the genetic evidence matched the positioning of the buried individuals. For instance, in the grave of the family of four, the mother was curled up on her side facing her son and the father was also on his side facing the other son with their arms interlinked. “By establishing the genetic links between the two adults and two children buried together in one grave, we have established the presence of the classic nuclear family in a prehistoric context in Central Europe,” explained Wolfgang Haak from the University of Mainz, currently doing research at the University of Adelaide.

The researchers gleaned even more information about the family by analyzing strontium isotopes from teeth. Since strontium food is incorporated into a person’s teeth over time, the relative amounts of different strontium isotopes can link the ancient remains with different regions. In fact, the results in case of the Eulau burials showed that the females spent their childhoods in other regions than did the males and children in the grave, suggesting the females moving to the location of the males for marriage. “Such traditions would have been important to avoid the inbreeding and to forge kinship networks with other communities,” said Alistair Pike, head of Archaeology at the University of Bristol and co-director of the project.

Burial as a nuclear family is different from the custom earlier in the neolithic era. Typically, archaeologists find mass graves of hundreds of individuals with little to distinguish them. Here, however, children related to the adults in the same grave were buried facing them; unrelated children were buried behind the adults. Undoubtedly, those who buried them had intimate knowledge of the victims’ family and social relationships and signified this genetic relationship in the way they lay the bodies out. However, this does not establish the elemental family to be a universal model or the most ancient institution of human communities.