Bronze Age Family Relations Mapped

A team of archaeologists and geneticists have been able to analyze the genomes of an extended family buried some 3,800 years ago in a mound at the site of Nepluyevsky in the southern Urals.

By Johannes Gutenberg University Mainz

A skeleton from the Nepluyevsky site. Credit: Svetlana Sharapova

32 individuals from a burial site in the southern Ural region show close kinship relations; only women came from other areas. The diversity of family systems in prehistoric societies has always fascinated scientists. A groundbreaking study by Mainz anthropologists and an international team of archaeologists now provides new insights into the origins and genetic structure of prehistoric family communities.

Signs of polygamy.

Researchers Dr. Jens Blöcher and Professor Joachim Burger of Johannes Gutenberg University Mainz (JGU) have analyzed the genomes of skeletons from an extended family from a Bronze Age necropolis in the Russian steppe. The 3,800-year-old Nepluyevsky burial mound was excavated several years ago and is located on the geographical border between Europe and Asia. Using statistical genomics, the family and marriage relationships of this society have now been deciphered. The study was carried out in cooperation with archaeologists from Ekaterinburg and Frankfurt am Main and was partly financially supported by the German Research Foundation (DFG) and the Russian Science Foundation (RSCF).

The burial mound or so-called kurgan investigated was the grave of six brothers, their wives, children, and grandchildren. The presumably oldest brother had eight children with two wives, one of whom came from the Asian steppe regions in the east. The other brothers showed no signs of polygamy and probably lived monogamously with far fewer children.

The first-born brother apparently had a higher status and thus greater chances of reproduction.

"The burial site provides a fascinating snapshot of a prehistoric family," said Dr. Jens Blöcher, lead author of the study. "It is remarkable that the first-born brother apparently had a higher status and thus greater chances of reproduction. The right of the male firstborn seems familiar to us, it is known from the Old Testament, for example, but also from the aristocracy in historical Europe."

The genomic data reveal even more: Most women buried in the kurgan were immigrants. The sisters of the buried brothers, in turn, found new homes elsewhere. Professor Joachim Burger, senior author of the study, explained: "Female marriage mobility is a common pattern that makes sense from an economic and evolutionary perspective. While one sex stays local and ensures the continuity of the family line and property, the other marries in from the outside to prevent inbreeding."

To avoid contamination, the prehistoric genomes are reconstructed in special clean rooms at JGU. Credit: Joachim Burger

Accordingly, the Mainz population geneticists found that the genomic diversity of the prehistoric women was higher than that of the men. The women who married into the family thus came from a larger area and were not related to each other. In their new homeland, they followed their husbands into the grave.

From this the authors conclude that in Nepluyevsky there was both patrilineality or the transmission of local traditions through the male line as well as patrilocality, i.e., the place of residence of a family is the place of residence of the men.

"Archaeology shows that 3,800 years ago the population in the southern Trans-Ural knew cattle breeding and metalworking. They subsisted mainly on dairy and meat products," commented Professor Dr. Svetlana Sharapova, archaeologist from Ekaterinburg and head of the excavation, adding that "the state of health of the family buried here must have been very poor. The average life expectancy of the women was 28 years, that of the men 36 years."

Location of the burial site in the southern Ural region. Credit: Joachim Burger

In the last generation, the use of the kurgan suddenly stopped and almost only infants and small children were found. "It is possible that the inhabitants were decimated by disease or that the remaining population went elsewhere in search of a better life," said Sharapova.

Multiple partners and many children for the putative firstborn son.

"There is a global connection between different family systems and certain forms of life-style and economy," said Blöcher. "Nevertheless, human societies are characterized by a high degree of flexibility. In Nepluyevsky, we find evidence of a pattern of inequality typical of pastoralists: multiple partners and many children for the putative firstborn son and no or monogamous relationships for most others."

The authors find additional genomic evidence that populations genetically similar to Nepluyevsky society lived throughout most of the Eurasian steppe belt. "It is quite possible that the local pattern we found is relevant to a much larger area," commented Burger. Future studies will show to what extent the Nepluyevsky model can be verified at other prehistoric sites in Eurasia.

• Provided by Johannes Gutenberg University Mainz

• Reference: J. Blöcher et al. Descent, marriage, and residence practices of a 3,800-year-old pastoral community in Central Eurasia. PNAS (2023). DOI:10.1073/pnas.2303574120