Scientists have always been captivated by the variety of family systems in prehistoric societies. The origins and genetic make-up of prehistoric family communities have recently been better understood thanks to research conducted by Mainz anthropologists and an international team of archaeologists.

The genomes of bones from an extended family from a Bronze Age necropolis in the Russian steppe have been examined by researchers Jens Blöcher and Joachim Burger from Johannes Gutenberg University Mainz (JGU). On the boundary between Europe and Asia, the 3,800-year-old Nepluyevsky burial mound was discovered few years ago.

The family and marriage ties in this society have now been analyzed using statistical genomics. The research was done in collaboration with archaeologists from Frankfurt am Main and Ekaterinburg, and it was published in Proceedings of the National Academy of Sciences.

The graves of six brothers, their spouses, kids, and grandkids were located in the kurgan (burial mound) that was under investigation. With two spouses, one of which was from the eastern Asian steppe regions, the brother who was apparently the oldest produced eight children. The other brothers appeared to be monogamous with much fewer offspring and exhibited no symptoms of polygamy.

Incredible image of a prehistoric family

"The burial site provides a fascinating snapshot of a prehistoric family," explains 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."

Even more is revealed by the genetic data. Immigrants made up the bulk of the women buried in the kurgan. The buried brothers' sisters, meanwhile, relocated to new residences elsewhere. According to Burger, "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."

Compared to men, prehistoric women had a higher level of genetic diversity

Therefore, the genomic diversity of the prehistoric women was larger than that of the men, according to the Mainz population geneticists. As a result, the ladies who married into the family were not linked to one another and came from a wider region. They accompanied their husbands into the grave in their new country. The authors draw the conclusion that Nepluyevsky had "patrilineality," or the transfer of regional customs through the male line, as well as "patrilocality," or the idea that a family's home is where the males live.

According to Svetlana Sharapova, an archaeologist from Ekaterinburg who is in charge of the excavation, "Archaeology shows that 3,800 years ago, the population in the southern Trans-Ural knew cattle breeding and metalworking and subsisted mainly on dairy and meat products. 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."

In the most recent generation, the kurgan was almost exclusively used by newborns and young children. Furthermore, according to Sharapova, "it is possible that the inhabitants were decimated by disease or that the remaining population went elsewhere in search of a better life."

The presumed firstborn son has had numerous partners and children

"There is a global connection between different family systems and certain forms of life-style and economy," says Blöcher. "Nevertheless, human societies are characterized by a high degree of flexibility." He adds, "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 uncover more genomic proof suggesting groups with ancestries similar to those of Neplujevsky culture existed across the majority of the Eurasian steppe region. According to Burger, "It is quite possible that the local pattern we found is relevant to a much larger area." The validity of the "Neplujevsky" paradigm at other prehistoric sites in Eurasia will be the subject of further research.