To date, knowledge about the biological side of familial organization in prehistoric societies has been limited. In particular, little is known about the structure of Bronze Age society in Eurasia at the village or household levels. Here, the skeletal community of a burial mound in the Southern Urals was studied using integrative methods from the fields of archaeology, anthropology, and palaeogenomics. It is suggested that the descent system of the 3,800-y-old livestock herders at Nepluyevsky was patrilineal and primarily determined by consanguinity between brothers. Monogamy was the marriage norm, and postmarital residence was patrilocal, with female membership being transferred to the husband’s group.
Our understanding of prehistoric societal organization at the family level is still limited. Here, we generated genome data from 32 individuals from an approximately 3,800-y-old burial mound attributed to the Bronze Age Srubnaya-Alakul cultural tradition at the site of Nepluyevsky, located in the Southern Ural region of Central Eurasia. We found that life expectancy was generally very low, with adult males living on average 8 y longer than females. A total of 35 first-degree, 40 second-degree, and 48 third-degree biological relationships connected 23 of the studied individuals, allowing us to propose a family tree spanning three generations with six brothers at its center. The oldest of these brothers had eight children with two women and the most children overall, whereas the other relationships were monogamous. Notably, related female children above the age of five were completely absent from the site, and adult females were more genetically diverse than males. These results suggest that biological relationships between male siblings played a structural role in society and that descent group membership was based on patrilineality. Women originated from a larger mating network and moved to join the men, with whom they were buried. Finally, the oldest brother likely held a higher social position, which was expressed in terms of fertility.