NEW YORK – A genetic analysis on samples going back thousands of years from a site in France has provided new insights into societal and population patterns present there during the Neolithic period.
For a paper appearing in Nature on Wednesday, researchers at the University of Bordeaux, the Max Planck Institute for Evolutionary Anthropology, and elsewhere used targeted DNA sequencing to profile the genomes of skeletal samples from the Gurgy "les Noisats" site in north-central France, focusing on 110 ancient individuals dated 6,500 to almost 6,900 years old.
"These results open a new window to observe social behavior in the past, [which is] especially difficult in prehistoric times," first and co-corresponding author MaÏté Rivollat, an archaeology researcher at Ghent University, said in an email.
"It doesn't mean that genomics will explain all the kinship in ancient groups, because kinship is much more complex than biological relatedness, but it is a step forward to understand the structure of groups living thousands of years ago," explained Rivollat, who is also affiliated with the University of Bordeaux, the Max Planck Institute for Evolutionary Anthropology, and Durham University.
Together with available archaeological data and strontium isotope dating clues, genetic profiles spanning some 1.2 million SNPs revealed relationships between individuals in the farming community, along with their geographic origins and potential societal roles.
Specifically, the team highlighted two main pedigrees at the burial site that included family members stretching over seven generations.
"Our results demonstrate that biological relatedness mattered in the organization of the necropolis, and that whatever combination of social principles organized biological reproduction in this group left behind a strongly patrilineal pedigree structure," the authors wrote.
Along with burial patterns, genetic ties between individuals sampled at the site suggested that the community was home to stable families headed by male individuals who remained in the community.
Because the site was home to full siblings that had reached adulthood, the investigators suggested that the community included fertile, healthy individuals in stable, long-term relationships, who were part of a broader society that supported one another.
The team's data also pointed to distinct ancestry for females buried at the site, suggesting women migrated between patrilineal communities in the region — a pattern known as exogamy that led to genetic mixing between individuals from communities that lived relatively close to one another.
"Some indicative elements that can be inferred from our data — female exogamy, monogamous reproductive partnering, emphasis on sublineage productive/reproductive units — are suggestive of specific kinship and union practices," the researchers added. "Nonetheless, these elements do not preclude the existence of other social conventions that contributed to complex kinship organization, which we cannot access with genetic data."
The investigators noted that the results from the Gurgy site in France may reflect societal and community patterns in other Neolithic groups in the region, though they cautioned that additional analyses on other ancient genetic and archaeological sites will be needed to explore that possibility.
"What remains to be determined is whether our findings are a unique constellation among the Neolithic societies in which the variety of different funerary cultural settings is striking, or whether Gurgy represents a set of normative social structures and kinship organization during the fifth millennium BC," the authors noted.