Reconstruction of the largest genetic family tree for Neolithic people in France using ancient DNA
Using ancient DNA, researchers generated two sizable Neolithic family trees.
An artist's interpretation of what each individual may have looked like, based on DNA. The dotted squares and circles represent male and female individuals, respectfully, who were not found at the site or whose remains lacked significant DNA. (Image credit: Drawing by Elena Plain; reproduced with the permission of the University of Bordeaux / PACEA)
The largest ancestral human record ever reconstructed, two elaborate Neolithic family trees that span several generations have been stitched together by French researchers using ancient DNA.
The Gurgy burial site in the Paris Basin region of northern France, which dates back 6,700 years, served as the foundation for the family trees. A study that was published on July 26 in the journal Nature describes how researchers began studying the genomes of 94 of the 128 people, including children and adults, whose remains were recovered from the site recently due to advancements in obtaining and analyzing ancient DNA data. The site was excavated in the middle of the 2000s.
Around 12,000 years ago, Neolithic societies initially appeared in the Near East, which includes West Asia, Southeastern Europe, and North Africa. Many human tribes switched from hunting and gathering to farming during this time. Due to the change in lifestyle, people were able to establish themselves and form long-lasting communities, which produced the expansive burial plot.
According to Maté Rivollat, a postdoctoral fellow in the Department of Archaeology at Ghent University in Belgium and the study's lead author, "the size of a family tree that huge for that time period" was mind-boggling. We came to the conclusion that we could investigate the community's sociological features.
The graveyard at the location was the only one around, and many of the bones were "not well preserved and corroded," according to Rivollat.
Nevertheless, "the bones were good enough [to extract] DNA," she affirmed, "and we were able to get DNA from 94 of the individuals."
Researchers concluded that the family's lineage could be traced back to just one "founding father." According to a statement, his skeleton was special because it was first interred at an unidentified location before being relocated to Gurgy to be close to his relatives. The archaeologists also discovered a woman's remains next to him, but they were unable to recover any DNA.
The researchers created two family trees by looking at the Y-chromosome (paternal lineages) and mitochondrial DNA (maternal lineages) data, as well as each person's age at death and genetic sex. The study found that the first tree, which was the largest to date and connected 64 people across seven generations, and the second, which contained 12 people across five generations.
An adult man (top skeleton) buried some 6,000 years ago in what is now France was a son of the man from whom dozens of people also buried at the site are descended. (Image credit: Stéphane Rottier)
A "patrilineal pattern" soon developed, connecting successive generations via the male line of ancestors. According to the statement, researchers also discovered that while the women left the village where they were born, the men remained.
The women who were interred there, according to Rivollat, "were not related and came from somewhere else." Inbreeding wasn't happening, either, and we believe that this system of female movements prevented it.
The absence of half-siblings and the fact that sons and girls had the same parents was another intriguing feature of the community, suggesting that its members were monogamous rather than polygamous, according to the statement.
It was clear that the heirs were aware of who was interred there, Rivollat stated. "The more closely related they were, the closer they were buried together."