The Giant Family Tree Reveals Seven Generations of Neolithic Life in the Buried Site of the Gurgy Manufacture
“This type of work really breathes new life into our understanding of ancient peoples,” says Kendra Sirak, an ancient-DNA specialist at Harvard Medical School in Boston, Massachusetts. She’s most curious about the man at the root of the family tree. I want to know what made this person so important.
This contrasts with a later Neolithic burial in the United Kingdom, Hazleton North, where researchers identified2 a man who had reproduced with four women. Chris Fowler was part of that study and he said that researchers need to make family trees from ancient burials to figure out what typical is.
The giant family tree revealed other previously hidden aspects of Neolithic life. A mother and father were present for all siblings. This suggests that no individuals had more than one partner. It is fairly straightforward and monogamous in this location. “Is that the standard life of the commoner and the non-elite?”
In the mid-2000s, archaeologists excavating a burial site in France uncovered a 6,500-year-old mystery. Among the remains of more than 120 individuals, one grave stood out. The skeleton was complete and had bones that looked like they had been moved from a different grave.
But they were astounded to discover that around two-thirds belonged to a single family tree that spanned seven generations. The closer people were buried, the more closely related they were.
A team from his office analysed the genomes of 94 of the 128 people recovered from the site, and figured out how they were related to one another. Some individuals were expected to be related, based on the composition of other Neolithic sites.
To gain independent information on individual mobility, we performed strontium isotope analyses (87Sr/86Sr) using laser ablation20 on 57 individuals (Fig. 3, Supplementary Note 11, Supplementary Table 23 and Extended Data Figs. 3 and 8). The values of the 87sr/86Sr ratio are lower for females and males that have no parents at the site. Although the geological reference map does not enable us to infer a specific geographical origin, this finding provides further evidence that these female individuals grew up in different places before joining the Gurgy community (Supplementary Note 11 and Extended Data Fig. 8). The published stable isotope data show a sex-biased diet for adults. Female individuals yielded higher 13C and 15N, and lower 34S values, than male individuals, which could reflect a separation by sex, but also signal female mobility. Genetic sex determination of subadults enabled us to confirm this difference also in childhood (P = 0.01019), which could be explained by a sex-related differential treatment at certain ages, determined by social rules (Supplementary Note 14 and Extended Data Fig. 5). When the children are buried with grave goods different from the adult’s, the funerary practices in Gurgy show a shift at around 7 years of age, and another at about 15 years of age. This pattern has previously been observed at other Neolithic sites in the northern half of France22 (Supplementary Table 1).
We observed that women of provenance that are genetically synthetic tend to be socially integrated into their partner’s burial area. A shortage of mothers and fathers were observed, with only 9 mothers and 20 fathers found at Gurgy. This indicates that male adults were twice as likely to be buried as females, and that’s in relation to the total number of adult burials. We therefore observed a potential sex bias in burials independent of female exogamy. This could be explained by different funerary practices being reserved for these mothers, or by other social factors mitigating against a co-burial with their reproductive partner’s group.