DNA analysis extracted from the remains of 35 people found buried in a tomb in Gloucestershire, England, has enabled scientists to piece together what is believed to be the world’s oldest family tree.
The group, who lived approximately 5,700 years ago, included five continuous generations of a single family.
Researchers studied DNA taken from bones and teeth found in the tomb at Hazleton North, a long cairn, or burial mound, in the Costwolds-Severn region that is one of the best-preserved Neolithic tombs in Britain.
Twenty-seven of the 35 people who lived during the 3700-3600 BC period were biological relatives.
The findings published in the science journal Nature stem from the first study to reveal in such detail how prehistoric families were structured.
A team of archaeologists from Newcastle University, UK, and geneticists from the University of the Basque Country, University of Vienna and Harvard University, found that most of those buried in the tomb were descended from four women who had all had children with the same man.
The fascinating findings provide a unique insight into kinship and burial practices observed during Neolithic times.
“It was difficult to imagine just a few years ago that we would ever know about Neolithic kinship structure,” said Ron Pinhasi, of the University of Vienna,
“But this is just the beginning and no doubt there is a lot more to be discovered from other sites in Britain, Atlantic France, and other regions.”
The remains of the adults and children, who lived about a century after farming had been introduced to Britain, were entombed in two L-shaped chambers to the north and south of the main “spine” of the linear structure.
Men were buried with their fathers and brothers, suggesting descent was patrilineal with later generations buried at the tomb connected to the first generation entirely through male relatives.
Two young daughters of the lineage were also buried in the tomb but the remains of adult daughters were not found. This led researchers to conclude that they would have instead been buried with their male partners or elsewhere.
While patrilineal ties played a central role in whether a person was laid to rest in the tomb or not, the choice between north and south depended on the first-generation woman from whom they were descended. This suggested that these first-generation women held a high status in the community.
There are also indications that stepsons may have been adopted into the lineage, researchers said, because men whose mother was buried in the tomb but not their father were laid in the same space. Their mother was found to have had other children with a male from the patriline.
The remains of eight people, including three women, were found to have no biological relatives in the family tree, meaning biological relatedness was not the only criterion for a place in the tomb.
Experts said it is possible that the women could have been partners of a male in the tomb but either did not have children or had daughters who reached adulthood and left the community.
Dr Chris Fowler of Newcastle University, the first author and lead archaeologist of the study, said the findings offer an “unprecedented insight into kinship in a Neolithic community”.
He said it was “extraordinary” to discover that two branches of the family were buried in the tomb, one in the north and the other in the south.
“This is of wider importance because it suggests that the architectural layout of other Neolithic tombs might tell us about how kinship operated at those tombs,” he said.
Inigo Olalde of the University of the Basque Country and Ikerbasque, the lead geneticist for the study and co-first author, said thanks to the excellent DNA preservation at the tomb, researchers had uncovered the “oldest family tree ever reconstructed”.
David Reich at Harvard University, whose laboratory led the ancient DNA generation, said the study indicated the promise that the field of study held. In future, study of ancient DNA might mean archaeologists will be able to apply “analysis at sufficiently high resolution to address the questions that truly matter”.
