Analyzing ancient DNA from a Neolithic tomb in Britain, an international team of geneticists and archeologists have mapped out the family tree of a group of 27 close biological relatives who lived around 3700 BC.
Working with the bones and teeth of 35 individuals buried in a single cairn, the research team successfully extracted enough DNA to determine that most of the individuals descended from four different women who had children with the same man.
The cairn at Hazleton North, one of the best-preserved Neolithic tombs in the UK, includes two L-shaped chambered areas located north and south of the main “spine” of the linear structure.
According to the research findings, published in Nature, men were generally buried with their father and brothers, suggesting that descent was patrilineal with later generations buried at the tomb connected to the first generation entirely through male relatives.
“The tomb at Hazleton North has two separate chambered areas, one accessed via a northern entrance and the other from a southern entrance,” explained Chris Fowler, of Newcastle University, the first author and lead archaeologist of the study. “One extraordinary finding is that, initially, each of the two halves of the tomb were used to place the remains of the dead from one of two branches of the same family. 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.”
While the researchers discovered two daughters of the lineage who died in childhood buried in the tomb, the absence of adult daughters suggests they were buried in the tombs of their male partners.
In terms of layout, the DNA analysis also revealed that individuals were buried in the north or south chambered area depending on the first-generation woman from whom they were descended. Socially, this suggests the first-generation women were significant in the community, or family at the very least.
“It was difficult to imagine just a few years ago that we would ever know about Neolithic kinship structures,” said Ron Pinhasi, associate professor in the Department of Evolutionary Anthropology, 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 DNA analysis also revealed that “stepsons” were adopted into the lineage. The researchers found DNA of males whose biological mother was buried in the tomb, but their biological father was not the male from the patriline that their mother had other children with.
The team found no evidence the other eight individuals in the tomb were biological relatives of the five continuous generations. However, three of them were woman, so it’s possible they had a partner in the tomb and either didn’t have any children or had only daughters who reached adulthood and moved on.
“This study reflects what I think is the future of ancient DNA: one in which archaeologists are able to apply ancient DNA analysis at sufficiently high resolution to address the questions that truly matter to archaeologists,” said David Reich, professor of genetics at Harvard Medical School, whose laboratory led the DNA analysis.
Photo: The analysis revealed five continuous generations of a single extended family. Credi:t Newcastle University/Fowler, Olalde et al.