Relatively little is known about the tribes of Neolithic farmers who, in the Stone Age, migrated from the Fertile Crescent to settle in Old Blighty and northwestern Europe. One thing we do know – they liked to build great big stone monuments (or megaliths), many of which are still scattered across the continent today.
Writing in Proceedings of the National Academy of Sciences, an international team of researchers led by Uppsala University, Sweden, studied human remains buried under five megalithic tombs standing in Ireland, Scotland, and Sweden. Using radiocarbon dating and genome sequencing, they discovered kin relationships among the buried, which could be traced for more than 10 generations. This, they say, suggests the megaliths served as graves for certain kindred groups living in northwestern Europe at the time.
The backbreaking practice of building vast rock monuments – the kind seen at Stonehenge – reached northwestern Europe circa 4,500 BCE. There are 35,000 or so known megalithic sites dotted along the coastlines in Europe and the Middle East. But while the origin and social hierarchy of the people who made them remain something of a mystery, it appears that funerary practice was at least one key function of these (often) giant structures.
To try and find out more about the builders of megaliths, the team collected the dental and skeletal remains of 24 individuals from Ireland, Scotland, and the Baltic island of Gotland in Sweden. Radiocarbon dating revealed they were buried between 3,800 and 2,600 BCE, while genome sequencing allowed the researchers to compare their DNA to the genetic variation of various Stone Age groups.
The results from the genome sequencing suggest the buried were closely related to Neolithic farmers in the northern and western parts of Europe, plus some groups living in Iberia. However, they were less closely related to Neolithic farmers living in central Europe.
What's more, they found extremely close kin relationships between the individuals. Indeed, there was even a pair they believe were parent and progeny, buried at two megalithic sites only 2 kilometers apart. This was surprising, says co-first author Federico Sanchez-Quinto. "It appears as these Neolithic societies were tightly knit with very close kin relations across burial sites," he said in a statement.
One site in Sweden reveals a burial tradition that lasted for more than 700 years, revealed co-first author Magdalena Fraser. Their genetics are "remarkably different" from the hunter-gatherers who dominated the region at the time, revealing the segmentation of certain groups with roots in the European Neolithic expansion.
Another thing the team noticed was the overrepresentation of male bodies in British megalithic tombs but, interestingly, less so in the Swedish.
"We found paternal continuity through time, including the same Y-chromosome haplotypes reoccurring over and over again," explained co-first author Helena Malmström.
"However, female kindred members were not excluded from the megalith burials as three of the six kinship relationships in these megaliths involved females."
So, what can we take away from all this?
"That we find distinct paternal lineages among the people in the megaliths, an overrepresentation of males in some tombs, and the clear kindred relationships point to towards the individuals being part of a patrilineal segment of the society rather than representing a random sample from a larger Neolithic farmer community," senior author, Mattias Jakobsson, explained.
Still, these are just the results of remains from five megaliths. As the researchers point out themselves, more research is needed to confirm whether these findings are unique to these particular sites or represents a general pattern for megalith burials.
