In County Meath in eastern Ireland sits the world heritage site of Brú na Bóinne. The late 4th millennium BC megalithic tombs have been labelled “passage tombs” by archaeologists because they typically feature a narrow passage leading to an internal chamber, covered by a large circular mound. Centuries of antiquarians and archaeologists thought they were burial places for the elite of Neolithic Irish society.
Genetic analysis of human remains within several of the tombs initially seemed to reinforce this. But our latest research has overturned this idea.
By integrating exciting new results from ancient DNA into archaeological models, combining archaeological and biomolecular data, we have been able to draw out a rich and complex picture of daily life, interactions, and social structure in Neolithic Ireland. Together, this evidence deconstructs the myth that only important individuals were socially active, which downplays the contribution made by collective action in the deep past.
What our research reveals is a complex pattern of small, mobile groups who moved frequently with their animals and gathered seasonally. These groups would meet with their extended community at their shared monuments to progress funerary rites for some of their dead, renew old relationships and form new ones. In this way, they built their kin networks over hundreds of kilometers and many generations through communal feasting, ceremonies, and work, as well as through having children together.
Burial within even the largest examples of “developed” passage tombs does not seem to have been restricted to venerated chiefs. Instead, it was part of a long sequence of rites and rituals that included cremation, the exposure or circulation of parts of bodies, and the eventual interment of partial sets of remains, some of which were later removed.
Genetic analysis revealed evidence of close biological relations, the kind of which is expected from the final resting-places of a dynastic lineage: from grandparents to grandchildren, siblings, uncles and aunts, nieces, nephews and first cousins. However, we have shown that only a few examples of these close family links occur, and not within passage tombs, but exclusively in smaller and earlier Neolithic tombs.
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Instead, in passage tombs, most biological relationships tend to have been distant (fifth degree or further, meaning second cousins or a great-great-great grandparent). This tells us that burial was not strongly determined by biological relatedness.
Nevertheless, there is something genetically distinctive about passage tombs.
Most of the individuals genetically sequenced from these monuments were more closely biologically related to each other than to the wider Irish population at this time. This means they formed a genetic cluster.
We argue that rather than this being evidence for an elite class in Neolithic Ireland, something else is responsible for this genetic patterning. Crucially, these individuals all postdate 3600BC.
By this time, people’s lifestyles had shifted, possibly becoming more mobile. Houses were temporary and modest in size, farming practices seemed to focus more on animal husbandry, while forests expanded and evidence for cereals reduced. This is the period when the Newgrange-style passage tombs were emerging. Compared to earlier tombs, Newgrange-style tombs were more architecturally complex, much larger and situated in more elevated, visible locations but at a remove from the everyday world of settlement and pasture. Their construction peaked between 3300 to 3000 BC.
Their complexity reflects multiple phases of construction and rebuilding stretching over generations and centuries of seasonal gatherings of widely dispersed communities. In tandem with this new style, social networks became more expansive, spanning ever-greater parts of the island.
Chemical signals locked in human bone and tooth enamel indicate that the people interred in these large monuments came from many different parts of Ireland, as did the artefacts placed in them and the materials from which they were built. People probably brought building materials with them as part of collective journeys to participate in rites that included both burying and building. Such repeated large-scale gatherings involving communal acts of labour contributed to a sense of shared identity and kinship by interconnecting participants with other people, places and things.
The distinct genetic clustering in individuals from passage tombs is likely to have emerged within the context of the extended kin groups created and maintained by such interactions. The genetic analysis shows that people within communities who used passage tombs more frequently chose to have children with each other rather than with people who used other tomb types for their funerary rites. These were sizeable but dispersed communities with extensive interaction networks.
We suggest it may simply have been easier to meet and connect with people who shared the same beliefs, cultural practices and seasonal cycles. Nevertheless people met, mingled, and had children with each other throughout the Irish Neolithic period, regardless of how they buried their dead. There is no evidence that patterns of marriage or reproduction within a given group were enforced or exclusive or that who your parents were reflected differences in status, rank, or importance.
More work, including more ancient DNA samples, is vital to achieve a fuller understanding of the social changes occurring in Ireland at the time of Newgrange. Yet, by interrogating the archaeological evidence in light of genetic findings, we are getting ever closer to understanding how peoples’ relationships changed through time.
Neil Carlin receives funding from Research Ireland
Catherine J. Frieman receives funding from Australian Research Council Future Fellowship FT220100024 ‘Kin and Connection: ancient DNA between the science and the social’.
Jessica Smyth receives funding from Research Ireland (Consolidator Laureate IRCLA/2017/206 'Passage Tomb People: investigating the social drivers of passage tomb construction')
This article was originally published on The Conversation. Read the original article.
