Newgrange remains may be offspring of incestuous union amongst social elite

An international team of archaeologists and geneticists led by Trinity College Dublin has shed fascinating new light on the society of Ireland’s first farmers in the Neolithic period (4,000BC–2,500BC). An article, published today in the leading journal Nature, reveals the remarkable results of scientific analyses of human remains excavated from key National Monuments across the country.

Among their stunning findings is the discovery that an adult male buried in the heart of the Newgrange passage tomb around 3,200BC may have been among a ruling social elite. Other ruling dynasties from the archaeological world include the Inca god-kings and Egyptian pharaohs, though the Irish Neolithic period is much earlier than those civilizations.

Analysis of the skeletal remains of this adult male, which were retrieved during archaeological excavations led by Professor MJ O‘Kelly at the UNESCO World Heritage Site in the 1960s, marks him as the offspring of a first-order incestuous union, meaning, in plain language, his parents were very closely related. Such unions are a near-universal taboo for biological and cultural reasons, though given his privileged burial within the chamber of the Newgrange monument, his parentage was very likely to have been socially sanctioned.

The Trinity College Dublin research group notes that socially sanctioned mating of this nature is very rare, and in global scientific studies has been documented almost exclusively among politico-religious elites—specifically within royal families that are headed by god-kings. In globally documented cases of this, such as in Hawaii, the Inca empire and in ancient Egypt, such behaviour is typically limited to ruling families whose perceived divinity exempts them from social convention. Researchers have generally viewed such close unions as a means of intensifying hierarchy and legitimising power.

The evidence from this study suggests a similar dynamic may have existed here in Ireland during the Neolithic period which heralded the introduction of farming and saw the construction of large megalithic burial and ritual monuments.

This suggestion of a close family ‘royal’ dynasty during the middle of the Neolithic period coincides with the building of the great passage tombs of Newgrange, Knowth and Dowth and echoes medieval folklore associated with the World Heritage Site of Brú na Bóinne. The 12th century Book of Leinster records the tale of a union between a sister and a brother which lent itself to the ancient name for Dowth.

The team of scientists also revealed a web of distant familial relations between the man buried at Newgrange and other individuals buried at passage tombs across the country, namely the cemeteries of Carrowmore and Carrowkeel in County Sligo, and the tomb at Millin Bay in County Down.

The genome survey led by Trinity College Dublin stretched over two millennia and unearthed other unexpected results. Within the oldest known burial structure on the island, Poulnabrone portal tomb in the Burren, built around 3,800BC, the earliest yet diagnosed case of Down Syndrome was discovered in a male infant buried there.

The remains were excavated by Dr. Ann Lynch of the National Monuments Service in the 1980s as part of urgent conservation work at the spectacular burial monument. Isotope analyses of this infant showed a dietary signature of breastfeeding. In combination with being afforded burial in the chamber, an honour afforded to very few, the researchers suggest this provides an indication of care and that visible difference was no barrier to prestige burial.

Additionally, the genetic analyses showed that the monument builders were early farmers who migrated to Ireland and replaced the Mesolithic hunter-gatherers who preceded them. The scientific evidence suggests that there was a swamping of the earlier population rather than any forced displacement or extermination.

The findings are dramatic in the ever-dynamic retelling of our past. The results will hopefully lead to further research on other human remains which will help tell us even more of the people of ancient Ireland and their society. While we do already know much about the monuments they built, some of them our most prized National Monuments in State Care, we still know relatively little about those who built them. As scientific endeavour grows and ever more complex analytical possibilities develop, we have the potential to learn much more.

The research was funded by a Science Foundation Ireland/Health Research Board/Wellcome Trust Biomedical Research Partnership Investigator Award to Professor Dan Bradley and an earlier Irish Research Council Government of Ireland Scholarship to Dr Lara Cassidy of TCD.