[Researchers found] an adult male buried at the 5,000-year-old Newgrange monument; his DNA revealed that his parents were first-degree relatives, possibly brother and sister.
He was one member of an extended “clan” that was buried at impressive stone monuments across Ireland.
The Irish elites were established during Neolithic times, when people first started farming. The researchers extracted DNA from 44 ancient individuals from across Ireland and sequenced their genomes (the full complement of genetic material contained in the nuclei of cells).
Evidence of incestuous unions like that found at Newgrange are rare in human history; they are taboo for inter-linked biological and cultural reasons. Where they do occur, it is often within royal dynasties that have been granted divine status.
Brother-sister marriages are found among the pharaohs of ancient Egypt and the “god-kings” of South America’s Inca Empire. Tutankhamun’s parents, for example, are thought by some to have been full siblings.
The Newgrange monument in County Meath is a kidney-shaped mound covering an area of more than one acre. It’s part of a tradition of elaborate monuments built with large stones, or megaliths, in Atlantic Europe during the Neolithic.
“The prestige of the burial makes this very likely a socially sanctioned union and speaks of a hierarchy so extreme that the only partners worthy of the elite were family members, said Prof Dan Bradley.