Would you guess that some ancient Irish origins ultimately came from the Middle East?
A team of geneticists from Trinity College Dublin and archaeologists from Queen’s University Belfast have unearthed some intriguing findings about Ireland’s people and culture after sequencing the first genomes from ancient Irish humans.
The team sequenced the genome of a Neolithic farmer woman who lived near Belfast about 5,200 years ago, as well as three men who lived in Ireland about 4,000 years ago in the Bronze Age, which occurred after the introduction of metalworking.
Irish genetics have long intrigued researchers since the country lies at the edge of many European genetic gradients, according to the press release. For instance, Ireland has the world’s highest frequencies of genetic variants that code for lactase persistence — or the continued ability to digest lactose into adulthood — as well as certain genetic diseases, including one of excessive iron retention, called haemochromatosis.
There’s been divided opinions on whether the transition from the hunter-gatherer lifestyle to one based on agriculture and the transition from stone to metal use were due to local adoption of new ways, or if these influences came from influxes of new people.
By embarking on a kind of “genetic time travel,” the researchers were able to find some answers to the questions about the origins of Ireland’s heritage, and the sequenced genomes “show unequivocal evidence for massive migration.”
"There was a great wave of genome change that swept into Europe from above the Black Sea into Bronze Age Europe and we now know it washed all the way to the shores of its most westerly island," said Professor of Population Genetics in Trinity College Dublin, Dan Bradley, who led the study.
He added, "This degree of genetic change invites the possibility of other associated changes, perhaps even the introduction of language ancestral to western Celtic tongues.”
Interestingly, DNA analysis of the Neolithic woman revealed that she was most similar to modern people from Spain and Sardinia, but her ancestors ultimately came from the Middle East. The men from the Bronze Age differed, with about a third of their ancestry coming from ancient sources in the Pontic Steppe.
The farmer woman more resembled southern Europeans with black hair and brown eyes, but the genetic variants circulating within the three Bronze Age men has the most common Irish Y chromosome type and blue eye alleles.
The men also had the most important variant for the genetic disease, haemochromatosis, and this C282Y mutation is so frequent in Irish people that it’s sometimes referred to as a “Celtic disease.”
Dr Eileen Murphy, Senior Lecturer in Osteoarchaeology at Queen's University Belfast, said, "It is clear that this project has demonstrated what a powerful tool ancient DNA analysis can provide in answering questions which have long perplexed academics regarding the origins of the Irish.”
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