Geneticists at Trinity College have sequenced the genomes of ancient Irish farmers, discovering that haemochromatosis (known as the ‘Celtic curse’) was inherited by people from the Pontic Steppe 4,000 years ago.
Working with archaeologists at Queen’s University in Belfast, the Trinity researchers first looked at the remains of a female farmer from the north of the island, who lived 5,200 years ago.
They then looked into the remains of three men found on Rathlin Island who lived 1,200 years later, during the Bronze Age.
The make-up of an Irish person, it seems, changed dramatically somewhere in between.
Reconstruction of Ballynahatty Neolithic skull by Elizabeth Black. Her genes tell us she had black hair and brown eyes, via Barrie Hartwell.
Whereas the early farmer resembled southern Europeans, with black hair and brown eyes, an influx of migrants from the East appears to have started soon after.
The genetic variants circulating in the three Bronze Age men had the most common Irish Y chromosome type, blue eye alleles and the most important variant for the genetic disease haemochromatosis.
These ancient Irish genomes each show unequivocal evidence for massive migration, according to the resarchers.
The earlier farmer has a majority ancestry originating ultimately in the Middle East, where agriculture was invented. The Bronze Age genomes are different again, with about a third of their ancestry coming from ancient sources in the Pontic Steppe.
A wave of 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 Dan Bradley, professor of population genetics in Trinity College Dublin, who led the study, “and this degree of genetic change invites the possibility of other associated changes, perhaps even the introduction of language ancestral to western Celtic tongues.”
The C282Y mutation that indicates haemochromatosis risk is so frequent in people of Irish descent that it has earned the moniker of the Celtic disease or the Celtic curse. This discovery therefore marks the first identification of an important disease variant in prehistory.
“Genetic affinity is strongest between the Bronze Age genomes and modern Irish, Scottish and Welsh, suggesting establishment of central attributes of the insular Celtic genome some 4,000 years ago,” added PhD Researcher in Genetics at Trinity, Lara Cassidy.
The study has been published in Proceedings of the National Academy of Sciences.
Main Celtic cross image via Shutterstock