Scientists have sequenced the first ancient human genomes from Ireland, shedding light on the genesis of Celtic populations.
The ancient Irish genomes show unequivocal evidence for mass migration in both cases.

DNA analysis of the Neolithic woman from Ballynahatty, near Belfast, reveals that she was most similar to modern people from Spain and Sardinia. But her ancestors ultimately came to Europe from the Middle East, where agriculture was invented.

The males from Rathlin Island, who lived not long after metallurgy was introduced, showed a different pattern to the Neolithic woman. A third of their ancestry came from ancient sources in the Pontic Steppe - a region now spread across Russia and Ukraine.

"There was a great wave of genome change that swept into [Bronze Age] Europe from above the Black Sea... we now know it washed all the way to the shores of its most westerly island," said geneticist Dan Bradley, from Trinity College Dublin, who led the study.