It's a "long-standing archaeological controversy": whether the Irish shifted from hunter-gatherers to farmers because of adaptation or migration. A new DNA analysis of remains from several people, dating back thousands of years, may settle the question—as well as provide a better sense of where the Irish came from. Reporting this week in the Proceedings of the National Academy of Sciences, geneticists from Trinity College Dublin and archaeologists from Queen's University Belfast sequenced the genomes of a 5,200-year-old female farmer buried near Belfast and three men found on Rathlin Island who hail from the Bronze Age between 3,000 and 4,000 years ago, after metalworking was introduced. The analysis reveals that the Irish have distinct genetic variants from the Middle East and what would become parts of Russia and Eastern Europe, per a press release.
Specifically, the early farmer was mainly of Near Eastern origin, while the men's ancestry came in part from ancient sources in the Pontic steppe of southern Russia. As the Guardian puts it, "the emergence of agriculture and the advance of metallurgy were not just culture shifts: they came with new blood. An earlier population of hunter gatherers was successively overwhelmed by new arrivals. And in Ireland, these new settlers began to define a nation." Geneticist Dan Bradley frames it in a similarly poetic manner: "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." (The lowly snail has also revealed secrets of Ireland's origins.)