Ancient genome analysis of Irish ancestors reveals Irish origin in a first scientific study of its kind conducted by geneticists with the Queen’s University Belfast and Trinity College Dublin.

Human DNA is a comprehensive history book spelled in billions of associations. With every closer look, something new is revealed. The geneticists team from the two institutions have conducted their analysis on genomes of ancient Irish ancestors. One of the study cases was a woman, an early Neolithic farmer found in a region close to Belfast. The early Neolithic farmer would have lived approximately 5,200 years ago. The second study case looked at the genomes of a group comprising three men. The three Bronze Age men would have lived approximately 4,000 years ago.

The ancient genome analysis of Irish ancestors reveals Irish origin against the background in which the early Neolithic farmer and the three Bronze Age men shared common traits. The results of the intriguing study are published in the Proceedings of the National Academy of Sciences journal.

What clues did the Neolithic woman and the Bronze Age men reveal to the scientific team regarding Irish heritage? For once, lactose tolerance was a prominent feature of these Irish ancestors. From the Neolithic to the Bronze Age, ancient humans of the insular Celtic region were prone to consuming milk and milk products.

On the other hand, particularly the Bronze Age group shared genomes indicative of a genetic disease called haemochromatosis. Haemochromatosis stands for excessive iron retention. The genome analysis of the Irish ancestors showed that by the Bronze Age, this was already well established. One possibility is that excessive iron retention developed at first to compensate for the lack of sufficient iron intake.

As for the origin of the Irish people, the genome analysis showed quite different paths. Migration has always been a much debated topic of archeology, genetics and other scientific fields. For the Irish, as much as elsewhere in the world, scientists have wondered whether transitioning from hunter-gatherer social forms to farming and then metal use was an in-bred evolution or influenced by migratory influxes.

The early Neolithic farmer and the three Bronze Age men revealed intriguing details on the matter. While the farmer woman showed striking resemblance to Sardinia and Spain people, the genome analysis indicated that her genetic inheritance is shared with Middle East migratory groups. It was in the Middle East that agricultural practices were first invented. With influxes of people from the Middle East to Europe, agriculture and farming became established practices in Europe as well.

The genome analysis conducted on material collected from the three Bronze Age men revealed a different path. The men shared one third of their genetic inheritance with the ancient humans of the Pontic Steppe. Located between modern-day Ukraine and Russia, the Pontic Steppe was the start point of another migratory influx that influenced the origin and practices of the Irish ancestors.

In a nutshell, the farmer woman living 5,200 years ago had black hair and brown eyes. The group of men already had blue eyes, a well established variant of the excessive iron retention genetic disease and a prominent Y chromosome type indicative of lactose tolerance.

Photo Credits: geograph.org.uk