The majority of Irish men are descended from farmers who came to the country 6,000 years ago, not from an older line of hunter-gatherers as previously believed, a study has found.
Researchers at Britain’s University of Leicester have discovered that 85% of Irish males are descendants of farmers who migrated to the country from Turkey and surrounding Mediterranean areas, bringing agriculture with them.
The information contradicts previous theories that suggested the primary genetic legacy of Irish males is from hunter-gatherers who survived in Spain and Portugal during the last Ice Age.
The researchers also found a different pattern in female genetic material, suggesting the farmers, when they arrived in Ireland, appealed to women more than the indigenous hunter-gatherers.
Patricia Balaresque, first author of the study, said: “Most maternal genetic lineages seem to descend from hunter-gatherers. To us, this suggests a reproductive advantage for farming males over indigenous hunter-gatherer males during the switch to farming. Maybe, it was just sexier to be a farmer.”
The study, funded by the Wellcome Trust, examined the diversity of the Y chromosome, which is passed from father to son. It focused on the most common lineage in Europe, which it found to be present in 85% of Irish men.
The authors used different lines of evidence to shape the latest theory: the pattern of distribution of the chromosome’s lineage in men, the diversity within it, and estimates of its age.
These all suggested that the lineage spread with farming from the Near East. Jobling said: “This particular kind of Y chromosome follows a gradient, gradually increasing in frequency from Turkey and the southeast of Europe to Ireland, where it reaches its highest frequency.”
In Britain, the lineage trait is in 60%-65% of the population, and in parts of the Iberian peninsula it’s almost as high as in Ireland.
“We are saying that most of that original hunter-gatherer male population in Ireland was probably replaced by incoming agricultural populations,” said Jobling.
The invention of farming was perhaps the most important cultural change in the history of modern humans.
Increased food production led to the development of societies that stayed put, rather than wandering in search of food. This led to population explosions.
Times Online
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