LONDON (Reuters) - Irish geneticists have used surnames and the male Y chromosome to reconstruct a one thousand year-old genetic map of Ireland that shows the Irish really are a race apart.
"When you look at this old genetic geography of Ireland what you find is that in the West (of the country) we are almost exclusively of one type of Y chromosome," Daniel Bradley told Reuters.
The Y chromosome is passed down exclusively from father to son. It is a favourite of geneticists because it accentuates differences between populations.
"It is inherited as a unit so the information you get from it is of a special type," Bradley said in a telephone interview.
Bradley and his colleagues at Trinity College in Dublin examined the Y chromosomes of men with Gaelic surnames in the western-most province of Connaught, and found that 98.3 percent had a group of genes on the Y chromosome known as haplogroup 1.
"When you look at Gaelic surnames they are different in frequency of Y chromosome types from non- Gaelic surnames," Bradley said.
In a report in the science journal Nature, he and his colleagues said that even within Ireland they found differences.
More than 98 percent of men with Gaelic names in western Ireland had haplogroup 1 but numbers dropped drastically on the east of the Emerald Isle.
Much further east in Turkey only 1.8 percent of men carry haplogroup 1.
"Ireland may tell us something about European diversity because it is on the edge of Europe. Genetic diversity follows geography to some extent," Bradley said.
The researchers said there is a gradient of haplogroup 1 across Europe starting at almost zero in the Far East to almost 100 percent in the west of Ireland.
One of the most likely explanations for this is that farming, which was invented about 10,000 years ago in the near East and caused a fundamental revolution in the way humans lived, spread over across Europe with time but only arrived in western Ireland about 6,000 years ago.
"Ireland has been relatively untouched by this and the other great demographic movements because of its location. That gives us the ability to look at the west and surnames and to get a snapshot of what early European genetics may have been like," Bradley said.
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