Brits, Irish, what's the difference?

Nicholas Wade has a story in the New York Times about how the British and the Irish are genetically more similar than people would have been led to believe. The story revolves around a new book by geneticist Stephen Oppenheimer called "The Origins of the British: A Genetic Detective Story" (Carroll & Graf, 2006). This story is very reminiscent of a study done three or four years ago about how Israelis and Palestinians were virtually genetically indistinguishable, much to each group's consternation, I'm sure. Here are some of the more interesting parts, and my Jerry Springer-esque final thought at the end:

"Historians teach that they are mostly descended from different peoples: the Irish from the Celts and the English from the Anglo-Saxons who invaded from northern Europe and drove the Celts to the country’s western and northern fringes."

"Stephen Oppenheimer, a medical geneticist at the University of Oxford, says the historians’ account is wrong in almost every detail. In Dr. Oppenheimer’s reconstruction of events, the principal ancestors of today’s British and Irish populations arrived from Spain about 16,000 years ago, speaking a language related to Basque."

"The British Isles were unpopulated then, wiped clean of people by glaciers that had smothered northern Europe for about 4,000 years and forced the former inhabitants into southern refuges in Spain and Italy. When the climate warmed and the glaciers retreated, people moved back north. The new arrivals in the British Isles would have found an empty territory, which they could have reached just by walking along the Atlantic coastline, since the English Channel and the Irish Sea were still land."

"A different view of the Anglo-Saxon invasions has been developed by Mark Thomas of University College, London. Dr. Thomas and colleagues say the invaders wiped out substantial numbers of the indigenous population, replacing 50 percent to 100 percent of those in central England. Their argument is that the Y chromosomes of English men seem identical to those of people in Norway and the Friesland area of the Netherlands, two regions from which the invaders may have originated."

"Dr. Oppenheimer disputes this, saying the similarity between the English and northern European Y chromosomes arises because both regions were repopulated by people from the Iberian refuges after the glaciers retreated."

I never knew that the Irish identified themselves so fiercely as being different from the British. It illustrates once again, how in humans, the notion of blood ties are so closely linked to group affiliation, and also very importantly - vice versa.