All the Same

I found this article fascinating:

Britain and Ireland are so thoroughly divided in their histories that there is no single word to refer to the inhabitants of both islands. 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.

But geneticists who have tested DNA throughout the British Isles are edging toward a different conclusion. Many are struck by the overall genetic similarities, leading some to claim that both Britain and Ireland have been inhabited for thousands of years by a single people that have remained in the majority, with only minor additions from later invaders like Celts, Romans, Angles , Saxons, Vikings and Normans.

[…]

In all, about three-quarters of the ancestors of today’s British and Irish populations arrived between 15,000 and 7,500 years ago, when rising sea levels finally divided Britain and Ireland from the Continent and from one another, Dr. Oppenheimer calculates in a new book, “The Origins of the British: A Genetic Detective Story” (Carroll & Graf, 2006).

As for subsequent invaders, Ireland received the fewest; the invaders’ DNA makes up about 12 percent of the Irish gene pool, Dr. Oppenheimer estimates, but it accounts for 20 percent of the gene pool in Wales, 30 percent in Scotland, and about one-third in eastern and southern England.

The Normans, for all the importance that historians typically accord them, made only the tiniest dent in the genetic heritage of the English people.