There are no signs of a massacre–no mass graves, no piles of bones. Yet more than a million men vanished without a trace. They left no descendants. Historians know that something dramatic happened in England just as the Roman empire was collapsing. When the Anglo-Saxons first arrived in that northern outpost in the fourth century a.d.–whether as immigrants or invaders is debated–they encountered an existing Romano-Celtic population estimated at between 2 million and 3.7 million people. Latin and Celtic were the dominant languages. Yet the ensuing cultural transformation was so complete, says Goelet professor of medieval history Michael McCormick, that by the eighth century, English civilization considered itself completely Anglo-Saxon, spoke only Anglo-Saxon, and thought that everyone had “come over on the Mayflower, as it were.” This extraordinary change has had ramifications down to the present, and is why so many people speak English rather than Latin or Celtic today. But how English culture was completely remade, the historical record does not say.
Then, in 2002, scientists found a genetic signature in the DNA of living British men that hinted at an untold story of Anglo-Saxon conquest. The researchers were sampling Y-chromosomes, the sex chromosome passed down only in males, from men living in market towns named in the Domesday Book of 1086. Working along an east-west transect through central England and Wales, the scientists discovered that the mix of Y-chromosomes characteristic of men in the English towns was very different from that of men in the Welsh towns: Wales was the primary Celtic holdout in Western Britannia during the ascendance of the Anglo-Saxons. Using computer analysis, the researchers explored how such a pattern could have arisen and concluded that a massive replacement of the native fourth-century male Britons had taken place. Between 50 percent and 100 percent of indigenous English men today, the researchers estimate, are descended from Anglo-Saxons who arrived on England’s eastern coast 16 centuries ago. So what happened? Mass killing, or “population replacement,” is one possible explanation. Mass migration of Anglo-Saxons, so that they swamped the native gene pool, is another.
Most importantly, he found that inhabitants of the Dutch province of Friesland were indistinguishable genetically from the English town-dwellers. Friesland is one of the known embarkation points of the Angl0-Saxons–and the language spoken there is the closest living relative to English. (“Listening to a Frisian speak,” says Thomas, “is like listening to somebody speak English with a frog in their mouth.”)
This part was very striking, too. Who knew that this was the kind of detail that can still be figured out after 1,200 years?
The pattern of sexual exploitation by a dominant group seen in the preceding examples is not at all unusual in the human genetic record, says Reich’s frequent collaborator, Nick Patterson, a senior research scientist at the Broad Institute of MIT and Harvard. The Icelandic sagas record that the exiles who settled that island raided Scotland and Ireland, kidnapping Celtic women. And the genes corroborate this account. The mitochondrial DNA of the women is Celtic, the Y-chromosomes are Nordic. DNA has also revealed lost histories of Viking travel. A rare defect that causes mental retardation links the northwest coast of Norway to northern Ireland, says McCormick: “We knew the Danes had been in Dublin, but these are new data that are totally unexpected.” Similar stories are emerging everywhere around the globe as genetic population data become more common.
Not really news, to some of us. Although it does sort of serve to explain the affection of an Ulsterman (me) for a Scandinavian instrument (Willowflute). This “mental retardation”… it wouldn’t be autism by any chance?
Yes, I got the dead tree edition of this (alumni mag) a month ago. A pretty good overview article, for people who don’t normally follow what’s been happening in this field.
I only wish Shaw had devoted a bit more space to addressing the title question specifically, and had mentioned more about corroborative work coming from Continuity Theory. For example, it’s possible there was already a substantial shared Germanic substrate population in eastern Britain and Freisland long before the 5th century migrations. Which lowers the bar for the degree of population swamping required to account for the resulting genetic picture.
In any case, the key to appreciating the mind-boggling impact of population genetics is to be open to the idea that everything you think you knew about late prehistory may be completely and utterly wrong.
It surprises me that they would say that they knew that the Norsemen had been in Dublin, but that they seemed surprised to see evidence of them in the North. Heck, one of the most common surnames in the north is “McLaughlin,” which comes from “Mac Lochlann”…“Lakeman’s Son” (“Lakeman” being an Irish term for the Vikings). And “Donegal” (Dún na nGall) does mean “Fort of the Foreigner.” The Vikings were all over that island!