Genetic study finds 30% of white British DNA has German ancestry | Genetic

The Romans, Vikings and Normans may have ruled or invaded Britain for hundreds of years, but they barely left a mark on our DNA, the first detailed study of Briton genetics has revealed.

Analysis shows that the Anglo-Saxons were the only conquering force, around 400-500 AD, to significantly alter the genetic makeup of the country, with most white Britons now owing almost 30% of their DNA to the ancestors of the Germans in ‘today.

People living in southern and central England today generally share around 40% of their DNA with the French, 11% with the Danes and 9% with the Belgians, according to the study of more than 2,000 people . The French contribution, however, was not linked to the Norman invasion of 1066, but to a hitherto unknown wave of migration to Britain some time after the end of the last ice age nearly 10,000 years ago. .

Professor Peter Donnelly, director of the Wellcome Trust Center for Human Genetics at the University of Oxford, who co-led the research, said: “It has long been known that human populations differ genetically, but never before have we been able to observe such exquisite and fascinating detail.

The study found that people’s ancestral contributions varied widely across Britain, with people from parts of Wales, Scotland and Northern Ireland appearing as distinct genetic groups, providing for the first time a scientific basis for the idea of ​​regional identity.

Map of the UK showing the grouping of individuals based on genetics and its striking relationship to geography. Photography: Stephen Leslie/Nature/EuroGeographics

The Orkney Islands population was found to be the most genetically distinct, with 25% of DNA coming from Norwegian ancestors who invaded the islands in the 9and century.

The Welsh also showed striking differences from the rest of Britain, and scientists concluded that their DNA most closely resembled that of the first hunter-gatherers to arrive when Britain became habitable again after the Ice Age. .

Surprisingly, the study showed no genetic basis for a single ‘Celtic’ group, with people living in Scotland, Northern Ireland, Wales and Cornwall being among the most genetically different from each other.

“The Celtic regions might have been expected to be genetically similar, but they are among the most different in our study,” said Mark Robinson, archaeologist at the University of Oxford Museum of Natural History and co -author. “It emphasizes their genetic difference, it doesn’t mean there aren’t cultural similarities.”

The study, published Wednesday in the journal Nature, is the culmination of 20 years of work. Scientists began collecting DNA samples from people in Orkney in 1994 and gradually worked across most of the British Isles.

The participants were all white Britons, lived in rural areas and had four grandparents, all born within 80km of each other. Since a quarter of our genome comes from each of our grandparents, scientists were getting a snapshot of British genetics at the start of the 20th century.

Sir Walter Bodmer of the University of Oxford, who designed the study, said: ‘We go back in time before most population mixing, which would blur the story.

The team also looked at data from 6,209 individuals from 10 European countries to reconstruct their ancestors’ contributions to the genetic makeup of Britons.

The analysis shows that despite the considerable historical impact on British civilization of the Roman, Viking and Norman invasions, none of these events significantly altered the basic biological makeup of the people living here. The finds confirm records suggesting that few high Roman officials settled in Britain and that they and their families remained largely separated from the local Celts.

The Danish Vikings, who ruled large swathes of Britain from AD 865, are known to have intermarried with locals, but the latest study shows that the conquering force, although powerful, must have included relatively few fighters.

“There were huge numbers of people – hundreds of thousands – in those parts of Britain, so to have a substantial impact on genetics there would have to be huge numbers,” said Robinson. “The fact that we don’t see this reflects the numbers rather than the relative attractiveness or lack thereof of Scandinavian men to British women.”

The analysis also settles a long-standing dispute over the nature of the Anglo-Saxon takeover of England after the collapse of the Roman Empire. The replacement of the Celtic language by Anglo-Saxon and the complete shift to northwest German farming and pottery styles have led some to suggest that the local people must have retreated to the Land of Wales or even having been wiped out in a genocide.

“[Our results] suggest that at least 20% of the genetic makeup of this area came from Anglo-Saxon migrants and that there was admixture,” Robinson said. “This is not genocide or a complete disappearance of the British.”

The authors suggest that DNA analysis should now be seen as a powerful historical tool, sometimes providing more unbiased information than traditional sources.

“Historical records, archaeology, linguistics – all of these records tell us about the elites. History is said to be written by the winners,” Donnelly said. “Genetics complements that and is very different. says what happens to the masses… the ordinary people.

Chronology

9600 BC The last ice age ends and the land is settled by hunter-gatherers

2500 BC Influx of settlers from the eastern and western coastal routes

54 BC Julius Caesar invades Britain and defeats British tribal leader Cassivellaunus

410 AD Collapse of Roman rule in Britain, which plunges into the chaos of a failed state

400-500 AD Great influx of Angles and Saxons

600-700 AD Anglo-Saxon rule in much of Britain – Welsh kingdoms resist successfully

865 AD Large-scale invasion by Danish Vikings

1066 AD Norman invasion

For more on the study of the peoples of the British Isles, listen to Professor Peter Donnelly on the Science Weekly podcast on Friday

This article was modified on March 23, 2015 to correct a reference to a compliment rather than a complement.

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