for National Geographic News
When Anglo-Saxons first arrived in Britain 1,600 years ago, they created an apartheid-like society that oppressed the native Britons and wiped out almost all of the British gene pool, according to a new study.
By treating Britons like slaves and imposing strict rules, the small band of Anglo-Saxonswho had come from what is now Germany, Denmark, and the Netherlandsquickly dominated the country, leaving a legacy of Germanic genes and the English language, both of which still dominate Britain today.
The new theory helps explain historical, archaeological, and genetic evidence that until now had seemed contradictory, including the high number of Germanic genes found in modern-day England.
"An apartheid-like social structure could explain the big genetic and language replacements that we see," said Mark Thomas, a genetic anthropologist at University College London, who lead the study.
His team's findings appear in the current issue of The Proceedings of the Royal Society B.
Historical and archaeological data suggest that no more than 200,000 Anglo-Saxons arrived in Britain around the middle of the fourth century A.D.
This is less than half of the 500,000 newcomers that genetic models suggest would be needed to swamp the gene pool of the native Britons, who are believed to have numbered around two million.
And yet Germanic genes are abundant in the English population today. Genetic studies have shown that more than 50 percent of England's gene pool contains Germanic Y chromosomes.
Y chromosomes are genetic markers that are passed down from fathers to sons. (See an overview of human genetics.)
But the researchers say 200,000 Anglo-Saxons could have dominated the English gene pool in less than 15 generations if the newcomers held a higher social standing.
Historian Alex Woolf of Scotland's University of St. Andrews, who is not an author of the study, first suggested that early Britain may have had an apartheid-like society, Thomas says.
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