BioEd Online

They may not always have enjoyed the most cordial of relations, but English and German people have more in common than they might think. An analysis of the genetic make-up of today's British population suggests that almost all English people are descended from Saxon invaders who became masters of a two-tier society that battered indigenous Brits into submission.

The analysis lends weight to the theory that the Anglo-Saxon invaders, although relatively few in number, managed to take over almost the entire country by setting up a system of social segregation similar to apartheid in South Africa, in which the established locals were made second-class citizens.

The idea that modern English are of German descent is not new. Previous genetic studies have suggested that more than 50% of English Y chromosomes (the chromosome passed on unchanged from father to son) are all but identical to those of German and Danish natives.

But there has been a problem in explaining how the Anglo-Saxons managed to breed so successfully in Britain in the 300 years or so after their invasion in the fifth century AD. Simple mathematical analyses suggest that this level of breeding would have required an invading party more than half-a-million strong to make an impression on the estimated two million Britons living on the island at the time. Archaeologists argued that there is no evidence of such a mass influx of foreigners.

Easy advantage

This paradox disappears, however, if you consider a society in which the invaders muscled their way to the top of society, where they could breed more successfully, say the British researchers behind the new study. According to their computer model, somewhere between 10,000 and 200,000 invaders would have been needed to make their mark on the population, says Mark Thomas of University College London, who led the study.

The Anglo-Saxons may have forced indigenous Britons into servitude, while enjoying superior wealth, health and breeding potential, Thomas and his colleagues suggest in the journal Proceedings of the Royal Society B¹.

If the invading men were 1.8 times more likely than the locals to reproduce successfully, the researchers note, it would take only five generations, or 175 years, for the Germanic Y chromosome to exceed 50% prevalence in the population as a whole.

The study examined only the spread of the male lineage: sons fathered by Saxon men but born to native British women would therefore count as a spread of the Germanic line. "But I'm willing to bet that if you looked at the maternal line you would see the same pattern," says Thomas, although he thinks it may not be quite so starkly defined.

Lofty status

An apartheid-like system is the explanation that fits best with sociological evidence, Thomas argues. Historical records of the law of the time, for example, suggest that the fines payable to the family of a murdered Anglo-Saxon were far higher than those for a dead Briton. "There could conceivably have been wholesale slaughter or wholesale rape, but those explanations are the stuff of films really," he says.

Obvious signs of the invasion persist today. "Look at the language we speak it's Germanic. We are ostensibly German," Thomas says.

How did the German marauders manage to attain such a lofty status, given that they were in the minority? "They were invaders; they were trained," Thomas says. "And the British had been hammered by the Romans for years."

There are, however, corners of Britain that seem to have remained resolutely British. Thomas and his colleagues point out that, although most English and German Y chromosomes bear a strong similarity, both are markedly different from those of Welsh people today. "The differences still persist," says Thomas. "Even if not enshrined into law, people from different groups often tend not to interbreed."

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