Wednesday, January 20, 2016
The present-day English owe about a third of their ancestry to the Anglo-Saxons, according to a new study
Scientists have sequenced genomes from 10 skeletons unearthed in eastern England and dating from the Iron Age through to the Anglo-Saxon period. Many of the Anglo-Saxon samples appeared closer to modern Dutch and Danish people than the Iron Age Britons did. According to historical accounts and archaeology, the Anglo-Saxons invaded Britain from continental Europe in the 5th Century AD. They brought with them a new culture, social structure and language. Dr Stephan Schiffels of the Max Planck Institute for the Science of Human History in Germany sequenced genomes of human remains from Hinxton, Saffron Walden, Linton and Oakington - all of which are near Cambridge. The burials fall into three different age categories: Iron Age, early Anglo-Saxon and Middle Anglo-Saxon. In order to disentangle the Anglo-Saxon signal from the indigenous British genetic background, the researchers looked at many rare mutations across the whole genome. "We found that these rare mutations were the key to studying historical samples. We could compare our ancient samples with modern samples in an improved way," Dr Schiffels said. "We could look at these in a very large sample of modern Europeans. For example, we studied low frequency mutations that must have occurred in the ancestors of the Dutch over the last few thousand years. We found that these mutations were shared with the Anglo-Saxon immigrants at a factor of two more than they are with the indigenous Celtic people. These rare mutations are found only with whole genome sequencing." From there, the scientists could track the contribution made by those Anglo-Saxon invaders to modern British populations. They found that on average 25%-40% of the ancestry of modern Britons is attributable to the Anglo-Saxons. But the fraction of Saxon ancestry is greater in eastern England, closest to where the invaders settled. Even traditionally Celtic populations, such as the Welsh and Scottish show some Anglo-Saxon-like ancestry - even though it is typically lower than that of eastern England.