A breakthrough genetic study led by Oxford scientists has uncovered the enduring European tribal footprints that still mark in the United Kingdom’s population.
A pioneering new DNA studies by Oxford scientists has revealed that the longstanding population of the British Isles still occupies the same tribal areas as its various ancestors a millennium and a half ago.
The first detailed genetic map of any country in the world, it reveals genetic clusters that closely match the tribal groupings and kingdoms of sixth-century Britain. The full report is published in Nature, but project originator Sir Walter Bodmer, of Oxford’s Department of Oncology, has kindly allowed Oxford Today to provide as a downloadable pdf a summary he wrote for project volunteers, richly illustrated with maps that graphically show the results. Hot on the heels of this study came another from Oxford which compares the genes of current-day North and South Americans with African and European populations, identifying the genetic fingerprints of the slave trade and colonisation that shaped migrations to the Americas hundreds of years ago.
For the British study, Sir Walter’s team first gathered DNA samples for the Wellcome Trust Peoples of the British Isles project. From these, 2,039 samples were selected, from individuals in rural areas whose four grandparents lived within 80km of each other — effectively yielding the DNA of people born around 1885, before the larger modern migrations. Comparison with samples from more than 6,000 Europeans reveals clear traces of population movements into Britain over the past ten millennia.
Blind analysis, without reference to location, identified 17 clusters of similarities. Only after this were the clusters mapped geographically, uncovering a series of remarkable hidden histories.
The Welsh appear more similar to the earliest postglacial settlers of Britain. Migration across the Channel was at significant levels between the last Ice Age and the Roman occupation.
Yet there is no single Celtic genetic group in the UK. The Celtic areas — Wales, Cornwall, Northern Ireland and Scotland — are among the most different from each other genetically. The Cornish are much more similar to the English than they are to the Welsh and the Scots. Meanwhile a different genetic group occupies Devon, and the dividing line is almost exactly along the modern county line. And a distinct group in south-west Pembrokeshire matches an area sometimes known as ‘Little England beyond Wales’ because of its English-speakers, showing it to have persisted as an enclave for almost a thousand years.
A single homogeneous group occupies most of southern, eastern and central England, with a significant DNA element from Anglo-Saxon migrations. The finding seems to lay to rest a persistent historical debate by showing that the incoming Angles, Saxons and Jutes bred with the native population rather than replacing them.
The most genetically distinct population is in Orkney, where a quarter of DNA comes from Norwegian ancestors — but again this shows that the invaders did not simply replace the local population.
However, the Danish Vikings who controlled large areas of England from the 9th century — the Danelaw — have left no clear genetic signature, and nor have either the Romans before them or the Normans after them.
Sir Walter devised the study to identify meaningful levels of genetic differentiation in UK populations as a background to the study of genetic disease. It was funded by the Wellcome Trust and supervised by Sir Walter with Peter Donnelly of Oxford’s Wellcome Trust Centre for Human Genetics and Department of Statistics. Analysis was led by Professor Donnelly using techniques co-developed by Simon Myers of Oxford’s Department of Statistics. Contributions also came from Oxford’s Institute of Archaeology and Museum of Natural History, from University College London and from Australia’s Murdoch Children’s Research Institute.
Sir Walter Bodmer’s illustrated summary (downloadable pdf) — see link above right
Relief map of Great Britain and Ireland © Anton Balazh / Shutterstock.