Image of the Week: Genetic map of the British Isles
Legend: Map of the UK showing clustering of individuals based on genetics, and its striking relationship with geography. Each of the genetic clusters is represented by a different symbol (combining shape and colour, with legend at the sides). There is one symbol plotted on the map for each of the individuals in the study. The ellipses give a sense of the geographical range of each genetic cluster.
A landmark new study into the genetic makeup of the UK has revealed that there may be scientific evidence underpinning those local ties that so many of us feel. This colourful map of the British Isles shows the genetic clusters that exist across the country, and how in many cases, local populations share a similar genetic makeup.
Researchers from the People of the British Isles project, supported by the Wellcome Trust, used DNA samples from 2,000 people, all of whose grandparents were born within 80km of each other, resulting in a map of the genetic makeup of late 19th century Britain.
Among the findings is the intriguing discovery that sometimes a geographic or political boundary can also correspond to a distinct genetic boundary. In Devon and Cornwall the map shows a clear distinction between the genetic makeups of the two counties, with a separate cluster present either side of the modern county boundary.
Samples taken from Wales show that the Welsh are the most similar to the earliest settlers of the British Isles, but also that the three defined genetic clusters exist in the North and South of the country as well as along the border with England.
Orkney also emerged as the most genetically distinct from the rest of the UK with 25% of DNA from Norse ancestry – perhaps unsurprising given its history of Norwegian rule.
In total 17 distinct clusters were identified across the UK. Along with an understanding of the historical migrations into Britain, the researchers used a further 6,000 samples from modern day Europe to help explain how these genetic clusters may have emerged.