The DNA of modern Scots shows many live in the same areas as their ancestors did more than 1000 years ago in the Dark Ages, a study has revealed.
Experts created Scotland’s first comprehensive genetic map which reveals the country is divided into six main clusters of genetically similar individuals.
These are the Borders, the south-west, the north-east, the Hebrides, Orkney, and Shetland.
These groupings are in similar locations to ancient Dark Age kingdoms such as Strathclyde in the south-west and Pictland in the north-east.
The Dark Ages are widely considered to be from the end of the Roman Empire in 476AD to around 1000AD.
Researchers believe this type of population analysis could help uncover DNA differences that might play a major role in understanding human diseases.
The fresh data from Scotland means this is the first time a genetic map of the UK and the Republic of Ireland can be seen in its entirety.
The study discovered some of the founders of Iceland may have originated from north-west Scotland and Ireland, while the Isle of Man is genetically predominantly Scottish.
It looked at the genetic make-up of more than 2500 people from Britain and Ireland – including almost 1000 from Scotland – whose grandparents or great-grandparents were born within 50 miles of each other.
Researchers from Edinburgh University and RCSI (Royal College of Surgeons in Ireland) then compared this with the DNA of people who lived thousands of years ago.
Professor Jim Wilson, of Edinburgh University Usher Institute and MRC Human Genetics Unit, said: “It is remarkable how long the shadows of Scotland’s Dark Age kingdoms are, given the massive increase in movement from the industrial revolution to the modern era.
“We believe this is largely due to the majority of people marrying locally and preserving their genetic identity.”
Dr Edmund Gilbert, of RCSI, said: “This work is important, not only from the historical perspective but also for helping understand the role of genetic variation in human disease.
“Understanding the fine-scale genetic structure of a population helps researchers better separate disease-causing genetic variation from that which occurs naturally in the British and Irish populations, but has little or no impact on disease risk.”
Experts found Orkney and Shetland had the highest levels of Norwegian ancestry outside Scandinavia and many islands within the archipelagos had their own genetic identity.
The islands contained subtle, but notable, differences between people living a few miles apart.
The study – funded by the Medical Research Council, the Chief Scientist Office of the Scottish Government and Science Foundation Ireland – is published in the journal Proceedings of the National Academy of Sciences of the US.
