Friday, April 25, 2014
Scientists studying the Y chromosomes of hundreds of Scottish males have discovered that the rate of a key Celtic marker dating back to 6th Century Ireland is more than twice as common in the DNA of men in Glasgow and the west than Edinburgh and the east of Scotland
The data, which has been gathered as part of the Scotland's DNA project, is helping to shed light on major ancestral differences between Scotland's regional populations. One of the most significant discoveries to date is in the ratios of a marker known as R1b-M222, the "Ancient Irish" marker. Men carrying this on their Y chromosome - it can be passed only from father to son - are all distant descendants of Niall Noigiallach, a High King of Ireland who lived about 1500 years ago. Current data shows that it is present in the DNA of 12% of men living in west Scotland, against 5% in the east, a legacy of hundreds of years of Irish immigration. The researchers want to map the ratios of the Celtic markers, and determine whether men in the east are more likely to carry Germanic and Anglo-Saxon markers owing to the Anglian kingdom of Northumbria, which encompassed Edinburgh from the 7th to 10th centuries. Dr Jim Wilson, a geneticist and the chief scientist behind the Scotland's DNA project, said: "The most interesting thing for me is we can now break these groups up into subgroups. You can split the M222 up into about 20 different subtypes. The fact we can do that is interesting because maybe we can home in on whether it is one subtype of M222 that is responsible for the difference between east and west or multiple. If it is one, that might help us understand more clearly when in history this difference occurred. But to do that accurately, we need a lot more samples." The genetic picture is less distinct for women, possibly indicating increased movement and interbreeding creating more similar X chromosomes among Scotland's female population.