WHEN turning detective to research a family tree, leafing through dusty parish records and poring over yellowing birth certificates are all part of the paper trail. Yet scientific advances could not only reduce the time it takes to establish your roots, but also allow you to trace them with greater accuracy and further back in time than was ever before possible.
Research into Scotland's ancient clan network has already shown that one-fifth of MacDonald men are descended from the same person - the legendary 12th-century Celtic hero Somerled, although scientists now believe he was actually of Norse origin. DNA tests, using the male Y-chromosome as a genetic marker, have also revealed that one-third of men living in Shetland are descended from Viking invaders to Scotland.
Bryan Sykes, professor of human genetics at Oxford University, who has pioneered the link between genes and genealogy, first made the connection when he carried out DNA tests on people with his own surname.
"I found that about two-thirds of people with my name all had the same Y-chromosome, so they must have come from an original 'Mr Sykes' - which was absolutely stunning," he says.Sykes was intrigued to discover whether Scotland's clans were as closely knit as history would suggest. He carried out DNA tests on MacDonald, MacDougall and MacAllister men, who, according to legend, are all descended from Somerled, reputed to have swept the Norse from the Western Isles.
"I thought it would never work in Scotland," says Sykes, "because it is well known that a lot of people adopted the name of the clan chief, if they happened to live in his land or serve in his army, without an actual biological relationship.
"But amongst the hundred or so people I tested there was one Y-chromosome identifiable by its genetic fingerprint which I found in all three names - in roughly a quarter of all the people with the name MacDonald, and rather more for MacDougall and MacAllister. It looked as though it might well be the chromosome which had been passed down by this semi-mythical figure."
After compiling his research, Sykes wrote to the five clan chiefs who could trace direct descent based on written records.
"Sure enough, they all had this Y-chromosome - Somerled's chromosome," he says. "It is staggering and one would never have predicted anything like that.
"Something like a quarter of the MacDonalds that are walking around have no idea that they are descended from this man - Somerled - and are relatives of the clan chiefs, and even more in the case of the MacDougalls where it's 30 per cent and in the MacAllisters it's 40 per
Recent research in Shetland, which is about to be published in the Journal of Heredity, has shown that one-third of men are descended from Viking ancestors, adds Sykes.
"Using these Y-chromosome tests, you can identify individuals that have Viking Y-chromosomes or indigenous Celtic Y-chromosomes. In Shetland, for example, a third of the men are Viking descendents and two-thirds Pictish or Celtic." He adds this is rather ironic as most Shetlanders "want to be Vikings and don't want to be Scots."
Following worldwide interest in his research, Sykes set up a company in 2001 called Oxford Ancestors to satisfy demand for roots-tracing DNA tests.
“What better way to show your identity with a clan than to show you have the same DNA as the chief?", Sykes asks. He adds that the tests, which he says are "revolutionising genealogy", can save a great deal of time and effort in researching a family tree.
"If an American comes over to Scotland and wants to look at the records, if their ancestor's name is Donald MacDonald, it's impossible (to trace) really. The other good thing is that as more and more people get tested then they can link up through their genes, quite independently of these very unreliable, and sometimes impossible, written records of births, marriages and deaths."Most of the tests Sykes' company offers have to be carried out on men, as women do not have the Y-chromosome, though they can ask a male relative to provide a sample.
He adds: "The nice thing about the Y-chromosome is that it is coming down from the one person. So even if all your other genes are Pictish or Celtic, but your Y-chromosome is Viking, you know it must have come across in a Viking boat at some point, which is quite an awe-inspiring thought really."