Scotland’s DNA: Tracing the nation’s ancestral history

A computer illustration of the double-helix structure of DNA. Picture: Reuters
A computer illustration of the double-helix structure of DNA. Picture: Reuters
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A project aiming to discover the origins of Scots through the use of 
DNA, has come up with some startling findings – including how the 
invention of porridge changed Scotland, writes Alastair Moffat

EAGLES live immense lives, sometimes as long as 40 years and soaring high above the mountains and valleys, generations of the great birds have watched Scotland change. Beneath their stern gaze, some time around 9,500BC, they saw the land wake from millennia of slumber. The last Ice Age had blanketed the north, suffocating Scotland, creating a white, sterile and pitiless landscape of devastating beauty. But in a lifetime, the eagles flew over dramatic shifts in our climate.

As temperatures suddenly rose, the huge ice dome over Ben Lomond rumbled into movement. Its glaciers splintered, fraying and melting, bulldozing the landscape into its familiar shape. Moving east, the ice sculpted Stirling and Edinburgh Castle rocks. River courses were scratched out, mountainsides planed and sheared into cliff faces, and as the sea filled and rose, it pushed the long fingers of sea lochs into the heart of Scotland.

This was an astonishingly abrupt change. Between 1998 and 2004, scientists hauled a two mile long ice core out of the Greenland ice-sheet. It was a record of many thousands of years of climate change and it showed that the last ice age ended very quickly with dramatic movements taking place over decades.

By 9,000BC and possibly even earlier, the ice had gone. As summers warmed, a green tide of grassland and herbage flowed north, trees grew and animals migrated to graze and browse a vast wildwood. Predators followed. The eagles flew over the mountains once more and from the warmth of the south, people came, pioneers who gradually made their way into the virgin landscape that would become Scotland.

Who were these people and where did they come from, the first waves of immigrants? Archaeology can detect only gossamer traces of our earliest ancestors as they flitted through the shadows, barely rustling the leaves of the wildwood. They left no great monuments or records, only an 
occasional discolouration of the soil where they camped and lit fires, or a circle of postholes where they made a more permanent home. But, at last, answers to these fundamental questions are beginning to trickle into a quite different record of our early history.

Since November 2011, a project has been attempting to discover who the Scots are, to find out the genome of a nation. Using specially designed technology, scientists have been looking at Scottish DNA in an 
attempt to trace our ancestry in deep time, to light up the darkness of prehistory.

Tiny variations in our DNA can tell 
geneticists a great deal about our ancestry. These markers or lineages can be both dated and located in the part of the world where they arose. From extensive testing, the project, ScotlandsDNA has now gathered the beginnings of some answers to fundamental questions around a collective 
national identity. And they are very surprising.

Any thumbnail sketch of the constituent parts of Scotland’s identity might have included Celts, Picts, a scatter of Vikings, maybe some Irish immigrants and one or two other groups. And dark-haired people are often confidently informed that they are descended from shipwrecked sailors from the Spanish Armada. The reality is startlingly different. There are in fact no fewer than 100 
different male and female lineages present in the modern population. Scotland turns out to be a tremendously 
diverse nation.

Like the first pioneers who came after the ice, every Scot is an immigrant, and fascinating questions revolve around the time our people arrived and where they came from. For example, we have tested men whose male lineage originated in the ancient kingdom of Thrace on the Black Sea, the home of the gladiator-hero, Spartacus. We have men from the Roman province of Illyria on the Adriatic. Further afield, there are men and women from Siberia whose ancestors lived on the banks of the Yenesei River that flows into the Arctic.

There are Scots with an ancient lineage from Anatolia, and also one man whose marker came from the medieval West African kingdom of Denanke. We have Saracens from the Near East and women from the biblical kingdom of Sheba on either side of the Red Sea. The list is long and it is a national mosaic of glittering, exotic complexity. But so far, we have found no-one whose lineage dates from a half-drowned, shipwrecked Spanish sailor who crawled up a Scottish beach in 1588 after a storm smashed his ship against some Hebridean rocks.

In some ways the ScotlandsDNA project has supplied more questions than answers. Although the epic journeys of our DNA can be traced as lineages moved across the Earth on their way to Scotland, even those of the smallest groups, there remains the mystery of why. Why did so much genetic diversity arrive on these shores? Perhaps geography can supply part of an answer. Lying at the farthest north-western point of the vast Eurasian landmass, a place on the edge of beyond, Scotland had to be the end of many journeys, the narrowing or point of a huge funnel. Until the 16th century, it was not possible to go any further. It could be as simple as that.

One of the most intriguing questions asked by the ScotlandsDNA project is linked to the relative antiquity of male and female lineages. On present evidence, it looks as though most female lineages arrived before c3,000BC. By contrast, it seems that the majority of male lineages arrived after c3,000BC. Germanic, Teutonic, Alpine and Saxon Y chromosome DNA make up about a third of all male ancestry in Scotland, and there exists a very colourful fringe of smaller lineages such as Berber, Arabian, Kurgan and Balkan. Significant Irish lineages came to Scotland after c450AD, and by the end of the 8th century, Vikings were sailing the North Sea first to raid and then to settle.

In other words more of the ancestors of Scottish women have been here longer than the ancestors of most Scottish men. This imbalance is significant because it strongly suggests that later migrations to Scotland were largely male affairs, what one historian has described as waves of small groups of men in small boats.

It was different in the deeper past. Between 8,500BC and 4,500BC, it was possible to walk to Scotland across the lost sub-continent of Doggerland, now submerged under the North Sea, and it looks as though that was when family bands of men, women and children reached the farthest north-west of Europe. These were groups we have labelled as the Pioneers, the women from the Western Ice Age
Refuges, the Foragers and the Cave Painters. All very early lineages, all strongly present in modern Scotland.

More tentative conclusions are possible with this 
evidence. The largest male lineage in Europe, carried by 110 million men, is R1b-M269 and it is also very common in Scotland. Recent research persuasively suggests that it was this group that spread the revolutionary techniques of farming. The rationale is straightforward. In hunter-gatherer societies, the rate of population growth was very low. Infant teeth were the reason. Unable to deal with the diet produced by hunting and gathering roots, fruits, 
berries, eggs, fungi and the wild harvest of the pre-
historic landscape, infants were suckled by their 
mothers for a long time, perhaps four or five years, until their adult teeth developed. While nursing, most mothers are infertile and that meant a long birth 
interval, perhaps a total of only three or four births in the short, fertile life of a woman. And in prehistory not all of the babies would have survived. This meant a very slow growth in hunter-gatherer populations in Scotland and elsewhere.

Around c3,000BC, when the new techniques of farming arrived in Scotland, porridge changed the world. When cereals were grown, the ripe ears could be mashed into a pappy and nourishing porridge that did not need to be chewed. The birth interval halved and populations began to explode as farming was adopted. If its techniques were spread by men, then their DNA would have been at the heart of this explosion. And our DNA evidence confirms a very rapid spread of the male lineage, R1b-M269, at this time. That may well be the reason why our statistics show this imbalance either side of c3,000BC – how the invention of porridge changed Scotland.

This finding reverses previous thinking. It was believed that women spread the techniques of farming across Europe and into Scotland or that ideas and techniques were passed to neighbouring groups and, no doubt, both means of transmission took place, but our DNA research has altered radically our thinking about a period which has left only an archaeological record. As more and more people take tests, Scotland’s history will change and the conventional wisdom will be turned on its head once more.

What is attractive about being wrong about the spread of farming is the exciting possibility of being wrong about other things. For these are stories only DNA can tell. And more than that they are the lineaments of a different sort of history for Scotland, a people’s history. Instead of the usual parade of the usual suspects, kings and queens, the saintly and the notorious, DNA brings back to life and sets in centre-stage the people who made Scotland. And it 
begins to answer the age-old questions of who we are and where we come from.