by Bryan Sykes
The Y-chromosome might be decaying fast, and well on its way to sharing Oisin’s fate, but for the moment his clan’s Y-chromosome is doing extremely well in Ireland. Almost 80 per cent of Irish Y-chromosomes belong to the clan of Oisin. Within Ireland there was very little difference to be seen in the geographical distribution of the maternal clans in different parts of the island. However, with Y-chromosomes there certainly is. Dividing Ireland into the four ancient provinces, each roughly occupying a quadrant of the Irish rectangle, the differences between them are very striking indeed. In the south-east quadrant of Leinster, 73 per cent of Y-chromosomes are in the clan of Oisin. In Ulster, in the north-east, this rises to 81 per cent. The clan reaches an even higher frequency in the province of Munster, in the south-west, where 95 per cent of men are in the clan. However, in Connacht, occupying the north-west quadrant, the proportion of Y-chromosomes in the clan of Oisin reaches an astonishing 98 per cent. This was one of the first results from Dan Bradley’s genetic survey of Ireland, which he undertook in this instance with graduate student Emmeline Hill. But, rather than just leaving it at that, Dan took their analysis one stage further to look for an explanation. Recalling the twelfth-century Anglo-Norman invasion of Ireland, it occurred to them that one reason for the difference in Oisin Y-chromosome frequency between the provinces might have something to do with this invasion and the subsequent occupation. The invasion began in Leinster, in the south-east, and that was where the Oisin clan was in its lowest proportion.
The vehicle for testing this idea was to use surnames which, like Y-chromosomes, are also passed down the paternal line. There have been inherited surnames in Ireland for as long as anywhere in Europe. They were first adopted in about AD 950, a good 200 years earlier than in England. The Gaelic origin of many Irish surnames is evident from the prefix ‘Mc’ or ‘O’, meaning ‘son of’, as in McCarthy or O’Neill, but there are plenty more whose Gaelic origins required a little research. Fortunately, the enormous interest in genealogy over the last hundred years has led to the compilation of comprehensive surname dictionaries where the origin of almost any name can be found. Sure enough, when Y-chromosomes were compared to surname origins, Gaelic or Anglo-Norman, the correspondence was clear. Even in Leinster, the proportion of Oisin clan members was higher among the men with Gaelic names than among the men whose surname could be traced to Anglo-Norman origins. You will recall that, in his survey of blood groups, Professor Dawson explains the higher frequency of blood group A in Leinster by the Anglo-Norman invasion.
The comparison with the mitochondrial results is striking. All of the seven major maternal European clans, and most of the minor ones, were to be found in Ireland and there was not much difference in their proportions in the four provinces. Very obviously, in Ireland anyway, the version of history told by men and women was not the same. To explore this further, I want to look in more detail at the Irish Y-chromosomes, in particular the detail among the members of the clan of Oisin. A Y-chromosome fingerprint, or signature, consists of a set of ten numbers. Each of these is the number of stammering DNA repeats at the ten places on the Y-chromosome that we test. If there are 10 repeats at the first marker and 22 at the second one, the fingerprint starts off as 10–22. If there are 13 repeats at the third marker, the fingerprint continues as 10–22–13 and so on. When I am checking through 10 marker signatures from the DNA analyser, if there are Irish men among the batch it isn’t long before I find this particular signature: 11–24–13–13–12–14–12–12–10–16. It is very familiar indeed. This is the quintessential Oisin Y-chromosome and huge numbers of Irish men carry it. I am not the only person to have noticed this particular Y-chromosome combination. Dan Bradley certainly knows about it, and it has also been spotted by Jim Wilson, who worked for a time at University College London. Jim is a native of the Orkney Islands, just off the north coast of Scotland, and he had noticed this same combination among his fellow Orcadians. It also cropped up, interestingly, in surveys of Y-chromosomes among the Basques of north-eastern Spain and among the people of Galicia in the north-west of Spain. Its oceanic affinities led it to be christened, not Poseidon or Neptune, but the far more prosaic Atlantic Modal Haplotype, or AMH for short. I prefer to call it the ‘Atlantis’ chromosome. In the Isles it is by far the commonest Y-chromosome signature within the clan of Oisin, or any other for that matter.
Among the Oisin clan in Ireland, it certainly isn’t the only Y-chromosome fingerprint, but most of the others can be linked to it by one or two mutations. This gives us an opportunity to get an Irish date for the Oisin clan, rather as we did with the Ursulans and other maternal clans. The mutation rate of these Y-chromosome fingerprints is roughly one change per 1,500 years, much faster than the mDNA rate of one for every 20,000 years. By following exactly the same procedure for the Oisin clan as we did for the first Irish Ursulan calculation, we get a date of 4,200 years. This lies well within the time frame of human settlement in Ireland and, since it is still prey to the wide approximations of genetic dates, and thus quite close to the 5–6,000-year estimate for mDNA, it would be tempting to imagine we have solved the origins of the Irish.
However, we have done nothing of the sort, because we have overlooked the Martian factor. Remember that the original Irish Ursulan date was 50,000 years ago – older than Ursula herself and far too early to be a plausible date for the settlement of Ireland – assuming that all the mutations among Irish Ursulans had happened after the first ones reached Ireland. To get round this we had to decide which of the mutations happened on Irish soil, and which had already occurred before the clan reached Ireland. When we did this it made a huge difference to the date, bringing it forward to the much more plausible 7,300 years ago. Applying the same correction to the Irish Y-chromosome data brought the date forward to just 1,200 years in the past. This is far too recent to be plausible, even given the approximations involved. Something else must be going on. And it was, but it took me a while to realize the explanation. And it didn’t happen until I had done a lot more work. Not in Ireland, but in Scotland. Only then was I able to make sense of the strange behaviour of the Irish Y-chromosomes.
Nevertheless, we have made a good start. In Ireland, the maternal lineages are diverse and very old, while the Y-chromosomes are unexpectedly homogeneous, and at first glance look comparatively young. We have seen a difference between different regions of the island, a difference that may be an echo of the Anglo-Norman invasion of Ireland beginning in the twelfth century. We have seen some evidence of a genetic link between Ireland and Spain along the Atlantic fringe of Europe, which archaeologists are now beginning to realize was a much busier seaway than was once thought. What we don’t yet know is how the Irish results will fit with the rest of the Isles, and to begin to do that we shall travel across the shallow sea to Scotland.
10
SCOTLAND
It is barely 12 miles across the sea from Fair Head on the north-western tip of Ulster to the cliffs of the Mull of Kintyre, rising above the waves of the North Channel. Scotland is bounded on three sides by the sea: by the wild Atlantic to the west and north and by the temperamental North Sea beyond the eastern coastline. Across its historically fluctuating southern land boundary lies England, at different times enemy and friend, but never indifferent neighbour. The western sea boundary is fringed with several large, inhabited islands and hundreds of small ones deprived of inhabitants. Off the north coast lie the Orkney Islands, and 60 miles further to the north-east and halfway to Norway are the Shetlands. The total land area, including the islands, is just over 30,400 square miles, only slightly smaller than Ireland. Mountains dominate the mainland, with the rugged Scottish Highlands reaching to over 1,300 metres. Ben Macdui (1,309 metres), highest of the Cairngorms in the north-east, and Ben Nevis (1,344 metres) in the west are the highest mountains in the whole of the Isles.
The mountains continue all the way to the northern coast of Scotland, especially on the west side, where millions of years of erosion, compounded b
y the gouging action of the glaciers, which covered the whole of Scotland in the last Ice Age, have left a dramatic landscape. In the far north-west, Old Red Sandstone peaks like Suilven and Stac Pollaidh stand isolated above featureless country of bog and lochan. In the extreme north, the mountains relent, leaving a fertile coastal strip where the thin, acidic soil of the Highlands is invigorated by calcium-rich limestones and sandstones.
The effect of limestone, wherever it occurs, is always dramatic. It neutralizes the otherwise acidic soils and in so doing transforms the colour of the landscape from a yellow-brown to a vivid green. In the Highlands and the Hebrides, the occasional limestone outcrops are marked out by the rich growth of grass and wild flowers. But nowhere is the effect of neutralizing the soil more noticeable or more delightful than in the Western Isles, the long chains of islands that protect the mainland from the full force of the Atlantic. On the western edge of these islands are some of the most beautiful beaches in the world. Brilliant white in the sunlight and lapped by turquoise, translucent seas, they are not made of the usual sands to be found on the crowded holiday beaches of southern England. The white beaches of the Western Isles are composed of the pulverized shells of countless billions of sea creatures that have been ground to a coarse powder by the pounding waves of the Atlantic. The wind, which for 300 days out of 365 roars in from the ocean, has blown the shell sand inland for a mile or two. And there it works its magic on the soil, neutralizing the acid and supplying essential phosphates that are otherwise entirely lacking. The result is the machair, a thin strip of meadows and grassland which, so long as the sheep don’t get there first, is full of wild flowers – purple orchids by the hundreds, blue harebells and the purple and yellow flowers of heartsease, the wild pansy. A couple of miles further inland, beyond the reach of the wind-blown shell sand, the moss and dark rushes are back, signalling the return of the acid lands.
The white beaches are also spread along the north coast, but there they are not needed to help the soil. The older gneisses and schists of the Highlands, among the oldest rocks in the world, are replaced by alkaline sandstone. Green grass grows far inland in Caithness at the extreme north-east tip of the mainland, and is rich enough to support large herds of sleek black cattle. The fertility of the sandstone soil is even more remarkable in the Orkneys, now a few miles from the Caithness coast but joined to it until 7,000 years ago. On the east coast, there is good low-level farmland around the Moray Firth near Inverness and inland of Aberdeen, at the eastern edge of the Cairngorms. One deep geological fault divides the Highlands along the Great Glen, running between Inverness and Fort William. Another fault line runs between Stonehaven, on the east coast just below Aberdeen, and Loch Lomond to the north of Glasgow. This southern fault line separates the Highlands from the rich farmland of the Central Lowlands, which is also the location of the major cities of Dundee, Stirling, Glasgow and Edinburgh. Most of the 5.2 million Scots live in this Central Belt, a great many having moved there from the Highlands. Further south the ground rises again to form the hills of the Southern Uplands. Lower and less rugged than the Highlands, these hills have been eroded by glaciers into smooth-topped plateaux separated by narrow, flat-bottomed valleys. Beyond the hills, the valleys open out into the rolling farmland that surrounds the River Tweed, which flows into the North Sea at Berwick on the east coast. On the west side of the Southern Uplands, the hills give way to the Galloway peninsula and the flat lands bordering the Solway Firth.
Since the whole of Scotland was under thick ice until the end of the Ice Age and again during the cold snap of the Younger Dryas, it isn’t surprising that no evidence, yet, has been found in Scotland of Palaeolithic settlements such as remain in the Cheddar Caves in south-west England. The first signs of human occupation are not found until well after the cold snap and, as in Ireland, these are Mesolithic settlements at or near the coast. The earliest dated site is at Cramond, on the southern shore of the Firth of Forth, only 3 miles from the centre of Edinburgh. It is a picturesque spot, with a small terrace of old houses on one bank of the River Almond, where it flows into the Firth. Swans and ducks bob around in the quiet tree-lined bay and, when I visited on a crisp sunny day in November, I could not have imagined a better spot for a bit of hunter-gathering. A seashore for shellfish and wading birds, a medium-size freshwater river for salmon. All that would have been missing was the cappuccino that was steaming on the table in front of me. The Cramond remnants, a few microliths and the bony evidence of past meals, are dated to about 10,000 years ago. There are no signs of permanent settlement at Cramond, no post-holes as at Mount Sandel in Ireland, so it was probably just one of many places where the small bands of humans used to camp for a while as they moved around the country in search of food.
The seasonal movements of the Mesolithic hunter-gatherers from one site to another are nowhere better illustrated than on the island of Oronsay, off the opposite coast of Scotland from Cramond. Oronsay is a small island, roughly triangular in shape and each side only 3 kilometres long. Despite its small size, no less than five Mesolithic shell middens have been discovered, each containing vast numbers of mollusc shells. Limpets, winkles, whelks, oysters and scallops were all on the menu. Curiously shaped implements, made from the antlers of red deer, have also been found. Their use is immediately obvious when you watch the staff at work in an oyster bar. They are shaped exactly like the knives which, inserted between the two shells of an oyster, then twisted, open it to reveal the silver-grey flesh inside. It is a sight to behold – as it must also have been for the children of Oronsay, 8,000 years ago, for that is the date of the Oronsay midden.
The seasonality of the Oronsay middens has been discovered in a very curious way. As well as huge numbers of mollusc shells, the middens also contain the bones of saithe, a relative of the haddock that is still plentiful in the waters off the west coast of Scotland. The saithe grows rapidly in its first years of life and the age of a fish can be worked out from, of all things, the length of the ear bone or otolith. Otoliths within the same midden tend to be about the same length but there is a big difference in average otolith size between one midden and the next. The conclusion is that the middens marked different seasonal camps where the fish caught were at different stages of their development. What we do not know is if Oronsay was a permanent home or, like Cramond, another seasonal camp, occupied at the same time each year to take full advantage of the harvest of the sea.
Oronsay and its close neighbour Colonsay lie about 15 miles from the larger islands of Islay and Jura, themselves 10 miles or so from the long finger of the Kintyre peninsula. Clearly, the Mesolithic hunter-gatherers – an epithet to which we must surely add fishing – were well used to making these quite substantial sea crossings between the islands and the mainland. No boats remain, destroyed by millennia of decay, but they were probably made from animal skins stretched across a framework of hazel branches. They would have resembled the coracle, still, just about, used for fishing in the rivers of west Wales, and the more substantial curraghs of the west of Ireland. Whatever they used, these boats were perfectly good enough for coastal work and island hopping.
The sea has never been a barrier to the people of the Atlantic. It was their highway, just as the Pacific was to the Polynesians. There are confirmed Mesolithic sites on many of the islands lying off the west coast of Scotland, and where no evidence has yet been found there is a feeling among archaeologists that, with more field work, every island will be shown to have been occupied, if only for one part of the year. There is even indirect evidence, in the form of unusual patterns of soil erosion, that the Mesolithics reached Shetland, which would have involved a voyage on the open sea of 60 miles from Orkney, the nearest point. Valuable materials were also transported over long distances by sea. Flint is unknown in Scotland and other stones were used for making tools. Bloodstone quarried from the Isle of Rum, where there is a very early Mesolithic settlement, has been found in many sites around the west coast. The Mesolithic was a time of p
lenty for those bands who lived on the coasts of Scotland and Ireland. There was ample food within easy reach, both in the sea and in the dense woodland that lay behind the shoreline. It certainly wasn’t crowded. One recent estimate puts the total population of the whole of the Isles during the Mesolithic at less than 5,000.
There is one tantalizing fragment of evidence – a grain of wheat pollen from the Isle of Arran in the Firth of Clyde – that the Mesolithics were already experimenting with growing their own plant food, well before the arrival of agriculture proper. However, it is only with the arrival of farming that the whole way of life begins to change. Curiously enough, despite the major effect this transition from the Mesolithic lifestyle of thinly dispersed hunter-gatherers to full-blown farming must have had on the early inhabitants of Scotland, there is a distinct lack of material evidence from the early stages. Part of the reason is probably the later growth of thick layers of moss which have buried early field systems. In Ireland a whole patchwork of fields has been discovered at Ceidi, near Ballycastle, County Mayo in the north-west, lying under several feet of peat and visible only when this layer was cleared away. Even the megaliths suffered from the accumulation of moss and peat. The stone circle at Callanish on Lewis, where the stones reach nearly 5 metres in height, had been almost swallowed up by the peat before it was excavated in the nineteenth century. Only the tips of the tallest stones protruded above the peat.
Covering of a different kind obscured what, in my opinion, is the most remarkable archaeological site in the whole of the Isles. The settlement at Skara Brae in Orkney does not have the grandeur of Callanish or Stonehenge. It is altogether more domestic. Following a violent storm in the 1850s, the sand dunes which back on to the beach in the Bay of Skaill, on the west coast of the largest island, were stripped back to reveal the walls of houses. Unlike today, when such a discovery would precipitate an immediate excavation, nothing much was done either to excavate or even to protect the site until the early years of the twentieth century. Hidden beneath the sand was a small group of interconnecting stone houses, each about 5 metres in diameter and complete with stone beds, stone dressers, even waterproofed stone basins sunk into the floor to keep live lobsters and to soften limpet flesh for fishing bait.
