Meeting Report: The Prehistoric Peopling of Scotland: origins, genes, cultures, environments

22 November 2013
Dr Dermot Kennedy

Dr Dermot Kennedy gave a wide-ranging, well-presented talk to Dumfriesshire and Galloway Natural History and Antiquarian Society on the subject of The Prehistoric Peopling of Scotland. Aspects covered were Origins, Genes, Cultures and Environments. Retirement from the medical scene in the field of infectious diseases permits him to pursue this self-same field in prehistoric times. There are no easy answers in this new emerging science of population genetics, still in a formative period.

In pre-history five classic eras are recognised: Palaeolithic, Mesolithic, Neolithic, Bronze Age and Iron Age. In the stone ages females had greater equality. Subjugation came later under Indo-European influences.

In Palaeolithic times, until 12,000–13,000 years ago, Scotland was in the grip of an Ice Age and therefore unpopulated. Only the Rhinns of Islay was free of ice.

Once free of glaciation in Mesolithic times, the longest era, the land was exposed. People in southern Europe in the Franco-Cantabrian parts had only just survived the Ice Age. They were black-skinned. It then became possible for humans to spread out and eventually reach the north of Scotland. This was the origin of the first Scots, who were hunter-gatherers, moving around by boat. Pastoralism suited them better than farming.

The Neolithic era, 10,000–12,000 years ago, produced the greatest revolution in human terms when a dramatic increase in population took place. Successful coupling with Neanderthals brought about a change in the genome by mutation, not reproduction; white-skinned, red-haired people emerged; 1–49% of our DNA is acquired from Neanderthals. Thus 13% of Scots still have red hair; the Irish 11%. New diseases like measles and smallpox, caught from domesticated animals, were transmitted to humans in this period.

It has become possible to track our ancestry by studying mitochondrial DNA. Between 10 and 30% of our DNA is of Middle Eastern origin. The Welsh, Scots and Irish are not of Celtic origin. Unlike in males, female mitrochondrial DNA remains unchanged. In humans, mitochondrial DNA spans about 16,500 building blocks, representing a small fraction of the total DNA in cells. Mitochondrial genes are among the estimated 29,000 to 25,000 total genes in the human genome. Conditions like cancers are related to changes in the structure of mitochondrial DNA.

Some cave men were geniuses. Paintings in Chauvet Cave in the Ardèche region of France are circa 32,000 years old and are the earliest examples so far found. These artists understood perspective, a skill that then became lost until the Renaissance. There are over 300 Ice Age art caves in the Dordogne and Cantabria, but entry is forbidden to about 90% of them.

Geophysical and climatic change was brought about in the Holocene period of warmer air 18,000 years ago. Melt Water, estimated at 135 trillion tons, entered the Atlantic causing progressive loss of land. Ireland became an island. A tsunami flooded the East of Scotland. Many Mesolithic sites were lost.

On Oronsay studies of shell middens have afforded information on Mesolithic diet which appears to have been healthy, in that 90% was composed of fish, (hazel)nuts and shellfish. The Gaelic word for hazel is ‘Coll’, as in the name of the island of Coll.

In Neolithic times, 4,000–2,500 BC, there was a 20-fold increase in population in the first 1,000 of those years and 50-fold within 2,000 years. People advanced sporadically. Was it farmers or farming that caused the movement? Farming led to clearance of woodland, settlement and spare food. Some remarkable stone structures, the best in Europe, survive in Britain.

Migration up the Atlantic route from Basque lands involved conflict. Fortified structures for defence proved to be necessary. The metal smith provided military superiority. His status in society from the Bronze Age (2,500–700 BC) and the Iron Age (700BC–400 AD) was unrivalled.

About 3 billion people speak an Indo-European language but its origins are still unknown. Anatolean farmers invaded Europe about 7,000 BC. Many languages have spun off from that source. By contrast the Celtic language, which developed in Spain, is spoken by few. The Celts spread their culture but not their genes. The genetic lineage of the Celts has died out — not necessarily through conflict: it was maybe bred out. Celticism is cultural not genetic. Further information may be gleaned from Barry Cunliffe’s book, Celtic from the West.