A large scale study of Scottish people’s DNA is threatening to “rewrite the nation’s history”, according to author Alistair Moffat. Scotland, he told the Edinburgh international book festival, despite a long-held belief that its ethnic make-up was largely Scots, Celtic, Viking and Irish, was in fact “one of the most diverse nations on earth”. “The explanation is simple. We are a people on the edge of beyond; on the end of a massive continent. Peoples were migrating northwest; and they couldn’t get any further. We have collected them.” He and his colleagues have found West African, Arabian, south-east Asian and Siberian ancestry in Scotland. “The West African ancestry mostly originates in the 18th century, so it is almost certainly to do with the slave trade,” he said.