On the actual site they do go into details for each section.
Great Britain
Primarily located in: England, Scotland, Wales
Range: 0%—32%
Overview
About 12,000 years ago, sea levels were low enough for Stone Age hunter-gatherers to cross from northern Europe into what are now the islands of Great Britain. Farming came to the islands by about 4000 B.C., and the inhabitants erected their remarkable and puzzling stone monument like Stonehenge. The Romans, Anglo-Saxons, Vikings, and Normans all left their mark politically and culturally, but modern studies suggest that the earliest populations continued to exist by adapting and absorbing new arrivals.
Ireland/Scotland/Wales
Primarily located in: Ireland, Wales, Scotland
Range: 0%—14%
Overview
Ireland’s modern culture remains deeply rooted in the Celtic culture that spread across much of Central Europe and into the British Isles. Along with Wales, Scotland, and a handful of other isolated communities within the British Isles, Ireland remains one of the last holdouts of the ancient Celtic languages that were once spoken throughout much of Western Europe. And though closely tied to Great Britain, both geographically and historically, the Irish have fiercely maintained their unique character through the centuries.
