Tale of the snail tells us about Ireland's ancient origins

Listen close to the tale of the snail – it may tell us about the mysterious history of ancient Ireland.

New research published Wednesday in the journal PLOS ONE found that the snails in Ireland and the Pyrenees share genes not found in British snails. Since it’s improbable that the Irish snails made a slow, slimy crawl thousands of miles long from France and Spain, scientists suggest that the simplest explanation is that snails arrived with snail-eating migrants from southern Europe some 8,000 years ago.

That Ireland is genetically different from Britain and has genetic similarities to Iberia – with numerous species that are unique to it and Iberia, including the strawberry tree, the Kerry slug, and the Pyrenean glass snail – has long puzzled scientists. In tracing the snail’s genetic origins, this latest research joins a growing body of evidence that the first people of Ireland arrived from Iberia.

“The results tie in with what we know from human genetics about the human colonisation of Ireland — the people may have come from somewhere in southern Europe,” said Angus Davison, of the University of Nottingham and the co-author of the study, in a statement. “What we’re actually seeing might be the long lasting legacy of snails that hitched a ride, accidentally or perhaps as food, as humans travelled from the South of France to Ireland 8,000 years ago.”

Davison and Adele Grindon, also of the University of Nottingham, analyzed mitochondrial DNA found in muscle samples sliced from the feet of some 880 snails, from the species Cepaea nemoralis. Researchers and volunteers had spent two years collecting the little animals across Europe.

The researchers found that snails in Ireland share a mitochondrial lineage with the Central and Eastern Pyrenean snail populations, but not with snails collected elsewhere in Europe.

Researchers are unsure whether or not the snails travelled as stowaways or as snacks for the long-journeying migrants. Mesolithic or Stone Age humans in the Pyrenees are recorded to have eaten snails, or perhaps farmed them.