Snail trail reveals ancient human migration

Dr Angus Davison, Reader in Evolutionary Genetics at the University, and PhD student Adele Grindon, found that snails in Ireland and the Pyrenees are genetically almost identical, despite being thousands of miles apart. And -- as snails aren't renowned for their speed -- the simplest explanation is that snails hitched a ride with human migrants approximately 8,000 years ago.

The research is published in journal PLOS ONE on 19 June.

From France to Ireland

Dr Davison said: "There is a very clear pattern, which is difficult to explain except by involving humans. If the snails naturally colonised Ireland, you would expect to find some of the same genetic type in other areas of Europe, especially Britain. We just don't find them.

"There are records of Mesolithic or Stone Age humans eating snails in the Pyrenees, and perhaps even farming them. The highways of the past were rivers and the ocean -- as the river that flanks the Pyrenees was an ancient trade route to the Atlantic, 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.

"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."

The flora and fauna of Ireland

Despite being close geographically, Ireland is home to many plants and animals which aren't found in Britain.

Dr Davison said: "You would think that anything that gets to Ireland would go through Britain, but it has been a longstanding mystery as to why Ireland is so different from Britain. For these snails, at least, the difference may be that they hitched a ride on a passing boat."