Snails Tell Tales of a Human Migration from France to Ireland

Snails aren't known for their traveling abilities, but if a team of geneticists is correct, then a certain group of snails provides a unique look at human migration from the south of France to Ireland some 8,000 years ago.

Snails from the Pyrenees in France and Ireland, it turns out, are genetically identical. Given a snail's relatively slow speed, and the lack of genetically-identical counterparts in other places in Europe, including Britain, the simplest explanation is that the snails hitched a ride with humans heading to Ireland.

"There is a very clear pattern, which is difficult to explain except by involving humans. If the snails naturally colonized 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," said Dr. Angus Davison from the University of Nottingham.

While the snails themselves aren't of major interest, what they represent, and what they indicate about early humans is.

"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."

Ireland, while geographically connected to Britain, contains its own set of unique flora and fauna apart from its southern neighbor. The snails hint that the differences arise from the fact that Ireland was colonized separately.

"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,"

You can read the full published study in the journal PLOS One.