Scientists announced this week that a genetic similarity between snail fossils found in Ireland and those of the eastern Pyrenees suggests that humans probably migrated from southern Europe to Ireland 8,000 years ago.
According to Headline & Global News, the mollusks could have hitched a ride with settlers or were brought along as a snack.
Irish snails are almost genetically identical to a species in France, even though they're thousands of miles apart, a study by the University of Nottingham claims.
The only possible explanation for the similarity is that the snails were carried over by humans, most likely about 8,000 years ago.
'There is a very clear pattern, which is difficult to explain except by involving humans,' said Dr. Angus Davidson, professor of Evolutionary Genetics at the University of Nottingham, who led the study.
'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.'
Davidson said there are records of the Stone Age or Mesolithic people actually eating and farming the snails.
'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,' Davidson said.
Davidson said this seems to confirm a longstanding theory that Ireland was colonized by settlers from Europe at least 8000 years ago.
Most striking of all is that a lot of the native plants and animals found in Ireland are not found in nearby Britain. The team thinks this makes the snail's passage even more significant.
'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,' Davidson said.
The origins of flora and fauna that are only found in Ireland and Iberia, but which are absent from the countries between them, is one of the enduring questions of biogeography.
'The intriguing implication is that the genetics of snails might shed light on a very old human migration event,' Davidson said.