A SNAIL could hold the key to proving that ancient humans migrated from southern France to Ireland thousands of years ago.

Scientists at the University of Nottingham say that snails found in Ireland and the Pyrenees are genetically almost identical, despite being found thousands of kilometres apart.

According to experts, most snails travel at 1mm per second. The distance from Mayo, where the snail was found, to the Pyrenees is 2,166km, meaning the trip would take 601,667 hours, or more than 68 years. Some species of snail can live for up to 25 years.

Considering snails are not renowned for their speed, ability to scale mountains, traverse rivers, or cross seas, it's believed they were taken to Ireland and eaten as snacks by humans some 8,000 years ago when they made the trip west.

The ancient people probably farmed the Grove snail, Cepaea nemoralis, researchers believe.

The study, 'Irish Cepaea nemoralis land snails have a cryptic Franco-Iberian origin that is most easily explained by the movements of Mesolithic humans', is published in the journal 'Plos One'. It was completed by Dr Angus Davison in the University of Nottingham's School of Biology.

He said a specific strain of the common Irish land snail was only found elsewhere in a restricted region of the Eastern Pyrenees, and that it was a food source for Mesolithic humans.

The Garonne river which flanked the Pyrenees was an ancient route to the Atlantic, and the fact there was a continuous fossil record over 8,000 years of the snail suggested it was brought to Ireland by people living in the region.

"The surprising finding is that populations of one species of snail in Ireland seemed to originate from the northern flanks of the Pyrenees in southern France, and were not found in intervening countries," he said.

"The intriguing implication is that the genetics of snails might shed light on a very old human-migration event."

There is widespread evidence that they were eaten and possibly even farmed in the Mediterranean region, "so could have been included as a portable packed lunch," he added.

Advances in genetics have helped explain the phenomenon, which could account for the first wave of colonisation from Europe across Britain and Ireland.

Samples were obtained between 2005 and 2007, from remote locations in France, Spain, Ireland and the Pyrenees. DNA was extracted from thin slices of foot muscle, from 880 individual snails.

The specific strain of DNA from Cepaea nemoralis was only commonly found in southern France and Ireland, with a small number in the Isle of Man and a single specimen from Wales.

Researchers said that trading links were established between Ireland and Iberia which provided "ample opportunities" for land snails to be transported in cargo.

Archaeological evidence showed they were commonly eaten, while a Bronze-Age ship from Turkey shows that people have transported land snails across the oceans for at least 3,000 years.

Irish Independent