Snails are often collected during archaeological excavations as they can provide evidence of the environment – species variety by species variety. For example, they were a useful source of data in the recent Stonehenge Riverside Project. However, there is evidence some human groups ate snails as part of their regular diet. Eating snails may have a link with catastrophes – such as landscape fires. It seems that people living in SW France, in the foothills of the Pyrenees, may have developed a taste for snails and reared them as a delicacy, taking them with them on their travels. Whether they had a nice French sauce or scrummy gravy to go with them or not is unknown – but the taste buds have lingered into the modern day. Snails, with the same genetic DNA as snails in the Pyrenees region have been found in Ireland, dating from the Early Holocene, it is thought – see www.sciencedaily.com/releases/2013/06/130619195131.htm
It is being suggested that this is evidence of human migration – and it is known that after the end of the Ice Age people did expand northwards through France and Britain into Scandinavia etc. In particular, people that had evolved a society based on following the reindeer herds. Obviously, other groups were involved as well. These are interesting insights as thousands of years later early farmers are supposed to have migrated from Iberia to Ireland and western Britain, arriving in boats (presumably with their animals as well). The eastern side of the British Isles seems to have been colonised from the continent as after all, Britain was joined to the continent until at least 6000BC. Farmers, around 4150BC, are said to have spread across Britain very quickly, with an origin in eastern and central Europe. In turn, these early farmers in Europe are thought to have left Anatolia at around 6000BC – when considerable landscape changes appear to have occurred in various parts of the world. The question here is how do geneticists separate these early colonists from the older ones if they both have an origin in the same part of the world? Genetics are supposed to be able to map when certain groups of people moved into a new area – but would the data not be confused if two or more groups had arrived at the same destination from a similar starting point?
Over at www.sciencedaily.com/releases/2015/02/150227084555.htm … we learn that contacts with Europe continued right up to 8000 years ago, when Britain is thought to have become an island (or mostly so). No doubt contacts continued between 6000BC and 4000BC but they are looking at one particular site, on the Isle of Wight (dated just before the cataclysmic sinking of the Solent, all part of the flooding of large parts of the Channel and the North Sea basin, currently dated around 6000BC. The site is located at the bottom of Bouldnor Cliff and is mentioned by Steve Mitchell in one of his articles several years ago on changes in sea levels around the coastline of Britain. The point of the article is that marine archaeologists, still exploring the Bouldnor Cliff site, have found evidence of bread wheat in what is a Mesolithic context. It was not actual cereal grains but evidence that grain had been cooked and eaten – possibly as a bread or a porridge. Now, the assumption is that einkorn wheat was introduced with the early farmers who are consistently dated to around 4150BC and later. Einkorn, or bread wheat, arrived in eastern and central Europe after 6000BC – so they are saying Mesolithic people in Britain had access to wheat products prior to that date – even before farmers penetrated the Balkans. The truth is somewhere in between we might suspect. Whilst the great body of farmers were still occupying Anatolia and the Fertile Crescent (as far as Baluchistan in the east) small groups may have been on the move earlier. There is also the Cunliffe theory that people were visiting Britain in boats for a long period of time and they could have been travelling through the Mediterranean and hugging the coast of western Europe long before the first farmers arrived in mass. It is not impossible. One of the discoveries below Bouldnor Cliff was a Mesolithic boat yard – so the travelling doesn't have to have been in one direction only.
The paper is published in the journal Science 347 (6225): 998 DOI:10.1126/science1261 278 (2015) 'Sedimentary DNA from a submerged site reveals wheat in the British Isles before 8000 years ago'.