This geological map illustrates the location of the two cairns based on British Geological Survey and Ordnance Survey map data. (Image: NERC/Crown copyright)
The Mesolithic–Neolithic transition in Britain is a widely debated topic, particularly with regard to the role migration played in spreading Neolithic farming practices from the Continent to Britain. Now researchers from Durham University are using isotope analysis to examine the childhood origins of early Neolithic Britons, in an initiative aiming to address this question.
Concentrating on two Neolithic long cairns in Wales – Penywyrlod and Ty Isaf – the team examined nine skeletons from each. The human remains were radiocarbon dated and analysed for strontium, oxygen, and carbon isotopes to evaluate the individuals’ origins and migration history. The monuments lie less than 8km apart within a cluster of Neolithic monuments in the Black Mountains of south-eastern Wales. Despite their similarities, radiocarbon dates from the burials indicate that Penywyrlod (3960-3640 cal BC) may have been built and used earlier than Ty Isaf, and it has been suggested that they could have been used by different social groups.
The results also demonstrate that the two burial populations obtained their diet from different areas. The strontium-isotope analysis for Ty Isaf indicates that the individuals could have grown up in the area surrounding the cairn, hinting at them being a local, non-mobile community. Conversely, the majority of the samples from Penywyrlod had strontium-isotope values that did not match the local biosphere range, indicating that they probably obtained their childhood diet from elsewhere. They may not have exploited areas located too far away, however, as the Malvern Hills – as well as other regions in Britain – have a biosphere range comparable to the results for these individuals.
In addition, there was one enigmatic individual whose strontium-isotope results were not consistent with any currently recorded biosphere values within England or Wales – meaning they obtained their childhood diet outside this region and may therefore have moved to Britain from elsewhere, making this journey sometime after the formation of their wisdom teeth (which usually occurs around 14 years of age).
This person was also radiocarbon dated to 3770-3630 cal BC (95% confidence). As the beginning of farming in southern Wales is dated to approximately 3765-3655 cal BC, they could have been contemporary with the first appearance of Neolithic culture in the region. Intriguingly, their strontium-isotope ratios are comparable to ranges recorded in northwestern France, and current arguments, based on comparative analysis of ceramics, suggest that Neolithic culture and practices may have been introduced to western Britain by the migration of groups from this region. In any case, the results provide strong evidence to support the argument that migration between Britain and the Continent occurred during the Neolithic transition in Wales.
The paper outlining these findings was recently published in the American Journal of Physical Anthropology and can be read for free here: http://onlinelibrary.wiley.com/doi/10.1002/ ajpa.23279/full.
This article was published in CA 335.