The value of human remains and the potential of ancient DNA studies#
Rick Schulting, University of Oxford, and Oliver Craig, University of York#
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Human remains dating to the Mesolithic are rare in Britain (Meiklejohn et al 2011). This is unfortunate, as they provide a direct window into many different aspects of a long-vanished lifeway, pre-dating the arrival of farming. While the ideal case is an intentional burial, with its unrivalled combination of biological and cultural information, these are currently unknown for the period in Britain, with the possible exception of poorly documented early accounts, such as that of Aveline’s Hole, Somerset (Schulting 2005). This in itself might be telling us something important about how human remains were treated after death in the Mesolithic. Scattered and partial fragments of human bone, however, have been recovered from a variety of contexts, primarily caves, but also shell middens, rivers, and open-air sites. With the application of modern scientific approaches, these can provide a surprising amount of information, including insights into past diets and population relationships, which in turn have implications for the subsistence economy, territoriality and population density (Schulting 2010). It is clear that additional Mesolithic human remains do exist in museum collections, and the increasing use of AMS (Accelerator Mass Spectrometry) 14C dating, together with archival research, has resulted in a number of ‘new’ finds being identified in recent years. One of the best examples of this is the partial skeleton of ‘Tilbury Man’ found during the construction of the Tilbury Docks in 1883, now dated to the Late Mesolithic, c 6000 cal BC (Schulting in press). New excavations in targeted locations have also yielded human remains subsequently directly dated to the Mesolithic, most recently at Foxhole in South Wales (Schulting et al in press). This material presents new opportunities for research simply not available from any other source.
The field of ancient DNA (aDNA) research is one example of a new opportunity. This has advanced rapidly over the last few years and a major advance has been the application of next generation sequencing (NGS) technologies that are particularly well suited to analysing the short fragments of aDNA found in ancient biological material. The renaissance of research on aDNA driven by NGS is demonstrable through a series of recent successes in the analysis of prehistoric human bone, most notably the sequencing of Neanderthal remains and the identification of a new hominin species from c 40,000-year-old remains found in Southern Siberia. From later prehistoric contexts, ancient mitochondrial DNA has been sequenced from the bones of Mesolithic foragers and Early Neolithic farmers (8000–3000 cal BC) from a range of sites across Europe, whilst nuclear DNA has been recovered from Early Neolithic human bone from Central Europe. These landmark studies have provided new insights into the demographic changes associated with the shift to food production, showing in some cases large-scale replacement of Mesolithic huntergatherers with ‘incoming’ farming populations. As more later prehistoric bones are sequenced, more regional-specific and subtle inferences are beginning to emerge regarding the demographic history of Europe during this key period. Unfortunately, no prehistoric British human sequences have ever been published. Research in this area is a priority in order to achieve a better understanding the scale of migration at the start of the Neolithic period in Britain and the relationship between Britain and Europe during the Mesolithic period.