Moving On: The Contribution of Isotope Studies to the Early Neolithic of Central Europe

Article excerpt

Introduction

The strontium isotope ratio recorded in the teeth and bone of both human and animal skeletons can be used to infer movements made during an individual's lifetime (Price et al. 2001; Bentley et al. 2002; 2003a; 2003b; Bentley & Knipper 2005; Price & Bentley 2005; Bentley 2006). The [sup.87]Sr/[sup.86]Sr ratio remains constant as it passes from local geology into the water cycle and food chain. Thus the isotope ratio laid down in a skeleton is a geochemical marker for the region where individuals sourced the majority of their food (Bentley et al. 2002: 799). As adult teeth are formed between birth and 12-14 years, and bone is constantly turned over during life, any differences in [sup.87]Sr/[sup.86]Sr ratio between the teeth and the bone can indicate a change in living location or diet during an individual's lifetime (Price & Bentley 2005: 204). Further comparison of these ratios with the values from the local geology can indicate whether an individual moved into the region during later life (Price & Bentley 2005: 204). It must, however, be noted that bone is much more susceptible to contamination by groundwater and other agents in the burial environment than tooth enamel. As a result, the strontium content in bone can become in time more similar to the burial environment (Bentley 2006: 163-9).

The strontium isotope analysis of skeletal remains from Linearbandkeramik (LBK, c. 5500-4900 cal BC) sites in south-west Germany has presented a compelling case for high levels of mobility in these Neolithic communities (Price et al. 2001; Bentley et al. 2002; 2003a; 2003b; Bentley & Knipper 2005; Price & Bentley 2005; Bentley 2006). Two particular aspects of movement have been addressed through this research: the migration of farmers into Central Europe at the beginning of the Neolithic and possible social differences within established LBK communities (Price et al. 2001; Bentley et al. 2003a; 2003b; Price & Bentley 2005). While the method has offered archaeologists the opportunity to move from generalised arguments about migration and mobility to debating the specific forms that movement in the past may have taken, the conclusions drawn in these particular studies have not yet received wider critical consideration.

The problem we perceive with the way in which models based on isotopic data have been adopted in the literature is not unique to the LBK. As Milner et al. (2004: 18ff.) have pointed out, there is often a tendency to accept uncritically conclusions based on isotopic data, because the technique is derived from unfamiliar disciplines. However, isotopes are only one among several sources of evidence. As such, they can inform our reconstructions of the past to a considerable extent, but they cannot substitute for the archaeological groundwork and the careful and balanced appraisal of as many kinds of information as possible.

In this paper, we seek to evaluate the assumptions made in the interpretation of isotopic data and the models developed on this basis. The most salient issues to be addressed concern the dating framework and the kinds of mobility suggested. With the very significant evidence for regional variation found throughout the LBK (Modderman 1988; Gronenborn 1999; 2007a), over-generalising narratives of this period should be resisted. We suggest alternative interpretations by raising some of the contradictions between the isotope data and the archaeological material.

Mesolithic-Neolithic transition in south-west Germany

By the late 1990s, debates about the spread of the early Neolithic across Central Europe had reached a critical point. Long-standing models of demic diffusion and colonisation were increasingly challenged, with more scholars favouring varying degrees of indigenous involvement in the uptake of the Neolithic (Modderman 1988; Tillmann 1993; Whittle 1996; 2003; Kind 1997; 1998; Gronenborn 1999; Jeunesse 2000). …