Methodological Developments in the Use of Stable Isotope Analysis for Reconstructing Paleodiets

Understanding the composition of paleodiets is crucially important for the archaeological investigation of lifeways and subsistence practices within ancient societies. Among the numerous research methods capable of investigating various elements of paleodiets, the use of stable isotope analysis has become increasingly popular. Advantages of this research technique include its ability to recognize multiple types of dietary inputs through the examination of stable carbon and stable nitrogen isotopes, and to investigate dietary composition and variation at an individual level. This research paper examines how this methodology has developed through time. Specific attention will be directed toward both the procedural advances that continue to reshape the utility of this method, as well as changes in the theoretical assumptions that have guided its application. 1 Reconstructing the diet of prehistoric peoples is an essential objective for archaeologists interested in understanding the lifeways and cultural dynamics of past human societies. A basic premise that has been reiterated through time by archaeologists interested in investigating paleodiet is that " we are what we eat " (Schwarcz 1991; Parkington 1991; Beehr and Ambrose 2007). From this assertion we can derive two interrelated research questions: what do we eat, and who are we? Answering these complex questions requires a multidimensional research approach that relies on various supporting lines of evidence. While stable isotope analysis, or any single method, should not be relied on to provide the only evidence in the reconstruction of a paleodiet, this method's ability to measure dietary differences on an individual level has proven to be invaluable for the investigation of prehistoric foodways and paleodiets. In this paper I will trace the historical development of stable carbon and stable nitrogen isotope analyses within archaeology in order to demonstrate how this method has progressed through time, and the ways in which it continues to contribute to archaeological research. Research using stable isotope data continues to expand in new directions by incorporating a greater number of elements into research designs, such a strontium and oxygen, and examining new materials, such as ceramic residues, but these more recent developments will not be of primary concern in this paper. While there are a number of methods that can provide insights into diet reconstruction (see Ambrose 1987), stable isotope analysis is often selected for its ability to directly examine specific types of dietary inputs. Initially, this method was often 2 applied to various permutations of the research question, " …