Dietary reconstruction, mobility, and the analysis of ancient skeletal tissues: Expanding the prospects of stable isotope research in archaeology

The use of stable isotope ratio analysis in archaeology has exploded over the past few decades to the point where it is now an established tool that is routinely used to investigate questions relating to diet and mobility. Early applications focused mostly on the analysis of human skeletal tissues as a way to reconstruct major shifts in human diet, but current stable isotopic approaches have expanded to include high resolution analyses of human, animal, and plant remains, which are helping to better define the resource exploitation and management strategies that underscore changes in the human diet. In addition, stable isotopic data sets are now regularly filtered through interpretive archaeological theoretical frameworks to explore socially mediated food acquisition and consumption choices, mortuary practices, and social identity. Much work remains to be done in documenting the biological and ecological variation in the distribution of stable isotopes in ancient food webs and the mechanisms responsible for the isotopic signals observed in archaeological plant and animal tissues. Here, we identify several areas in stable isotope analysis where additional 'first principles' driven research would help to improve existing isotopic methods, or develop new ones, and consequently improve our ability to answer questions of archaeological significance. We consider the strengths and limitations of the application of stable isotope analysis to ancient skeletal material obtained from archaeological contexts. We also pay particular attention to nitrogen isotopic variation in ancient ecosystems, organic oxygen and hydrogen isotopes to;mixing models as a means of estimating source contributions in human diet, mobility, and isoscapes; and to how compound specific analyses may help detangle dietary routing. We conclude with a plea for greater scientific rigour and more informed use of stable isotope analyses and call for a closer integration of stable isotope analysis with other aspects of archaeological research programmes, in order to optimise the information that isotopes can provide.