van der Merwe With National Science Foundation support, Dr. Nikolaas van der Merwe will analyze bone, muscle and hair tissue from pigs which have been raised on 14 different controlled diets. These materials will be obtained from animals raised at the USDA Agricultural Research Service in Beltsville Maryland and Dr. van der Merwe will analyze the carbon and nitrogen isotopic ratios in amino acids in both dietary items and pig tissue. The goal of the research is to study biochemical routing from dietary components to consumer tissues at the amino acid level. The diets are designed to identify the dietary components used in the synthesis of pig protein tissues, particularly where more than one protein source (animal and/or plant) is available. Dietary items have been chosen for their characteristic stable carbon isotope characteristics, depending on whether the plant foods have a C3 or C4 photosynthesis or the animal proteins are derived from such plants. The food items and pig tissues will be separated into constituent amino acids and their isotope ratios measured to model the relevant biochemical pathways. The long-term goal of the study is to reconstruct past human diets through the isotopic analysis of archaeological human skeletons. This procedure has been in use for more than fifteen years and has had a major impact on the understanding of past human subsistence and processes. However contradictions between isotope data and other evidence suggest that the relationship between the dietary importance of a food and the isotopic signal in consumer bone tissue is not linear. It appears for example that protein dominates in the construction of consumer collagen, while bone carbonate averages the carbon from the total diet. The work on pigs will help to refine this biochemical model and allow improved application to archaeological materials. This research is significant for a number of reasons. It will help to refine a technique which is widely used in archaeo logical research and which has potentially wide application in nutritional and metabolic studies as well. The work will increase our understanding of how past populations made use of their environment.
