Amino Acid Isotope Investigations of Infant Feeding and Physiology

The investigation of infant feeding practices is critical for understanding trends in infant mortality, long-term health and population demographics, the socioeconomic roles of women, and family dynamics and subsistence. Stable carbon and nitrogen isotope analysis of bulk bone and dentine collagen revolutionized the way infant feeding practices are studied in the archaeological record. These methods have allowed us to obtain direct dietary information from individuals that can be interpreted against other skeletal markers of health and social status. In this project, we take the isotopic analysis of ancient skeletal proteins one step further by measuring isotopes of carbon and nitrogen in the amino acids that compose collagen (from bones and teeth) and keratin (finger nails). We aim to develop more sensitive proxies to identify the duration of exclusive breastfeeding, the types of foods provided to infants, and to distinguish between dietary and physiological sources of isotopic variation in human skeletal remains from archaeological sites across the North Atlantic world.