Doctoral Dissertation Improvement Grant: Isotopic Reflections of Mobility and Labor Patterns

University Of California-Davis, Davis CA

Investigators

Abstract

Candice Ralston, a Ph.D. candidate at the University of California-Davis, will conduct archaeometric research to study the relationship between social organization and the division of labor for hunter-gatherer populations. Place of residence after marriage, or postmarital residence, impacts the structure of societies and their kinship networks. Ralston's dissertation research will investigate the relationship between the relative importance of male versus female contributions to subsistence and diet, and postmarital residence. Advancements in stable isotope analysis of human skeletal tissues, permit archaeologists to generate nuanced data-sets with which to investigate ancient diet and mobility. Stable isotope analysis provides more direct evidence of paleomigration and diet for individuals, can distinguish individual-level residential and dietary patterns, and permit comparison between male- and female-mobility and dietary patterns. This study uses five isotopic discriminants (strontium, oxygen, sulfur, carbon, and nitrogen). Incorporating multiple lines of isotopic evidence enhances the interpretive power of these analyses for understanding human mobility and the food webs they exploit. This project will also further Ralston's academic and intellectual development. Evidence will come from two California Central Valley archaeological sites, CA-SAC-107 and CA-SJO-68, dating to the Early Period (ca. 5000-2500 BP). The California archaeological record shows temporal trends for 1) shifting subsistence-economies and 2) increasing differentiation of gendered labor. As such, the region is ideal to test how subsistence and labor co-vary with postmarital residence. Archaeological research conducted in California's Central Valley has traditionally focused on resource intensification, demographic forcing, and resource depression as drivers of cultural change. By contrast, the dynamics of cultural development and social organization have not been adequately addressed. Cross-cultural analyses suggest that economic systems, the division of labor between women and men, warfare, and territoriality are significant predictors of postmarital residence practices. These findings set up the central question of Ralston's research. Does the division of labor, and more specifically, a biased subsistence contribution to the overall diet, influence postmarital residence for Early Period populations in the Central Valley of California? Ralston will address the research question by 1) reconstructing marital mobility using isotope chemistry (strontium, oxygen, and sulfur) in skeletal tissues to ascertain postmarital residence, 2) interpreting subsistence practices using previously published faunal, botanical, and artifactual data from CA-SAC-107 and CA-SJO-68, and 3) reconstructing the diet of burial populations from the two sites using stable isotopes of carbon and nitrogen in bone collagen, and carbon in bioapatite. Ralston's dissertation research will clarify synchronic patterns of postmarital residence for the Early Period but also, when combined with site-specific data from different periods, provide a diachronic perspective that will elucidate the evolution of postmarital residence practices of indigenous groups of California and, more broadly, hunter-gatherers. Additionally, this study will demonstrate the significance of using multi-isotopic approaches to understanding ancient human behavior. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.