Human Ecology and Social Organization in the Prehistoric California Delta: An Examination of Strontium-87/Strontium-86 Isotope Ratios in the Human Burial Population at CA-CCO-548

Restricted residential mobility is of particular interest to anthropologists because there are numerous examples across time and space where people independently became sedentary. In addition, the changes in economic patterns, social complexity, and landscape use that accompany a shift in mobility have implications for social organization including marriage patterns, gender roles, and workloads within the economic system. Prehistoric California provides ideal circumstances to study the development of restricted residential mobility because there is intensification of resources, increase in population density, and development of social complexity that all seem to occur within a short time span beginning in the Early Period (ca. 5500-2500 BP). However, the shift to sedentism was not followed by the development of agriculture as in many other areas of the world. This dissertation seeks to elucidate the relationship between restricted residential mobility and modifications of social organization by testing the hypothesis that as population increases and human groups become more sedentary there is an impact on marriage patterns and other aspects of culture and society due to alterations in the relative importance of male and female activities.;The methodological approach in this dissertation is to use individualistic data, which provides a way to track small scale changes over a period of time. This is designed to inform on the social process under investigation by addressing questions about the life of individuals and the behavioral and genetic relationships of a particular group. Specifically, this project uses stable isotope ratios of 87Sr/86Sr to detect and compare the geographic origin of an individual's food resources during their childhood and again in their last few years of life. The strontium data are compared to oxygen isotopes, radiocarbon dates, sex, age, burial position, and other individualistic data collected at an archaeological site in the Sacramento -- San Joaquin Delta region of California (CA-CCO-548).;This study yielded several results. The comparison of 87Sr/ 86Sr data with other individualistic attributes at the site revealed a trend toward more restricted group mobility later in time with a shift from focus on the Coast Ranges toward the Delta and Central Valley. This result is consistent with predictions based on the current state of knowledge about prehistoric California, although the shift toward sedentism appears to have occurred earlier than was previously proposed. In addition, matrilocal post-marital residence dominates earlier in time, with a change to more even sex distribution of non-local individuals occurring after 3300 cal BP. This shift in post-marital residence occurs almost simultaneously with the restriction in mobility and therefore supports the hypothesis that changes in mobility have an influence on fundamentals in social organization.;The results obtained in this dissertation highlight the importance of studies at an individualistic level and also the need to continue adding to stable isotope research in California. Building on this data will enable archaeologists to provide a more fine-grained view of prehistory while allowing individuals from the past to reveal their own story.