An Isotopic Dietary Reconstruction of Texas Hunter-Gatherers

University Of Texas At San Antonio, San Antonio TX

Investigators

Abstract

With National Science Foundation support Dr. Robert Hard and Mr. Jeffrey Francis will coordinate the chemical analysis of a large series of prehistoric human skeletons excavated in a ca. 150,000 sq. km area of the coastal plain of Texas. Their goal is to use these data first to reconstruct diet and then to determine the relationship between subsistence strategy and settlement pattern. As the researchers note, the prehistory of the region is highly anomalous. In most portions of the world, hunting and gathering peoples lived in small mobile groups and buried their dead in individual locations, presumably because their territories were so large that they could not quickly transport the newly deceased to a central location. When domestic plants and animals were introduced, population size increased, sedentary villages emerged and groups began to bury their dead in central locations. In this region of Texas however beginning about 4000 years ago organized cemeteries began to be utilized along the major drainages and bays by native American mobile hunters and gatherers. Cemetery use continued through the last millennium of the prehistoric period. The cemeteries are paradoxical as their emergence suggests increased population, reduced mobility, aggregation and increased territoriality. Despite these changes however archaeological evidence indicates a band-level, mobile hunting and gathering adaptation. Prehistorically, domesticated plants were not used despite the existence of farming economies in adjacent areas and a climate which would have supported dry-farming. This pattern is in contrast to the North American Southeast and Southwest where agriculture was quickly adopted. Several theories have been proposed to explain this phenomenon and they share a belief that rich local wild food resources allowed for reduced mobility and territory size. They differ however in just what mix of foods might be involved, some focusing on fish and other marine resources, and others on abundant wild plants such as pecans. Because bone is remodeled over the human lifetime and the carbon and nitrogen in bone derives from dietary sources, bone chemical composition indirectly reflects the type of foods consumed. The researchers will analyze carbon and nitrogen isotope values from a large series of skeletons drawn from different subregions within the area. They will also examine strontium isotopes because these reflect individual movement over a lifetime. This research is important for several reasons. It will provide data of interest to many archaeologists and shed new light on a relatively unknown aspect of United States prehistory. It will also provide insight into the processes which shape social organization in relatively uncompelled societies.