"Risk, Climate Variability, and the Study of Southwestern Prehistory: An Evolutionary Perspective" (Larson, senior author, with Hector Neff, Donald A. Graybill, Joel Michaelsen, and E. Ambos) American Antiquity, 61(2): 1-30, 1996.

Abstract Two recent developments in southwestern archaeology are brought together in this paper. First, theoreticians have begun to argue that the archaeological record should be viewed as the product of selection-driven evolution. Second, tree-ring research has produced a highly detailed history of climate for a large area of the northern Southwest. We view the record of climatic oscillations and extreme events as a record of the strength of selection favoring stabilization of specialized agricultural strategies in the arid northern Southwest. Published data from Black Mesa provide a cultural record of sufficient precision to permit comparison with the climatic record, while new data from Vermillion Cliffs, southern Utah, document one local end-product of an evolutionary sequence shaped to an important degree by the long-term variability of climate. Anasazi occupation of many regions failed to persist through the "Great Drought" of the 1270s. From a local perspective, the "Great Drought" occasioned failure of the adaptations shaped by selection prior to the 1270s; from a broader temporal-spatial perspective, however, this extreme climatic event must be seen as part of the selective regime that shaped subsequent human adaptation to the northern Southwest.

This article is both a theoretical contribution and data analysis paper. It is based, in part, on the research conducted by the CSULB Field School in archaeology and geology. This paper presents a new climatic reconstruction going back to A.D. 100 and it is hoped that this information will be of great value to modelers of global climatic changes. Indeed, the climatic reconstruction that we completed for the northern Southwest is the most accurate reconstruction completed for this region and it has been cited in both archaeology and climatology as a major work. Furthermore we break new ground with neutron activation analysis of ceramics in the American Southwest, another effort to bridge theory and methods of archaeological data analysis.

This article would not have been possible without the field school excavations that we conducted in previous years. This effort reflects my commitment to publish the results of any excavation that I conduct in a timely manner.