We consider the Clovis vs. pre-Clovis debate from three perspectives: migration models; petroglyph and surface-artifact ages; and scientific method. First, we test the hypothesis that a Clovis migration can account for the temporal and spatial distribution of South American Paleoindian sites “accepted” by Clovis-first advocates. Using a Clovis-first model, site ages are underpredicted by approximately 1,500 years, suggesting that the Clovis hypothesis cannot be reconciled with accepted empirical data. Second, we present North American accelerator mass spectrometry (AMS) 14C minimum-limiting ages from petroglyphs and surface artifacts that demonstrate continued support for a pre-Clovis occupation of the dryland west, as well as a Beringian entry into the hemisphere. Third, the debate has been confounded by a widespread misstatement of the problem. Though Clovis occupation is a “solved” issue, the competing hypotheses are whether the first migration was Clovis or pre-Clovis; the presence of Clovis sites is simply a necessary prediction of both migration theories. The empirical implications of the Clovis-first hypothesis are virtually untested. Scientifically evaluating the first peopling controversy requires scrutinizing the empirical test implications and logical coherency of both competing hypotheses.

The settlement practices of the prehistoric Anasazi of the North American Southwest exhibited shifts from the occupation of dispersed settlements to aggregated villages in many locales both concurrently and at different times. Explaining the nature and timing of these shifts has long been a focus of interest to researchers working in the Southwest. We present a model that outlines the relations among population growth, population dispersion and aggregation, regional abandonments, the nature of specialized systems of production, labor organization, climatic change, and the role of natural selection in producing evolutionary explanations. We offer the hypothesis that aggregation is the product of changes in the organization of corporate labor related to the stabilization of specialized strategies of resource production in response to changes in environmental conditions.

Models of site structure, though common in the ethnoarchaeological literature, are rarely used in the interpretation of the archaeological record. In this study, Portnoy's (1981) model of settlement space and function provides an interpretive framework for inferences on the organization and use of space at the Bridges site, a late prehistoric settlement in south-central Illinois. Unlike its predecessors, this model focuses on the daily activities and interactions of the resident community and identifies a communal front region, a family front region, a family back region, and a communal back region. From this model, it is possible to derive the material consequences of the activities performed in each of the activity regions. Given the proper excavation strategy, it is then possible to define the site framework from the arrangement of structures and features and to infer the nature of the activities from the distribution of debris. As identified at the Bridges site, the nature and organization of the activity regions suggest the presence of an integrated settlement with communal work spaces. This interpretation of the site has important implications for our understanding of late prehistoric chronologies and settlement plans.

Antigua has substantially more preceramic sites than any other island in the Lesser Antilles. Archaic peoples made extensive use of the high-quality flint that is common on Antigua to produce industries dominated by unretouched flakes and blades. Analysis of the largest excavated Archaic assemblage from the island reveals that flaked-stone technology centered around the production of direct-percussion blades, and that the majority of other flake classes are by-products of blade production. The assemblage's five major morphological classes of blades appear to represent successive stages of core reduction.

High-quality cryptocrystalline silicates from the Oligocene-age White River Group of the central Great Plains (referred to here as White River Group Silicates [WRGS]) were widely used prehistorically for chipped-stone tools. There are three known source areas for WRGS: Flattop Butte in northeastern Colorado, Table Mountain in east central Wyoming, and the White River Badlands of South Dakota. Specimens from these sources are often visually indistinguishable, making it difficult to specify the source of WRGS from nonquarry archaeological sites. Using a quantitative method—neutron-activation analysis—these sources were differentiated. The sources of WRGS in two Central Plains archaeological sites also were determined using this technique. The results show that the technique has important implications for studies of prehistoric mobility and for the refinement of cultural-historical affiliation.

Samples of organic matter and rock varnish from seven rock-art sites in the Bighorn Basin of Wyoming and Montana were collected for dating purposes. Petroglyphs sampled include Dinwoody-style figures, shield-bearing warriors, and other well-known Plains rock-art motifs. Accelerator mass spectrometry (AMS) dating of 10 petroglyphs yielded dates from the Early Archaic to the Protohistoric periods. A strong numerical relation between varnish leaching and time was found for petroglyphs older than 1,000 years, permitting the derivation of a cation-leaching curve (CLC) and calibrated cation-ratio (CR) ages for 15 different petroglyphs. No clear numerical relation between varnish leaching and time was found for petroglyphs less than 1,000 years old, possibly due to historical damage or past environmental conditions. As a result, calibrated CR ages could not be derived for six petroglyphs, and they are considered to be only younger than 1,000 years. Although further research is needed to establish whether one CLC can be used for all petroglyphs in the region, these studies constitute the first numerical chronology for rock art in the Bighorn area. Results indicate the occurrence of spatially discrete, but temporally concurrent styles in the Bighorn Basin during the last 800-900 years.