The primary focus of this research is the poorly understood relationship between water insufficiency and broad-scale social change, in the semi-arid lower Salt River Valley, in central Arizona. The overarching research question guiding this research is if water insufficiency could have prompted sociopolitical change among the Hohokam. Specifically, the research investigates if long-term water deficits were a catalyst for the two most consequential transformations in Hohokam history – the Preclassic/Classic transition (A.D. 1070-1100/1150) and the early to late Classic period transition (ca. A.D. 1300).

This research used extensive historical aerial photographs and cultural resource management excavation data to complete the largest-scale reconstruction of Hohokam irrigation. These lines of evidence provided exceptional insight into the developmental histories of eight major irrigation systems along the lower Salt River, four of which are newly defined here. Also, historic Salt River streamflow trends are leveraged to refine previously reconstructed annual flow discharges. The irrigation system reconstruction provided the means for estimating irrigation demand through irrigated acreage, and monthly streamflows supplied the amount of water available during key points in the two agricultural cycles per year. Together, irrigation demand and water availability provided necessary data to identify persistent water shortages during Hohokam history between A.D. 740 and 1450.

The findings discussed in this dissertation demonstrate that water insufficiency likely had no notable effect related to either the Preclassic/Classic or early to late Classictransitions in the lower Salt River Valley. Instead, there was possibly enough water through time for Hohokam farmers to meet agricultural demands. Three substantial additional insights were gained from this research. First, an extremely large flood, occurring either during the late Colonial or early Sedentary periods, may have profoundly altered irrigation agriculture and social organization in the valley. Second, during at least the Sedentary and Classic periods, Hohokam irrigation was structured into standardized irrigation units (SIU), a far more complex and efficient method of irrigation than previously perceived along the lower Salt. Third, a bedrock reef located near Canal System 2, and not at other lower Salt irrigation systems, is plausibly a determinate in Canal System 2’s longevity.

Archaeologists have long contended that large-scale human migrations played an essential role in the cultural development of pre-Hispanic central Mexico. During the Epiclassic period (600-900 CE), migration is implicated in the appearance of new forms of material culture, sociopolitical disruptions, and the emergence of new regional polities. Sweeping social changes accompanied these developments, including demographic reorganization and increased levels of violence. Research across the social sciences finds that violence directed at individuals perceived as categorically distinct also typically increases during such periods of socio-political upheaval. This dissertation investigates identity-based violence in the Epiclassic Basin of Mexico to consider how diverse social identities contributed to the selection of victims of ritual violence.

This research examines the skeletal remains from a sacrificial deposit at the Epiclassic shrine site of Non-Grid 4 in the Basin of Mexico, where a minimum of 180 human crania were interred as ritual offerings. The project reconstructs patterns of paleomobility and biological relatedness to determine whether individuals with distinct categorical social identities were more likely to become victims of human sacrifice. It answers the questions: (1) Were the sacrificed individuals predominantly locals who lived in the Basin of Mexico throughout their lives?; (2) Were the sacrificed individuals comprised of a single kin-group biologically continuous with pre-extant populations in the Basin of Mexico?; and (3) If victims were migrants biologically discontinuous with antecedent populations, from where in ancient Mesoamerica did they originate?

Results indicate that a majority of sacrificial victims were immigrants originating north and south of the Basin of Mexico. Biogeochemical analyses of sacrificed individuals find that 80% are non-local migrants into the Basin, suggesting that they were likely targeted for violence based on their divergent residential histories. Multi-scalar biodistance analyses of Non-Grid 4 sacrificial victims demonstrate that they represent two biologically distinct groups. There was evidence, however, for both biological continuity among victims and pre-extant central Mexican populations, as well as for migration from northern and southern Mexico. This project therefore not only improves knowledge of migration during the central Mexican Epiclassic, but also contributes to broader anthropological understandings of the social context of violence.

Foodways in societies at every social scale are linked in complex ways to processes of social change. This dissertation explores the interrelationship between foodways and processes of rapid social transformation. Drawing on a wide range of archaeological and ethnographic data from the Cibola region, I examine the role of foodways in processes of population aggregation and community formation and address how changes in the scale and diversity of social life interacted with the scale and organization of food production and consumption practices. To address the interrelationships between foodways and social transformations, I employ a conceptual framework focused on two social dimensions of food: cuisine and commensality. This study comparatively examines cuisine and commensality through time by investigating a range of interrelated food activities including: food production, storage, preparation, cooking, consumption and discard.

While settlement patterns and other more obvious manifestations of aggregation have been studied frequently, by examining foodways during periods of aggregation and social reorganization this study provides new insights into the micro-scalar processes of social transformation, cuisine change, and economic intensification associated with increases in settlement size, density, and social diversity. I document how food production and preparation intensified in conjunction with increases in the size of settlements and the scale of communal commensal events. I argue that foodways were a critical aspect of the social work of establishing and maintaining large, dense communities in the 13th and 14th centuries. At the same time, widespread changes in commensal practices placed a larger burden on household surplus and labor and women were likely the most affected as maize flatbreads and other foods made with finely ground flour were adopted and became central to cuisine. As such, this study provides insights into how rapid social transformations in the late 13th and 14th centuries were experienced differently by individuals, particularly along gendered lines. Studies of foodways, and specifically the social dimensions of food, offer a promising and often underutilized source of information about past processes of population aggregation, social integration, and transformations in the political economies of small-scale societies the past.