Migrations, past and present, fundamentally influence human interaction, community building, and social evolution. Studies of contemporary migrations demonstrate that the form and intensity of interaction migrants maintain between homeland and host communities shape social dynamics, innovations, and identities. This dissertation applies a contemporary theoretical framework and biogeochemical analyses to elucidate the scale, processes, and impacts of migration in the hinterland of the pre-Hispanic Tiwanaku polity (ca. AD 500-1100). Social diversity is examined by reconstructing the migration histories and dietary choices of individuals interred at the Tiwanaku-affiliated site of Omo M10 in the Moquegua Valley of southern Peru.

Radiogenic strontium and stable oxygen isotope data from human dental and skeletal elements are used to characterize intra- and inter-individual paleomobility patterns at Omo M10. When contextualized with archaeological evidence, these data reveal multigenerational interaction through migration between communities in the highland Tiwanaku heartland and at Omo M10. The observed greater mobility of females and juveniles at Omo M10 indicates that women and families played an essential role in maintaining social relationships and persistent cultural continuity in Moquegua Tiwanaku life. Contact with the highlands waned over time as disruption in the urban highland centers likely weakened ties to peripheral lowland communities.

Stable carbon and nitrogen data from human dental and skeletal elements are employed to estimate intra- and inter-individual paleodietary patterns. Results indicate diet at Omo M10 varied depending on an individual’s community affiliation, sex, age, and level of mobility; diet broadly changed over time with shifting levels of interaction with highland Tiwanaku communities. Intra-individual biogeochemical analyses of migration and diet at Omo M10 contribute a nuanced perspective on the diverse experiences of multigenerational colonists on the periphery of the Tiwanaku polity.

Many models of colonial interaction are build from cases of European colonialism among Native American and African peoples, and, as a result, they are often ill-suited to account for state expansion and decline in non-Western contexts. This dissertation investigates social organization and intraregional interaction in a non-western colonial context to broaden understanding of colonial interaction in diverse sociocultural settings. Drawing on social identity theory, population genetics, and social network analysis, patterns of social organization at the margins of the expansive pre-Hispanic Tiwanaku state (ca. AD 500-1100) are examined.

According to the dual diaspora model of Tiwanaku colonial organization in the Moquegua Valley of southern Peru, Chen Chen-style and Omo-style ethnic communities who colonized the valley maintained distinct ethnic identities in part through endogamous marriage practices. Biodistance analysis of cranial shape data is used to evaluate regional gene flow among Tiwanaku-affiliated communities in Moquegua. Overall, results of biodistance analysis are consistent with the dual diaspora model. Omo- and Chen Chen-style communities are distinct in mean cranial shape, and it appears that ethnic identity structured gene flow between ethnic groups. However, there are notable exceptions to the overall pattern, and it appears that marriage practices were structured by multiple factors, including ethnic affiliation, geographic proximity, and smaller scales of social organization, such as corporate kin groups.

Social network analysis of cranial shape data is used to implement a multi- and mesoscalar approach to social organization to assess family-based organization at a regional level. Results indicate the study sample constituted a social network comprised of a dense main component and a number of isolated actors. Formal approaches for identifying potential family groups (i.e., subgroup analysis) proved more effective than informal approaches. While there is no clear partition of the network into distinct subgroups that could represent extended kin networks or biological lineages, there is a cluster of closely related individuals at the core of the network who integrate a web of less-closely related actors. Subgroup analysis yielded similar results as agglomerative hierarchical cluster analysis, which suggests there is potential for social network analysis to contribute to bioarchaeological studies of social organization and bioarchaeological research in general.