Diet and gender in the Tiwanaku colonies: Stable isotope analysis of human bone collagen and apatite from Moquegua, Peru

South American Archaeological Isotopic Database, a regional-scale multi-isotope data compendium for research

The South American Archaeological Isotopic Database (SAAID) is a comprehensive open-access resource that aggregates all available bioarchaeological stable and radiogenic isotope measurements, encompassing data from human individuals, animals, and plants across South America. Resulting from a collaborative effort of scholars who work with stable isotopes in this region, SAAID contains 53,781 isotopic measurements across 24,507 entries from individuals/specimens spanning over 12,000 years. SAAID includes valuable contextual information on archaeological samples and respective sites, such as chronology, geographical region, biome, and spatial coordinates, biological details like estimated sex and age for human individuals, and taxonomic description for fauna and flora. SAAID is hosted at the PACHAMAMA community within the Pandora data platform and the CORA repository to facilitate easy access. Because of its rich data structure, SAAID is particularly well-suited for conducting spatiotemporal meta-analyses. It serves as a valuable tool for addressing a variety of research topics, including the spread, adoption, and consumption intensification of food items, paleo-environmental reconstruction, as well as the exploration of mobility patterns across extensive geographic regions.

Quinoa, potatoes, and llamas fueled emergent social complexity in the Lake Titicaca Basin of the Andes

The Lake Titicaca basin was one of the major centers for cultural development in the ancient world. This lacustrine environment is unique in the high, dry Andean altiplano, and its aquatic and terrestrial resources are thought to have contributed to the florescence of complex societies in this region. Nevertheless, it remains unclear to what extent local aquatic resources, particularly fish, and the introduced crop, maize, which can be grown in regions along the lakeshores, contributed to facilitating sustained food production and population growth, which underpinned increasing social political complexity starting in the Formative Period (1400 BCE to 500 CE) and culminating with the Tiwanaku state (500 to 1100 CE). Here, we present direct dietary evidence from stable isotope analysis of human skeletal remains spanning over two millennia, together with faunal and floral reference materials, to reconstruct foodways and ecological interactions in southern Lake Titicaca over time. Bulk stable isotope analysis, coupled with compound-specific amino acid stable isotope analysis, allows better discrimination between resources consumed across aquatic and terrestrial environments. Together, this evidence demonstrates that human diets predominantly relied on C₃ plants, particularly quinoa and tubers, along with terrestrial animals, notably domestic camelids. Surprisingly, fish were not a significant source of animal protein, but a slight increase in C₄ plant consumption verifies the increasing importance of maize in the Middle Horizon. These results underscore the primary role of local terrestrial food resources in securing a nutritious diet that allowed for sustained population growth, even in the face of documented climate and political change across these periods.

Multi-isotopic and morphometric evidence for the migration of farmers leading up to the Inka conquest of the southern Andes

We present isotopic and morphometric evidence suggesting the migration of farmers in the southern Andes in the period AD 1270–1420, leading up to the Inka conquest occurring ~ AD 1400. This is based on the interdisciplinary study of human remains from archaeological cemeteries in the Andean Uspallata Valley (Argentina), located in the southern frontier of the Inka Empire. The studied samples span AD 800–1500, encompassing the highly dynamic Late Intermediate Period and culminating with the imperial expansion. Our research combines a macro-regional study of human paleomobility and migration based on a new strontium isoscape across the Andes that allows identifying locals and migrants, a geometric morphometric analysis of cranio-facial morphology suggesting separate ancestral lineages, and a paleodietary reconstruction based on stable isotopes showing that the migrants had diets exceptionally high in C₄ plants and largely based on maize agriculture. Significantly, this migration influx occurred during a period of regional demographic increase and would have been part of a widespread period of change in settlement patterns and population movements that preceded the Inka expansion. These processes increased local social diversity and may have been subsequently utilized by the Inka to channel interaction with the local societies.

Paleopathology and children in the Andes: Local/situated biologies and future directions

In the decades since Verano (1997) published his foundational piece on Andean paleopathology, scholars have recognized the importance of the bioarchaeology of childhood. Yet, scholarship on ancient childhood in the Andes deemphasizes paleopathology. Nonadult paleopathological data are often employed in large-scale, biocultural studies focused on environmental or political adaptations; however, they can also elucidate children's individual lived experiences and roles in society. To generate culturally-meaningful paleopathological data, we must take a contextualized approach to our analyses and interpretations. Disparate use of chronological age in published datasets makes synthesis across studies problematic, and ethnohistorical and ethnographic data on Andean children demonstrate that developmental age categories, rather than chronological age ranges, are most appropriate. Further, paleopathological data can best inform our investigations when they are combined with related datasets such as those on sex, diet, activity, and mobility. With that in mind, we use the theoretical framework of "local biologies" (and the related "situated biologies"), where biology is viewed as heavily contingent on culturally-specific beliefs and practices and local physical, sociocultural, and political environments (Lock, 1993, 2001; Niewöhner and Lock, 2018). Local biologies approaches can enrich social bioarchaeology and paleopathology to by specifically situating children and their experiences within the ancient Andean world.

Spatial paleopathology: A geographic approach to the etiology of cribrotic lesions in the prehistoric Andes

OBJECTIVE

The ubiquity of cribra orbitalia in skeletal samples has led to rigorous debate over their etiology, with most concluding that nutrition, physiological stressors, and environmental disease vectors synergistically contribute to lesion development. To parse the relative contributions of these etiological factors in the prehistoric Andes, this spatial paleopathological meta-analysis investigates the relationship between population-wide prehistoric Andean cribra orbitalia rates and geographic, climatic, and hydrological variables.

METHODS

Crude prevalence patterns of cribra orbitalia from 61 archaeological sites were plotted and analyzed with geostatistical methods to explore spatial patterns in the distribution of anemia-associated lesions. Multiple linear regression modeling was performed on 19 spatial variables suspected to contribute to various forms of anemia that result in cribrotic lesions.

RESULTS

Spatially-clustered high cribra orbitalia rates exist around the Central Peruvian coast, but are paradoxically low on the Ecuadorian coast. Multiple regression shows that elevation, temperature, and precipitation were not predictive of lesion rates. Multiple regression models show that aridity and seasonal variability in freshwater supply, together, explained a third of the variation in lesion rates.

CONCLUSION

While cribra orbitalia has long been tied to coastal proximity, these results suggest environmental constraints such as the need for water storage could have promoted malnutrition and pathogenic infection more than mere coastal proximity.

LIMITATIONS OF THIS STUDY

This analysis is limited by the paucity of data from highland sites and by the assumption that burials are local to the excavation site.

SUGGESTIONS FOR FUTURE RESEARCH

Future studies will integrate isotopic and remotely-sensed data into models to explore links between water security, nutrition, and disease.

Evaluating elbow osteoarthritis within the prehistoric Tiwanaku state using generalized estimating equations (GEE)

OBJECTIVES

Studies of osteoarthritis (OA) in human skeletal remains can come with scalar problems. If OA measurement is noted as present or absent in one joint, like the elbow, results may not identify specific articular pathology data and the sample size may be insufficient to address research questions. If calculated on a per data point basis (i.e., each articular surface within a joint), results may prove too data heavy to comprehensively understand arthritic changes, or one individual with multiple positive scores may skew results and violate the data independence required for statistical tests. The objective of this article is to show that the statistical methodology Generalized Estimating Equations (GEE) can solve scalar issues in bioarchaeological studies.

MATERIALS AND METHODS

Using GEE, a population-averaged statistical model, 1,195 adults from the core and one colony of the prehistoric Tiwanaku state (AD 500-1,100) were evaluated bilaterally for OA on the seven articular surfaces of the elbow joint.

RESULTS

GEE linked the articular surfaces within each individual specimen, permitting the largest possible unbiased dataset, and showed significant differences between core and colony Tiwanaku peoples in the overall elbow joint, while also pinpointing specific articular surfaces with OA. Data groupings by sex and age at death also demonstrated significant variation. A pattern of elbow rotation noted for core Tiwanaku people may indicate a specific pattern of movement.

DISCUSSION

GEE is effective and should be encouraged in bioarchaeological studies as a way to address scalar issues and to retain all pathology information.

Crypt fenestration enamel defects and early life stress: Contextual explorations of growth and mortality in Colonial Peru

OBJECTIVES

This study provides a comprehensive analysis of crypt fenestration enamel defects (CFEDs) from the Eten and Mórrope communities, Colonial period (A.D. 1,530-1,750), Lambayeque Valley, Peru. The goal is to help clarify the role of these lesions as reflections of early life environments as well as relationships growth and survival at future ages.

MATERIALS AND METHODS

CFED absence/presence was recorded in the mandibular canines of 105 individuals and 202 teeth. Defect prevalence was compared between the Eten and Mórrope sites using a proportions test. Femoral growth residuals were compared between CFED present and absent samples. Mortality risk was evaluated using Kaplan-Meier survival analysis.

RESULTS

CFED frequencies at Eten and Mórrope were similar to previous studies. Greater frequencies of CFEDs were found at Eten compared to Mórrope. There was no association between skeletal growth and CFEDs. No differences in mortality were found between CFED present and absent individuals within each site. General survivorship at Eten was significantly greater than Mórrope. However, individuals without CFEDs at Eten had greater survivorship than those with and without CFEDs at Mórrope. Individuals with CFEDs at Eten had greater survivorship than those with CFEDs at Mórrope. These differences begin around 1.7 years.

CONCLUSIONS

CFEDs may be associated with stress experience, but associations with growth and survivorship at later ages is context dependent. CFED prevalence is an ambiguous indicator of stress when used in the absence of mortality data, and even under those circumstances, appears limited by differences in local demography.

Multiethnicity, pluralism, and migration in the south central Andes: An alternate path to state expansion

The south central Andes is known as a region of enduring multiethnic diversity, yet it is also the cradle of one the South America's first successful expansive-state societies. Social structures that encouraged the maintenance of separate identities among coexistent ethnic groups may explain this apparent contradiction. Although the early expansion of the Tiwanaku state (A.D. 600-1000) is often interpreted according to a centralized model derived from Old World precedents, recent archaeological research suggests a reappraisal of the socio-political organization of Tiwanaku civilization, both for the diversity of social entities within its core region and for the multiple agencies behind its wider program of agropastoral colonization. Tiwanaku's sociopolitical pluralism in both its homeland and colonies tempers some of archaeology's global assumptions about the predominant role of centralized institutions in archaic states.