Investigating economic specialization on the central Peruvian coast: A reconstruction of Late Intermediate Period Ychsma diet using stable isotopes

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.

The diet at the onset of the Andean Civilization: New stable isotope data from Caral and Áspero, North-Central Coast of Peru

OBJECTIVES

The subsistence system of the first urban centers with monumental architecture from the North-Central Coast of Peru, the core area for the social complexity process of Central Andes, has been debated since the late 1960s. To shed light on this aspect, we report paleodietary data from the two most important sites of the Supe Valley: Caral (3000-200 BC), the major settlement of the middle valley, and Áspero (3000-1800 BC), a notable coastal settlement. Our main objective was to test the Maritime Foundations of Andean Civilization hypothesis.

MATERIALS AND METHODS

Stable isotope values (δ¹³ C_col , δ¹³ C_ap , and δ¹⁵ N) from 52 individuals (70 samples: 44 bones and 26 teeth) were analyzed using conventional methods and Bayesian Mixing Models to address the role of marine products and plants in people's diet at both sites over time.

RESULTS

Our results suggest high C₃ carbohydrate consumption (55%-68% total calories in Áspero and >70% in Caral). The consumption of marine resources was stable for Áspero between 3300 and 1800 BC, but it decreased for Caral between 2550 and 200 BC.

DISCUSSION

Marine protein was more important in Áspero than in Caral over time. C₃ plants, possibly tubers, formed the foundation of the diet in both sites during the Formative period (~3000-200 BC). Maize was a marginal food (<12% of calories) at least until 800 BC (29% of calories). The Maritime Foundations hypothesis does not completely account for these findings. Our results suggest the predominance of crop-focused agriculture during the evaluated period.

Climate and demography drive 7000 years of dietary change in the Central Andes

Explaining the factors that influence past dietary variation is critically important for understanding changes in subsistence, health, and status in past societies; yet systematic studies comparing possible driving factors remain scarce. Here we compile the largest dataset of past diet derived from stable isotope δ¹³C‰ and δ¹⁵N‰ values in the Americas to quantitatively evaluate the impact of 7000 years of climatic and demographic change on dietary variation in the Central Andes. Specifically, we couple paleoclimatic data from a general circulation model with estimates of relative past population inferred from archaeologically derived radiocarbon dates to assess the influence of climate and population on spatiotemporal dietary variation using an ensemble machine learning model capable of accounting for interactions among predictors. Results reveal that climate and population strongly predict diet (80% of δ15N‰ and 66% of δ13C‰) and that Central Andean diets correlate much more strongly with local climatic conditions than regional population size, indicating that the past 7000 years of dietary change was influenced more by climatic than socio-demographic processes. Visually, the temporal pattern suggests decreasing dietary variation across elevation zones during the Late Horizon, raising the possibility that sociopolitical factors overrode the influence of local climatic conditions on diet during that time. The overall findings and approach establish a general framework for understanding the influence of local climate and demography on dietary change across human history.

Paleopathology of the Ychsma: Evidence of respiratory disease during the Late Intermediate Period (AD 1000-1476) at the Central Coastal site of Pachacamac, Peru

OBJECTIVE

To investigate evidence for maxillary sinusitis and pulmonary inflammation in archaeological skeletons dating to the Late Intermediate Period (AD 1000-1476) at the site of Pachacamac, Peru.

MATERIALS

Thirty-nine individuals (male, female, and unknown sex; 16+ years age-at-death) were analyzed for inflammatory periosteal reaction (IPR) on the visceral (inner) surfaces of the ribs, and 16 individuals were analyzed for evidence of maxillary sinusitis.

METHODS

All individuals were macroscopically examined for bony changes in the maxillary sinuses and new bone formation on the ribs according to pre-established criteria.

RESULTS

Some 33.3% (13/39) of individuals had IPR on the ribs and 93.8% (15/16) had bony changes in the maxillary sinuses.

CONCLUSIONS

Respiratory disease was likely prevalent in people buried at Pachacamac during the Late Intermediate Period. A number of factors may have increased the risk of developing respiratory disease, including exposure to poor air quality and increased crowding and social mixing, resulting from pilgrimage to this important ritual center.

SIGNIFICANCE

This paper represents one of the first systematic analyses of evidence for respiratory disease in Peruvian and South American human skeletal remains, demonstrating the suitability of the region for further study.

LIMITATIONS

A limited sample was available for analysis. Additionally, the site's skeletal preservation was excellent, meaning the sample available for assessment of maxillary sinusitis was smaller, being limited to individuals with post-mortem breakage.

FURTHER RESEARCH

The results of this study should stimulate further much needed systematic investigation of evidence for respiratory disease in other Peruvian and South American populations.

Early specialized maritime and maize economies on the north coast of Peru

We assess diet and economies of middle Holocene (∼7,500 to 4,000 calibrated [cal] B.P.) humans at coexisting mound sites (Huaca Prieta and Paredones) in north coastal Peru and document regular consumption of maize by ∼6,500 to 6,000 cal B.P. and its earliest use as a staple food in this area of the Andes between 5,000 and 4,500 cal B.P. Stable isotope data from enamel carbonates and dentin collagen (childhood diet) and dental microwear texture analysis (adult diet) demonstrate dietary and economic specialization. Previous studies revealed maize and mixed-food refuse at both sites, but this study documents actual food consumption, showing that these communities situated a few hundred meters apart had significantly distinct diets in childhood and adulthood. Huaca Prieta focused on marine resources, although there are some contributions from terrestrial meat. Paredones individuals primarily consumed maize during childhood (up to 70% of the juvenile diet), as shown by δ¹³C values, apatite-collagen spacing, and discriminant analysis of δ¹³C_coll, δ¹³C_carb, and δ¹⁵N values. Maize was likely used as a weaning food (e.g., gruel and/or chicha-a maize beverage), hinting at the significant role of breastfeeding mothers, weanling infants, and children in the development of maize as a staple crop. Additionally, dental microwear data show Paredones adult diets are high in abrasives, potentially from maize processing. The distinct foodways at these neighboring sites result from and also reflect their social and political distinctions. These differences in food production, distribution, and consumption generated opportunities for exchange, an interaction that bound them together in mutual benefit.