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.

Heavy Metals in Archaeological Soils

Portable X-ray fluorescence (pXRF) spectroscopy is commonly used for testing toxic levels of heavy metals in modern industrial waste sites, and it has seen growing applicability in the context of archaeological survey and soils. In this study, we present the results of our pXRF analysis of surface soils at a historic silver refinery located near Puno, Peru, in the western Lake Titicaca Basin. The results of our analysis identified hazardous levels of antimony (Sb), arsenic (As), mercury (Hg), and lead (Pb) in excavation soils, necessitating the relocation of planned excavation units and the use of personal protective equipment. This study highlights the advantages of rapid, in situ pXRF analysis of surface soils in contaminated industrial archaeology sites to assess potential harm to human health.

Ancient genomes reveal long range influence of the site and culture of Tiwanaku

Tiwanaku was a civilization that flourished in the Lake Titicaca Basin (present-day Bolivia) between 500 and 1000 CE. At its apogee, Tiwanaku controlled the lake’s southern shores and influenced certain areas of the Southern Andes. There is a considerable amount of archaeological and anthropological data concerning the Tiwanaku culture; however, our understanding of the population of the site of Tiwanaku is limited. To understand the population dynamics at different stages of the Tiwanaku cultural development, we analyzed 17 low-coverage genomes from individuals dated between 300 and 1500 CE. We found that the population from the Lake Titicaca Basin remained genetically unchanged throughout more than 1200 years, indicating that significant cultural and political changes were not associated with large scale population movements. In contrast, individuals excavated from Tiwanaku’s ritual core were highly heterogeneous, some with genetic ancestry from as far away as the Amazon, supporting the proposition of foreign presence at the site. However, mixed-ancestry individuals’ presence suggests they were local descendants of incomers from afar rather than captives or visiting pilgrims. A number of human offerings from the Akapana Platform dating to ca. 950 CE mark the end of active construction and maintenance of the monumental core and the wane of Tiwanaku culture.Significance StatementTiwanaku was an important pre-Inca polity in South America and an example of primary social complexity on par with civilizations in the Indus and Nile river valley. Flourishing between 500 and 1000 CE, Tiwanaku exercised control in the south Titicaca basin and influenced a vast area in southern Peru, Bolivia, and northern Chile. Comprehensive archeological studies provided information about the rise, expansion, and fall of the Tiwanaku culture, but little is known about the monumental site’s population. To address this lacuna, we generated low coverage genomes for 17 individuals, revealing that while the Titicaca basin’s residential population was homogenous, the individuals excavated from the ritual core of Tiwanaku drew their ancestry from distant regions.

The Life Force Materialized in the Andean Religion

Focusing on evidence from Titicaca basin, this chapter discuss how we are trying to comprehend the worldview of its past residents. This interaction with the landscape became part of a relationship that could not be escaped. Part of this relationship was played out in their constructed spaces where they gathered to interact, which included the sharing of food. These gathering spaces were the core of these early settlements, manifested in their architecture and displayed in the material. These exchanges embodied the animation of the world, as did the symbolic images they carved on the land and in stone, steadily crafting their society over 1500 years. Around 200 BC a shift occurred in society where social power was harnessed differently, in association with different performances, gifting, and labor.

Late Intermediate Period Plant Use at a Colla Hillfort, Puno, Peru (AD 1300–1450)

In the Lake Titicaca Basin during the Late Intermediate period (LIP; AD 1100–1450), people's lives were overwhelmingly structured by warfare. Previous research in the region has shed light on how martial conflict between and possibly among competing ethnic groups motivated people to live in fortified villages on defensive hilltops. At the same time, there was a centuries-long drought that threatened agricultural production. Little is known about the plant use of people living in hillforts during this arduous time. Drawing on macrobotanical information collected from Ayawiri, one of the largest hillforts in the northern Titicaca Basin, I argue that the food stuffs and plants used were locally grown. Additionally, these findings indicate a possible departure from earlier symbolically charged and ritually important plant consumption practices based on the lack of imported maize. This research sheds light on how people adapted their domestic and agricultural strategies to warfare and climate change during the LIP.

Diurnal Cycle of Convection over Lake Titicaca Basin Based on the Satellite Data from the Climate Prediction Center Morphing (CMORPH)

This paper examines the diurnal cycle of convection (DCC) over Lake Titicaca Basin (LTb) during summertime months based on the high spatial resolution (8 x 8 km2) and hourly temporal resolution, estimates of Climate Prediction Center Morphing technique (CMORPH). Analysis was performed using observed data from rain gauges (Rg-SENAMHI) for the period 2002 to 2013. Graphical comparisons and several statistical metrics such as correlation coefficient, bias, and root mean square error were used to evaluate CMORPH product. Spatial maps and graphic metrics of diurnal cycle were developed to assess CMORPH data, spatial dependency an accuracy over the LTb. Approximately, 43% of the total Rg-SENAMHI variation is explained CMORPH data. The correlation between Rg-SENAMHI and CMORPH is positively over southeast and northern LTb, and negatively in the central and southern LTb. A underestimation bias is observed over most the LTb areas and overestimation bias (e.g., Lagunillas, Isla Suana and Desaguadero stations). In general, spatial patterns of rainfall over the LTb were captured through CMORPH data. Over the surrounding lake area, high mountain, and plateau area, maximum peaks of precipitation occur in the early evening, neverhtheless over low areas such as the lake, surrounding and valleys, maximum precipitation values occur early morning. The results show that DCC its very related by surface exchange processes and local circulation resulting from solar radiation and heterogeneous topography.