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Abstract The squash family (Cucurbitaceae) contains some of the most important crops cultivated worldwide and has played an important ecological, economic, and cultural role for millennia. In the American tropics, squashes were among the first cultivated crop species, but little is known about how their domestication unfolded. Here, we employ direct radiocarbon dating and morphological analyses of desiccated cucurbit seeds, rinds, and stems from El Gigante Rockshelter in Honduras to reconstruct human practices of selection and cultivation of Lagenaria siceraria, Cucurbita pepo, and Cucurbita moschata. Direct radiocarbon dating indicates that humans started using Lagenaria and wild Cucurbita starting ~ 10,950 calendar years before present (cal B.P.), primarily as watertight vessels and possibly as cooking and drinking containers. A rind directly dated to 11,150–10,765 cal B.P. represents the oldest known bottle gourd in the Americas. Domesticated C. moschata subsequently appeared ~ 4035 cal B.P., followed by domesticated C. pepo ~ 2190 cal B.P. associated with increasing evidence for their use as food crops. Multivariate statistical analysis of seed size and shape show that the archaeological C. pepo assemblage exhibits significant variability, representing at least three varieties: one similar to present-day zucchini, another like present-day vegetable marrow, and a native cultivar without modern analogs. Our archaeobotanical data supports the hypothesis that Indigenous cucurbit use started in the Early Holocene, and that agricultural complexity during the Late Holocene involved selective breeding that encouraged crop diversification.

Measurement(s) radiocarbon age Technology Type(s) accelerator mass spectrometer Sample Characteristic - Location global Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.15152097

South America is a megadiverse continent that witnessed the domestication, translocation and cultivation of various plant species from seemingly contrasting ecosystems. It was the recipient and supplier of crops brought to and from Mesoamerica (such as maize and cacao, respectively), and Polynesia to where the key staple crop sweet potato was exported. Not every instance of the trans-ecological expansion of cultivated plants (both domesticated and wild), however, resulted in successful farming. Here, we review the transregional circulation and introduction of five food tropical crops originated in the tropical and humid valleys of the eastern Andes—achira, cassava, ahipa, sweet potato, and pacay—to the hyper-arid coastal valleys of the Atacama Desert of northern Chile, where they have been found in early archeological sites. By means of an evaluation of the contexts of their deposition and supported by direct radiocarbon dating, stable isotopes analyses, and starch grain analysis, we evaluate different hypotheses for explaining their introduction and adaptation to the hyper-arid soils of northern Chile, by societal groups that after the introduction of cultigens still retained a strong dependence on marine hunting, gathering and fishing ways of life based on wide variety of marine coast resources. Many of the studied plants were part of a broader package of introduced goods and technological devices and procedures, linked to food, therapeutic medicine, social and ritual purposes that transformed previous hunter-gatherer social, economic, and ideological institutions. Based on archeological data, we discuss some of the possible socio-ecological processes involved in the development of agricultural landscapes including the adoption of tropical crops originated several hundred kilometers away from the Atacama Desert during the Late Holocene.

The radiocarbon dating record from sites in the territory that comprises the Plurinational State of Bolivia has been previously included in datasets that are either obsolete, inaccurate, or incomplete. The Bolivian Radiocarbon Database compiles over three thousand radiocarbon dates produced in the context of archaeological and other paleo-scientific research. By conducting an exhaustive review and correcting various errors from previous regional datasets, this database currently incorporates the largest and most accurate information of radiocarbon dates from the country of Bolivia. In addition to describing how the data was collected and the structure of the database, here I also summarize some general patterns and emergent trends from this data.

Radiocarbon dating is one of the most useful and widely used chronometric techniques available for archaeologists and other paleo-scientists. Although generally used for answering specific research questions, radiocarbon dates from archaeological sites have become increasingly used to reconstruct population change at meso and macro temporal and spatial scales, and Bayesian modeling of locally and regionally available dates is facilitating interrogating the synchronicity, correlation, and interaction among various socioecological variables. Because the results of these meta-analyses largely depend on the available data, comprehensive compilations of radiocarbon dates and their associated information are critically important. Moreover, a thorough assessment of these compilations can reveal research spatiotemporal foci, trends, and biases, which should be considered when meta-analyses are attempted. In this review, based on the recently compiled Bolivian Radiocarbon Database, I provide a general assessment of the temporal, geographic, and thematic interests that have driven archaeological and paleoecological research in Bolivia over the last seven decades. Along with a detailed review of research in three broad geographical regions (Andean highlands, inter-Andean valleys, and tropical lowlands), I encourage researchers interested in meta-analysis to critically consider biases in data compilations by means of increased engagement with local experts and interdisciplinary collaboration.

The floristic composition and distribution of plant communities is the product of species-specific responses to localized environmental conditions often structured following environmental gradients. Although the importance of Andean high-elevation wetlands (bofedales) for provisioning ecosystem services has been critically emphasized in various studies, very little is known about how different micro-environmental factors shape their zonation and community assembly. Here we examined and quantified differences in herbaceous plant composition, alpha diversity, and aboveground biomass within waterlogged and dry habitats in three bofedales located in western Bolivia. Our results show that although alpha diversity was similar between both habitats, obligate wetland taxa were more abundant in waterlogged habitats whereas upland graminoids and halophytes were predominant in desiccated habitats. Furthermore, aboveground biomass of obligate wetland graminoids was higher in waterlogged habitats, while saline tolerant forbs exhibited higher aboveground biomass in desiccated habitats. Together these results suggest that soil water and organic matter content largely governs plant composition and biomass production but not alpha diversity in the studied high-altitude Andean wetlands. These results have important consequences for predicting plant species’ response to changes in the hydrological cycle due to habitat degradation and aridification caused by land use intensification and global climate change.

Forecasting the effects of climate change on the distribution of Andean trees (Polylepis, Rosaceae) is important to understand how species respond to climate variability and to assess their resilience to the ongoing climate crisis. Here, paleodistribution modelling is used to assess distribution shifts of 17 Polylepis species during the Last Glacial Maximum (LGM), mid-Holocene (MH), and the Anthropocene in the central Andes. Species distribution models (SDMs) were computed by combining presence records and current climatic conditions using Maxent and projected onto three climatic scenarios for the LGM (~22,000 yr BP), the MH (~6,000 yr BP), and the Anthropocene (1,970–2,000). Subsequently, current refugia hotspots were identified by intersecting suitable habitat over the LGM, MH, and anthropogenic conditions for all the studied species. SDMs for the LGM and MH showed a contraction of climate suitable habitat for most of the species in comparison to the Anthropocene. Four current refugia hotspots were identified: central Cordillera of Peru, Lake Titicaca basin, western Cordillera of Bolivia, and northern Chile. In general, SDMs were consistent with patterns proposed with pollen records, and partially with available phylogeographic studies. Current hotspots are highly important areas for the conservation of Polylepis and associated biota. This study assists in understanding distribution shifts over millennia of Andean tree species in response to climate change and identifying key conservation areas for the delineation of future conservation strategies.

Se presentan los resultados del análisis zooarqueológico de dos conjuntos de artefactos Tiwanaku (400-1100 DC), procedentes de la localidad de Amaguaya, en Bolivia. Los conjuntos se componen de una importante cantidad de artefactos orgánicos (estuches, bolsas de cuero, textiles y fibras de lana). Mediante el análisis microscópico de pelos y fibras provenientes de los artefactos y su comparación con muestras de colecciones de referencia, se logró la identificación de la totalidad de las muestras estudiadas. Se determinó que, con excepción del jaguar (Phantera onca), el resto de las pieles y fibras con que fueron elaborados los artefactos pertenecen a especies de distribución local. Los conjuntos de Amaguaya proporcionan importante información acerca del ritual en Tiwanaku así como de las relaciones de intercambio e interacción generadas con la región de la Cordillera Oriental durante el Horizonte MedioIn this article I present the results of the zooarchaeological analysis of two archaeological sets of Tiwanaku (AD 400-1100) artifacts from Amaguaya, Bolivia. These sets are formed by an important quantity of organic elements (e.g. cases and leather bags, textiles and wool fibers). The identification of the entirety of the studied samples was achieved through the microscopic analysis of the hairs and fibers of the archaeological samples and their comparison with samples derived from a reference faunal collection. Excluding the cases that were made with jaguar leather (Phantera onca),the rest of the artifacts were elaborated with skins and fibers of animal species with a local distribution. The Amaguaya sets provide important information about the relationships of exchange and interaction between Tiwanaku and the eastern cordilleran region of the Andes during the Middle Horizon

Se presentan los resultados del análisis zooarqueológico de dos conjuntos de artefactos Tiwanaku (400-1100 DC), procedentes de la localidad de Amaguaya, en Bolivia. Los conjuntos se componen de una importante cantidad de artefactos orgánicos (estuches, bolsas de cuero, textiles y fibras de lana). Mediante el análisis microscópico de pelos y fibras provenientes de los artefactos y su comparación con muestras de colecciones de referencia, se logró la identificación de la totalidad de las muestras estudiadas. Se determinó que, con excepción del jaguar (Phantera onca), el resto de las pieles y fibras con que fueron elaborados los artefactos pertenecen a especies de distribución local. Los conjuntos de Amaguaya proporcionan importante información acerca del ritual en Tiwanaku así como de las relaciones de intercambio e interacción generadas con la región de la Cordillera Oriental durante el Horizonte Medio

We report on previously unknown early archaeological sites in the Bolivian lowlands, demonstrating for the first time early and middle Holocene human presence in western Amazonia. Multidisciplinary research in forest islands situated in seasonally-inundated savannahs has revealed stratified shell middens produced by human foragers as early as 10,000 years ago, making them the oldest archaeological sites in the region. The absence of stone resources and partial burial by recent alluvial sediments has meant that these kinds of deposits have, until now, remained unidentified. We conducted core sampling, archaeological excavations and an interdisciplinary study of the stratigraphy and recovered materials from three shell midden mounds. Based on multiple lines of evidence, including radiocarbon dating, sedimentary proxies (elements, steroids and black carbon), micromorphology and faunal analysis, we demonstrate the anthropogenic origin and antiquity of these sites. In a tropical and geomorphologically active landscape often considered challenging both for early human occupation and for the preservation of hunter-gatherer sites, the newly discovered shell middens provide evidence for early to middle Holocene occupation and illustrate the potential for identifying and interpreting early open-air archaeological sites in western Amazonia. The existence of early hunter-gatherer sites in the Bolivian lowlands sheds new light on the region's past and offers a new context within which the late Holocene "Earthmovers" of the Llanos de Moxos could have emerged.