Archaeobotanical evidence supports indigenous cucurbit long-term use in the Mesoamerican Neotropics

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.

Pre-Columbian cultivation of vegetatively propagated and fruit tree tropical crops in the Atacama Desert

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.

p3k14c, a synthetic global database of archaeological radiocarbon dates

Archaeologists increasingly use large radiocarbon databases to model prehistoric human demography (also termed paleo-demography). Numerous independent projects, funded over the past decade, have assembled such databases from multiple regions of the world. These data provide unprecedented potential for comparative research on human population ecology and the evolution of social-ecological systems across the Earth. However, these databases have been developed using different sample selection criteria, which has resulted in interoperability issues for global-scale, comparative paleo-demographic research and integration with paleoclimate and paleoenvironmental data. We present a synthetic, global-scale archaeological radiocarbon database composed of 180,070 radiocarbon dates that have been cleaned according to a standardized sample selection criteria. This database increases the reusability of archaeological radiocarbon data and streamlines quality control assessments for various types of paleo-demographic research. As part of an assessment of data quality, we conduct two analyses of sampling bias in the global database at multiple scales. This database is ideal for paleo-demographic research focused on dates-as-data, bayesian modeling, or summed probability distribution methodologies.

A Paleogenomic Reconstruction of the Deep Population History of the Andes

There are many unanswered questions about the population history of the Central and South Central Andes, particularly regarding the impact of large-scale societies, such as the Moche, Wari, Tiwanaku, and Inca. We assembled genome-wide data on 89 individuals dating from ∼9,000-500 years ago (BP), with a particular focus on the period of the rise and fall of state societies. Today's genetic structure began to develop by 5,800 BP, followed by bi-directional gene flow between the North and South Highlands, and between the Highlands and Coast. We detect minimal admixture among neighboring groups between ∼2,000-500 BP, although we do detect cosmopolitanism (people of diverse ancestries living side-by-side) in the heartlands of the Tiwanaku and Inca polities. We also highlight cases of long-range mobility connecting the Andes to Argentina and the Northwest Andes to the Amazon Basin. VIDEO ABSTRACT.

Early Holocene crop cultivation and landscape modification in Amazonia

The beginning of plant cultivation is one of the most important cultural transitions in human history^1–4. Based on molecular markers showing the genetic similarities between domesticated plants and wild relatives, south-western Amazonia has been proposed as one of the early centres of plant domestication^4–6. However, the nature of the early human occupation and the history of plant cultivation in south-western Amazonia are still little understood. Here, we document the cultivation of Cucurbita at ca. 10,250 cal yr BP, Manihot at ca. 10,350 cal yr BP and Zea mays at ca. 6,850 cal yr BP in the Llanos de Moxos. We show that, starting ca. 10,850 cal yr BP, pre-Columbians created an anthropic landscape made of approximately 4,700 artificial forest islands within a treeless seasonally flooded savannah. Our results confirm the Llanos de Moxos as a hotspot for early plant cultivation and demonstrate that ever since their arrival, humans have caused a profound alteration of Amazonian landscapes, with lasting repercussions for habitat heterogeneity and species conservation.

Archaeological assessment reveals Earth’s early transformation through land use

Environmentally transformative human use of land accelerated with the emergence of agriculture, but the extent, trajectory, and implications of these early changes are not well understood. An empirical global assessment of land use from 10,000 years before the present (yr B.P.) to 1850 CE reveals a planet largely transformed by hunter-gatherers, farmers, and pastoralists by 3000 years ago, considerably earlier than the dates in the land-use reconstructions commonly used by Earth scientists. Synthesis of knowledge contributed by more than 250 archaeologists highlighted gaps in archaeological expertise and data quality, which peaked for 2000 yr B.P. and in traditionally studied and wealthier regions. Archaeological reconstruction of global land-use history illuminates the deep roots of Earth’s transformation and challenges the emerging Anthropocene paradigm that large-scale anthropogenic global environmental change is mostly a recent phenomenon.

Chemical evidence for the use of multiple psychotropic plants in a 1,000-year-old ritual bundle from South America

Over several millennia, various native plant species in South America have been used for their healing and psychoactive properties. Chemical analysis of archaeological artifacts provides an opportunity to study the use of psychoactive plants in the past and to better understand ancient botanical knowledge systems. Liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to analyze organic residues from a ritual bundle, radiocarbon dated to approximately 1,000 C.E., recovered from archaeological excavations in a rock shelter located in the Lípez Altiplano of southwestern Bolivia. The site is located at an elevation of ∼3,900 m above sea level and contains evidence of intermittent human occupations during the last 4,000 years. Chemical traces of bufotenine, dimethyltryptamine, harmine, and cocaine, including its degradation product benzoylecgonine, were identified, suggesting that at least three plants containing these compounds were part of the shamanic paraphernalia dating back 1,000 years ago, the largest number of compounds recovered from a single artifact from this area of the world, to date. This is also a documented case of a ritual bundle containing both harmine and dimethyltryptamine, the two primary ingredients of ayahuasca. The presence of multiple plants that come from disparate and distant ecological areas in South America suggests that hallucinogenic plants moved across significant distances and that an intricate botanical knowledge was intrinsic to pre-Columbian ritual practices.

Persistent Early to Middle Holocene tropical foraging in southwestern Amazonia

The Amazon witnessed the emergence of complex societies after 2500 years ago that altered tropical landscapes through intensive agriculture and managed aquatic systems. However, very little is known about the context and conditions that preceded these social and environmental transformations. Here, we demonstrate that forest islands in the Llanos de Moxos of southwestern Amazonia contain human burials and represent the earliest settlements in the region between 10,600 and 4000 years ago. These archaeological sites and their contents represent the earliest evidence of communities that experienced conditions conducive to engaging with food production such as environmental stability, resource disturbance, and increased territoriality in the Amazonian tropical lowlands.