Persistent Early to Middle Holocene tropical foraging in southwestern Amazonia

Abstract

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.

The origins of Amazonian landscapes: Plant cultivation, domestication and the spread of food production in tropical South America

“…As has been previously suggested for central Amazonia (Neves, 2007) and eastern Brazil (Araujo et al, 2005), a recent analysis of archaeological radiocarbon data shows a decline in population during the middle Holocene across SA, including Amazonia, after 8.6ka (Riris and Arroyo-Kalin, 2019). We should take into account that the absence of archaeological evidence could be related in part to geomorphic processes (Lombardo et al, 2012;Lombardo et al, 2019) or the lack of archaeological work in many regions. New archaeological projects are progressively filling this gap.…”

“…They are predominant in early archaeobotanical records across lowland Amazonia, and changes in vegetation composition to greater proportions of palm is closely associated with humans from their first appearance (Morcote-Ríos and Bernal, 2001). The diets of these early settlers and first cultivators were certainly complemented by other faunal and terrestrial resources (Capriles et al, 2019;Morcote-Ríos et al, 2020;Roosevelt et al, 1996). Intriguingly, many of the earliest plants consumed by humans in the tropics later became Amazonian hyperdominants (shown in bold below in Table 1) (Levis et al, 2017).…”

“…New archaeological projects are progressively filling this gap. For example, forest islands of SW Amazonia that started as shell middens are some of the few sites that provide us with a continuous window to the Amazon past from the early to the late Holocene (Capriles et al, 2019;Lombardo et al, 2020;Lombardo et al, 2013b;Pugliese et al, 2018). New evidence is also emerging in the northern rim of the Amazon.…”

Early Holocene crop cultivation and landscape modification in Amazonia

“…They are nowadays consumed by indigenous groups 19 and probably provided a considerable part of the calories consumed by the first inhabitants of the LM. Large herbivores and fish available in the savannahs 12 , 13 would have complemented a mixed economy. The fertile FIs were probably the home gardens where these crops were cultivated.…”

“…All of these differences make it possible to exclude any contamination of phytoliths coming from the ceramic to the pre-ceramic contexts. For a description of archaeological excavations at Isla del Tesoro (SM1), La Chacra (SM3), and San Pablo (SM4) see Capriles et al 13 …”