The dominant theme of archaeologists’ interpretations of Amazonia is the question of the role of the tropical forest in human cultural and biological evolution. Environmental determinism was the explicit paradigm of the first archaeologists to espouse a theory; Betty J. Meggers and Clifford Evans of the Smithsonian Institution. Like many early scientific archaeologists, they believed that the tropical forest environment strongly limited human cultural evolution. Influenced by theoreticians such as Julian Steward, they considered the habitat so poor in resources that early foragers could not have penetrated it. The archaeological sequence thus only could have begun in late prehistory when pottery-using migrants from agricultural Andean civilizations invaded Amazonia. In the tropical environment, their cultures would have deteriorated into horticultural village societies and foraging bands. Their small, shifting settlements and limited subsistence activities would have left the forest essentially virgin of human impacts.
Archaeologists who came to work in Amazonia after Meggers and Evans suggested variations to the environmental determinist hypotheses. They argued that, although poor interfluvial resources might have limited cultural developments, humans in the rich alluvial floodplains could have intensified agriculture and fishing and developed complex cultures. Donald Lathrap’s idea was that manioc had been the staple, whereas Anna Roosevelt thought that maize would have been a staple in some areas. Lathrap felt that competition over floodplain resources had led to migrations into the interfluves, where peoples’ cultures would have deteriorated in the poor environment. Roosevelt thought that the deterioration only happened after the European conquest of Amazonia. For earlier occupations, Lathrap doubted that Palaeo-Indian hunter-gatherers could have survived on Amazon resources, whereas Roosevelt thought that they could.
The early theoretical thinking of scientific archaeologists about Amazonia was consistent with the main paradigm of the New Archaeology movement of the 1970s, itself an extrapolation from Julian Steward’s ideas. Like New Archaeologists, the early Amazonianists assumed that the environment shaped the trajectories of local cultural evolution. In their explanations, agriculture was the basis for village sedentism and the evolution of state societies involved agricultural intensification, population growth, monumental public works, and high art.
The phase of field and lab research that followed the early phase of theory making in Amazonia has motivated the revision of many early theoretical ideas and the formulation of some significantly different understandings of human history and prehistory there. By the 1990s, archaeological field research had revealed an unexpectedly long and complex cultural sequence for Amazonia. The discovery of tropical forest Palaeo-Indians and Early Holocene ceramic foragers and farmers constituted problems for neoevolutionary optimal foraging theory and for diffusionary explanations that attributed Amazonian cultures to Andean intrusions. The diverse complex cultures unexpectedly found in interfluves as well as floodplains complicated 1970s theories about the role of intensive agriculture in social evolution, and the apparent lack of stratification and centralized rulerships in some of the complex cultures encouraged alternative explanations from heterarchy theory. Moreover, recognition of the historical role of the European conquest in the disappearance of the complex societies undermined adaptationist explanations of ethnogenesis in Amazonia. Finally, evidence that the environment itself might have coevolved with prehistoric humans has placed in doubt aspects of theory and practice in conservation biology.
Since the first and second phases of systematic theoretical thinking, however, the debates among Amazonian archaeologists have not really moved into new directions. Although a few archaeologists are addressing issues from historical ecology, critical theory, and heterarchy, many continue with assumptions from New Archaeology theory. Current theoretical arguments often focus on minor refinements of conclusions, rather than questions about the appropriateness of paradigms. Such questions include: whether a particular Palaeo-Indian group lived in savanna or rainforest, whether a complex society’s site catchment was varzea or interfluvial forest, whether it had manioc or maize as a staple, whether certain complex societies had classes and central rule, and where certain cultures originated.
However given the role of the tropical forest as an archtype in determinist evolutionary theory, the new evidence for more mutual causality, greater complexity, and more lines of development than expected makes Amazonian prehistory a potent stimulant for major new paradigms. A new paradigm that acknowledged the human role in the evolution of habitats and cultures and recognized the dynamic character of the interrelationships might well transform general theory not only in anthropology but throughout the natural sciences and beyond.
World History
