ABSTRACT
This chapter deals with one of the most fascinating and controversial topics in the: study of indigenous South American cultures, namely, the environmental constraints, evolutionary potentials, and societal regulatory features that have characterized recent and ancient adaptive systems all across the 6 million square kilometers of the vast Amazon Basin. It examines the data from three of the most interesting studies that have been carried out of indigenous terra firme groups; Robert and Yolanda Murphy's 1950s study of the Mundurucú of the upper Tapajos River; Napoleon Chagnon's ongoing thirty-year study of the Yanomamo of the upper Orinoco River; and Michael Harner's late 1950s-early 1960s study of the Jívaro, usually called the Shuar, of the cloud forests of the eastern Ecuadorian Amazon. The chapter examines the ethnohistorical data on the Omagua chiefdoms that lived along the varzea niche of the main channel of the Amazon River, several hundred kilometers upstream from its confluence with the Rio Negro.
