This study deals with some contested issues regarding prehistoric cultural development in Amazonia and the colonial impact on the native inhabitants of the area. It focuses on the relation between groups belonging the language families of Tupí and Gê, on one hand, and the different ecological zones that they inhabit, on the other. GIS mapping is used to visualise the distribution and movements of these groups in relation to ecology and the impact of European colonization. GIS is shown to be a useful methodology for analysing historical data derived from written sources and maps. The results of these analyses are discussed in the light of different theoretical perspectives.