The Role of Information Exchange in the Colonization of Sahul

The earliest populations of modern humans to successfully expand their range beyond the tropical savannahs of Africa dispersed rapidly southward through South Asia and on to Australia circa 70,000-50,000 years ago. Colonization of the previously uninhabited Australian continent was contingent on the use of watercraft, and it has been argued previously that this involved planning depth for which symbolic communication was a fundamental prerequisite. Symbolic communication also accounts for the flexible social and economic strategies that are indicated by the rapid settlement of diverse and unfamiliar habitats. Despite this, it has been argued that there is an apparent dearth of material symbols in the Australian Pleistocene record. Material remains that arguably served as identity markers or played a role in information exchange or that represent complex technologies involving planning depth are identified. This provides a basis for evaluating the abundance and significance of material symbols in the Australian record. These types of material traces are, in fact, a conspicuous, if poorly dated, component of the early Australian record, even though population densities were low and migratory events rare. This suggests that extensive information exchange between groups, and marking of identity within them, was critical in fostering their accumulation.