Long-distance social networks have a far deeper ancestry than Facebook. At some point in the Paleolithic past, hunter-gatherers began exchanging 'non-utilitarian' artifacts like beads over hundreds and thousands of miles. These networks symbolically link distant groups, acting as mutual insurance policies should local resources fail. This project uses strontium (Sr) geochemistry of ostrich eggshell beads from Paleolithic archaeological sites in southern Africa to examine (1) when this behavior originated and (2) how it developed through time. An ostrich’s strontium signature, obtained via its drinking water and forage, reflects the underlying geological composition of its range. A bead’s Sr isotopic signature can thus reveal where the egg was collected and the bead made. Charting the evolution of long-distance social networks will help determine when, why and how our species began harnessing culture to mitigate risk.
Presented at University of Tübingen, Germany.