Hunter-gatherers strung a social safety net across much of southern Africa starting at least 33,000 years ago, a new study suggests. And it was held together with ostrich eggshell beads.
Some of these carefully crafted beads — excavated at two high-altitude rock-shelters in the African nation of Lesotho — were found to have originated more than 100 kilometers away, while others came from more than 300 kilometers away, say anthropological archaeologist Brian Stewart of the University of Michigan in Ann Arbor and his colleagues. Ages of the beads span nearly the last 33,000 years, the scientists report March 9 in the Proceedings of the National Academy of Sciences.
Hunter-gatherers inhabiting inland desert or grassland regions probably started a regional exchange network toward the end of the Stone Age, somewhat akin to how many modern hunter-gatherer groups give gifts back and forth to foster cooperation, Stewart says. Ostriches lived in those dry, flat grasslands, but not at the rock-shelter sites. Inland residents could have made the beads from collected ostrich eggshells. The beads were probably then passed from one group of people to another over long distances, Stewart says. The findings indicate that this activity went on for tens of thousands of years longer than anyone previously has demonstrated for a system of cooperation-currying gift exchanges.
It’s “highly plausible” that ostrich eggshell beads were transported over long distances in ancient Africa, says archaeologist Nick Barton of the University of Oxford, who was not part of the new study. More work is needed to tell if inland hunter-gatherers perhaps obtained ostrich eggshells near southern Africa’s east coast, where seashells were also collected for bead making during the Stone Age. If so, bead distribution may have started near the east coast, Barton says.