Scientists have discovered what may be the world’s first social network, a chain of trade and communication that connected ancient humans across southern and eastern Africa some 50,000 years ago. The breakthrough was made possible by a trail of tiny artifacts: beads made of ostrich eggshells, one of the earliest forms of personal adornment.
Researchers based in Germany studied more than 1,5000 of these beads unearthed in 31 sites spanning 1,800 miles of the African continent. Analysis of the beads’ shell thickness and diameter found that hunter-gatherers had manufactured them in a “nearly identical” shape and style despite the vast distances separating each community, suggesting a coherent regional network. The study, published in Nature, suggested that the beads were exchanged as symbols to strengthen alliances.
“It’s like following a trail of breadcrumbs,” Jennifer Miller, a co-author of the study and a researcher at the Max Planck Institute for the Science of Human History in Jena, told the Guardian. “The beads are clues, scattered across time and space, just waiting to be noticed.”
Ostrich eggshell beads—still manufactured by Indigenous African communities today—are among the oldest known form of self-adornment in the archaeological record, with evidence of their use dating to 75,000 years ago. Scientists believe the earliest kind of decoration was likely ochre, a rust-colored clay pigment, which has been used by humans for at least 200,000 years.
The study of self-decoration has been instrumental in revealing the cognitive abilities and social patterns of prehistoric humans. Eggshell jewelry crucially illustrates how, and when, humans began to modify natural shapes into a variety of forms for aesthetic and practical purposes.
The route uncovered by the researchers also helped scientists establish that a “patchwork of populations” in southern and eastern Africa were in communication. It remains unclear if the eggshells studied were directly traded, or if it was the knowledge of how to manufacture them that was shared.
What is clear, though, is that the planet’s oldest social network eventually collapsed. Around 33,000 years ago, bead-wearing disappeared from southern Africa, but remained popular in east Africa. The authors propose that “environmental circumstances” caused the regional split.