African Ostrich Eggshell Beads Analyzed Over 50,000 Year Time Period
Over a 27,000 year time period, eggshell beads barely changed and a sudden stylist shift is likely due to climate change separating cultures and trade networks
Among the many artifacts humans have exchanged throughout culture and time, ostrich eggshell beads are ideal. First of all, they are the world’s fully manufactured ornament. Unlike stone tools which rely natural size of shape of the stone that varies, the egg shells can be modeled to produce any variety beads. Subsequently, each different culture has produced beads of different shapes, styles.
An interesting paper in Nature1 was published on this topic. The authors assembled the largest database of ostrich eggshell beads. They compared and contrasted over 1,500 beards from 31 different southern and eastern African archaeological sites. These sites span over 3,000 km distance. The oldest bead were 50,000 years old. This took over a decade to curate. This alone is a feature in of itself.
The authors characterized different diameters, such as the total bead diameter and the aperture diameter, or the size of the hole. They also compared and contrasted the shell thickness. Curiously, between 50,000 and 33,000 years ago, people were creating and selecting for nearly identical beads. That is surprising as the implications are there was a single cultural selection for a style of beads for over 27,000 years in a large region of Africa.
Could you imagine modern humans wearing the same jewelry style for that long?
During this time, eastern Africa was particularly wet. But around 33,000 years ago, precipitation shifted. This dramatic change in the climate likely created a geographic or ecological barrier such as the Zambezi River catchment. The periodic flooding most likely disrupted cultural exchanges and trade of beads.
Through these tiny beads, the authors creatively strung together a story about our prehistoric past that was unknown to us. We can see that human behavior was constant in bead manufacturing for thousands of years. Sudden and dramatic climate changes drove people apart and as a subsequent effect, bead styles varied.
Isn’t that cool?
Miller, J.M., Wang, Y.V. Ostrich eggshell beads reveal 50,000-year-old social network in Africa. Nature (2021). https://doi.org/10.1038/s41586-021-04227-2