Even today, hunters and collectors in southern Africa give themselves jewelry pearls from ostrich eggs in order to consolidate extensive social networks. A study now shows how deeply this tradition is rooted: Analyzes of jewelry pearls found revealed that people were connected over enormous distances over 33,000 years ago.
It is called the Hxaro exchange system: through visits and gifts, the traditionally living communities of ǃkung-San in the Kalahari region maintain social relationships with partner groups, some of whom live several hundred kilometers away. These networks provide mutual support in emergencies, the exchange of information and also marriage brokerage. Necklaces made of pearls, which are made from the shells of ostrich eggs, form a kind of social currency when exchanging gifts as part of the Hxaro.
As part of their study, the researchers at Brian Stewart University of Michigan in Ann Arbor have now investigated the roots of this tradition. Finds of the decorative elements at an excavation site in Lesotho formed the basis. Some of the finds were dated to be up to 33,000 years old. The researchers were particularly interested in the fact that no ostriches live in the mountainous surroundings of the site of the discovery, and this was probably the case before. Thus, it was reasonable to assume that the jewelry items once came from far away to the site.
Where did the ostrich pearls come from?
In order to trace their origin, the researchers subjected the eggshell beads to an isotope analysis: the focus was on the strontium-87 content. As the scientists explain, they reflect where the ostriches from which the eggs came from lived. It is particularly significant in this context that the volcanic highlands of Lesotho have a certain strontium signature, which differs in a characteristic way from surrounding regions. In combination with information about the former distribution areas of ostriches, the researchers were able to draw conclusions about the origin of the eggshell pearls.
The researchers came to the conclusion: “Many of the pearls found in Lesotho have traveled long distances,” says Stewart. Some of the pieces, which are over 30,000 years old, came from regions that were at least 325 kilometers away from the site. According to the analysis results, they may even have been manufactured up to 1000 kilometers away.
An extensive network
Based on the results, one can now imagine the following story of the ostrich pearls found in Lesotho: About 33,000 years ago, an ostrich in the Karoo region ate grass that strontium had taken up from the ground. These atoms then became part of the shell of an egg, which the bouquet later laid. It then became the meal of a person, who then turned the shell of the egg into small pearls with holes. They later became a gift for friends who lived far to the east. Later they continue to give the pearls until the jewelry finally reaches a distant group that lived high in the eastern mountains. 33,000 years later they rediscovered the archaeologists there.
As the researchers explain, their results now reveal a large network that at that time extended across regions with different ecological characteristics in southern Africa. “These exchange networks were probably used for information about resources such as animals, plant foods and the condition of landscapes. And they also played a role in social life – possibly spouses were also mediated through the contacts, ”says Stewart. The results reflect how important social networking was and is for human success, he and his colleagues summarize.
Source: University of Michigan, technical article: PNAS, doi: 10.1073 / pnas.1921037117