It is difficult to known when, how, and why different populations were able to connect in the past. The answer to these questions are crucial for interpreting biological and cultural diversity that is seen in modern human. While DNA research has uncovered genetic interactions, it cannot address the cultural exchanges in these ancient meetings. However, thanks to the work of two scientists from the Max Planck Institute for the Science of Human History have found an unexpected source to answer these questions, ostrich eggshell beads. This new study by Dr. Jennifer Miller and Dr. Yiming Wang reports on the connection and isolation in southern and eastern Africa over 50,000 as the result of rainfall patterns through these beads.
     The Ostrich Eggshell beads are the perfect artifacts for studying these relations as they are the oldest fully manufactured ornaments. Due to the extensive shaping that takes place during the production of these beads it allows for a larger variation in style, which can then be traced archaeologically. "It's like following a trail of breadcrumbs," says Miller, lead-author of the study. "The beads are clues, scattered across time and space, just waiting to be noticed."
     The results showed a clear distinction in the region as the beads were largely identical between 50,000 to 33,000 years ago. This suggested that, des"pite the 3,000 km between the regions, they were connected. "The result is surprising, but the pattern is clear," says Wang, co-corresponding author of the study. "Throughout the 50,000 years we examined, this is the only time period that the bead characteristics are the same."
     Sometime after the 33,000 year mark, the regional work disappears, which corresponds to changes in the global climates, resulting in increased rainfall in the larger areas of eastern and southern Africa. The results bring new insight into the variability of social strategies between the two regions.
     "These tiny beads have the power to reveal big stories about our past," says Miller. "We encourage other researchers to build upon this database, and continue exploring evidence for cultural connection in new regions."
   
Edited from Nature Magazine, Max Planck Institute (20 December 2021)