There’s evidence human beings have occupied the city of Damascus in Syria for 11,000 years. But that’s nothing compared to the Panga ya Saidi cave network in Kenya’s Rift Valley. Ruth Schuster at Haaretz reports that its 1,076-square-foot main chamber has been occupied by Homo sapiens for 78,000 years.
A new study published in the journal Nature Communications offers a testament to how human technology and culture have changed over that time.
The cave sits in a unique spot, an ecotone where grassland and coastal tropical forest meet. Because of that, occupants of the cave could exploit the resources from both environments. The location also spared the cave from climatic fluctuations over the centuries. While drought may have impacted the savannah or the forest at certain times, the international and interdisciplinary team of researchers found the site of Panga ya Saidi seems to have received plenty of precipitation. That may explain why humans decided to stick around more or less continuously since finding the spot.
The oldest artifacts found in the cave are Middle Stone Age toolkits dating back around 78,000 years. A distinct change occurs in newer layers that emerged 67,000 year ago in the Later Stone Age, where toolkits become much smaller, showing a switch in technologies. However, following layers dating back 60,000-50,000 years reveal a mix of tool types, which pushes back against the idea posited by archaeologists that change happens during technological “revolutions” where a new technology is quickly and widely adopted.
The jewelry that the cave dwellers wore tells its own story of change. The earliest bead ever discovered in Kenya, dating between 67,000 and 63,000 years ago, comes from the cave. Beginning 33,000 years ago beads made from shells plucked from beaches along the Indian Ocean about 9 miles away became the accessory of choice. Around 25,000 years ago, ostrich shell beads became all the rage, before the seashells came back into vogue around 10,000 years ago. Other decorative or ritual objects such as carved bones and chunks of red ochre were found throughout the layers, which also indicate that there were no significant cultural or cognitive “revolutions” at the Panga ya Saidi site. Taken together, the tools and decorative artifacts paint a picture of a culture that changed slowly over time.
Another important find at the cave is what wasn’t there—lots of seafood. “Despite being relatively close to the coast, we do not have evidence that the hunter-gatherer populations occupying the cave were in any way dependent on coastal resources,” co-author Michael Petraglia of the Max Planck Institute for the Science of Human History tells Schuster. “Instead, they were reliant on inland, terrestrial resources in their tropical forest and grassland ecosystem.”
That adds to growing evidence that early humans did not simply follow coastal resources. Instead, it shows humans were adaptable and able to survive in inland habitats as well. “The finds at Panga ya Saidi undermine hypotheses about the use of coasts as a kind of 'superhighway' that channeled migrating humans out of Africa, and around the Indian Ocean rim,” Petraglia says in the press release.
Project principal investigator Nicole Boivin of Max Planck predicts this knowledge will cause a shift in the way human evolution is understood. “The East African coastal hinterland and its forests and have been long considered to be marginal to human evolution so the discovery of Panga ya Saidi cave will certainly change archaeologists’ views and perceptions,” Boivin says.
People only stopped living in Panga ya Saidi in the relatively recent past reports Schuster, though it is still used by locals for religious ceremonies and burials.