In the late ‘80s, a team of Soviet and West African archaeologists discovered an African rainforest site that had the potential to rewrite at least a chapter of human evolutionary history. Artifacts encased in several layers of sediment hinted that some early humans had settled and thrived there, during a time when it was thought that they evolved primarily on savannas. Almost nobody paid attention.
There were three reasons. First, the group published its findings in Russian, which relatively few scientists outside the Soviet Union could read. Second, West Africa was then not considered a major scene in human evolution. And third, the team lacked the technological tools to accurately date the tools, plant remains, and layers of dirt.
Over 30 years later, a new group — guided by one of the original team members — returned. This time they showed humans had lived in this rainforest about 150,000 years ago, according to an article in Nature. That’s nearly 10 times longer than previous evidence for African rainforest occupation, and more than twice as long as the next most recent human rainforest habitat globally, found in Southeast Asia.