Just how long has humanity been exploiting rainforests? There can be a popular tendency to see such habitats as essentially pristine wilderness, little troubled by our knack for adapting the environments that we call home. When we picture early activity by Homo sapiens in Africa, for instance, it is often bands of hunters stalking big game on grassy plains of savannah that spring to mind. While it is easy to imagine the more intrepid members of such groups frequenting the margins of the rainforests, their depths are typically seen as a very different prospect. The dense vegetation, high rainfall, and less abundant big game appear symptomatic of an environment that was far harder to master than rolling plains.
Until recently, this perception was a good fit with the available dating evidence. The earliest human activity that had been detected in African jungle was just 18,000 years ago – comparatively late for a species that has been around for roughly 300,000 years. Looking at the world more widely did little to dispel the impression that rainforest was hardly humanity’s habitat of choice, with the earliest possible dates from the jungles of Asia running to 73,000 years ago. Even so, there were grounds to wonder if these results were in part a reflection of modern archaeological practices. After all, the same poor visibility so often seen as a barrier to early human activity also hinders modern archaeological site-prospecting. It is well established, too, that rainforest in Africa could either expand or retract and fragment in response to shifts in climate. As a result, finding a stone tool in a modern rainforest offers no guarantee that the area was already jungle many millennia ago when the implement was being used.
Such considerations mean that any attempt to seek out early activity in African rainforests requires a very special kind of site: one where stone tools, dating materials, and environmental evidence are all preserved. A candidate for just such a site was identified near Anyama, in the Côte d’Ivoire, in the 1980s. There, two geologists noticed deeply stratified layers in a cliff-section that had been exposed by a river, and felt that the find would be of interest to archaeologists. The site became known as Bété I, and was investigated from 1982 to 1993 by a joint Ivorian-Soviet mission, led by the Ivorian Palaeolithic researcher François Yiodé Guédé at the Université Félix Houphouët-Boigny. The team excavated a step trench to a depth of 14m, and recovered a wealth of stone implements from several layers. The dates of these tools, though, and the nature of the environment when they were deposited, remained uncertain.
