Tools from about 40,000 years ago reveal human adaptation to the rainforest

For the first time, it has been possible to document the systematic occupation of the African equatorial forests by Homo sapiens.

This discovery has been carried out by an international team that includes researchers from the National Museum of Natural Sciences (MNCN, attached to the Higher Council for Scientific Research (CSIC) in Spain), as well as the Catalan Institute of Human Paleoecology and Social Evolution (IPHES). .

The discovery was made in the archaeological sites of Río Campo, in Equatorial Guinea.

Research has revealed how our ancestors not only survived, but thrived in one of the most challenging ecosystems on the planet, thanks to advanced stone technology and a remarkable capacity for social organization.

The stone tools found evidence a sophisticated technological tradition that allowed these communities to face the difficulties of an environment of dense vegetation, high temperatures and unpredictable resources.

This evidence transforms what is known about how modern humans adapted to environments as complex as the African equatorial rainforests. The tools found reflect both advanced technical knowledge and an extraordinary capacity for cultural adaptation, as explained by Professor Antonio Rosas, project director and lead author of the study.

An exceptional site in a little-studied region

During the archaeological surveys carried out in the Río Campo region, the team examined 30 stratigraphic outcrops corresponding to the Quaternary. Of them, 16 provided highly complex lithic tools dated, using radiocarbon and optically stimulated luminescence (OSL) techniques, to between approximately 76,000 and 20,000 years ago. This interval places the occupation of the area in the second half of the Upper Pleistocene.

Juan Ignacio Morales, IPHES researcher and expert in lithic technology, highlights the importance of this discovery: “The tools found in Río Campo show a technological tradition that connects with other lithic industries in central and southern Africa, such as the Acheulean and the Sangoense. . “This points to a transmission of technical knowledge sustained over millennia and a deeply rooted cultural heritage.” Among the 418 lithic artifacts recovered, bifacial points, Levallois cores and large tools associated with hunting and material processing activities stand out. These pieces reflect planning and organization that were crucial for survival in such a hostile environment.

Lithic tools of great complexity, dated between approximately 76,000 and 20,000 years ago, found in Río Campo, Equatorial Guinea. (Photo: MNCN)

Central Africa: a new focus in human evolution

Traditionally, research on human evolution has focused on arid or semi-arid regions of Africa. However, this study highlights the importance of Central Africa as a key setting for understanding the diversity of adaptive strategies of Homo sapiens.

“With the results from Río Campo, we expand the map of prehistoric human behavior and place Central Africa as a fundamental piece in the cultural and biological evolution of our species,” says Rosas. The discovery also demonstrates that tropical rainforests, despite their adverse environmental conditions, were essential settings in the evolutionary history of modern humans.

Future prospects

This finding opens new lines of research into how early Homo sapiens adapted to extreme and complex environmental contexts. The team plans to continue detailed excavations and analysis in Equatorial Guinea to deepen our understanding of early human occupations in Central Africa and their relevance to the evolution of our species.

“The manufacture of such complex tools implies a structured cultural transmission over time, reinforcing the idea that Central Africa was a crucible of innovation and technological adaptation, playing a crucial role in the history of Homo sapiens,” concludes Morales.

The study is titled “Middle Stone Age (MSA) in the Atlantic rainforests of Central Africa. The case of Río Campo region in Equatorial Guinea.” And it has been published in the academic journal Quaternary Science Reviews. (Source: IPHES / MNCN)