Redacción HC
25/05/2025

Early Jungle Dwellers: Homo sapiens in Africa’s Rainforests 150,000 Years Ago

For decades, the prevailing view in human evolution has been that our ancestors avoided Africa's dense rainforests, favoring open savannahs or coastal environments. These lush and humid forests were considered ecological barriers—too resource-poor, too disease-ridden, or simply too challenging for early Homo sapiens to survive in. But a groundbreaking archaeological study published in Nature has just rewritten that narrative. New evidence from Côte d'Ivoire reveals that Homo sapiens were living in wet tropical forests in West Africa as far back as 150,000 years ago—more than eight times earlier than previously thought.

Rethinking the Human Story: The Forests Were Never Empty

The conventional timeline suggested that humans only entered tropical forests around 18,000 years ago in Africa, and about 45,000 years ago in Asia. This assumption had less to do with hard evidence and more with lack of exploration and preservation bias. Now, with new interdisciplinary tools and regional collaboration, researchers are filling in the gaps.

The central question of this new study was direct: Did early Homo sapiens live in Africa's wet tropical forests 150,000 years ago—and if so, what evidence proves it?

A Multi-Disciplinary Approach in the Heart of West Africa

The research focused on a single but significant archaeological site—Bété I, near Anyama in Côte d'Ivoire. The excavation yielded stone tools embedded in ancient sediment layers, providing a rare snapshot of past human activity in what was, and still is, dense rainforest.

To establish a timeline, scientists used two advanced dating techniques:

• Optically Stimulated Luminescence (OSL) to date quartz grains
• Electron Spin Resonance (ESR) to measure radiation-induced signals in sediments

Both methods independently confirmed human presence around 150,000 years ago.

To reconstruct the surrounding environment, researchers combined:

• Stable isotope analysis of sedimentary waxes
• Phytolith analysis (plant silica microfossils)
• Pollen studies to identify vegetation types

These techniques revealed a dense, humid, tropical forest ecosystem, not a savannah or mixed woodland as previously assumed.

Groundbreaking Discoveries: Tools, Trees, and Time

Tools of the (Very) Ancient Trade

Stone tools found at Bété I belong to the Middle Stone Age, with features suggesting planned, skilled manufacturing. Their direct association with the sediment layers and dating confirms that early Homo sapiens were active forest dwellers at this time.

"This is the earliest evidence for Homo sapiens in a tropical rainforest anywhere in the world," notes co-author Eleanor M.L. Scerri of the Max Planck Institute.

An Ancient Forest, Undisturbed

Analyses of biomarkers and plant remains paint a vivid picture: a closed-canopy, humid forest, rich in trees and poor in grasses. This environment differs significantly from open savannahs, requiring specialized survival strategies such as foraging, tool use for processing diverse plants, and possibly early forms of social cooperation.

A Radical Shift in the Timeline

Previously, the oldest confirmed rainforest occupation by humans was in Sri Lanka (45,000 years ago) and parts of South Asia (~70,000 years ago). The 150,000-year-old record from Africa not only pre-dates these finds—it doubles or triples their antiquity, suggesting that Homo sapiens' ecological range was broader much earlier than assumed.

Why It Matters: From Evolutionary Models to Forest Protection

Redrawing the Map of Human Evolution

These findings demand a re-evaluation of long-standing models of human dispersal and adaptation. Far from being forest-averse, early Homo sapiens appear to have had the cognitive flexibility and technological tools to thrive in one of the world's most complex biomes.

This supports a pan-African view of human origins, one that embraces ecological diversity rather than concentrating on arid regions or grasslands alone.

Implications for Conservation and Cultural Heritage

The study also raises urgent concerns. The Bété I site is currently threatened by nearby mining activities, underscoring the fragility of such archaeological evidence. Protecting rainforest sites is no longer just about biodiversity—it's about preserving our species' deep history.

"Our ancestral story is written in stone—and in soil, pollen, and forest waxes," says lead author Eslem Ben Arous of the Max Planck Institute and CENIEH.

From Ivory Coast to the Amazon: A Global Call for New Exploration

Expanding the Search

The authors call for broader archaeological efforts in tropical forests—not just in Africa but also in Southeast Asia, the Amazon, and the Congo Basin. Many of these areas remain underexplored due to logistical challenges and low preservation rates, but could hold key insights into early human migration, diet, and technology.

Bringing the Forest into the Classroom

This finding isn't just for academics. It can reshape school textbooks, museum exhibits, and even national heritage policies. In African nations like Côte d'Ivoire, this offers a powerful narrative of deep-rooted human presence and innovation in forest landscapes.

Conclusion: Rethinking Rainforests in Human History

This study marks a historic leap in our understanding of human evolution. The idea that Homo sapiens adapted early to diverse and challenging environments, including dense rainforests, reveals a remarkable level of resilience and creativity. More than just a new data point, it's a paradigm shift—one that reminds us that forests are not peripheral to our story. They were there at the beginning.

As we face growing threats to tropical ecosystems today, perhaps it's worth remembering: these forests are not just vital to our future—they were home to our past.

Topics of interest

History