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Rainforests represent a significant biome, and it was long believed that they were largely inhospitable to early human populations until relatively recently. However, new findings suggest that humans may have inhabited rainforests in Africa as far back as 150,000 years ago, challenging previous assumptions about our species’ history.
Humans are thought to have originated in Africa approximately 300,000 years ago, yet the intricate ecological conditions underpinning our evolutionary journey remain inadequately understood. Traditionally, rainforests were considered barriers to human settlement; recent research seeks to redefine this perspective.
A groundbreaking study published in Nature by an international research team presents evidence that human groups thrived in the rainforests of modern-day Côte d’Ivoire much earlier than was once believed. The findings indicate that these early communities existed within rainforest environments by 150,000 years ago, promoting the idea that human evolution unfolded across diverse ecological contexts.
The exploration leading to this revelation traces back to the 1980s, when Professor Yodé Guédé of l’Université Félix Houphouët-Boigny participated in a joint Ivorian-Soviet archaeological mission. During that initial investigation, researchers uncovered a stratified site containing stone tools within the present-day rainforests, although the exact age of the tools and the ecological conditions at the time of their deposition remained unclear.
Professor Eleanor Scerri, who leads the Human Palaeosystems research group at the Max Planck Institute of Geoanthropology, noted, “Recent climate models indicate that this region may have served as a rainforest refuge, even during periods of environmental change.” With the site identified as a potential key to unlocking ancient rainforest habitation, a new investigation was organized.
Dr. James Blinkhorn, a researcher at both the University of Liverpool and the Max Planck Institute of Geoanthropology, emphasized the importance of the study’s state-of-the-art methodologies, which were not accessible during earlier research phases. The re-examination of the site proved crucial, as mining activities later led to its destruction.
Prior to this research, the oldest confirmed evidence of human presence in African rainforests dated back only around 18,000 years, while evidence from Southeast Asia suggested rainforest habitation occurred about 70,000 years ago. Dr. Eslem Ben Arous, lead author of the study and a researcher at the National Centre for Human Evolution Research, remarked, “Our findings extend the timeline of human rainforest habitation by more than twice the previous estimates.”
The research team utilized advanced dating techniques such as Optically Stimulated Luminescence and Electron-Spin Resonance, which confirmed the age of the site at roughly 150,000 years. In addition, the investigation entailed analyzing sediment samples for pollen and phytoliths, revealing that the area was densely forested and aligned with the characteristics of humid West African rainforests, rather than a narrow strip of land.
Professor Guédé expressed excitement about the significance of these findings, stating, “This groundbreaking discovery is merely the beginning; there are several other sites in Ivory Coast slated for exploration to further examine early human activity in rainforests.”
Professor Scerri added, “There is compelling evidence that ecological diversity is fundamental to our species’ history. This suggests a nuanced narrative of population diversification, as different groups occupied varied ecological niches. Future inquiries should investigate the influence early humans had on their environment and the extent to which they altered pristine natural habitats.”
The study was supported by funding from the Max Planck Society and the Leakey Foundation.
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