New evidence from West Africa is reshaping our understanding of early human migration and adaptation, challenging long-held assumptions about the environments our ancestors inhabited. A recent study published in Nature reveals that early humans were capable of thriving in tropical rainforests far earlier than previously believed. Researchers uncovered 150,000-year-old stone tools in Ivory Coast, pushing back the timeline of human habitation in these dense and humid ecosystems by nearly 100,000 years. This discovery suggests that early humans did not exclusively rely on open savannas but were also capable of exploiting the rich but challenging resources of rainforests much earlier than expected.

A Discovery That Reshapes Human History

For decades, the earliest known evidence of humans living in rainforests dated back 70,000 years in Asia and only 18,000 years in Africa. Scientists believed that early Homo sapiens favored open environments. The dense vegetation and limited resources of rainforests were thought to be barriers to human expansion.

However, the Bété I site in West Africa tells a different story. Using optically stimulated luminescence (OSL), a technique that determines when objects were last exposed to sunlight, researchers dated the unearthed tools to 150,000 years ago. This not only pushes back the timeline of rainforest habitation but also suggests that early humans were far more adaptable than previously believed.

How Scientists Dated the Ancient Stone?

The discovery of these tools in a dense rainforest environment indicates that early humans had already developed innovative survival strategies. Unlike open savannahs, where large prey was abundant, rainforests present unique challenges—limited visibility, diverse but unpredictable food sources, and a high concentration of predators.

Archaeological analysis suggests that these ancient humans crafted tools for hunting small animals, processing plant materials, and possibly even building shelters. The presence of Hunteria and oil palm remains, which are characteristic of humid tropical forests, further confirms that this region was a thriving rainforest even 150,000 years ago.

A New Perspective on Early Human Migration

The new findings challenge the traditional view that Homo sapiens evolved solely in Africa’s grasslands before dispersing into other environments. Instead, it appears that early humans were thriving in multiple ecosystems simultaneously.

“We know humans did not have one single ‘birthplace’ in Africa,” explains lead researcher Eslem Ben Arous from the Max Planck Institute of Geoanthropology. “Our results indicate that we are looking at the latter scenario.”

Surviving in the Rainforest: A Complex Challenge

Living in a rainforest presents a starkly different set of survival challenges compared to open grasslands. Thick vegetation makes it difficult to spot prey, resources can be seasonally unpredictable, and large predators pose an ever-present threat.

However, evidence from Bété I suggests that early humans successfully adapted to this environment, possibly relying on a diverse diet of fruits, nuts, tubers, and small animals.

Their ability to craft specialized tools further supports the idea that these early populations modified their behaviors to fit their surroundings. Ben Arous notes that the study could change how we view early human interactions.