Surprise: The jungles were not a barrier to the first humans, but a home 150,000 years ago

Now, Guédé has returned to the place with modern ‘weapons’ to investigate those deposits and the surprise has been capitalized: the tools date from 150,000 years ago and that place could have a vegetation similar to the current one. This means that human populations have already colonized the jungle at that time, twice as many years before what was thought. The results, which also imply that humans became ‘strong’ in various types of habitats from an early age, have just been published in a study in the magazine ‘Nature‘.

Giving things for granted

It is believed that our species emerged about 300,000 years ago in Africa. However, those first moments of Homo Sapiens still present many questions. Until now, to try to understand how those populations had expanded, some circumstances such as that the tropical jungles had been more a natural barrier than a place where they lined up.

Decades after the findings of Guédé, the Human Paleosystems team of the Max Planck Institute, then proposed to investigate the place. “With the help of the teacher we could find the original trench and re -investigate it using state -of -the -art methods that were not available thirty or forty years ago,” explains James Blinkhorn, a researcher at the University of Liverpool and the Max Planck Institute of Geoantropology.

Relising the investigation there was no accident or whim. “Several recent climatic models suggested that the area could also have been a tropical jungle refuge in the past, even during dry periods of forest fragmentation,” says Eleanor Scerri, leader of the human paleosystems research group in the institute Max Planck of Geoantropology and main author of the study. “We knew that the site presented the best possible opportunity to find out to what extent in the past the room extended in the tropical jungle.” In addition, it was done right in time: shortly after, the site ended up destroyed by local mining.

70,000 to 150,000 years

Until then, the most reliable evidence of the first humans who had inhabited the jungles was in a deposit that dates back 70,000 years in Southeast Asia. On the other hand, in Africa, there was no evidence until much later: 18,000 years. “This delays the oldest known evidence of humans in tropical jungles in more than double the estimate known above,” explains Eslem Ben Arous, a researcher at the National Center for Research on Human Evolution (CENIEH), located in Spain, and main author of the study.

The researchers used several dating techniques, including optically stimulated luminescence and electronic spin resonance, to reach a date of approximately 150,000 years ago in time. In parallel, sediment samples were investigated separately in search of pollen, silicified plant remains and leaf wax isotopes. The analyzes indicated that the region was densely wooded, with pollen and waxes typical of the wet jungles of western Africa. The low grass pollen levels showed that the site was not in a narrow strip of forest, but in a dense forest.

“This exciting discovery is the first of a long list, since there are other sites in Ivory Coast that expect to be investigated to study the human presence associated with the tropical jungle,” says Guédé. For its part, Scerri Judgment that «there are convergent evidence that demonstrates without a doubt that ecological diversity is the basis of our species. This reflects a complex history of subdivision of the population, in which different populations lived in different regions and types of habitat ».