For decades, the prevailing theory among scientists was that early modern humans initially inhabited only small areas of Africa, specifically the savannas of the eastern and southern parts of the continent. It was believed that these humans then moved north into Asia, Europe, and beyond, bypassing West and Central Africa, particularly the tropical forests, which were thought to be populated much later.
However, recent research has challenged this narrative. Scientists working in Senegal, Cameroon, Malawi, and other regions have uncovered evidence suggesting that early humans spread across much more of Africa before venturing elsewhere. This work is transforming our understanding of how multiple groups of early modern humans intermingled and spread across the continent, providing a more nuanced picture of our species’ complex origins.
Eleanor Scerri, an archaeologist at the Max Planck Institute of Geoanthropology in Jena, Germany, states, “It’s becoming more and more clear that humans didn't originate in a single population in one region of Africa. If we really want to understand human evolution, we need to look at all of the African continent.”
Most researchers agree that early modern humans emerged in Africa between 200,000 and 300,000 years ago and spread to other parts of the world about 60,000 years ago. Until recently, it was thought that these humans populated West and Central Africa, especially the tropical forests, only within the past 20,000 or so years.
Sarah Tishkoff, a geneticist at the University of Pennsylvania, has been working to unravel Africa’s deep genetic lineage for over two decades. She notes that the lack of evidence for early human settlement in West and Central Africa was due to the focus on easier-to-study regions in East and South Africa. The climate and terrain in West and Central Africa make fossil preservation and research more challenging.
Cultural bias may also have played a role, as most research has been spearheaded by people from the global North, who were more interested in how people got out of Africa. As a result, most scientists have focused on sites in South and East Africa, contributing to the idea that early modern humans primarily inhabited these regions.
Recent discoveries have started to change this perspective. A study from last year found that modern humans lived at a site on the coast of Senegal 150,000 years ago, much earlier than the previous estimate of 30,000 years ago. Another study from 2022 analyzed DNA from the bones of 34 people who lived across sub-Saharan Africa between 5,000 and 18,000 years ago, showing that populations that had been fairly isolated began to interact across large swaths of the continent.
A study from 2020 examined the remains of two children found at a rock shelter in Cameroon, detecting four separate human lineages between 60,000 and 80,000 years ago, including a previously unknown lineage that probably lived in West Africa. These findings provide more support for the idea that humans have been in West Africa for far longer than previously realized.
Scientists have also developed innovative approaches to establish early-human habitation. For instance, Jessica Thompson and her colleagues studied the environment around Lake Malawi, finding an abundance of charcoal that suggests humans were living in the region and burning wood on a significant scale.
A key aspect of this new understanding is the Pan-African hypothesis, which argues that modern humans probably evolved from the intermingling of different groups from a range of areas of the continent. Eleanor Scerri explains, “There were a number of modern human populations living in different regions of Africa, and we emerged over time from the complex interactions between them.”
Brenna Henn and her colleagues at the University of California at Davis examined the genomes of almost 300 Africans from across the continent, finding that modern humans descended from at least two distinct populations who lived in different parts of the continent. Scerri has also found evidence to support the Pan-African idea, showing that Middle Stone Age culture persisted in West Africa until quite recently.
While not everyone is convinced of the Pan-African origins theory, the field is experiencing an exciting time with new perspectives and ongoing research. Eleanor Scerri feels vindicated that the new perspective has caught on, stating, “Right now, this is such an exciting area to work. It’s really an incredible story, one that’s emerging before our eyes.”
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