Key Phases of Human Evolution Coincide With the Fluctuation in Eastern Africa’s Climate
Published:19 Oct.2022    Source:University of Cologne
The research team extracted two continuous 280-metre sediment cores from the Chew Bahir Basin in southern Ethiopia, an area where early humans lived and developed during the Pleistocene. The cores yielded the most complete record for such a long period ever extracted in the area, revealing how different climates influenced the biological and cultural transformation of humans inhabiting the region. Archaeologists, evolutionary biologists, and evolutionary anthropologists then identified phases of climatic stress as well as more favourable conditions and interpreted how these factors changed human habitats, influencing human biological and cultural evolution as well as their dispersal.
 

A phase with significant climate swings resulting in regularly transformed habitats in the area from approximately 275,000 to 60,000 years BP repeatedly resulted in environmental shifts from lush vegetation with deep fresh water lakes to highly arid landscapes with the extensive lakes reduced to small saline puddles. In this phase, the population groups gradually transitioned from Acheulean technologies to more sophisticated Middle Stone Age technologies. This crucial phase also encompasses the emergence of Homo sapiens in eastern Africa as well as key human social, technological, and cultural innovations that could have buffered early Homo sapiens from the impacts of severe environmental changes. “These innovations, such as more varied toolkits and long-distance transport, would have equipped modern humans with an unprecedented adaptability to the repeated expansions and contractions of habitats,” said Dr Foerster, the paper’s lead author.