In Milan, Italy – A recent study sheds light on a critical period in human history about 900,000 years ago when our ancestors faced near-extinction, reduced to a mere population of 1,300 individuals. This bottleneck, as researchers call it, coincided with a mass migration of humans out of Africa, providing new insight into the challenges our early human ancestors faced.
The study links this population decline and migration to a significant environmental event known as the Mid-Pleistocene Transition, marking a time of significant climate change and turmoil on Earth. As our early ancestors ventured into Europe and Asia, they encountered new challenges and environments, sparking multiple waves of migration that would shape the genetic diversity of modern humans.
Two recent studies have independently connected human migration to a population bottleneck, with one focusing on the genetic diversity loss around 900,000 years ago and another pinpointing the bottleneck to 1.1 million years ago. These findings highlight the complexity of early human migration patterns and the impact of environmental factors on population dynamics.
Researchers from the University of Milan and Columbia University conducted a detailed analysis of early hominid habitation sites across Eurasia, dating a cluster of sites to 900,000 years ago. By comparing this data with marine sediment records reflecting climate change, they unveiled a correlation between the population bottleneck and migration out of Africa during the Mid-Pleistocene Transition.
The study suggests that the environmental changes during this period, particularly enhanced aridity, may have pushed early Homo populations in Africa to adapt or migrate to avoid extinction. The combination of severe climate triggers and the availability of land routes into Eurasia likely facilitated the mass migration that helped our ancestors survive and thrive.
Published in the Proceedings of the National Academy of Sciences, these findings provide a deeper understanding of the challenges early humans faced and how they adapted to ensure the survival of future generations. By unraveling the complexities of our ancient history, researchers continue to piece together the puzzle of human evolution and migration.