Early humans survived in a range of extreme environments before global migration, study says

Early Humans Adapted to Extreme Environments Before Global Migration

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WASHINGTON: Humans possess the unique ability to thrive in almost every environment on Earth, from the lush rainforests to the harsh deserts and frozen tundras. This remarkable adaptability isn't a recent development. A groundbreaking study published in Nature reveals that ancient Homo sapiens evolved the flexibility to survive by discovering sustenance and essential resources across diverse and challenging habitats long before their dispersal from Africa approximately 50,000 years ago.

"Our superpower is that we are ecosystem generalists," explained Eleanor Scerri, an evolutionary archaeologist at the Max Planck Institute of Geoanthropology in Jena, Germany.

Our species initially emerged in Africa around 300,000 years ago. Although earlier fossil discoveries indicate that some groups ventured outside the continent previously, sustained human settlements in other regions didn't occur until a series of migrations roughly 50,000 years ago.

"What was different about the circumstances of the migrations that succeeded - why were humans ready this time?" questioned study co-author Emily Hallett, an archaeologist at Loyola University Chicago.

Previous theories proposed that Stone Age humans might have achieved a pivotal technological advancement or developed a novel method of information sharing. However, researchers have yet to uncover concrete evidence supporting these hypotheses.

This study adopts a different perspective by examining the trait of flexibility itself.

The researchers compiled a database of archaeological sites demonstrating human presence throughout Africa from 120,000 to 14,000 years ago. For each site, they modeled the prevailing local climate during the periods when ancient humans inhabited those areas.

"There was a really sharp change in the range of habitats that humans were using starting around 70,000 years ago," Hallet said. "We saw a really clear signal that humans were living in more challenging and more extreme environments."

While humans had long flourished in savannas and forests, they expanded into a variety of environments ranging from dense rainforests to arid deserts in the period leading up to 50,000 years ago, developing what Hallet called an "ecological flexibility that let them succeed."

Although this surge in capabilities is noteworthy, it's crucial not to assume that Homo sapiens were the only species to achieve it, cautioned University of Bordeaux archaeologist William Banks, who was not involved in the research.

Other groups of early human ancestors also departed Africa and established enduring settlements elsewhere, including those that evolved into Europe's Neanderthals, he noted.

The new research provides insights into why humans were prepared to expand across the globe long ago. However, it doesn't address the fundamental question of why only our species has survived to this day.