The ancient human species went extinct as recently as 110,000 years ago. Modern humans, Homo sapiens, only emerged about 300,000 years ago.

Co-author Michael Petraglia, Director of the Australian Research Centre for Human Evolution at Griffith University, says their nearly 2-million-year existence makes Homo erectus a “species survival success in the human evolution story”.

“That success came down to their ability to survive over a long period marked by many changes to the environment and climate,” says lead author Julio Mercader from Canada’s University of Calgary.

The new study shows just how adaptable Homo erectus was.

The researchers used biogeochemical analyses, chronometric dating, palaeoclimate simulations, biome modelling, fire history reconstructions, palaeobotanical studies, faunal assemblages and archaeological evidence to assess the habitats that Homo erectus was able to conquer.

They showed that the ancient Tanzanian gorge was a semi-desert shrubland – much as it is today.

Homo erectus was able to live in these harsh conditions by occupying areas carved out by rivers and streams. The ancient humans would have needed to leverage water availability and not get caught up in dangerous animal gathering places.

“Debate has long centred on when the genus Homo acquired the adaptability to thrive in extreme environments such as deserts and rainforests,” says Abel Shikoni of the University of Dodoma, Tanzania. “Traditionally, only Homo sapiens was thought capable of sustained occupation in such ecosystems, with archaic hominins seen as restricted to narrower ranges.”

“However, the biogeochemical, palaeoenvironmental, and archaeological evidence we analysed suggests early Homo had the ability to adapt to diverse and unstable environments from the East African Rift floor and Afromontane areas as early as 2 million years ago,” Petraglia adds.

Such resistance to different environments was likely key to Homo erectus lasting so long and dispersing across continents.

“This adaptive profile, marked by resilience in arid zones, challenges assumptions about early hominin dispersal limits and positions Homo erectus as a versatile generalist and the first hominin to transcend environmental boundaries on a global scale.”

“This adaptability likely facilitated the expansion of Homo erectus into the arid regions of Africa and Eurasia, redefining their role as ecological generalists thriving in some of the most challenging landscapes of the Middle Pleistocene,” says Paul Durkin of the University of Manitoba, Canada.