Three fossil skulls unearthed in China's Hubei province between 1989 and 2022 have just upended the chronology of our genus. A new dating study, published in Science Advances, assigns the Yunxian people an age of 1.77 million years, nearly 700,000 years older than previous estimates. If this result is confirmed, it would require a fundamental revision of the history of human migrationsMigrationsLong-distance movements of populations; a major driver of human history (the exit from Africa, the peopling of continents, Neolithic and steppe expansions).→ out of AfricaOut of AfricaThe dispersals of Homo sapiens out of Africa, including a major expansion c. 70,000 to 60,000 years ago and earlier exits.→ and possibly even the origins of Homo erectus.1

Fossilised Homo erectus skull, Pleistocene, Southeast Asia
Fossilised Homo erectus skull from the PleistocenePleistoceneThe geological epoch of the great ice ages (c. 2.6 Ma–11,700 BP), spanning most of human prehistory.→ of Southeast Asia. The Yunxian skulls, recovered in Hubei Province (China), belong to this species or a closely related group. The new dating to 1.77 million years would make them the oldest known Homo erectus in China. Credit: James St. John / Wikimedia Commons, CC BY 2.0.

The two previous datings of the Yunxian people had already produced discordant results. The first, based on the age of small mammal teeth found near the skulls, indicated approximately one million years. A second, using electron spin resonance, suggested 1.1 million years. Christopher Bae and his team this time employed a more robust method: cosmogenic nuclide burialBurialThe intentional deposition of a body, sometimes with offerings; a marker of symbolic behaviour.→ dating applied to quartz grains sampled deep within the encasing sediments. This technique measures how long crystals have been shielded from cosmic rays by burial, providing a reliable geochemical clock for ancient deposits.2

The result, 1.77 million years, places the Yunxian people in the same temporal bracket as the famous Dmanisi fossils (Georgia), currently the oldest confirmed Homo erectus outside AfricaAfricaThe cradle of humankind: the continent where the first hominins appeared, then Homo sapiens around 300,000 years ago, before the expansion to the rest of the world.→ (1.78 to 1.85 million years). Yet Dmanisi lies in western Asia, thousands of kilometres from central China. If Yunxian really dates to 1.77 million years, it would require accepting that Homo erectus covered this immense distance in a very short geological time, less than 100,000 years under some scenarios. Alternatively, lithic tools discovered in China and dated to 2.1 to 2.3 million years suggest that a homininHomininMember of the subtribe Hominina, comprising the human lineage (Homo, Australopithecus, Paranthropus…) but excluding orangutans and gibbons. The term progressively replaces "hominid" in its narrow sense.→ population may already have been present in the region well before the known fossils.

The morphology of the Yunxian skulls adds another layer of complexity: their cranial capacity appears higher than that of other known Homo erectus of this period, raising questions about their species attribution. According to earlier research, the Yunxian people may belong to a lineage that later diverged to give rise to the Denisovans. "If they are right about the age of the skulls, it may be necessary to push back the origins of Homo erectus to 2.6 million years," Christopher Bae told LiveScience, a hypothesis that would overturn the entire human evolutionary narrative.3