A recent computer reconstruction of the million-year-old fossil of a skull thought to belong to a member of our Homo erectus ancestors has revealed that it is instead from an individual from a species that is much more closely related to modern humans. This, combined with genetic evidence outlining the close lineage between our two species, may very well double the age of humankind, pushing our origins back a million years into the past.

When they were first excavated from a site near China’s Han River in 1989 and 1990, the fossilized skulls belonging to the two individuals known as “Yunxian Man” were, while described as complete, so “crushed and distorted” that their appearance led the paleontologists that made the discovery to classify them as belonging to Homo erectus, one of our ancient forebears that lived one million years ago, the era that the fossils were positively dated to.

But after the distortions in the second skull were corrected by a joint reconstruction effort led by China’s Fudan University and the Natural History Museum, London, the resulting model more closely resembled that of Homo longi, a human subspecies recently linked to the Denisovans, making Yunxian Man more closely related to Neanderthals and modern humans than H. erectus.

But the age of the fossils presented a problem: having been definitively dated as approximately one million years old, this implied that a subspecies very closely related to modern humans walked the earth at least a thousand millennia ago; and when combined with genetic evidence that shows that H. longi and Homo sapiens co-existed for roughly the same amount of time, that means modern humans have been around for about twice as long as previously believed, pushing our genesis back to about a million years ago, instead of the 500,000 years ago when H. erectus split off into H. sapiens and Neanderthals.

“From the very beginning, when we got the result, we thought it was unbelievable,” remarked Fudan University Professor Xijun Ni, who co-led the study. “How could that be so deep into the past?

“But we tested it again and again to test all the models, use all the methods, and we are now confident about the result, and we’re actually very excited.”

“There is some genetic evidence that points to the even earlier emergence of our species which may have recombined with our lineage, but this is not yet proven,” cautioned Professor Chris Stringer of the Natural History Museum, London, who also co-led the study. Stringer pointed out that there are numerous million-year-old human fossils recovered from Africa and Europe that need to be added to their analysis that should provide a more complete picture.

These fossils are between 800,000 and 100,000 years old but have proven to be difficult to classify, making it hard for researchers to determine how they fit into our family tree. However, if H. neanderthalensis, H. longi and H. sapiens—Neanderthals, Denisovans and modern humans, respectively—extend as far back in time as Ni and Stringer’s findings suggest, these so-called “muddle in the middle” fossils could very well fall into one of these three otherwise closely-knit subspecies.

One might imagine what it might have been like, living alongside another species that is markedly different from ours, and yet so similar? Whitley explores this possibility in his 2018 novel, New. Pick up a copy of and explore the possibilities today!