New analysis finds ‘deep genetic links’ between Homo erectus and modern humans, raising the ‘question of whether we know what Homo erectus even is’
For the first time, researchers have sequenced genetic material that is 400,000 years old. Homo erectus fossils – and the results reveal deep genetic connections to modern humans and enigmatic Denisovans.
H. erectus was the first human ancestor to travel out of Africa and successfully spread to Europe, Asia and Oceania 1.8 million years ago. Boasting a relatively large brain and the ability to make complex stone tools, H. erectus was the oldest human ancestor until its disappearance approximately 108,000 years ago. But paleoanthropologists have long wondered whether H. erectus superimposed and crossed with Homo sapienswhich evolved around 300,000 years ago in Africa.
Two of these amino acid variants surprised the researchers: one was present in all six H. erectus individuals but not in any other human lineage, while the other was present in all H. erectus samples as well as in Denisovansa group of archaic humans who lived in Asia and became extinct around 30,000 years ago. This amino acid variant was then passed from the Denisovans to some H. sapiens groups resulting from crossbreeding tens of thousands of years ago.
The results are the first to show “deep genetic links” between these H. erectus modern individuals and humans today, the researchers wrote in a declaration. The results also represent a step forward for the relatively new technique called paleoproteomicswhich allows scientists to sequence genetic material that lasts longer than DNA.
“I don’t believe any DNA or proteomics have been done before” on H. erectusstudy first author Fu Qiaomeidirector of the Ancient DNA Laboratory at the Institute of Vertebrate Paleontology and Paleoanthropology, part of the Chinese Academy of Sciences, in Beijing, told Live Science in an email. But “how they evolved into modern humans and are related to the Denisovans, we really need to understand DNA understand that,” she said.
DNA has a shorter shelf life than proteins, and so far, researchers have found none H. erectus Sequenceable DNA. However, Denisovan’s DNA has been sequenced.
Scientists have analyzed this Homo erectus tooth from the Zhoukoudian site in China.
(Image credit: Qiaomei Fu)
The confusion in the middle
The Middle Pleistocene era (also called the Chibanian age) extended from 774,000 to 129,000 years ago. At this time, a number of ancient human groups overlapped in Africa, Europe and Asia, including H. erectus, H. sapiensNeanderthals and Denisovans, which presents paleoanthropologists with the difficult task of understanding how they were all related – a confusion they call a “confusion.”
“Scientists called this ‘the Middle Pleistocene confusion'” John Hawksa paleoanthropologist at the University of Wisconsin-Madison who was not involved in the study, told Live Science in an email, “and now we know the confusion is just a mix-up.” New study of 400,000-year-old enamel proteins shows mixing of different evolutionary branches was important for our evolution“even earlier than the DNA evidence can show us,” Hawks said.
But what exactly do these new results mean for the evolution of H. erectus – and the possibility that he crossed with the modern H. sapiens in Eurasia — the situation is still murky. “I think it raises the question of whether we know what Homo erectus it even is,” Hawks said.
Paleoanthropologists often define an ancient human species based on a group’s physical characteristics, such as the size and shape of their bones and teeth – a method called the “morphological species concept.” But that way to determine species has been complicated by the rise of genomic analysis over the past two decades, which has revealed crossovers between groups such as Neanderthalsthe Denisovans and modern humans, proving that there is some biological overlap between these groups.
But while the genetic information shared between groups around 50,000 years ago in Europe and Asia is relatively clear thanks to DNA and genomic analysis, amino acid variations recently revealed in 400,000-year-old fossils from China are only the first step toward clarifying the “Middle Pleistocene confusion.”
“What I conclude is that paleoanthropologists of the past were probably too willing to transfer these Middle Pleistocene fossils from China to Homo erectus“A lot of these fossils are probably Denisovan relatives, or maybe they come from other groups that we call ‘erectus’ just because we don’t really understand them.”
The bottom line, Hawks says, is that the new study is an excellent piece of work. “It’s hard to look at data like this and not be impressed by the uncertainty of boundaries and their mixing in these people of the past,” he said.
Fu, Q., Wu, Z., Bennett, E.A., Xing, S., Ji, Q., Dong, Z., Rao, H., Gu, X., Dang, Y., Xing, J., Zhou, K., Feng, X. (2026). Six enamel proteins Homo erectus specimens across China. Nature. https://doi.org/10.1038/s41586-026-10478-8
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