CNN
—
The greatest mystery of human evolution, which arose 15 years ago from a pinky bone about 60,000 years old, finally began to be revealed in 2025.
Analysis of DNA extracted from the fossil shocked the scientific community in 2010, when it revealed the existence of a previously unknown human population that, in the distant past, encountered and mixed with our own species, the A wise man. This enigmatic group became known as the Denisovans, in reference to the Denisova Cave in the Altai Mountains of Siberia, where the little finger was found.
Despite the deep knowledge of the genetic composition of this population, whose traces are carried today by millions of people, scientists knew nothing about what the Denisovans looked like, or where they lived, or why they disappeared. The discovery, and the questions it unleashed, galvanized an entire generation of geneticists, archaeologists, and paleoanthropologists.
Some of that work bore fruit this year, and scientists were finally able to put a face to the Denisovan name thanks to new clues gleaned from another well-known fossil: a prehistoric human skull that didn’t fit into any known group. Now, other pieces of the puzzle are beginning to fall into place.
When the skull came to light in Harbin, northeast China in 2018 after being hidden for decades at the bottom of a well for safekeeping, some scientists suspected it could be a Denisovan.
DNA sequences from this group had been detected in the genomes of current Asian populations, but not in European ones, suggesting that this region was where the Denisovans predominantly lived.
Based on its distinctive shape, the researchers attributed the skull to a new species they named A long man or “Dragon Man”. The dozen Denisovan fossils identified since 2010 using DNA were too small and fragmentary to justify an official species name.
Obtaining ancient DNA from the skull, estimated to be about 146,000 years old, was key to determining whether there was a link between Dragon Man and the Denisovans. But it wasn’t easy.
A team led by Qiaomei Fu, a geneticist and professor at the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences in Beijing, analyzed six bone samples from Dragon Man’s only preserved tooth and the petrosal bone of the skull, a dense part at the base of the skull that is often rich in DNA. However, the samples did not yield any results.
But Fu, who as a young man had been part of the team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, that first discovered the Denisovans, reported in June that his team had managed to recover Denisovan genetic material from an unexpected source: Dragon Man’s dental tartar, the dirt left on the teeth that over time can form a hard coating and preserve the mouth’s DNA.
That information was not a definitive result. The genetic material the researchers had recovered was mitochondrial DNA, which, unlike nuclear DNA, is only inherited maternally, providing an incomplete picture of an individual’s genomic ancestry. This finding potentially meant that Dragon Man could have been a mix of two species, something that is not unprecedented. In 2018, scientists revealed a fossilized bone from Denisova Cave that belonged to a girl with a Neanderthal mother and a Denisovan father.
However, the team also recovered protein fragments from petrous bone samples, which, although less detailed than DNA, suggested that the Dragon Man skull belonged to a Denisovan population.
Together, these two lines of evidence “clarified some of the mystery surrounding this population,” Fu told CNN in June, when the research was published. “After 15 years, we know the first Denisovan skull.”
The discovery of the DNA makes it likely that A long man become the official designation for the dozen remaining Denisovan fossils, Chris Stringer, a paleoanthropologist and research leader in human evolution at the Natural History Museum in London, said in an email.
Ryan McRae and Briana Pobiner, paleoanthropologists at the Smithsonian’s National Museum of Natural History, agreed, although they noted that the name “Denisovan” will probably continue to be used popularly, just as most people today call Neanderthals “Neanderthals.” Homo neanderthalensis.
“While more work is needed to gather evidence and give scientists a more complete view of Denisovan anatomy, habitat, and behavior, being able to link complete fossils to molecular evidence is a major advance,” McRae and Pobiner wrote in an annual list of the top stories in human evolution.
Researchers suggest there could be additional evidence waiting to be identified, which could lead to momentous revelations in 2026.
A skull fossil, with its telltale bumps and ridges, can reveal a lot about an individual’s appearance, according to John Gurche, a paleoartist who creates reconstructions of ancient human ancestors for museums, including the Smithsonian and the American Museum of Natural History. Gurche recreated the Dragon Man’s face for National Geographic.
Assuming that Dragon Man’s skull belonged to a typical Denisovan individual, scientists claimed that this ancient human would have had pronounced brow ridges, large teeth, and lacked our high forehead. However, if dressed in modern clothing, this prehistoric relative might not attract too much attention in a subway car.
Gurche explained that he uses known relationships between soft tissues and bone in humans and apes to recreate facial features, such as the width of the eyeball, the dimensions of nasal cartilage and the thickness of soft tissues in different areas of the face. More difficult were features about which the skull “offers little information,” such as the shape of the lips and ears, and the location of the hair.
With molecular evidence now linking Dragon Man to the Denisovans, it will be easier for paleoanthropologists to identify other possible Denisovan remains, including skull fossils from sites in China that have long defied classification.
More revelations could emerge from another skull discovered in China in 2022, which has not yet been formally described in scientific literature. It is the third skull unearthed at the site known as Yunxian, in the Chinese province of Hubei, and is believed to date back to around 1 million years ago. The other two skulls were found in 1990.
A digital reconstruction published in September of the second skull, which was severely deformed, suggested it was an early ancestor of Dragon Man, meaning the lineage could have originated much earlier than previously thought.
The researchers’ broader analysis, based on reconstruction and more than 100 skull fossils, also significantly pushes back the chronology of the emergence of species like ours by 400,000 years. A wise manand the Homo neanderthalensis.
However, the findings raised some skepticism. More details about Yunxian’s third skull would allow the team to check the accuracy of the reconstruction and its location in the human family tree.
A 200,000-year-old tooth, similar in appearance to the molar still attached to Dragon Man’s skull, could revolutionize what is known about the Denisovans and the broader human family tree next year and beyond. Researchers found the tooth during an excavation in Denisova Cave in 2020.
Stéphane Peyrégne, a researcher at the Max Planck Institute for Evolutionary Anthropology, and his colleagues have since analyzed the molar and managed to recover from it the complete genome of a Denisovan, a very detailed set of genetic information that can reveal genetic diversity and evolution of the past.
It is only the second time that scientists have managed to sequence a “high coverage” Denisovan genome from a Denisovan fossil, the first was from the finger fossil that revealed the existence of this group.
The scientists shared the genome analysis in October on what is known as a preprint server, which allows study authors to post preliminary versions of their work online, and it is being reviewed by other researchers. Peyrégne declined to comment on the article until it is officially published next year. Stringer called the findings “very important.”
The genome allows us to investigate in greater depth Denisovan biological traits that could influence current human health. For example, a study published in August suggested that a Denisovan genetic variant involved in mucus and saliva production may have helped the A wise man to adapt to new environments.
The new genome is also much older than the first and allows geneticists to delve deeper into the history of the Denisovans and reconstruct relationships between different ancient populations.
The genome represents a Denisovan man who lived in a small group 200,000 years ago in the Denisova Cave. Analysis of the group revealed that not only had their ancestors apparently mixed with early Neanderthals, but the individual also had ancestry from an unknown “super archaic” group for which there is currently no ancient DNA match.
The Smithsonian’s McRae noted that traces of these “ghost lineages” have been found in the DNA of modern humans, and that scientists are not sure who they were. They could represent other extinct hominids, such as the The man stood up or the Homo floresiensissometimes known as “hobbit.”
“Or they could represent hominids that we haven’t really found in the fossil record. They are ghosts until we have something that allows us to track them,” he said by email.
Determining the identity of this group will be a new mystery that experts in human evolution will have to solve in 2026.
