Not only have researchers identified several of these prehistoric viruses, but they hope to recreate them to see how they compare to modern ones.
Tbviola/Wikimedia CommonsChagyrskaya Cave, where the remains of nine Neanderthals were discovered in 2022.
Back in 2022, researchers came across the remains of nine Neanderthals in a Siberian cave. That discovery alone was astounding enough — the remains were a whopping 50,000 years old, after all — but these Neanderthals have also proven to be remarkable in another way. A new study has uncovered a number of viruses in their genetic code that have now been identified as the oldest human viruses ever found.
They include viruses familiar to our modern age, including herpes, papillomavirus, and the adenovirus that can cause, among other things, the common cold. Some researchers even suspect that these viruses may have played a role in ushering in the Neanderthals’ extinction.
The Discovery Of The Oldest Known Human Viruses
After the discovery of the Neanderthals in Siberia’s Chagyrskaya Cave, researchers from the Federal University of São Paulo decided to test the DNA of two of the remains. In a preprint paper available on bioRxiv — which has not yet been peer reviewed — they describe how they searched the Neanderthals’ DNA sequences for the genomes of certain human viruses.
They were looking for the genetic code of three viruses: adenovirus, herpesvirus, and papillomavirus. And the researchers found all three present in the Neanderthals’ DNA, making them the oldest known human viruses ever discovered. Previously, this title belonged to traces found in 31,600-year-old Homo sapiens remains which were also recovered from Siberia.
Public DomainA depiction of a Neanderthal family. The Neanderthals found in Chagyrskaya Cave were genetically related to each other.
“We were not surprised [to find the viruses],” study author Marcelo Briones told All That’s Interesting in an email. “All these three viruses infect a wide range of mammals and of course, other primates as well. We would be surprised if these were not to be found at all in Neanderthals.”
Though it’s possible that the remains were contaminated, either by animals or humans, the researchers are confident that these are 50,000-year-old viruses.
So what did these viruses mean for the Neanderthals who had them?
What Did These Viruses Mean For Neanderthals?
Scientists today are well versed in viruses like papillomavirus, herpesvirus, and adenovirus. Papillomavirus is sexually transmitted and best known for its link to cervical cancer. Herpesvirus is the root cause of diseases like mononucleosis and multiple sclerosis. And andenvorius can cause a range of ailments in modern humans, from a cold to gastroenteritis.
But some research suggests that viruses like these were much more devastating to the Neanderthals who carried them, and may have even played a role in their eventual extinction.
Public DomainA depiction of Neanderthals in the snow. Researchers suspect that a number of factors, from a changing climate to diseases, played a role in their extinction.
“It is possible that the Neanderthals were more susceptible to diseases carried by [anatomically modern humans],” the researchers explained in their study. “This could have had a significant impact on their ability to survive and reproduce… disease, especially infectious diseases, could have played a relevant role in Neanderthal extinction.”
The study’s authors acknowledge that the extinction of Neanderthals was likely the result of a number of factors, including competition with modern humans, interbreeding with modern humans, and changes in the climate. But viruses like the ones discovered in these Neanderthal remains may have also played a role in their demise.
“It is very hard to speculate on this right now,” Briones remarked to All That’s Interesting. “These are contagious viruses that can cause significant reduction in fitness and reproduction, and therefore it is expected to affect a natural population.”
Briones further explained that he and his team are hoping to determine if the “viral genome remnants found in these Neanderthals are endemic to these populations or were introduced by modern Homo sapiens.”
Next, he and his team are hoping to learn more about how these prehistoric viruses differ from their modern counterparts. They plan to recreate the viruses and infect present-day cells so that they can more closely examine how the two are different from each other. Though some some scientists have expressed skepticism about the project, Briones is confident that it’s possible.
“It is feasible since the difference between Neanderthal viruses and the modern counterparts is not that big,” he told All That’s Interesting. “Just a few amino acids in some of the viral proteins. It is much less than the difference, for example, between ape adenovirus and human adenovirus, and ape adenovirus can infect human cells without problems.”
Perhaps this will help answer questions about the Neanderthals, and how they vanished from the Earth 40,000 years ago.
After reading about the discovery of the oldest known human viruses, read about the 4,500-year-old herpes found in Bronze Age remains. Then, learn about the Neanderthal-Denisovan hybrids found inside a Russian cave.
Kaleena Fraga
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