In a Scientific First, Researchers Recovered Ancient DNA That Humans Left Behind on Rock Art and Cave Walls

Add as preferred source Scientists collected samples from 11 caves in Spain and Portugal. © Alberto Martínez Villa Scientists have long been fascinated by prehistoric cave art, which offers a rare glimpse into the creative minds of our ancestors. Now, they might finally be able to “meet” some of the artists who created these masterpieces thousands of years ago. Traces of ancient DNA from humans can survive for millennia on cave walls and in rock art, scientists report in a new paper published in June in the journal Nature Communications. In the past, scientists have extracted ancient DNA from cave dirt, chewing “gum” and a 20,000-year-old pendant. But no one had recovered it from rock art, until now. “It’s the start of a new era,” study co-author Genevieve von Petzinger, a paleoanthropologist at University of the Witwatersrand, tells NewScientist’s Alison George. “This gives us the potential to meet the actual artists, the individuals who did this art. It’s extraordinary.” Researchers think prehistoric artists primarily created cave art by applying red ochre paint with their hands or spitting it from their mouths, meaning traces of their skin or spit may have ended up in the final piece. Scientists visited 11 caves that contain rock art in Spain and Portugal between 2022 and 2025. They collected samples from areas in and around 24 rock art panels, either taking thin shavings of red ochre paint or the calcite crusts that hardened on top of them over time. For comparison, they also collected samples from parts of the cave walls with no art. When they analyzed these samples, they found traces of ancient DNA from humans in a pigmented calcite crust from the Escoural Cave in Portugal. Based on the results, they think the DNA was deposited in the Escoural Cave directly through human saliva, sweat or other bodily fluids rather than indirectly, such as via sediment transfer or water movement. If the human DNA had been deposited indirectly, scientists would have expected the samples to contain traces of animal DNA, too. But, in this case, the human DNA was “unaccompanied by faunal DNA,” they write in the paper. Scientists couldn’t pinpoint the exact age of the DNA because there wasn’t enough of it. However, they say the DNA is at least 2,000 years old—and probably older. Escoural Cave was closed off to the outside world starting around 4,000 or 5,000 years ago, so it likely predates that period, per NewScientist. They also can’t prove the DNA was left behind by the artist who created the cave art. It’s possible the DNA came from someone else—perhaps an individual who visited the cave later and simply touched or sneezed on the art, for instance. The scientists were shocked to find ancient DNA from humans in samples collected from unpainted areas of the Escoural Cave in Portugal and the Covarón Cave in Spain. Some of these samples produced both human and animal DNA, suggesting they may have been contaminated by sediment from the cave floor. Of the 120 total samples the researchers collected, only five produced ancient DNA from humans. Still, the findings hint at the possibility that caves are an untapped resource for scientists who study human ancestors. “This is not just about rock art,” study co-author Hipólito Collado Giraldo, archaeologist for Spain’s Extremadura region, says in a statement. “It's about understanding how people used caves and where they left their marks.” In the future, researchers hope to be able to use ancient DNA preserved on cave walls to answer longstanding questions. “Were the artists men or women or both?” Francesco d’Errico, an archaeologist at the University of Bordeaux who was not involved with the study, says to NewScientist. “Were animal [drawings] from the same panel made by a single artist? Can we find Neanderthal DNA … or Denisovan DNA … The potential is huge.” Already, scientists have uncovered identifying details about some of the individuals who left their DNA behind in the caves. Three of the samples appear to have come from women, and one seems to have come from a man. Two of the samples also appear to align closely with known groups of western hunter-gatherers that lived between 5,200 to 16,700 years ago. Since the preservation of human DNA on cave walls seems to be highly variable, researchers are now working to refine their methods to increase their chances of success. They also hope to test more sites, as well as different art styles and techniques, especially hand stencils and figurative art. They are already collecting additional samples from other caves in Spain, including the Ardales and Nerja caves where researchers think Neanderthals might have made art. “All of these things we can speculate; we can wonder,” von Petzinger tells National Geographic’s Nicholas St. Fleur. “But until you have it directly pulled off a wall, you don’t know for sure.” Sarah Kuta is a writer and editor based in Longmont, Colorado. She covers history, science, travel, food an

In a Scientific First, Researchers Recovered Ancient DNA That Humans Left Behind on Rock Art and Cave Walls

Key takeaways

More in publications