Researchers have identified ancient human DNA on cave walls for the first time, opening a new window into how prehistoric people lived, moved and interacted with underground spaces. The study, published in Nature Communications, analyzed rock art panels across caves in Spain and Portugal.
A New Genetic Archive
The team examined 24 rock art surfaces in 11 caves, using careful sampling methods on pigment, calcite crusts and nearby wall areas. The most significant result came from Escoural Cave in Portugal, where a red ocher dot sealed beneath calcite contained damaged mitochondrial DNA consistent with ancient human origin.
Because the sample showed no animal DNA, researchers believe the genetic material likely came from direct human contact, such as touch, breath or skin cells. That makes cave walls a potential archive not only of art, but also of presence and movement.
What the Findings Suggest
Ancient human DNA was also detected on unpainted wall samples from Escoural and Covarón Cave in Spain. In one case, nuclear DNA linked the sample to western hunter-gatherers, a population that lived in Europe thousands of years ago. Some wall samples even hinted at biological sex, showing how this method may help researchers study who entered and used these spaces.
Still, the results come with limits. Only one painted sample yielded clearly ancient human DNA, and the researchers stress that more work is needed to separate direct human traces from later contamination. Future studies will likely combine genetic analysis with advanced dating methods to build a clearer timeline.
Even so, the discovery expands the reach of palaeogenetics beyond bones, teeth and sediments. Cave walls may now help scientists map behavior, ritual activity and the social use of prehistoric spaces with far greater detail. It marks a promising step toward a richer understanding of early human creativity and movement, with the potential to reshape how the deep past is read in the future.