- Archaeological News
-
Image Credit: José Miguel Soares, CC BY-SA 3.0, via Wikimedia Commons
Ancient DNA Found on Cave Walls Opens New Window into Prehistoric Human Presence
A new study has shown that traces of ancient human DNA can survive on cave walls for thousands of years, raising new possibilities for studying prehistoric populations and their activities in decorated caves.
The research examined pigment and wall samples from 24 rock art panels in 11 caves across Spain and Portugal. The samples included simple marks, hand stencils, and figurative paintings, as well as nearby unpigmented wall surfaces used for comparison. The aim was to investigate whether rock art and cave walls could preserve genetic traces left by the people who entered, touched, or possibly decorated these underground spaces.
The most notable result came from Escoural Cave in Portugal, where researchers recovered ancient human mitochondrial and nuclear DNA from a pigmented calcite crust near a rock art panel. A nearby unpigmented wall sample from the same cave also yielded ancient human DNA. In both cases, no ancient faunal DNA was detected, suggesting that the DNA may have been deposited through direct human contact with the cave wall.
Other unpigmented samples from Escoural and Covarón Cave in Spain contained both human and animal DNA. This mixture points to a different kind of deposition, possibly through cave sediments transferred to the walls or other natural processes. In Covarón, the recovered human DNA showed genetic affinities with western hunter-gatherer populations, although the samples did not come directly from painted surfaces.
The study does not prove that the recovered DNA belonged to the people who created the rock art. The researchers emphasize that the pigment and the DNA may have been deposited at different times. This is an important caution, especially because human contact with cave walls can happen for reasons unrelated to artistic production, such as movement through the cave or touching surfaces during other activities.
Despite these limits, the findings demonstrate that cave walls themselves can preserve ancient human genetic traces, even outside excavated floor deposits. This adds a new source of evidence to ancient DNA research, which has traditionally relied on bones, sediments, and artefacts.
This discovery could expand the role of ancient DNA research in archaeology. In the future, cave wall samples may help researchers understand which human groups used particular caves, how far they moved inside them, and whether specific activities were concentrated in certain areas. The method may also be useful in caves where excavation is difficult, restricted, or not possible for conservation reasons.
Published on: 24-06-2026
Edited by: Abdulmnam Samakie
Source: Nature Communications
