Ancient Human DNA Extracted from Iberian Cave Walls and Ochre Markings

The First Art project team sampled paint shavings and calcite layers from 11 caves in Spain and Portugal between 2022 and 2025. They targeted hand stencils, dots, and abstract figures created by spitting or finger application of ochre, plus bare-wall controls. DNA was extracted and sequenced to distinguish human from environmental sources. Four samples from Escoural yielded usable endogenous human DNA showing exclusive human profiles without the mixed faunal signals typical of sediment deposits.

Genetic profiles aligned with western hunter-gatherers active 5,200–17,000 years ago. Three samples were predominantly female and one male. Because Escoural was sealed 4,000–5,000 years ago, the DNA predates that closure. The exclusive human signature supports direct contact rather than secondary sediment transfer, expanding cave surfaces as potential archives even without visible art.

Prior sediment DNA studies showed mixed species signals; wall samples here demonstrate cleaner, contact-derived profiles. This enables future attribution of specific artists versus later visitors, though current data cannot yet distinguish creators from subsequent touch. Larger sample sets from sealed contexts and improved decontamination protocols would strengthen claims of authorship.

Ongoing sampling at Nerja and Ardales caves will test whether Neanderthal-era layers also preserve DNA. If successful, the approach could resolve long-standing questions about authorship of the oldest European cave art.