Human DNA in Cave Paintings Can Survive For Millennia, Study Finds

What can the pigments of Paleolithic cave paintings tell us about the artists who painted them? Deep in the ancient caves of Spain and Portugal, scientists have discovered evidence of ancient human DNA on cave walls. The find proves for the first time that DNA can survive for millennia within the paint applied to rock walls, opening a future pathway to recovering the identities of ancient artists from thousands of years ago.

A new study published in the journal Nature Communications on June 23 examines ancient DNA preserved within pigment samples extracted from 24 rock art panels within 11 caves across Spain and Portugal. The team, led by Alba Bossoms Mesa, is largely from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, but the research is a part of a much larger, multinational project called First-Art. The consortium includes a network of archaeologists, geologists, scientists, and cultural heritage specialists in Spain, Portugal, Italy, China, Germany, and the United Kingdom, each working to date and examine the chemical composition of prehistoric rock art. The discovery of DNA in this artwork has created a new window into the past that goes beyond researchers’ previous reliance on human bones, sediment, teeth, and faunal remains to reconstruct Paleolithic communities.

Pigmented cave wall sample from Balmori Cave, Spain (© Kevin Nota, courtesy Max Planck Institute for Evolutionary Anthropology)

The researchers examined simple marks found in nine sites of the eleven total caves, as well as hand stencils discovered in the Maltravieso Cave at Extremadura and figurative paintings at the Cave of Altamira in Cantabria. Although only a limited amount of these samples contained human DNA, the scientists note that “given the diversity of rock art techniques and contexts, it remains possible that rock art from other sites, periods, or styles could more consistently yield ancient DNA.” Some of the most spectacular rock art known today is outside of Europe and China, in South America. It is possible that the methods developed in Spain and Portugal may now give us more insight into the artists who painted the Cueva de las Manos (Santa Cruz Province, Argentina), which contains hundreds of handprints dating between 13,000 and 9,500 years ago.

Hands at the Cuevas de las Manos on the Río Pinturas, near the town of Perito Moreno in Santa Cruz Province, Argentina (photo public domain via Wikimedia Commons)

Whether it is the chemistry needed to create synthetic pigments like Egyptian Blue or the understanding of kiln thermodynamics necessary for ceramicists to fire their pottery, science and visual art have often had a symbiotic relationship. Monica Green, a specialist in the history of science and ancient DNA (also called “aDNA”), noted the importance of this area of study in comments to Hyperallergic:

“Retrieving molecular evidence of the past, whether of humans themselves or the lifeforms they interacted with, has been revolutionizing our understanding of everything from mass migrations to pandemics,” Green said. “‘Data’ can come from anywhere: from the plaque on teeth to the floor of a cave.”

Artist Karina Åberg swabs a 14th-century da Vinci family letter from the State Archive in Prato for biological clues, following research initiated by Rossella Lorenzi. (photo Paolo Agazzi via Archivio di Stato di Prato / Italian Ministry of Culture)

Green and many others have long contended that the developing field of archaeogenetics offers more opportunity than ever to recover the histories of people, pandemics, and migration. New analyses of everything from the linen strands of the Shroud of Turin to the artworks of Leonardo da Vinci also illustrate the latent potential of aDNA analysis for the field of art history.

While there are definite limits to what archaeogenetic data can and cannot reveal, microscopic clues are telling us more than ever about prehistoric, ancient, and medieval artists, and even the forgeries of yore. As we are only starting to understand, artworks carry much more than a visual message. They are also biological archives that provide access to our past.