Ancient-DNA Recovered from Cave Walls Sheds Light on Rock Art Makers

Overview

A science article reports direct evidence of ancient human DNA preserved on cave walls across 11 sites in Spain and Portugal, suggesting that rock art and the surrounding walls can store genetic information about the people who entered these spaces. While this opens a path toward linking artworks to past communities, it also underscores the challenge that DNA transfer and contamination pose for identifying the exact artist responsible for a painting.

• Ancient-DNA recovered from cave walls indicates connections to hunter-gatherer populations
• Wall samples provide pigment context via X-ray fluorescence spectroscopy and dating methods
• Hand stencil debates, such as Maltravieso, could benefit from genetic data
• Authorship cannot be definitively proven due to DNA transfer and contamination risks

Source: Nature

Background

Rock art, also known as cave paintings, are found worldwide and offer snapshots of ancient cultures, including symbolic communication and social identity. Common motifs include animals, hunting scenes and hand stencils believed to be created by blowing pigment over a hand.

New Genetic Frontiers

A recent study conducted across 11 sites in Spain and Portugal systematically sampled both painted and unpainted cave-wall surfaces. Remarkably, scientists recovered ancient human DNA directly from the walls, demonstrating that these surfaces can serve as reservoirs for genetic information about the people who entered these spaces and possibly created some of the art.

Findings and Context

Some wall samples are dated to at least 4,000 years ago, with two samples from Covarón cave in northern Spain yielding human DNA attributable to ancient western hunter-gatherers. A sample from Escoural cave in Portugal yielded traces of ancient DNA as well, though preservation varied. The research also discusses pigment preservation identified by techniques such as X-ray fluorescence spectroscopy, which helps identify red ochre and charcoal, and carbon-14 dating on minute organic material to time the art's creation.

Controversies and Limits

The study highlights a controversial 66,700-year-old hand stencil at Maltravieso cave in Extremadura, Spain, which predates modern human arrival in Europe and has spurred arguments that Neanderthals may have produced some cave art. The ability to recover DNA from cave walls offers a potential route to addressing such debates, but the authors caution that DNA presence does not prove authorship of a painting. DNA can be transferred through everyday activities and environmental processes such as rain, making it difficult to attribute a work to a single individual at a precise time.

Implications for Archaeology

Overall, the research establishes a powerful methodological framework for studying prehistoric art alongside the people who created it. It points toward a future in which we can connect rock-art with population dynamics, migration routes and social structures, while acknowledging that linking specific artworks to individual artists remains highly unlikely due to contamination and transfer risks.