The painted caves of southern France and northern Spain have been known to archaeology since the late nineteenth century, when the figures of Altamira were identified as genuinely prehistoric after decades of scepticism. What has changed in recent decades is less the basic inventory of sites - though some important caves, including Chauvet, were only discovered in 1994 - than the methods available for studying them. Laser scanning, portable spectroscopy and high-resolution photography have made it possible to examine the paintings in ways that were impossible for earlier generations of researchers.

The first and most striking result of these techniques has been a revision of the chronology. Early interpretations, relying on stylistic comparisons, assumed that the more detailed animal figures must be younger than the simpler outlines. Radiocarbon dating of the charcoal pigments used in many paintings has largely confirmed this order for some sites but overturned it for others. Chauvet, in particular, has been dated to around 36,000 years ago, making some of its sophisticated horse and lion paintings older than many simpler figures elsewhere. The implication - that advanced pictorial skill was available to artists at the very beginning of European painting, rather than emerging gradually over millennia - has required much of the old literature to be reconsidered.

The second revision concerns the authors. It was long assumed, largely without evidence, that cave painters were male. Recent work on the hand stencils that accompany many animal figures has challenged this assumption. Hand stencils are made by placing a hand against the wall and blowing pigment over it, producing a negative outline. Anthropologist Dr. Luisa Navarre, working with the University of Barcelona, measured the proportions of hundreds of hand stencils across several sites and compared them with a reference database of modern hands. She concluded that a majority of the stencils, at least in the caves she studied, were made by women. Her results have not been universally accepted, but they have broadened the discussion.

A third set of findings relates to the places within the caves that were chosen for painting. The great majority of images are not in the rooms closest to the entrance but in deep interior galleries, sometimes reachable only through narrow passages. Several researchers have linked this to acoustic properties. In 1988, the acoustician Iegor Reznikoff showed that at several French caves, the walls bearing images also happened to be those with the strongest resonant acoustic response, suggesting that the artists may have selected places where sound behaved in particular ways. Later work by Dr. Navarre's team has reinforced this pattern using more systematic measurements, though the interpretation of why resonance mattered remains speculative.

Meaning is the hardest question. The paintings are clearly not random; animals dominate, human figures are rare, and certain species - horses, bison, lions, rhinoceroses - appear repeatedly while others do not. Theories have ranged from hunting magic to shamanistic vision to social record-keeping. Each has proponents, and each struggles to account for all the evidence. The historian David Lewis-Williams has argued that the paintings reflect altered states of consciousness experienced during ritual, and has drawn parallels with the practices of modern hunter-gatherer societies. His interpretation is influential but contested, in part because its central comparison relies on communities that are geographically and culturally remote from prehistoric Europe.

Preservation itself has become a major concern. The opening of Lascaux to tourists in 1948 led, within fifteen years, to the growth of algae and moulds on the walls that seriously damaged the images. The cave was closed to the public in 1963, and a replica, Lascaux II, was built nearby in 1983 to allow viewing without further damage. Chauvet was never opened to the public; instead, an elaborate replica opened in 2015, and study of the original is restricted to small teams of researchers. Dr. Navarre has argued that replicas are not substitutes for the originals but are nonetheless the best way of sharing what the paintings offer, because the originals cannot survive sustained human presence.

The painted caves are therefore in several senses moving targets: targets whose dates and authorship are being revised as new techniques appear, and whose physical preservation depends on keeping most people away. What they show beyond doubt is that the visual imagination of our species was already highly developed tens of thousands of years before the appearance of writing, and that any history of human communication that begins with the invention of the alphabet starts very late in the story.