The Wolf Within. Professor Bryan Sykes

damp, ancient and strangely alive. One by one they carefully removed the small rocks surrounding the vent until they came to a narrow cleft through which the air was escaping. It was too narrow for any of them to squeeze through, so next day they returned with hammers and a small pneumatic drill and set to work widening the crack. They found themselves faced with a narrow shaft descending into the black depths. Being experienced, not to say fearless, potholers they squeezed through the gap until they reached a point where a gallery opened out in front of them. It was clear, only from inside, that the main cave entrance had been blocked by an ancient rock-fall and that they had somehow found their way into the main cavern through the roof.*

      As they explored the cave system over the following days the true wonder of their discovery began to dawn on them. Gleaming stalagmites rose up from the cave floor to meet their counterparts, delicate stalactites, suspended from the roof. Formed by the steady drip-drip-drip of calcium-rich water, their pristine condition showed that no animal or human had disturbed these hidden depths for thousands of years. On the floor lay scattered bones and skulls of cave bears petrified beneath a glassy coating of calcite.

      This image actually comes from an exact replica of Chauvet cave that opened in Vallon-Pont-d’Arc in 2012, as access to the ancient caves is severely restricted for the protection of the artwork. The replica art was created using the same tools and methods as it is believed were used by the original artists. (Getty/AFP/Staff)

      As Chauvet and his companions pushed further and further back along the galleries they saw in front of them the first of the paintings. Dozens of crude human hand prints outlined in red ochre covered one of the walls to a height of nearly two metres. These were only an introduction to the treasures which lay further back. There, on the deliberately smoothed cave walls, were drawn the images of lions, bears, mammoths, rhinoceros, horses and giant deer. These are the oldest morphologically accurate depictions anywhere in the world. What strikes home about them is their beauty. These are not merely crude outlines like the hand prints in the antechamber. They have form, expression and movement.

      A painting from Chauvet cave that shows the head and horns of two aurochs, an extinct form of wild cattle that would have been a key prey animal for both humans and wolves. (JAVIER TRUEBA/MSF/SCIENCE PHOTO LIBRARY)

      As well as being objects of wonder in themselves, these paintings have naturally led us to contemplate the reason they were drawn in the first place. What a task it must have been. Working deep underground without any natural light, the artists, for that is what they were, could only illuminate their lithic canvases by the light of glowing wooden torches. Streaks on the walls show where they had rubbed the dying embers to rejuvenate the flames. Carbon-dating the charcoal smeared on the walls was the means of discovering how long ago the drawings were made.

      All organic material contains carbon, and this can exist in two forms called isotopes. Carbon 14 is very slightly radioactive. The other isotope, carbon 12, is not. After an animal or plant dies, or is burned in the case of the wooden torches, the radioactive carbon 14 slowly decays with a half-life of almost 5,000 years. In other words after 5,000 years there is only half as much carbon 14 remaining. By comparing the content of the two isotopes using a mass spectrometer to count the atoms, the age of the specimen can be estimated. Atmospheric carbon 14 is generated by ionising radiation from the sun high up in the atmosphere, some 32 kilometres above the ground. The proportions of the two carbon isotopes in the atmosphere are more or less in equilibrium. Thus the ratio of the carbon isotopes in a freshly dead animal or plant is equal to the atmospheric ratio at the time.

      There are many factors that can change this ratio artificially and consequently introduce errors in dating. One is contamination of old material with modern carbon, for example from the archaeologists who recovered the specimen. This tends to make the material appear younger than it actually is. As is well known, carbon dioxide levels in the atmosphere have rocketed due to human activity since the Industrial Revolution. This carbon is ancient, coming as it does from the burning of fossil fuels that are millions of years old and no longer radioactive. This tends to reduce the carbon 14 in a specimen and artificially increase its apparent age. Nuclear testing also affects atmospheric carbon but in the opposite direction. Enormous amounts of carbon 14 are released into the atmosphere by a nuclear explosion, which in turn reduces the time estimate for radio-carbon dating. Nowadays these influences are incorporated into the calculations and the dates produced are referred to as ‘calibrated’. The original pioneers of radiocarbon dating did not take these influences sufficiently into consideration, and as a result many of the dates claimed in the earlier days of carbon-dating are wrong.

      Thankfully, Chauvet cave was not discovered until the modern era of calibrated radiocarbon dating, and the dates obtained from the charcoal and other organic material in the caves can be relied upon. They show that Chauvet cave has been used for at least 80,000 years, first by cave bears, the skulls and bones of which litter the cave floor, then by an assortment of more recent Upper Palaeolithic mammals including hyenas and a couple of wolves.

      There appear to have been two distinct phases of human ‘occupation’. The first was between 37,000 and 33,000 years ago and most of the drawings date to this phase. A later phase of occupation which produced the crude hand prints outlined in red ochre lasted from 31,000 to 28,000 years ago.

      Chauvet cave is one of a handful of decorated caves from this remarkable and crucial phase in human evolution, the others being Lascaux in the Dordogne region of south-west France and Altamira in Calabria, northern Spain. Unlike the other two, Chauvet is in pristine condition, never having been open to any but bona fide researchers under strict instructions not to disturb the cave in any way. Altamira and Lascaux were open to the public for many years before the damaging effects of exhaled moisture and carbon were fully appreciated. They are now effectively closed to prevent further damage, though visitors can enjoy the visual impact of the caves and their paintings in nearby reconstructions.

      In many people’s opinion the Upper Palaeolithic warrants comparison with other transformational periods in human cultural history: the rise of democracy in ancient Greece, the Italian Renaissance, the Age of Reason. So many new things were happening to the way we lived and most importantly to our interactions with the world around us. Many of these developments remain unseen and only reveal themselves in very special circumstances. Such a one is the discovery of Chauvet cave. There must be other caverns like it still sealed inside their limestone tombs, waiting for their breath to percolate to the outside. These caves give us rare glimpses into a vanished world, so very different from our own. Yet we see from the drawings that in many ways the artists were very much like ourselves. We understand the murals. Without difficulty we sense their beauty.

      There are no human remains in Chauvet cave and, other than the drawings, very little sign of human presence. Nobody lived in Chauvet. What then was the purpose of these drawings, made with such effort and such skill? Clearly they were not purely decorative in the way we might hang a favourite painting on the wall above the fireplace. Although we will never know for certain, to many eyes these beautiful drawings are a tangible expression of a world of imagination and spirituality that marked the rise of truly modern humans.

      An aspiration to go beyond what is absolutely necessary for function is also apparent in the stone tools our ancestors left behind. Whereas Neanderthals made perfectly functional tools like hand axes and thrusting spear points, they appear clumsy in comparison to the beautifully fashioned arrow points of the Upper Palaeolithic. The flint itself was traded over long distances and it supplied the raw material for individual craftsmen to demonstrate their skill. Fashioning a flint arrowhead or spear point was an opportunity not just to replace equipment lost in the hunt but also to demonstrate a high level of dexterity.

      Quite suddenly, archaeological sites of the period were flooded with personal adornments. Excavations in south-west France reveal the appearance of bracelets, pendants and beads exquisitely fashioned from bone, antler and ivory. Seashells from the Mediterranean are found in sites