Some of the oldest cave paintings in the world have revealed how the ancients had relatively advanced knowledge of astronomy.
The works of art, in places throughout Europe, are not simply representations of wild animals, as previously thought. Instead, animal symbols represent constellations of stars in the night sky, and are used to represent dates and mark events such as comet attacks, the analysis suggests.
They reveal that, perhaps 40,000 years ago, humans followed the notion of time using knowledge of how the position of the stars changes slowly over thousands of years.
The findings suggest that ancient people understood an effect caused by the gradual change of the axis of rotation of the Earth. The discovery of this phenomenon, called precession of the equinoxes, was previously credited to the ancient Greeks.
Around the time the Neanderthals became extinct, and perhaps before humanity settled in Western Europe, people could define dates within 250 years, according to the study.
The findings indicate that the astronomical knowledge of ancient people was much greater than previously believed. Their knowledge may have aided navigation in the open sea, with implications for our understanding of prehistoric human migration.
Researchers from the Universities of Edinburgh and Kent studied details of Palaeolithic and Neolithic art with animal symbols on sites in Turkey, Spain, France and Germany.
They discovered that all sites used the same method of maintaining the date based on sophisticated astronomy, even though art was separated in time by tens of thousands of years.
Researchers clarified previous findings from a study of stone carvings at one of these sites, Gobekli Tepe in modern-day Turkey, which is interpreted as a memorial to a devastating comet attack around 11,000 BC. It was thought that this strike had started a mini ice age known as the Younger Dryas period.
They also decoded what is probably the best-known ancient work of art: the Lascaux Shaft scene in France. The work, which features a dying man and several animals, can commemorate another comet attack around 15,200 BC, the researchers suggest.
The team confirmed their findings by comparing the antiquity of many examples of rock art, known for the chemical dating of the paintings used, with the positions of stars in antiquity, as predicted by sophisticated software.
The oldest sculpture in the world, the Lion Man of the Hohlenstein-Stadel Cave, from 38,000 BC, was also found to fit this ancient system of timing.
This study was published in History journal of Athens.
Dr. Martin Sweatman, from the School of Engineering at the University of Edinburgh, who led the study, said: "Cave art shows that people had advanced knowledge of the night sky in the last ice age. They were not different for us today.
"These findings support a theory of the multiple impacts of comets in the course of human development, and will likely revolutionize the way prehistoric populations are viewed."