Ben Bacon, a London-based furniture conservator, appears to have uncovered the reason for Ice Age hunter-gatherers drawing cave paintings.
The amateur archaeologist has analysed 20,000-year-old markings of the drawings, and came to the conclusion they were mapping a lunar calendar.
Bacon’s discovery led to a specialist team proving early Europeans would also make these notes referring to the timing of animals' reproductive cycles.
On realising what hunter-gatherers from tens of thousands of years had been communicating, Bacon remarked it felt “surreal”.
Paintings of animals such as reindeers, fish and cattle have been discovered in various caves around Europe.
Many of the depictions were accompanied by dots or marks on the paintings, but their meaning was unknown. Bacon became intrigued by this mystery and took on trying to decipher their meaning
He used the internet and the British Library to study cave paintings and “amassed as much data as possible and began looking for repeating patterns”.
Over time he focused on the 'Y' sign displayed on some cave paintings, which he started to consider as being a symbol for “giving birth” because it showed one line growing out from the others.
As his research deepened, he sought advice from friends and senior academics. They recognised the progress he appeared to be making and encouraged him to keep probing.
He combined his research with experts, which led to them working out birth cycles of similar present-day animals. They recognised that the number of marks on the cave paintings was a keeping record, by lunar month, of the animals' mating seasons. Their discovery was later published in the Cambridge Archeological Journal.
“The results show that Ice Age hunter-gatherers were the first to use a systemic calendar and marks to record information about major ecological events within that calendar,” said Prof Paul Pettitt of Durham University.
“In turn, we're able to show that these people, who left a legacy of spectacular art in the caves of Lascaux [in France] and Altamira [in Spain], also left a record of early timekeeping that would eventually become commonplace among our species,” Pettitt continued.
Bacon said that his findings brings to light how our European ancestors were “a lot more like us than we had previously thought. These people, separated from us by many millennia, are suddenly a lot closer”.