Alcohol was thought to have been first brewed by Neolithic farmers around 9,000 years ago when northern Chinese villagers made the happy discovery that fruit and honey could be fermented into an intoxicating liquor.
But new evidence suggests our ancestors had become accustomed to drinking nearly 10 million years before.
Scientists now believe that when primates left the trees and began walking on two feet they also started scooping up mushy, fermented fruit which was lying on the ground. And over time their bodies learned to process the ethanol present.
Experts at Santa Fe College in the US studied the gene ADH4 which produces an enzyme to break down alcohol in the body.
It was hypothesised that the enzyme would not appear until the first alcohol was produced by early farmers. But scientists were amazed to find it 10 million years earlier, at the end of the Miocene epoch.
The findings could explain why tree-dwelling orang-utans still cannot metabolize alcohol while humans, chimps and gorillas can.
“This transition implies the genomes of modern human, chimpanzee and gorilla began adapting at least 10 million years ago to dietary ethanol present in fermenting fruit,” said Professor Matthew Carrigan, of Santa Fe College.
“This conclusion contrasts with the relatively short amount of time – about 9,000 years – since fermentative technology enabled humans to consume beverages with higher ethanol content than fruit fermenting in the wild.
“Our ape ancestors gained a digestive enzyme capable of metabolizing ethanol near the time they began using the forest floor about 10 million years ago.
“Because fruit collected from the forest floor is expected to contain higher concentrations of fermenting yeast and ethanol than similar fruits hanging on trees this transition may also be the first time our ancestors were exposed to – and adapted to – substantial amounts of dietary ethanol.”
Any primates unable to digest the fermented fruits would have died before passing on their genes, but those who could would have passed the drinking gene on to their offspring.
The evolutionary history of the ADH4 gene was reconstructed using data from 28 different mammals, including 17 primates, collected from public databases or well-preserved tissue samples.
The first evidence of man making alcohol comes from the Neolithic village Jiahu in China where clay pots were found containing residues of tartaric acid, one of the main acids present in wine.
Some archaeologists have suggested that the entire Neolithic Revolution, which began about 11,000 years ago, was fuelled by the quest for by drinking and intoxication.
Archaeologist Patrick McGovern of the University of Pennsylvania claims that prehistoric communities cultivated wheat, rice, corn, barley, and millet primarily for the purpose of producing alcoholic beverages.
He believes that early farmers supplanted their diet with a nutritious hybrid swill which was half fruit and half wine.
This article was originally written by Sarah Knapton for The Telegraph.