Adnkronos Milan, April 23 (Adnkronos Salute) – They are sitting in a circle, like three old friends, in the center a shared 'African breadfruit'. The stolen shot does not portray humans, but chimpanzees. And what they are sharing is not a cocktail, but something very similar. The 'gossip' – actually a very scientific piece of news – is that even anthropomorphic primates 'drink', or rather consume alcohol, in company.
The chimpanzees in the photo – caught for the first time in this way – are sharing 'alcoholic' fruit, specifically a fermented African breadfruit. The 'scoop' comes from a research team led by the University of Exeter, who installed cameras in the Cantanhez National Park in Guinea-Bissau.
Footage of chimpanzees sharing fermented African breadfruit, which has been confirmed to contain ethanol (alcohol), raises intriguing questions about whether they deliberately seek out alcohol and why they do so, say the authors of the paper published in Current Biology.
Humans are thought to have been consuming alcohol since early in our evolutionary history, with beneficial effects on social bonds. The new study suggests our closest relatives may be doing something similar. "We know that in humans, drinking alcohol releases dopamine and endorphins, which lead to feelings of happiness and relaxation," says Anna Bowland, from the Centre for Ecology and Conservation at Penryn Campus in Exeter, Cornwall. "We also know that sharing alcohol, including through traditions such as feasting and revelry, helps form and strengthen social bonds. So now that we know that wild chimpanzees eat and share fruits containing ethanol, the question is: could they get similar benefits?"
The researchers used motion-activated cameras to film the chimps sharing the fermented fruit on 10 separate occasions. This fruit was analysed for alcohol content. The highest level found was 0,61% ABV (Alcohol By Volume, a measurement used in alcoholic beverages), a relatively low percentage. But the researchers say this could just be the 'tip of the iceberg', as 60-85% of the chimps' diet is made up of fruit, so low levels of alcohol in various foods could translate into significant consumption. The researchers stress that it is unlikely that the chimps would get 'drunk', as this would clearly not improve their chances of survival.
The impact of alcohol on chimpanzee metabolism is unknown, experts say. However, recent discoveries of a molecular adaptation that significantly increased ethanol metabolism in the common ancestor of African apes suggest that fermented fruit consumption may have ancient origins in species such as humans and chimpanzees.
"Chimpanzees don't share food all the time, so this fermented fruit behavior could be important," says Kimberley Hockings, University of Exeter. "We need to find out more about whether they deliberately seek out ethanolic fruits and how they metabolize them, but this behavior could be an early evolutionary stage of 'feasting'. If so, she concludes, it suggests that the human tradition of social feasting may have roots very deep in our evolutionary history."