A group of wild chimpanzees getting drunk on palm wine are helping scientists understand more about evolution.
Chimps in Guinea, west Africa, discovered they could extract alcohol – ranging in strength from 3.1 per cent to 6.9 per cent - from raffia palms that had been tapped by people. They used leaf sponges to get the drink - and treated themselves to several sessions on the sauce.
Scientists watched more than 20 “drinking sessions involving 13 adult and immature individuals” - both male and female – and found that “some of the chimpanzees at Bossou consumed significant quantities of ethanol and displayed behavioural signs of inebriation”.
In some cases, an individual chimp was observed drinking the equivalent of a bottle of wine in one sitting.
The paper adds: “We observed individuals repeatedly consuming fermented palm sap - often in large quantities - suggesting that accidental ethanol ingestion is unlikely.”
Sure, some of them may have passed out (or, as the scientists say, “rested directly after imbibing fermented sap”) but according to the research, published in the journal Royal Society Open Science, they are also making a valuable contribution to our understanding of life on the planet.
The “drunken monkey” hypothesis argues that natural selection worked for primates who were attracted to alcohol because it was associated with “proximate benefits” such as making them more hungry, Increasing the amount they ate meant they were more likely to survive.
There is no word on whether they were gorging on pizza and fizzy pop in a vain attempt to combat a hangover the next day, though.
Still the next time someone tells you off after you've had a few, you can tell them you're just doing your bit for science. And also, just possibly, you're more evolved.