Alcohol tolerance may have saved humanity’s ancestors from extinction

5 December 2019, 04:13 | Updated: 5 December 2019, 04:16

A tolerance to alcohol may have saved our ancestors from extinction
A tolerance to alcohol may have saved our ancestors from extinction. Picture: PA
Nick Hardinges

By Nick Hardinges

Our ape ancestors may have been saved from extinction due to their ability to digest booze, scientists claim.

African apes who lived around 10 million years ago supposedly developed the ability to break down ethanol, the chemical compound found in alcohol.

Dr Kim Hockings and Dr Robin Dunbar say this characteristic helped them survive alongside other rival monkey species who preferred eating unripe, alcohol-free fruit that was still attached to plants.

In a newly-released book called Alcohol And Humans: A Long And Social Affair, the pair of professors explain that these ancient primates evolved to the point where they could metabolise fermented, overripe, boozy fruits.

Therefore, they did not have to compete with their unripe fruit-eating rivals, which would have helped keep extinction at bay.

Our early predecessors eventually evolved to become humans, chimps, bonobos and gorillas, all of which carry a protein that facilitates the processing of alcohol.

Our ancestors' ability to process fermented fruit prevented competition
Our ancestors' ability to process fermented fruit prevented competition. Picture: PA

Apes, much like humans, have trouble processing fruits that have not ripened, whereas monkeys struggle to tolerate the levels of ethanol in overripe fruits - a similar difference to that theorised by the two scientists.

They suggest this differing source of calories “might have brought apes back from the brink” of extinction.

Dr Hockings, a senior lecturer in conservation science at the University of Exeter, said: "Even today we see great apes eating fermented fruit and even drinking palm wine produced by humans.

"It's hard to be certain of why they do this, and this reflects the complex history of our own relationship with alcohol.

"One interesting point is that the alcohol level in fallen fruit is usually about one to four per cent - something like weak beer - yet much of the alcohol consumed by humans today is far stronger than this."

The research even suggests that alcoholism in humans may be more than just a medical issue and in fact may be part of the "social fabric of many human societies both past and present."

Dr Dunbar, a professor of evolutionary psychology at the University of Oxford, said: "Across cultures and in different time periods, it [alcohol] has consistently been a major part of the way humans socialise with each other.

"Increasingly, alcohol is viewed as a medical issue, but alcohol abuse is only a small part of a much wider social pattern of alcohol use by humans."