In a new book, scientists claimed that alcohol tolerance saved the early ancestors of humans from going extinct. The book also indicated that although alcoholism is viewed as a social problem, it has played a huge role in the evolution of human culture.

The book, titled “Alcohol and Humans: A Long and Social Affair,” was written by Kimberly Hockings of the University of Exeter and Robin Dunbar of the University of Oxford. It was published by the Oxford University Press on Dec. 5.

In one of the chapters of the book, the authors discussed how evolving to withstand the effects of alcohol on the body prevented apes, which are the early ancestors of humans, from going extinct. Hockings, a lecturer in conservation science, and Dunbar, who is a professor of evolutionary psychology explained, that around 10 million years ago, ape populations were declining due to the growing number of monkey species.

Since apes struggled to eat unripe fruits, they were losing to other monkey species that could. This caused apes to consume fruits that have already fallen on the ground. Many of these overripe fruits have already gone through fermentation process and became alcoholic.

According to Hockings and Dunbar, the apes that were able to consume the fermented fruit went through genetic adaptation that allowed their bodies to successfully endure and process alcohol. The authors noted that this evolutionary process became a turning point in saving the apes from extinction as it provided them with a new food source.

Since monkeys cannot tolerate the ethanol found in overripe fruits, the ape population was able to bounce back.

“Even today we see great apes eating fermented fruit and even drinking palm wine produced by humans,” Hockings said in a press release. “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 1-4% – something like weak beer – yet much of the alcohol consumed by humans today is far stronger than this,” he continued.

This is a representational image of a mug of beer. Pixabay