Biologists at the University of California, Berkeley collected fruits eaten and discarded by koats, and took urine samples, and found that monkeys are actively looking for fruits that are so overripe that the sugars in them have fermented and formed ethanol.Discuss
Robert Dudley, a biologist who has studied humans' love of alcohol for the past 25 years, and in 2014 wrote a book suggesting it started in our monkey ancestors , who found that the smell of alcohol indicates the ripeness of fruit. and expands our understanding of how the love of alcohol first formed in the human brain.
Ateles geoffroyi's Koata was at the center of the new study. Biologists have found that the concentration of alcohol in the fruits eaten by primates ranged from 1% to 2%. Alcohol is a natural fermentation by-product of yeast that feeds on the sugar in ripening fruit.
What's more, the researchers collected the urine of these monkeys and found that the urine contained secondary metabolites of alcohol. This result shows that the animals did indeed use alcohol for energy – it didn't just pass through their bodies.