On the face of it, that human beings consume alcohol is bizarre. Alcohol is a dangerous chemical that makes us sick and can potentially poison us. It kills a shocking number of us every year. Yet we continue to hammer the booze, and it turns out, it might be a trait we evolved well before we became humans.
Scientists have known for a while that animals love getting tanked, but it wasn’t clear if it was an accident and they got drunk looking for food, something individual animals learned, or something with a genetic basis. So researchers at Dartmouth got two Daubentonia madagascariensis, better known as the aye-ayes, and partied it up by serving them nectar fermented to varying degrees. What they found wasn’t definitive, but it was definitely intriguing: The aye-ayes, and a slow loris involved in the study, could not only tell the difference in alcohol concentration between the different cups, they sought out the higher concentrations of alcohol. They even nudged at the cup when it was gone, indicating that they wanted more of the high-alcohol nectar.
The main question, of course, is what evolutionary advantage is conferred by getting hammered when you’re an animal that lives in a tree. So far, the best guess is that higher concentrations of alcohol indicate a higher concentration of calories, and the drawbacks of slurping up naturally fermented booze are outweighed by having those calories in your system. Or, you know, living in a tree with like 80 other primates makes you want to get drunk. Can you really blame them?