The Buzz About ‘Scrumping’: How Apes’ Love of Fallen Fruit May Explain Humanity’s Tolerance for Alcohol
A newly coined term, “scrumping,” is giving scientists a fresh lens through which to view the evolutionary origins of humanity’s unique relationship with alcohol. Researchers suggest that the habit of apes consuming fermented fruit fallen from trees may have driven genetic adaptations that allow humans to efficiently metabolize ethanol.
A Behavior Long Overlooked
For years, scientists have observed apes foraging for fruit on the forest floor, but the significance of this behavior wasn’t fully appreciated. As one researcher explained, “we never bothered to differentiate fruits in trees from fruits on the ground.” This distinction is crucial, as fallen fruit often undergoes fermentation, creating ethanol. The team, led by researchers at Dartmouth and the University of St Andrews in Scotland, argues that this previously undefined behavior – now termed “scrumping” – deserves a specific name to facilitate further study.
The word itself has historical roots, stemming from the medieval German “schrimpen,” meaning “shriveled” or “shrunken,” used to describe overripe fruit. Interestingly, “scrumpy” is also the name for a cloudy apple cider in England, containing between 6-9% alcohol by volume.
The Genetic Link to Alcohol Metabolism
A 2015 genetic study posited that consuming fermented fruit may have triggered a genetic mutation in the last common ancestor of humans and African apes, boosting their ability to process alcohol by a remarkable 40 times. However, until now, there was limited data to test this hypothesis. “It’s a fascinating idea, but nobody studying these ape species… had the data to test it,” a senior researcher noted.
To investigate, the team analyzed dietary reports of orangutans, chimpanzees, and gorillas, cross-referencing feeding events with the height of the fruit source. They found that African apes regularly engage in “scrumping,” while orangutans do not. This finding aligns with the 2015 gene-sequencing study, which indicated that orangutans have a less efficient enzyme for metabolizing ethanol.
Beyond Nutrition: The Evolutionary Advantages of Scrumping
The researchers propose that scrumping offered several evolutionary advantages to African apes. By consuming fermented fruit, they could avoid competition with monkeys for unripe fruit in the trees. Furthermore, foraging on the ground reduced the risk of dangerous falls associated with climbing. A 2023 study by the same research team confirmed that climbing poses a significant threat to ape physiology, potentially influencing human evolution.
The implications are significant. Given that chimpanzees consume approximately 10 pounds of fruit daily, the team estimates they ingest a substantial amount of alcohol. This chronic, low-level ethanol exposure may have been a key driver in the development of human alcohol tolerance. “Scrumping by the last common ancestor… about 10 million years ago could explain why humans are so astoundingly good at digesting alcohol,” one researcher stated. “We evolved to metabolize alcohol long before we ever figured out how to make it.”
The Social Side of Scrumping
The benefits of scrumping may extend beyond physiology. Researchers also suggest a potential link to the social aspects of human alcohol consumption. Catherine Hobaiter, a professor of psychology and neuroscience at St Andrews, explained, “A fundamental feature of our relationship with alcohol is our tendency to drink together.” The team plans to investigate whether shared feeding on fermented fruits influences social bonds in other apes.
A New Term for Scientific Discourse
The researchers hope that “scrumping” will gain traction within the scientific community, much like terms such as “symbiosis” (coined in 1877) and “meme” (introduced in 1976) have become integral to scientific discourse. “These are great examples of words that we never knew we needed, until we did,” a researcher commented. “If the term is useful, then it will catch on. That’s natural selection at work!”
The next step involves measuring fermentation levels in fruits both on the trees and on the ground to refine estimates of alcohol consumption in chimpanzees. This research promises to further illuminate the fascinating connection between our primate ancestors, fermented fruit, and humanity’s enduring relationship with alcohol.
