Primate frugivory and the "drunken monkey" hypothesis: Is alcoholism in modern humans an evolutionary hangover?

February 11, 2025 @ 12:00 pm to 01:00 pm

Robert Dudley, University of California, Berkeley

001 Chemical and Biomedical Engineering Building
University Park

Abstract:
Ethanol, as the preferred inebriant for much of the world’s human population, derives biotically from the fermentation by yeast of plant sugars. The association of yeasts with the fruits of flowering plants originated in the Cretaceous, and dietary exposure of diverse vertebrate taxa to ethanol within fruits is similarly ancient. Fruit-eating is ancestral in primates (originating ~56 Ma) and in hominids (~12 Ma), suggesting regular consumption of low-concentration ethanol within fruit pulp by primates, and also by our immediate ancestors during much of ape evolution. For all fruit-eaters, volatilized alcohols from fruit can serve in olfactory localization of transient nutritional resources, whereas ethanol consumed during the course of frugivory may act as an appetitive stimulant. Preference for and excessive consumption of alcohol by modern humans may accordingly derive from pre-existing sensory biases associating ethanol with nutritional reward (i.e., the "drunken monkey" hypothesis). The routine availability of high-concentration ethanol solutions is a recent phenomenon in human history, but is particularly effective in co-opting (at times maladaptively) these ancestral nutritional strategies of our frugivorous precursors.

About the Speaker:
Robert Dudley is a Professor in the Department of Integrative Biology at the University of California–Berkeley, and a Research Associate at the Smithsonian Tropical Research Institute in Panama. He received a B.S. in Zoology in 1983 from Duke University, and a Ph.D. in Zoology in 1987 from the University of Cambridge where he was a Marshall Scholar. From 1987–1992, Robert was a postdoctoral fellow with the Smithsonian Institution, working in Panama at the Barro Colorado Island field station. Following appointments at the University of Texas at Austin from 1992–2002, he moved to Berkeley in 2003 where he has held multiple endowed chairs, and also served from 2016–2021 as Chair of the Department of Integrative Biology. Robert's research is primarily concerned with the evolution, physiology, and biomechanics of flight in insects and hummingbirds. In addition, he has developed an evolutionary hypothesis to explain routine low-level as well as excessive consumption of alcohol by modern humans, as detailed in his 2014 book entitled "The Drunken Monkey: Why We Drink and Consume Alcohol".

Contact

Jean-Michel Mongeau
jmm1175@psu.edu