Hominids adapted to metabolize ethanol long before human-directed fermentation.

Bibliographic Collection: 
Publication Type: Journal Article
Authors: Carrigan, Matthew A; Uryasev, Oleg; Frye, Carole B; Eckman, Blair L; Myers, Candace R; Hurley, Thomas D; Benner, Steven A
Year of Publication: 2015
Journal: Proc Natl Acad Sci U S A
Volume: 112
Issue: 2
Pagination: 458-63
Date Published: 2015 Jan 13
Publication Language: eng
ISSN: 1091-6490
Keywords: Adaptation, Physiological, Alcohol Dehydrogenase, Amino Acid Sequence, Animals, Diet, Ethanol, Evolution, Molecular, Fermentation, Fruit, Genetic Variation, Hominidae, Humans, Kinetics, Molecular Sequence Data, Phylogeny, Primates, Sequence Homology, Amino Acid

Paleogenetics is an emerging field that resurrects ancestral proteins from now-extinct organisms to test, in the laboratory, models of protein function based on natural history and Darwinian evolution. Here, we resurrect digestive alcohol dehydrogenases (ADH4) from our primate ancestors to explore the history of primate-ethanol interactions. The evolving catalytic properties of these resurrected enzymes show that our ape ancestors gained a digestive dehydrogenase enzyme capable of metabolizing ethanol near the time that they began using the forest floor, about 10 million y ago. The ADH4 enzyme in our more ancient and arboreal ancestors did not efficiently oxidize ethanol. This change suggests that exposure to dietary sources of ethanol increased in hominids during the early stages of our adaptation to a terrestrial lifestyle. Because fruit collected from the forest floor is expected to contain higher concentrations of fermenting yeast and ethanol than similar fruits hanging on trees, this transition may also be the first time our ancestors were exposed to (and adapted to) substantial amounts of dietary ethanol.

DOI: 10.1073/pnas.1404167111
Alternate Journal: Proc. Natl. Acad. Sci. U.S.A.