From the February 2017 issue of National Geographic:
The story of humanity’s love affair with alcohol goes back to a time before farming—to a time before humans, in fact. Our taste for tipple may be a hardwired evolutionary trait that distinguishes us from most other animals.
The active ingredient common to all alcoholic beverages is made by yeasts: microscopic, single-celled organisms that eat sugar and excrete carbon dioxide and ethanol, the only potable alcohol. That’s a form of fermentation. Most modern makers of beer, wine, or sake use cultivated varieties of a single yeast genus called Saccharomyces (the most common is S. cerevisiae, from the Latin word for “beer,” cerevisia). But yeasts are diverse and ubiquitous, and they’ve likely been fermenting ripe wild fruit for about 120 million years, ever since the first fruits appeared on Earth.
From our modern point of view, ethanol has one very compelling property: It makes us feel good. Ethanol helps release serotonin, dopamine, and endorphins in the brain, chemicals that make us happy and less anxious.
To our fruit-eating primate ancestors swinging through the trees, however, the ethanol in rotting fruit would have had three other appealing characteristics. First, it has a strong, distinctive smell that makes the fruit easy to locate. Second, it’s easier to digest, allowing animals to get more of a commodity that was precious back then: calories. Third, its antiseptic qualities repel microbes that might sicken a primate. Millions of years ago one of them developed a taste for fruit that had fallen from the tree. “Our ape ancestors started eating fermented fruits on the forest floor, and that made all the difference,” says Nathaniel Dominy, a biological anthropologist at Dartmouth College. “We’re preadapted for consuming alcohol.”