How’s the head? Hope you didn’t use the Festival of Mammon to hit the electric sauce too hard.
Our ability to process the ethanol present in alcohol (at least, in moderation!) has been regarded as a relatively recent evolutionary characteristic of Homo sapiens. After all, the first evidence that man knew how to brew alcohol – clay pots found in the Neolithic village of Jiahu in China contained residues of tartaric acid, one of the main acids present in wine – dates back to as recently as around 9,000 years ago. We owe a lot to those Neolithic farmers who made the happy discovery that a mixture of fruit and honey could make an intoxicating beverage. Without the exposure to liquids containing more ethanol than would be found in fruit our bodies wouldn’t need to produce an enzyme to break it down.
However, scientists from Santa Fe College investigating the evolutionary history of ADH4, the gene which produces an enzyme to break down the alcohol in our bodies, say that it has been present for the last 10 million years.
Taking data from 28 different mammals, including 17 primates, to track the gene’s evolutionary history they believe that the defining moment was when primates started to leave the trees and walk on two legs. Down on the forest floor they would find mushy, fermented fruit lying on the forest floor. Such fruit would contain higher concentrations of fermenting yeast and ethanol than similar fruits hanging on the branches. And so the bodies of the primates over time adapted to be able to process the ethanol present. It was this which morphed into the rather handy gene, ADH4, which allows us to break down alcohol.
It also probably explains why the tree-dwelling orang-utan is still unable to metabolise alcohol – a handy thing to know if you get the opportunity to share a bottle of wine with you – whereas chimpanzees and gorillas can.
If you believe some archaeologists, then Neolithic life was a bit of a blast. Some, like Patrick McGovern of the University of Pennsylvania, claim that prehistoric communities grew wheat, rice, corn, barley and millet primarily to produce alcoholic beverages, supplanting their diet with a swill which was half-fruit, half-wine. Seems as though we have missed out somewhere along the line!