The search for unpolluted drinking water is as old as civilization
itself. As soon as there were mass human settlements, waterborne
diseases like dysentery became a crucial population bottleneck. For
much of human history, the solution to this chronic public-health
issue was not purifying the water supply. The solution was to drink
alcohol. In a community lacking pure-water supplies, the closest
thing to "pure" fluid was alcohol. Whatever health risks were posed
by beer (and later wine) in the early days of agrarian settlements
were more than offset by alcohol's antibacterial properties. Dying of
cirrhosis of the liver in your forties was better than dying of
dysentery in your twenties.
Many genetically minded historians believe that the confluence of
urban living and the discovery of alcohol created a massive selection
pressure on the genes of all humans who abandoned the hunter-gatherer
lifestyle. Alcohol, after all, is a deadly poison and notoriously
addictive. To digest large quantities of it, you need to be able to
boost production of enzymes called alcohol dehydrogenases, a trait
regulated by a set of genes on chromosome four in human DNA. Many
early agrarians lacked that trait, and thus were genetically
incapable of "holding their liquor". Consequently, many of them died
childless at an early age, either from alcohol abuse or from
waterborne diseases.
Over generations, the gene pool or the first farmers became
increasingly dominated by individuals who could drink beer on a
regular basis. Most of the world's population today is made up of
descendants of those early beer drinkers, and we have largely
inherited their genetic tolerance for alcohol. (The same is true of
lactose tolerance, which went from a rare genetic trait to the
mainstream among the descendants of the herders, thanks to the
domestication of livestock.)
The descendants of hunter-gatherers -- like many Native Americans
or Australian Aborigines -- were never forced through this genetic
bottleneck, and so today they show disproportionate rates of
alcoholism. The chronic drinking problem in Native American
populations has been blamed on everything from the weak "Indian
constitution" to the humiliating abuses of the U.S. reservation
system. But their alcohol intolerance most likely has another
explanation: their ancestors didn't live in towns.
Or, as W.C. Fields put it, "Water? Never touch the stuff.
Fish fuck in it."
