22-May-2007 (Tue)
Wherein we toast chromosome four.

I just finished reading The Ghost Map, a book about London's 1854 cholera epidemic. It's really fascinating. Anyway, I thought you folks might be interested in this bit on how booze made cities possible. He says:

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."

21 Responses:

  1. strangehours says:

    Brief perusal of this paper (sorry, you won't be able to get the full text) suggests that the ADH locus is under purifying selection in primates, and isn't showing any signs of selective pressure in humans.

    If you were going to spin the role of alcohol in the birth of civilization, the best place to start would be its impact on sociability. I doubt that alcohol consumption, cholera and the end of the hunter gatherer lifestyle are linked. Cholera kills small children. Additionaly, the hunter gatherer lifestyle was well and truly gone by the time that cities were large enough to become reserviors of danitation related diseases. Finally, alcohol doesn't protect puppies from cholera.

    • jwz says:

      In the 1854 epidemic, cholera was killing adults within 12 hours of infection. Don't eat poop!

    • error27 says:

      Regular diarrhea kills children but cholera is one of the fastest killing diseases there are. You can lose up to a fifth of your body weight in hours. You need to be guzzling that glucose drink or you'll get behind.

    • lherrera says:

      Why do you talk like you know what you are talking about?

      • strangehours says:

        Perhaps it's because I'm doing a bioinformatics PhD studying the evolution of malaria, so I think a lot about these types of things? There's no evidence to back up the hypothesis presented and to my mind there are a lot of reasons to think that it's unlikely a priori.

  2. seems like i will have to pick up this book. did you get it local or online?

  3. anti_tim says:

    so your drinks are strong for my health? Awesome! and thanks!!

  4. kehoea says:

    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.

    Bollocks. East and South Asians have been living in cities for millennia, and they have terrible tolerance for alcohol. See also the Muslim world.

    • sclatter says:

      They solved the same problem by drinking tea. Boiling the water for the tea kills pathogens.

      No urban society the world over has had a habit of drinking straight water.

      • kehoea says:

        I did no such thing. Please examine the paragraph I quoted.

        • sclatter says:

          No one could afford to drink water.

          There were primary two adaptations. One was to drink beer. One was to drink tea.

          Those who adapted by drinking beer evolved to be suited to drink beer.

          Those who drank tea (eg, most Asians) needed no adaptation to drink beer, thus continue to have crappy alcohol tolerance to this day.

          If you are quibbling with the assertion that "most" people evolved from beer drinkers as opposed to tea drinkers, I grant that that is probably untrue. It's a western-centric mindset error.

    • greyface says:

      If you think that East Asians have poor tolerance for alcohol, I heartily encourage you to go drinking with the North Chinese... under their drinking rules. You'll either have a really good time, or you'll recognize your mistake while throwing up in a toilet (depending on your personal alcohol tolerance).

      Also, don't under-estimate the value of exaggerated displays of drunkenness in socially repressive modern societies. As soon as their color changes (and that happens awfully fast for most East Asians), they have an excuse with an "any activity" adapter.

      • kehoea says:

        Pukey Asian night was mostly bulmic North Chinese, then, yeah?

        And I don't underestimate the value of exaggerated displays of drunkeness in, say, Japan; but I think the reactions of people from that part of the world in cultures where holding one's drink is important, are also worthwhile data in working out how we're all put together. And those reactions are not particularly comparable, IM (perhaps limited) E.

        But yeah, tea, awesomeness. And I suppose coffee for the historical Muslim world.

        • jwz says:

          You realize "the Muslim world" is only a bit over a thousand years old, right?

          • kehoea says:

            I do.

            Historically, most of the European population was engaged in agriculture, as was true of everywhere else. The cities, throughout the Dark and Middle ages, had declining populations, and you had comical things like sending people to St. Kilda, one of the more remote and backward Scottish islands, for the sake of their health. It’s only been a few hundred years, if that, that the West has been predominantly urban.

            The Muslim world managed water supplies and living in cities a bit better, in the same period; cf. the Qanats and that the medieval irrigation systems in Sicily and Andalusia were of Moorish construction. But I’m sure Istanbul and Baghdad nonetheless needed its citizens to drink sterilised water, of whatever form, to be sustainable.

            • edouardp says:

              Historically, no-one anywhere drank sterilized water, because the notion of invisible organisms causing disease is less than 150 years old. They tried to drink "clean" water, which meant wells or aqueducts from distant rivers, or whatever. But they didn't drink sterilized water, because they had no notion of what "sterile" was.

  5. omni_ferret says:

    That was a cool book. I picked it up at his Long Now talk recently, but I got there late...

    Hm. Here's a broad but relevant page, with a summary & audio.