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Ability To Consume Alcohol May Have Shaped Human Evolution
sciencehabit writes Craving a stiff drink after the holiday weekend? Your desire to consume alcohol, as well as your body's ability to break down the ethanol that makes you tipsy, dates back about 10 million years, researchers have discovered. The new finding not only helps shed light on the behavior of our primate ancestors, but also might explain why alcoholism—or even the craving for a single drink—exists in the first place.
You don't need to cook when everything is pickled.
You speak as though 'selective breeding' is some sort of conscious thing where you do the selecting. Evolution has its own ideas (metaphorically - I'm not getting all teleological on you). But seriously, selectively breeding for what? Things change, selective pressures change, what's adaptive in your eyes might not be in the long run. Keep throwing the dice! ;-)
That's just due to the dilemma set up in our brains every time we try to cook: Do we cook the potato, or turn it into vodka and drink it? Do I make this wheat into bread, or beer? Add this barley to soup, or make whiskey?
Not a sentence!
Anyone who has woken up next to someone they hooked up with while drunk can tell you that alcohol completely undermines selective breeding.
Funny -- TFA actually argues that "being a cheap date" was a disadvantage and selected against:
"If you were the ancestor without this new mutation in ADH4 [to metabolize alcohol], the ethanol would quickly build up in your blood and you'd get inebriated much faster," Carrigan says. "You'd be a cheap date." This easy inebriation, he says, would have been a disadvantage to the monkeys without the mutation, making them more easily get sickâ"or drunkâ"off fruit, enough so that they couldn't defend their territory and seek out food. Primates with the new mutation could get more food, his group hypothesizes, and the gene was selected for in the human and chimpanzee lineage.
But then the next paragraph makes a 180-degree turn and claims that alcoholism evolved to be associated with pleasure because, I guess, being drunk is fun (and, apparently, tasty). So, apparently "being a cheap date" is also something that is selected FOR in evolution, or alcoholism doesn't evolve, accroding to TFA:
Carrigan says the discovery might explain why human brains evolved to link pleasure pathways with alcohol consumptionâ"ethanol was associated with a key food source. "It's not a whole lot different from the addictions some people have towards food," he explains. "At the right dose, when you didn't have alcohol and candy at every corner, it was hard to get too much of this sort of stuff, so when you found it, you wanted to be programmed to overconsume."
Argh. Wasn't it just yesterday that I was complaining about evolutionary biologists making up random "just-so" stories that conveniently show how anything could evolve?
In TFA, wanting to get drunk is bad for natural selection, until it's good for natural selection... in the freakin' next paragraph. Really, guys?
Obviously those who are able to process alcohol will get the biggest evolutionary advantage from eating food with it (as you say), but how does that lead to alcoholism unless you begin to select for people who can't control their alcohol intake and drink to excess (which is the opposite trend)?
Alcoholism isn't getting drunk easily, it's not being able to control your intake.
The article argues that alcohol tolerance made more food sources available. If this food was scarce but beneficial, a genetic craving for it would provide an advantage. It only turns into alcoholism when the source is no longer scarce, which is a (evolutionarily speaking) recent thing.
William of Ockham had no beard. The most likely explanation is that it was chewed off by squirrels every morning.