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.

Comments

Of course it did

[GrumpySteen]

Anyone who has woken up next to someone they hooked up with while drunk can tell you that alcohol completely undermines selective breeding.

Re:Of course it did

[sgage]

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! ;-)

Re:Of course it did

[AthanasiusKircher]

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?

Re:Of course it did

[jellomizer]

Your problem is you are missing the idea of balance.
If you get drunk too quickly, then you are open up to predation, or allowing the sick and weak to mate with you, creating weak and sick offspring.
However if you don't get enjoyment from the buzz, then you may starve due to not having a diverse food source.

Now balance isn't ying and yang or positive vs negative.
The function of benefit vs loss over consumption is not linear but much more complex.
Let's say the benefit of a buzz grows linerally, while the disadvantage grows exponetionally. You will be receiving a net benefit until you reach eqalibram. As there are point in a lineral function early on the exceed an exponential function.

Birds Get Drunk Too, and maybe the squirrels

[Gim Tom]

I read the article and while interesting it doesn't fully explain a phenomenon I have observed first hand for many years. I have two wild cherry trees on my property and sometimes the cherries remain on the tree long enough to begin fermenting. When this happens every bird for miles fights over the boozy cherries! The squirrels also seem to prefer these somewhat fermented cherries. Humans may have evolved a better way to metabolize ethanol, but I don't think we were the first creatures to appreciate a wee dram every now and then.

Re:Birds Get Drunk Too, and maybe the squirrels

[kwiecmmm]

Many animals have been known to get drunk. I once saw a nature special where a lot of African animals ate the fruit off a grove of trees and all got drunk. After this happened most of them passed out next to each other. So there was an awesome site of monkeys, zebras and lions all sleeping a few feet away from each other.

I think what the article is pointing out is that our ability to process more alcohol allowed us to eat more fruit without getting drunk, which allowed us to be more mobile and defend territory better while not getting drunk. It also probably helped us defend ourselves better against predators, than those that were drunk.