Saturday, March 24, 2007

Questions of Scale and the Uncertain Origins of Life

by Tom Bozzo

Someone left last month's Wired at the gym, in which a variety of scientists and science journalists took on Big Unanswered Questions. Then there was Gregg Easterbrook, assigned to the question, "Where did life come from?" His review of the classic abiogenesis experiments starts off almost as if he doesn't have an ax to grind:
Famously, in 1952 Harold Urey and Stanley Miller mixed the elements thought to exist in Earth’s primordial atmosphere, exposed them to electricity to simulate lightning, and found that amino acids self-assembled in the researchers’ test tubes. Amino acids are essential to life. [Link in original.]
You might think, hey, that's pretty cool! And pretty neutral so far, even if he doesn't mention that followers-on have managed to synthesize all the protein-forming amino acids in the lab. But pretty soon, Easterbrook is reminding us what those smarty-pants scientists didn't do, as if he were writing a Conservapedia entry with slightly above-average balance:
[Easterbrook, continuing directly:] But the ones in the 1952 experiment did not come to life. Building-block compounds have been shown to result from many natural processes; they even float in huge clouds in space. But no test has given any indication of how they begin to live - or how, in early tentative forms, they could have resisted being frozen or fried by Earth’s harsh prehistoric conditions.
The thing Easterbrook might have noted, in a universe where he wasn't a hack, is that the "natural experiment" on Earth played out on a vastly greater scale. I'm too lazy to look up how much primordial soup Urey, Miller, and other researchers in the area sought to make (*), but let's assume for a realistic figure something on the order of a cubic meter (perhaps a lot less — that's a thousand liters, after all), allowed to stew for a relatively short time — on the order of weeks or years at most. Earth's oceans, meanwhile, have a volume on the order of a billion (10^9) cubic kilometers, or about 10^18 cubic meters. So imagine a quintillion versions of these experiments running simultaneously and interacting with each other. Moreover, nature ran its "experiment" for hundreds of millions of years.

So, while it's technically conjecture to say so, if you can get some building blocks of life to self-assemble in a relatively limited experiment, it doesn't seem like a huge stretch of the imagination to think that scaling up the experiment by 20 or more orders of magnitude would get results that might actually impress an Easterbrook. Easterbrook, instead, chooses to preach to the Intelligent Design (sic) choir (**):
Did God or some other higher being create life? Did it begin on another world, to be transported later to ours? Until such time as a wholly natural origin of life is found, these questions have power. We’re improbable, we’re here, and we have no idea why. Or how.
The question of the nature of our origin is interesting, no doubt, but how does appeal to a designer help answer them? If you're going to push the 'why' question back beyond the ability of essential chemicals to form themselves, why shouldn't the action of the designer be subject to question?

Moreover, if Easterbrook and/or the ID'ers were in some ways correct, one might imagine they might be disappointed to discover that we're The Sims 25 running on a really big computer.

------------------------------------

More (3/26/07): PZ Myers picks up on the Poor Man Institute's take and links a useful review post from last year of a book that covers the actual science!

Ginger Yellow notes in the comments that it's "boneheaded" for Easterbrook to scratch his head over how early life can survive the harsh conditions of the primordial Earth one sentence after you've said that building-block compounds float around in space. Perhaps needless to say (though Easterbrook didn't say it), there are many critters adapted to environments that would be decidedly hazardous to human health, as well as polymers such as prions that are resistant to heat and/or radiation damage.

(*) Interested readers may consult the intertubes for additional information.

(**) Unusually abundant in the Wired readership?!

(Cross-posted at Total Drek.)

Labels: , , ,

Comments:
The thought that Wired paid Gregg Easterbrook for his opinion is scary enough.

Using the DeLong Standard, Wired will be lucky to last 15 years (which will still make them one of the last non-refereed print organs).
 
" So imagine a quintillion versions of these experiments running simultaneously and interacting with each other."

And with a vast variety of conditions of temperature, pressure, mineral balance, contact with atmosphere or substrate, etc, which would all vary with location.

But, no, a middlin' beaker failed to make life, so it must've been some cosmic spook.
 
In a manner Mr Easterbrook might understand, that's thought 1, opinion nil.
 
No, no, no, Peter - Easterbrook would never use the word "nil" in a sports article. He covers American football, and not the vastly superior form that is actually popular outside the US - the form in which the phrase "one-nil" is actually commonplace.

Not to mention the fact that 1-0 is an impossible score to get in an American football game (in fact, I think it's the *only* impossible score). The lowest possible score is actually 2-0.
 
I don't know much about football, but if 1-0 is an impossible score, wouldn't 2-1 be impossible too?
 
Post a Comment

<< Home

This page is powered by Blogger. Isn't yours?