Thursday, April 17, 2008

The Question Deserves an Answer

As I’m watching The Daily Show and The Colbert Report, there are seemingly endless commercials for Ben Stein’s creationist movie, Expelled. In the commercial, Stein is a student in a classroom where his instructor tells the students that evolution is unguided and undesigned. “How did life begin in the first place, dude?” Stein whines in his trademark monotone. This question is supposed to be terrifying to his professor--so terrifying that Stein is, you know, expelled.

It’s not like we have no idea. There are many competing hypotheses that attempt to explain the origin of life. Although scientists don’t necessarily agree on what it means to be alive, there is agreement that living organisms arose from non-living material in a long, slow process—there was no single moment when the first cell “sprang to life.” Hypotheses about the origin of life, collectively called abiogenesis, differ on which component of living cells arose first. Some postulate that some sort of cellular membrane had to arise first. Others suggest that self-replicating genetic molecules must have formed as the initial step toward life. One of the most widely cited hypotheses is the RNA-world idea, which says that short segments of RNA similar to modern ribozymes were the first components of cells to arise. Ribozymes are bits of RNA that are just large enough to self-replicate and to catalyze simple metabolic reactions. Another category of abiogenesis hypothesis proposes that simple metabolic pathways were the first step toward life. One particularly attractive hypothesis suggests that the reverse citric acid cycle was the original metabolic pathway and would have used ambient energy, perhaps from volcanic vents, to assemble the organic chemicals needed for life to begin.

The short answer to Stein’s question is that we don’t know how life began. However, this doesn’t mean that a supernatural explanation is necessary. The question of the origin of life is not scary to real scientists. The “intelligent design” idea that Stein endorses answers every question with “God did it.” From a scientific point of view, this is no answer at all.


Powerfunk said...

Absolutely! Stein is so dazzlingly smug in the previews; it's such a turnoff. What's Stein saying? Because we don't know EVERYTHING about the universe that it was OBVIOUSLY created by a god? I don't have a problem with people believing in creationism, but Stein's attitude and argument are absurd.

Kevin Clark said...

Although it's a matter of faith to say that since we don't know how something happened, it must be a direct act of God, isn't it also a matter of faith to say that no physical phenonenon is an act of God? The conviction that all phenomena are explainable through science is a philosophical worldview, and not a scientific principle.

Keifus said...

Rather convenient isn't it Kevin, to keep shuttling God into those undiscovered margins? May He can fit still into those places that are unknowable, as opposed, maybe to just unknown, but at the same time, it seems to circumscribe Him. (I admit that's how I like to conceptualize the universe when I'm in such a mood.) And I'd make a statement of principle that even if some things are unknown, or appear unknowable, we should probably keep trying to figure them out anyway. Saying "God did it" is something of an intellectual conversation-killer.

Arch, that's an interesting summary of abiogenesis. I've only (with the exception of panspermia, which I have no idea if people take seriously) heard of it quickly and in a really vague handwaving fashion ("first, there were biomolecules," that sort of thing). An "RNA world" tickles my fancy--probably a function of my ignorance.

Archaeopteryx said...

Kev--you're right, that would be a matter of faith, but that's not what I'm saying, and not what most scientists would say. Even Dawkins said on the Bill Maher show the other day that science couldn't disprove the existance of God. But like Keifus points out, science grinds to a halt if we decide that some phenomena are inexplicable, and we don't really have much in the way of experience that would lead us to believe that any observable phenomena can't be explained.

Keifus--The RNA world hypothesis has a lot of supporters in the abiogenesis community. My own personal favorite is the reverse-Krebs-cycle idea. Not for any reason--I certainly don't have any special knowledge about any of the hypotheses. I just think it's cool.

Powerfunk--welcome to the site and thanks for commenting.

steve said...

Stein is an idiot, period. Can't stand this smug, know-it-all. How he gets his mug on CBS Sunday Morning, and whatnot is beyond me.