8/23/2007

TIME TO RETHINK ABIOGENESIS?

Abiogenesis, the question of how life began, is distinct from the domain of TENS (the Theory of Evolution by Natural Selection). The latter is interested in the question of how life diversified after it got started, and quite a few sincere laymen have been non-plussed to learn that they are not only kicking a dead horse----they're kicking the wrong dead horse. This confusion has led more than a few of them to conclude (incorrectly, but understandably) that those of us who defend evolution education are performing some kind of 'bait-and-switch'.

At any rate, abiogenesis is not only not a distinct question, it differs in status from TENS. As its full name suggests, TENS is a theory: it is a widely-accepted, well-tested model that has significant predictive and explanatory power, feeding a number of different productive research programs.

Abiogenesis scenarios, meanwhile, do not rise to that status. At best abiogenesis is a hypothesis, which as a premise is consonant with, but not essential to, TENS. In the popular mind it is forever associated with a fifty-year old research program (the Urey-Miller experiments) that, skillful creationists argue, is invalidated by the revelation that this program often relied upon simulations of Earth's early atmosphere that are now known to be inaccurate.

Robert Shapiro argues, therefore, that it is time for a new paradigm. Whether he is right or not, this is a good demonstration that science as practiced is a pretty brutal competition of ideas, not an exercise in 'Aristotle says...'. Please note that both models Shapiro discusses are entirely natural---and consistent with TENS. And yet, no doubt, some quote-miner will descend upon the SciAm article as offering support for creationism.

2 comments:

Anonymous said...

In the popular mind it is forever associated with a fifty-year old research program (the Urey-Miller experiments) that, skillful creationists argue, is invalidated by the revelation that this program often relied upon simulations of Earth's early atmosphere that are now known to be inaccurate.

I don't think that should invalidate the hypothesis. Just because they don't know exactly what the conditions were, or the exact mechanism by which life first arose, doesn't invalidate the general theory that it arose from materials and conditions already present on earth.

I mean, all of our observations in the present verify that all life now arises from "naturally occurring" conditions. It should not be necessary for experimental abiogenesis to actually show how life arose, but simply to show that it could have arisen.

People who criticize this don't really understand science; they are infatuated with the idea that everything must be "actually true" in order to be accepted as true.

--emerod

Scott Hatfield . . . said...

I don't think it invalidates the hypothesis either. The 'skillful creationist' often omits the fact that simulations with different atmospheric compositions yield comparable results.

It should not be necessary for experimental abiogenesis to actually show how life arose, but simply to show that it could have arisen.

For the purposes of doing science, I agree. I am much impressed with Jack Szostak's research along these lines. However, I think that even if we do succeed in creating life through a series of steps arguably permitted by past circumstances, creationists will still argue that this will be no proof it happened that way. They will probably claim that, sure, we created something alive, but how do we know it's got the 'staying power' of the 'real thing?' So I despair, privately, of any research program overthrowing that sort of mindset. The kind of arguments I make can only work with rational people whose skepticism is based on honest doubt.