http://www.talkorigins.org/faqs/abioprob/abioprob.html#Intro
extract:
No matter whether the first self-replicators were single molecules, or complexes of small molecules, this model is nothing like Hoyle's "tornado in a junkyard making a 747". Just to hammer this home, here is a simple comparison of the theory criticised by creationists, and the actual theory of abiogenesis.
Note that the real theory has a number of small steps, and in fact I've left out some steps (especially between the hypercycle-protobiont stage) for simplicity. Each step is associated with a small increase in organisation and complexity, and the chemicals slowly climb towards organism-hood, rather than making one big leap [
4,
10,
15,
28].
Where the creationist idea that modern organisms form spontaneously comes from is not certain. The first modern abiogenesis formulation, the Oparin/Haldane hypothesis from the 20's, starts with simple proteins/proteinoids developing slowly into cells. Even the ideas circulating in the 1850's were not "spontaneous" theories. The nearest I can come to is
Lamarck's original ideas from 1803! [
8]
Given that the creationists are criticising a theory over 150 years out of date, and held by no modern evolutionary biologist, why go further? Because there are some fundamental problems in
statistics and
biochemistry that turn up in these mistaken "refutations".
Conclusions
The very premise of creationists' probability calculations is incorrect in the first place as it aims at the wrong theory. Furthermore, this argument is often buttressed with statistical and biological fallacies.
At the moment, since we have no idea how probable life is, it's virtually impossible to assign any meaningful probabilities to any of the steps to life except the first two (monomers to polymers p=1.0, formation of catalytic polymers p=1.0). For the replicating polymers to hypercycle transition, the probability may well be 1.0 if
Kauffman is right about catalytic closure and his phase transition
models, but this requires real chemistry and more detailed modelling to confirm. For the hypercycle->protobiont transition, the probability here is dependent on theoretical concepts still being developed, and is unknown.
However, in the end life's feasibility depends on chemistry and biochemistry that we are still studying, not coin flipping.