Seed and Caps, the problem I have with assigning probabilities to life arrising (on earth or elsewhere) is that a) we don't know (and maybe can't know) EXACTLY what the environment was like, nor exactly where it occurred. For all we know, there was a small area of the earth that made everything just PERFECT for life. Until there's a time machine, it will remain at least partially a mystery. b) Defining what "life" is can become a tricky, when is something just a chemical reaction, and when do we concider it alive? Where is the line? and c) Based on a and b, the probablities become a little like enron accounting. You can make them what you want them to be by (even unconciouly) making certain assumptions.
Now Seed, I have a small issue with what you said. While it may be true that a reaction isn't certain between any TWO atoms...we'll even say a 1 in 100 chance for argument's sake....when two chemicals are mixed, how often is it only one atom? Two ittsy bittsy gass bubbles contain more atoms that any normal person can fathom...so what if only 1% react? There is still a reaction and a product thereof.
I do notice, however, that it's only creationists of one form or another who argue that life is almost impossible, and therefore it must have been created.
Huh.
Well, I know someone who won the lotto, too. Jerk didn't share a penny....