On Nov 12, 2007 1:43 PM, Alexanian, Moorad <alexanian@uncw.edu> wrote:
> I do not think anyone knows how to calculate possible outcomes from given
> initial conditions. Unless one can know what the possible outcomes can be,
> how is one to calculate probabilities for individual outcomes? One does not
> know dynamics that well to make any sort of predications.
>
I think this is rather missing the point of Koonin's argument.
His argument is to take the current front-runner theory of the origin of
life (RNA - world), and the assumption that in order to kick start the
process of evolution, we need to have translation and replication in
process. This is a chance event that has to happen once only. Then, given
generous estimates of RNA replication rates, and of the number of planets in
the observable universe, ... under all these assumptions, then he finds that
the probability of this chance event, for which he has done a conservative
estimate, is vanishingly small for a single universe. And what you have is
a conservative estimate, with RNA jiggling about on every square millimetre
of every planet in the universe whether hospitable for life or not. The
real probability (which we can't estimate) is likely much smaller, but we've
at least had a shot at an upper bound.
The reason I don't find this valid is probably the same as yours, David's
and Michaels - ie that we don't know how it might have happened, and that
therefore, if the current model gives a vanishingly small probability of it
happening then the current model is wrong and we haven't solved the problem.
A better theory will no doubt emerge in time as we get to know more, which
gives a much higher probability of life starting up. The low probability
argument proves neither the multiverse hypothesis, nor the Intelligent
design hypothesis. All it proves is that we don't know yet how life got
started up.
What I was objecting to is the notion that you can airily dismiss it by
saying "oh... well extremely unlikely events happen all the time". That's
what I think is a silly argument. Supposed you were facing a firing squad,
or marksmen whose guns were loaded with live or blank ammunition based on a
coin-toss. 100 bangs go off and you walk away unscathed. Are you really
going to walk away with a shrug of the shoulders and say "well, 100 heads is
just as likely as any other combination, so I'm not surprised I escaped at
all"? Of course not, because with any of the other 2^100-1 (equally likely)
possibilities you are going to end up dead.
Iain
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Received on Mon Nov 12 09:46:03 2007
This archive was generated by hypermail 2.1.8 : Mon Nov 12 2007 - 09:46:03 EST