Tuesday, March 14, 2006

Improbable events

I have been a little sidetracked by a discussion here, which started off with a dismantling of an earlier argument of mine. I hope I was able to show in comments that the bits that were dismantled weren't actually part of the structure, but you can make your own minds up ....

I responded to one of the comments that Steve made, and I wanted to bring the response here as well.
I am still unimpressed with the UPB, even if the argument I linked to is invalid. For one thing there are plent of examples of information that have a probability of less than 10-150.
You are right about low probability events abounding. That is why Dembski is arguing based on "specified" events of low probability. A random string of 105 characters is low probability - but so what, it's just a random string. However, supposing the program that generated the supposedly random string came up with "Four score and seven years ago our fathers brought forth on this continent..." Both events are improbable - but only the second one would lead you to the conclusion that somebody has been tampering with the program.

Evolution requires a whole series of specified events; ID argues that they are low probability. One of the most obvious classes of events is the production of new proteins from amino acids (note that there are a few dozen low probability specified events that need to take place before this is even a factor!). Obviously (well, obviously to anybody who knows anything about proteins) the specified event isn't that a precise DNA sequence needs to arise and be expressed. But to get a protein that (say) can get energy from the conversion of ATP to ADP, and use this to provide the power to catalyse another reaction at a time and place that is appropriate to the cell - this is still a specified event.

The whole ID debate isn't simply over low-probability events; it's about specified events, and the debate as to whether they are sufficiently high probability for us to assume that RM+NS are going to be powerful enough to allow evolution to happen.

Obviously, I don't think they are - but then, I put a relatively high estimate on the probability of an alternative explanation (that there is a designer). People who oppose ID and support evolution think that the probability is high - or rather, they have to assume that it is high. One of the big problems at the moment is that this key question of probabilities seems to be verging on the intractable. I don't think it is, and elsewhere on my blog I have started exploring some ideas which might allow progress to be made (and yes, I realise that this might falsify my beliefs!).