Wednesday, March 18, 2009

Weaseling around with Randomness

When I read the Blind Watchmaker, Richard Dawkins, I was impressed with his Weasel program. Just recently I re-discovered it on a website, written in Java, as opposed to the original BASIC. The link is Take a look at it, run it a few times, it's a blast. You can even scroll up and down and look at the results. Change the 'update every' setting from 10 to 1 and you can see each step.
For those of you unfamiliar with the Weasel program, it is a little sample program written by Dawkins to address the role of randomness in evolution. Now before you hoot and holler, it is NOT a representation of evolution, but a simple example designed to refute people who say things like comparing monkeys on typewriters and tornadoes building space shuttles. The point those folks are usually trying to make the entire evolutionary process as nothing but random behavior.

I have posted about randomness before (Arguments XIII - The 747 or a Shakespearean monkey) but this program really is a great way to look at it. It's more an example of how selection, combined with random action, can develop complexity. Again, don't think this is all there is to evolution, but think of it in the terms of selection and it makes perfect sense.

So you start with a completely random collection of letters, numbers, and other symbols. As one changes it is compared to an end result. If it is closer to the result, it's kept and other letters are changed. The idea being that making random changes by itself doesn't get you far, but you have to have some selection mechanism. Here it's compared to an end result, in the real world, nature does the selecting.

Like I said, it's a great way at looking at things!

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