Friday, June 03, 2005

Arguing Against the Evolutionary Origin of Species

Forget the acrimonious debate over intelligent design and the notion that evolution explains the origin of life on Earth.  Don't let emotion or politics get in the way.  Just think about the numbers.  One reason that an evolutionary origin of life seems implausible is that, if one starts with a gmisch of simple chemicals, it seems highly unlikely (implausible) that an intelligent being would emerge after a while as a result of unguided chemical processes.  At first glance, the concept of intelligent design seems to overcome that.  This is because once the chemical processes are driven by an intelligent being, you no longer need to imagine a process of random choices over a period of billions of years, all culminating in the formation of intelligent life forms.  The hypothesis, then, is that Intelligent Design is a more likely explanation for the origin of life than natural selection.  Call that the argument by plausibility.

But is that really the case?  Imagine yourself as a Creator, setting out with a blank canvas, and starting to paint.  There is no particular assignment, you just have to paint something that looks like you, in some way.  (I'll grant you, for the purpose of this argument, that it is reasonable to say that humans were created in the image of God.)  So you pick up a brush.  Stop.  

What was the probability that you would have picked that brush out of the infinite variety at your disposal?  

You dip the brush in paint.  Stop.  

What was the probability that you would have chosen that particular color, out of the infinite variety that you have available?  

You make the first stroke on the canvas.  Stop.  What was the probability that....?

Remember, you have at fingertips an infinite variety of brushes and paints.  Therefore, there is an infinite number of ways that you drawn that particular line in that particular spot.

This informal exercise would seem to show that one origin (Intelligent Design) is neither more nor less plausible than another origin (natural selection.)  Both explanations for the origin of life require equally long, and equally implausible, chains of events.  Therefore, the argument-by-plausibility fails to distinguish between the two.

But wait!  If there is an Intelligent Designer, then the selection of a brush was not random.  There must have been some reason for the selection of that brush.  Perhaps.  But if so, it is equally true that there must be some reason that ultraviolet light can damage DNA, thereby causing a mutation.  Postulating that there must have been some reason for something still fails to distinguish between the two explanations, because it does not tell you whether the reason was due to intelligence, or just some law of physics.