Darwin, God, Science, and Occam's Razor

A running stream of blog entries from Hugh over at the Shuttle is causing some discussion as always seems to be the way when science meets religion. As certain commonalities keep cropping up I think some basic grounding in science is necessary.

For the most part religion tends to stay away from science, you rarely hear big debates about whether to teach children astronomy or physics. Biology, however, gets the blood up particularly Darwin and the Theory of Evolution. Amusingly much of the arguments used against this theory are ones that can be levelled against other branches of science but rarely are by those of religion.

The classic is the "it's only a theory". Yep so is relativity, but I don't see anyone contesting that being taught in schools on religious grounds.The other is that it lacks conclusive evidence.

So allow me to introduce Occam's Razor. The original quote would make most people go "Huh?" so allow me to Keep It Simple. That's it - Keep It Simple, feel free to add the Stupid on the end if you wish. Time for an example.

You come down from bed in the morning to the kitchen and find a cereal box knocked from a counter-top and spilled out over the floor. The explanation of this requires a theory.

1. The cereal box attained sentience and leapt to its death from the shelf.
2. Extra-terrestrials beamed into your kitchen for a late-night snack.
3. Burglars broke in and scared themselves by knocking over the cereal box.
4. Your cat jumped up on the counter and knocked it over.

Most people would consider anyone jumping to conclusions 1-3 as being slightly odd and this is exactly the same reaction scientists have to those who try and shove God into their theories.

However if you went about this the scientific way you'd look for evidence of your conclusions. If you found a scrawled suicide note option 1 looks more likely, a strange glowing patch on the flaw will lean towards option 2 while a broken door window might point to option 3. However in the absence of any conclusive evidence option 4 stands firm.

There lies the difference - your religious types will insert in option 5. God did it. And as there's no evidence for the other theories than option 5 is the winner

However if the action was not observed there's no way of telling; ever! Oh sure you could set up a camera and the cereal box and record what happens tonight, but that might not be the same as what happened last night. Just because the cat jumped up tonight doesn't mean it wasn't aliens last night. It does make it more probable that it was though.

Except again the religious types appear and insist on option 5 being the answer, because there's no evidence the cat did it last time.

And that's how it works for the Theory of Evolution. We can't go back and take a look, and the movement of the Earth and the soft organic nature of a large number of extinct animals leaves little fossil record. What we can do is look at what is happening now and formulate a theory. If when clearing up you find a paw-print on the counter that strengthens your theory, if your son's girlfriend appears and says "Oops that must have been me last night" it demolishes it. Same with science.

In the case for evolution we have the paw-print on the counter, cat's hairs on the box and the cat itself on the floor eating the cereal. It still might be God with the midnight munchies, but I'm going to bet it was the cat.