In this article, I'm going to follow the example of these books, laying out as simply and clearly as I can what conservation of information is and why it poses a challenge to conventional evolutionary thinking. I'll break this concept down so that it seems natural and straightforward. Right now, it's too easy for critics of intelligent design to say, "Oh, that conservation of information stuff is just mumbo-jumbo. It's part of the ID agenda to make a gullible public think there's some science backing ID when it's really all smoke and mirrors." Conservation of information is not a difficult concept and once it is understood, it becomes clear that evolutionary processes cannot create the information required to power biological evolution.
There is no debate that biological designs are astronomically unlikely. Evolutionary theory addresses this with its concept of natural selection. Yes the species and mechanisms we observe are intricate, but of all the randomly occurring designs that happen to arise, those that contribute to fitness will reproduce more often. And so the evolutionary process is not random, but directed.
This is, simply put, how evolution creates nature’s exquisite designs. But does this explanation really work? The conservation of information suggests there is more to the story. As Dembski concludes:
This is the relevance of conservation of information for evolution: it shows that the vast improbabilities that evolution is supposed to mitigate in fact never do get mitigated. Yes, you can reach the top of Mount Improbable, but the tools that enable you to find a gradual ascent up the mountain are as improbably acquired as simply scaling it in one fell swoop. This is the lesson of conservation of information.
Regardless of where you stand this latest contribution from Dembski is well worth a read.