Satellites orbiting the earth have recently discovered some interesting markings in the Chinese desert. New Scientist makes a convincing case that, given what one can see when the photos are blown up, they're designed by the Chinese military to serve as an artillery range.
Even so, suppose we were unable to magnify the pics. What would you attribute these patterns to:
Would you think them to be the products of purely natural causes, like wind, water, and chemical activity? If not, why not? Most of us doubtless ascribe these lines to intelligent agency, but why? It's not as if they showed some regular geometric pattern. The lines appear random except for their borders, but I suspect that even if the borders were irregular most of us would still think the lines to be intentionally constructed, even if we didn't know who did it, or why, or how.
This recognition of intelligent agency is precisely the intuition that underlies the believe that life is not solely the product of random natural processes. The probability of blind, natural processes being able to produce the Chinese lines is far higher than the probability of natural processes producing by chance a living, reproducing proto-cell. Yet, despite the sheer improbability of the latter, many folks nevertheless immediately assume it happened even as they would scoff at the notion that the lines in the desert were produced in the same way.
Why is that? The only way it makes any sense is if the existence of an intelligent designer of some kind is ruled out apriori, but that would be to reject the conclusion of the argument before the argument is allowed to make its case. It begs the question to assume there is no designer and then dismiss any evidence which might establish that a designer exists.
This, however, is what the materialist (or more precisely, the physicalist) does. He's certain that there's nothing to reality other than matter, energy, and force, and thus he excludes any explanation for any phenomenon that relies on a purposeful mind. There's no room in his worldview for any kind of God, and so he has no trouble imputing to intelligent human agents the Chinese lines but imputing to chance and the laws of physics the almost infinitely less likely emergence of life and biological information.