Landsburg does not doubt biological evolution. It's just an argument about complexity being inherent in the laws of nature, reality. And what it has to do with rationality, it's thought provoking. And rationality is a means to an end in succeeding to reach your goals. If your goal is to fathom the nature of reality these thoughts are valid as they add to the pile of possibilities being worthy of consideration in this regard.
I'm not sure "thought-provoking" is actually a good thing any more than "reflectively coherent" is a good thing. "Thought-provoking" is just a promise of future benefit from understanding; that promise is often broken.
A monthly thread for posting rationality-related quotes you've seen recently (or had stored in your quotesfile for ages).
ETA: It would seem that rationality quotes are no longer desired. After several days this thread stands voted into the negatives. Wolud whoever chose to to downvote this below 0 would care to express their disapproval of the regular quotes tradition more explicitly? Or perhaps they may like to browse around for some alternative posts that they could downvote instead of this one? Or, since we're in the business of quotation, they could "come on if they think they're hard enough!"