evolution is not design churn

Q: Why in the Age of Dinosaurs was there never anything as large as a blue whale?
A: Because nature hadn't learned how to build a beast that big yet. Because it's a lot easier to scale up to a large flesh eating monster if you're starting as a small flesh eating monster than it is to fashion a giant plankton sieve on a hippo. Which is pretty much what happened evolutionarily with the whale, when you get right down to it.

Just a guess here, but I'm thinking that the finely tuned stuff, the grace at the extremities - quality of vision and articulation of digits - all the refinement that really lets God in - this gets progressively clumsier the further back you go. Which should be taken to mean that things are actually moving in a positive direction, at least as far as complexity goes.

Q: What is the greatest urban design crime?
A: Tearing down something solid to build something fashionable.

Design churn is the unholy duo of ignorance and arrogance tricking you into abandoning best practices of the past. Evolution is kaizen.