@PJM
It depends what you mean by "improvement", of course. Any creature that survives better than its ancestors is an improvement. All living things are simply machines for passing on DNA. Whatever passes on DNA more efficiently is, therefore, improved. To that extent, evolution is a matter of improvement - albeit in the context of a fairly malleable scale of comparison.

(Neitzsche makes a nice point along these lines in Twilight of the Idols: "To call the taming of an animal its 'improvement' is in our ears almost a joke. Whoever knows what goes on in menageries is doubtful whether the beasts in them are 'improved'. They are weakened, they are made less harmful, the become sickly beasts through the depressive emotion of fear, through pain, through injuries, through hunger. - It is no different with the tamed human being..." ("The Improvers of Mankind", sec. 2).)
( Enzyme is powered by sunlight, Thu 17 Jul 2008, 10:12, Reply)