I love Evolution for many reasons...the character bits, both with the guest actor and Wesley. The treatment of both an alien species and an artificial intelligence (this episode gets 5 stars simply for there being no Kirk to talk the AI to death). The indroduction to the masses of nanotechnology. The use of baseball metaphors. The wonderful music and FX. There really is nowhere this episode goes wrong.
I liked the idea
of the nanites, but it didn't feel like much was really done with it. They cause a bit of havoc on the ship, they attack the scientist, and then after he gives a quick apology they're gone.
It also seemed like a stretch that a couple of Wesley's escaped nanites could take control of the ship and develop an intelligence in a matter of hours
. Yeah I know he's supposed to be a genius and all, but come on.