Well. don't ask me...

It's the same as Civ3, which was the same as Civ2, which was the same as Civ.

Seriously, I tried it last night, played 1 tiny map with 1 opponent, won by beating him to space (so I went through the entire evolving thing). It all felt exactly the same as last time I played civ3.

We will see what happens during a more thorough playtesting.