Thanks to Dennis for bringing this computer game to my attention. Since it has not yet appeared on this website though, I have decided to share the glory that is Spore.
Spore is a game where the player starts out as a micro organism in a petree dish/raindrop/blob of ooze and evolves. After a certain number of points are scored the player gains access to an editor in order to alter the appearance and advance the level of the species. Eventually you will evolve into a sea creature and eventually into an intelligent land walker.
From there game will turn into an RTS as you upgrade your species brain. Your creature will form tribes and compete against other tribes. Eventually, you can build cities for your species and even ultimately conquer the galaxy!
Here are some links if you would like to know more:
Spore website (Not a whole lot of content)