I am of the understanding that you actually evolve your creature over time, from bacteria to civilization building, planet spanning vehical users.
From there, the stars. If you've not seen the demos of it, and Will Wright's discussion of the principles involved, then you probably will have a "well, I guess that's kinda neat." additude about it. If you've seen the demo of it, then you probably will have a more upbeat "It looks great." additude, more or less.
If you haven't already I highly suggest sitting through the 1 hour demo of it from E3 2005 and maybe even the one from E3 2006. The 2006 one has more on the galactic metagame (millions of planets... OMGWT*!). You can find both of those on google. Or even over at Wikipedia I believe.
Spore, Wikipedia
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There are no truths in science, only the falsifiable hypotheses and explanations of the people who test them.
Hyper Physics
Hyper Math
Wikipedia
