A lot of articles are popping up thanks to the Comic Con!  For this article, Gamespy shares what they have to say:

Going back to his roots, Wright studied the pop culture images that enthralled him during childhood. Aliens, robots — what sort of science-fiction themes repeat themselves over and over again? The team also looked at hundreds of old pulp science-fiction magazine covers, picking out themes. Over and over again the art depicted stylized aliens, spaceships, vehicles, buildings, strange planets (and the occasional hot blonde). With the possible exception of the blondes, Wright wanted to ensure that Spore would allow players to play around with all of those themes.

“I always want to bring reality to my games,” Wright said, shifting gears away from the (often silly) imagined futures of decades past. He again referred to Kubrick’s “2001,” which took great pains to portray space travel realistically. To that end, he and the team looked at the classic film “The Power of 10,” and they worked with real biologists and experts on evolution. (Some of their joint efforts will be aired in a National Geographic Channel special this September.)

Gamespy:  Will Wright’s Inspirations