What's with our logo?
We based our logo off of a phylogenetic tree of life prepared by David Hillis, Derreck Zwickil and Robin Gutell of UT-Austin.
A higher-res version can be found here (PDF).
Each line depicts a specific species. The center of the circle depicts the oldest species. The closer to the edge you go, the more recent the species is. This particular tree of life only depicts about 3,000 species--less than 1 percent of known species. Humans are depicted on the tree, located here:
Why use this as a logo?
Courtesy of guardian.co.uk
Evolution is a powerful, yet elegant idea. We don't worship Darwin, but we certainly respect him and admire his contributions to science and the world as a whole. This particular representation of the tree of life is not only cool-looking, but gives us a real sense of perspective and humility. Although we are a special species, we are only one species out of many, with a common ancestor with every other species who has ever lived.