For an explanation of the stages of evolution, click here.

http://commons.wikimedia.org/wiki/File:Ancestors.gif

Remember that throughout much of this time the nervous system and MINDS were evolving too – although it is still hotly controversial what role sponge like creatures had in our origins.

Note that this morphing depiction is not to be taken literally in every detail. As a visitor to the site pointed out for one example, we did not evolve directly from chimpanzees, but a common ancestor with chimpanzees, around 6-7 million years ago. This depiction should be understood at a conceptual level, not a precise anatomic level.