Gaskell could not abide this indecorous version of his beloved linear progress theory. He could not bear to imagine that the grand procession from jellyfish to man, orchestrated by an ever-increasing mass of nervous tissue, once paused in its stately and orderly march toward human consciousness in order to execute a fancy little flip, a clever jig of inversion, just at the sublime and definitive moment of entrance into the vertebral home stretch.
Stephen Jay Gould