"Jellyfish Dreams" --Caltech: Sleep is an Ancient Behavior, Untouched by Millennia of Evolution (WATCH Today's 'Galaxy' Stream)

Jellyfish and humans may seem wildly different, but both still need to sleep. At first glance, humans seem to have very little in common with Cassiopea, a primitive jellyfish. Cassiopea is brainless, spineless, and spends essentially its entire life sitting...