Tiny cavefish may help humans evolve to require very little sleep
(PHYSorg.com Biology)

We all do it; we all need it-humans and animals alike. Sleep is an essential behavior shared by nearly all animals and disruption of this process is associated with an array of physiological and behavioral deficits. Although there are so many factors contributing to sleep loss, very little is known about the neural basis for interactions between sleep and sensory processing.