Post-REM Sleep Evolution: A Broad Outline

Today I discovered from Matthew Walker's Why We Sleep that at the earliest, R.E.M. sleep evolved from non-R.E.M. sleep during the Age of Reptiles.  We know this because some species of lizard are currently the most primitive species to engage in R.E.M. sleep.  Birds and mammals both evolved this most interesting sleep stage separately when they split apart from the reptiles after the extinction of the dinosaurs.  

R.E.M. sleep is so interesting because it's the only sleep state that allows us to dream.  All mammals do it, not just us.  One of our evolutionary advantages is the ability to sleep in an extended R.E.M. stage, which allows our brains to store information more efficiently.  Basically, this means humans are so intelligent because we enter the R.E.M. state far more often than any other species.

If we consider the astral plane in various esoteric philosophies to be the location in which dreams take place, we may conjecture that the higher planes of existence could be reached by evolving further sleep states past the R.E.M. stage.  By accessing ultra-R.E.M., as it might be called, we could theoretically "dream" on the mental plane, a place where emotions are restrained and thought-forms are visualized more clearly.  Telepathy is thought to happen frequently on this plane, so while we're dreaming on it, communicating with others without using words may be possible.  Indeed, some humans have already reported this, though many claims are dubious because we don't all have this blessed mutation.  

Even higher evolution would call for access to planes that are higher than the mental one- planes where we might dream on transcendental themes.  In these dreams we'd feel a godly connection to all that is around us.  Our spirits would strongly associate with a collective morphology that only the quantum states of matter could illustrate.  We'd see things in extra dimensions, the arrow of time would cease to exist.  We'd feel emotional states and mental ones simultaneously, as a balanced system, a totality of existence.