There is a school of thought that TOS is in its own Universe, and the movies and series that followed are probably each in their own Universes, only loosely related, just as the 2009 movie could itself be in another alterniverse.
This notion isn't shared by everybody, but it can be useful in reviewing the origins of concepts in TREK.
This notion isn't shared by everybody, but it can be useful in reviewing the origins of concepts in TREK.