A concept first mentioned in The Choices We Make.  After six teenage girls appear, each claiming to be a daughter of Jake and Dawn, Sarah, Mina, Fawn, Yuta or Katia, Mato reveals their origin.  The girls were from the futures of alternate quantom realities.  To quote Jake (and Star Trek), 'For every event, there is an infinite number of possible outcomes.  The choices we make determine what outcome will follow.  But there is a theory, in quantom physics, that all possibilities that can occur, do occur, in alternate quantom realities.'