User blog comment:B1littlehero/Speculation of the Origin of Species/@comment-7622429-20140611002324/@comment-7622429-20140611014242

Oh, I know they are all tied together by the Darkness, but I feel that's the only real connection. That, and a hatred of Humanity. Specifically, the Hive definitely feel like their very origins lie within the Darkness itself. The other three races, not so much. The Cabal is definitely its own entity, and likely "guns for hire" for the Darkness to put an end to Humanity and the Traveler, just like the various Houses of the Fallen, and possibly the Vex. Though, the organic/robotic nature of the Vex leads me to believe they came from the future to aid the Darkness, possibly even a future where the Darkness already rules.