you misunderstand my saying, im talking in aspect of a story plot, and that the jedi purebloods(Zithesians) are a species aswell. They would teach the ways of the force(lightside) to that of other species, instead of interbreeding with other species like the sith species did, this intern would actually make them truly pureblood, and quite frankly they should be able to do this, remember SWTOR never finished the the Galactic stories they stopped and never explained how the first signs of the force came to be, so they have a little wiggle room with Lucas arts to do something like that.