Which brings up a lot of questions the series doesn't bother explaining.
Did ALL these completely different species just evolve from the same genetic stock over only a few million years? Quite possible, sure, it happened on Earth; a much wider pool of worlds only increases the odds. I just don't see what Earth thing something like the Goa'uld would evolve its form of possession from. Maybe they really were made by another species...
Did these species already exist, and were killed off and reseeded by the Dakara Device, starting their civilizations from zero? Or did some survivors exist on colonies or ships somewhere far from any Astria Porta? Do they hate the Alterrans for what they did to their people, and want revenge on them for the genocide, or on their descendants now that they are out of reach?
Did the PLAGUE ITSELF survive in such a place, just in hibernation of sorts? I mean, it remained on Earth in that one frozen lady left behind risking reinfection of at least that world if not the galaxy.
...for that matter, why didn't the Dakara Device wipe *her* from existence?
And why didn't the Lantaeans use another such device to wipe out the Wraith? This one I can kinda understand if the Wraith had tech which was immune to the effect and would shield them from it.
sigh Maybe Babylon 5's carefully structured and planned-out ahead of time writing spoiled me.