Complex sentence: The inhabitants were "independently" evolved humans, like those of Klovia and many other worlds, ultimately traceable back to Arisian life-spores permeating space at the time of the Coalescence.
Split into simpler sentences: The inhabitants were "independently"-evolved humans like those of Klovia and many other worlds. They are ultimately traceable back to Arisian life-spores permeating space at the time of the Coalescence.