When, or where, does PSO occur?

[Forge]

I really doubt that it's our future. Don't read this if you don't want to be spoiled for the Phantasy Star Two ending...

o The Pioneer Plan - born of desperation facing the destruction of their home worlds. (Multiple worlds, possibly three, and so it could be the Algo star system just renamed Coral.)
o The Spaceship Noah and Mother Brain from PSII - Earthmen destroyed their planet, so set out into space to colonise another, found the Algo system and set up Mother Brain, who controlled everything. 1000 years later, Mother Brain starts playing up and begins to produce monsters which start killing off people, and the automated farming systems stop working. The people have become weak, and so would die out, had Rolf not destroyed Mother Brain and the Earthmen. (I doubt that the Earthmen would have two futures in the same series, so Coral cannot be earth. I also believe that the Ruins are the remains of the Spaceship Noah, yet I've no evidence for this yet.)

But the odd thing is, so many of the enemies are very similar to the original series, especially the Dark enemies. The Chaos Sorcerer and Chaos Bringer are almost identical to the same named enemies in PSIV. The Grass Assassin looks remarkably similar to the Locust in PSII. And the Mothmants are remarkably similar to the Sworms in PSI. Furthermore, Ragol sounds very similar to Algol.

But in that case, where are the other two planets. And why is there no previous civilisation? This rules out the possibility that Ragol is Algo, but not that Coral is.

And whiteninja, just because Palma in PSI had forests, as did Motavia in PSII, does not mean that they are earth. Sure, it's similar, but it can't be the same...