Originally Posted by
Vyrerus
If they lived through the process, yes. It's clear blow for blow in the game text, and you even see some of the Eorzean Alliance leaders' main beef be, "There will be no one left!"
Of course, though, the Sundering occurred after the Final Days, and they still haven't given us any missing link for the, "New Life" that Zodiark made/caused, so I assume if what races there are now were post Final Days but pre-Sundering we might also stay the same, physically.
Of course, all of the playable races and even a few of the ones that aren't are capable of breeding with each other, so we already are the same species, really. We just look different cause this magical world is magically jank like that, yo.