Let's talk about the people of Gaia. We've got standard humans, hippo-folk, rat-folk, clown-folk, moogles, chocobos, mole-folk (mentioned, but not seen), bird-folk, walrus-folk and Queen Brahne. I'm sure I've missed a few. The point is that many species have gained human-level sentience; how? Do you think there was an origin of all the walking, talking, sleeping, spending peoples of Gaia? Did the humans evolve from monkeys, the hippo-people from hippos etc., until they were all at roughly the same level? Or was there a single species, that would be the basis of all sentient life, that specialised in different ways?
I can't help but feel that the standard model of evolution works the same way in Gaia. :/