Yoshida has said in an interview or q&a that the speciation we’ve seen has evolved since the sundering. I assume Oda agrees? It makes little sense to me precisely bc the idea of humanity on each shard branching into the same subspecies due to random evolution beggars belief, but it seems to be the answer. At least for the moment. I mean it’s not actually specified in the game yet, so I think it’s up for changes till it is.