I think Japan is a bit more unique geographically in this context. Sure there were people in England that long ago (and same for Greece too) but Japan has been

I think Japan is a bit more unique geographically in this context. Sure there were people in England that long ago (and same for Greece too) but Japan has been isolated by more water, and their gene pool has remained more or less the same. They know their history and it's all their own. Citing 30,000 years as I did was just a bit in jest and probably an exaggeration.