"Who says they're still living on their original planet?"

They had heard no reports of any virus spread beyond the three original planets.

Nothing is left of the original planet except for mammoth crystals in an array of colors.

They insisted that on the original planet, whatever it was, mankind had already been split into subgroups of varying pigmentation.

They are intending to colonise another planet, because their original planet was "doomed".

Most likely the nova-burned cores of the system's original planets.

They are generally thought to have been formed in situ at the same time as the coalescence of the original planet.

There is one simple difference between Old and New Earth: the original planet has fossils; the duplicate does not.

He insists that it is the original planet of the human race, though this is not generally accepted.

Thus they could not be native to the Ringworlders' original planet.