Fossil Pokemon
Gen 1: Scientist in lab on isolated island seeks rare fossils to clone ancient Pokemon.
Gen 2: No way to revive fossils.
Gen 3: Large corporation that creates new pokeballs etc also can clone fossil pokemon.
Gen 4, 5: Cloned by shockingly well funded museum's staff.
Gen 6: Another research lab that clones fossil pokemon.
Gen 7: MAN IN PARKED RV ACROSS FROM MOTEL WEARING FARMER'S CLOTHING TURNS FOSSILS INTO POKEMON.
