>>28626937Some of the evolved forms are altered probably because only the evolved form experienced whatever hardship would lead to it needing to change. Cubone has a canonically explained reason, the Cubone children are protected by Marowak. Marowak needed to adapt to be able to protect them better. Cubone didn't need to adapt because it was being protected by Marowak
>but it evolves into needing to adapt just by getting olderPokemon evolution is pure fantasy so you have to suspend your disbelief when justifying it in conjunction with more realistic evolution.
It could be the case that all Cubone in Alola have adapted: adapted into having the ability to becoming alolan Marowak. It's just not an adaption that changes them on the surface because it doesn't need to until they've evolved. This will be supported if, going forward, Cubone caught in Alola still evolve into Alolan Marowak when traded to other games.
