I have been thinking deeply, researching, coming up with conclusions about this and i think it's possible that pikachu is the original, origin of pokemon, the first strand of pokemon dna came from pikachu.
My reason for thinking so is, because look at every new generation. Think about it for a moment. See a pattern huh? if not look again. ok you give up now huh. EVERY gen has a pikachu look alike.
gen 3=minum, plusle gen 4= the squirrel (forgot name, i think it was parischu) gen 5= emolga
as far as i am concerned, these pokemon are not related to each other or pikachu, it is a strange thing they all look similar. My theory is that, of course, pikachu is the origin of all pokemon, evolution occurs and splits it into various species we all know of today, such as tyrouge, cacturne, marowak, ferrathorn ,etc. These pika-look-alikes just still look very much similar to pikachu because they really didn't need to evolve.
For instance lets look at real life animals. They say cockroaches have never evolved over the millions of years of their existance, that's what i'm trying to say with these pika-pokes. Now lets look at animals like dolphins and whales. These creatures have finger bones yet they are not present or used for their bodies at ALL. This implies they may have started off as a 4 legged land creature and over time, evolution, natural selection, darwinism and all that occurs and millions of years later we have the whale we know today. And again this is what i'm saying with pikachu, same thing happened. Some pikachu's adapted to new enviroments, and became completely new pokemon over the years such as aggron, hitmonlee, dunsparce, snorlax etc.
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