Obviously there are some pokemon that only evolve when traded and some that need held items.
Well, I heard that using the GTS can evolve them. Supposedly if you leave the pokemon in there for a day and take them out they will evolve upon returning.
So if for instance I entered a poliwhirl with a king's rock into the GTS and asked for a level 9 and under reshiram and took it out the next day will the poliwhirl evolve into politoad? or is this a bogus rumour?