Karkat Vantas
Virile God-Snake Tower of Masculinity
Big bump, big bump, it's in my head~
Well, I personally believe that Magikarp grew so unaccustomed fighting that they had no need to learn how to defend themselves. However, the cells that were needed for it to evolve into Gyarados are still there, dormant. When those cells are made active due to either training, the need for self defense, or electromagnetic waves (ie, the radio tower evolution signal), the Magikarp suddenly revert to their original form, thus allowing for them to evolve into Gyarados.
Well, I personally believe that Magikarp grew so unaccustomed fighting that they had no need to learn how to defend themselves. However, the cells that were needed for it to evolve into Gyarados are still there, dormant. When those cells are made active due to either training, the need for self defense, or electromagnetic waves (ie, the radio tower evolution signal), the Magikarp suddenly revert to their original form, thus allowing for them to evolve into Gyarados.