Evolution

Evolution is, when an organism in Birthdays the Beginning starts to grow into a completely new species. This happens in the first Episode called The Cube is born during the mission Birth of Callunia to the seaplant Callunia, which evolves into Baragwanathia. Asteroxylon on the other hand, is a Mutation of Baragwanathia.

Related

 * Seed of Evolution
 * Mutation