Limitations!

In this world, there are limitations.

For example, before the knowledge of 'Dust', the human genes were severely limited.

There was a limit placed on the human body, in such a way that a man could not jump beyond a certain point, or possess pure physical strength beyond a certain point. 

The limit was even more obvious in certain circumstances like reaction speed, flight and even intelligence. 

However, under the presence of 'Dust', the cells become activated, absorbing 'Dust' to strengthen themselves. (Genetic Soldier)

Thereafter, the cells gradually loosen the genetic chain to a certain point where they create spaces in the genetic code, this spaces are called Functional Genetic Spaces.

Notwithstanding, the body itself can only strengthen and cannot evolve even with the presence of 'Dust', hence the merging of Super cells.