Evolution in fiction is when a story shows how characters change or grow over time. It is like watching something grow up or turn into something new. In a story, a character's personality, situation or even his or her physical appearance can change over the course of the story, just like in real life. The character might go through a lot of struggles and overcome them to become a better person and make different choices that lead to different experiences and a different path in life. This process is called evolution.