How does Kino change from the beginning of the book to the end? Why does he change?

In the beginning, Kino lives a calm life centered around his wife and his child and the dreams he has for the future if he could ever make any money and escape oppression. He assumed that the pearl would bring him the fulfillment of his dreams; in fact, it brought him the death of his son and a new awareness of just how cruel people could be.