Why do firms experience evolutionary cycles in which there is a fit between strategy and structure, punctuated with periods in which strategy and structure are reshaped

Why do firms experience evolutionary cycles in which there is a fit between strategy and structure, punctuated with periods in which strategy and structure are reshaped? Provide examples of global firms that have experienced this pattern.
Choose a CEO of a prominent firm that you believe exemplifies the positive aspects of strategic leadership. What actions does this CEO take that demonstrate effective strategic leadership? What are the effects of those actions on the firm’s performance?