This article describes a classroom exercise that is designed to help students understand the basic tenets of population ecology (also known as organizational ecology). The macro-level, longitudinal approach to understanding organizations can be difficult for students to conceptualize as it involves systems thinking. This exercise makes the theory come alive by asking students to put themselves directly into the role of an organizational decision maker in an evolving industry. Over the course of one class, students get to experience how organizational size/age, environmental factors, and even random chance can affect organizational success and the makeup of an industry. Simulating up to a decade or more, students learn that populations of organizations change in predictable ways. We have tested this exercise with hundreds of students and we present evidence that it is effective in teaching the principles of population ecology (postexercise testing average of 92%) and also engaging and enjoyable for students.