Students are introduced to the concept of interdependence in an ecosystem and its effect on the evolution of populations through a family of rabbits that include five offspring: one small rabbit, three medium sized rabbits, and one large rabbit. Each size of rabbit eats a different type of grass. All three types of rabbits are thriving in the environment until a dam is introduced. The dam reduces the amount of water that flows into the bottom half of the environment. The grass that the large rabbit eats needs less water, so the large grass and large rabbit continue to do well in the environment. The small and medium-sized grasses need more water to thrive, so they begin to die out, causing the population of the small and medium-sized rabbits to die out. When students remove the dam, they observe the ecosystem slowly return to its original state. A Teacher's Guide link can be found near the the download button. The guide includes lesson plans, answers to the questions in the activity, and detailed instructions on using the features of the simulation. This activity is number eight out of a ten part series of evolution readiness education activities by the Concord Consortium.