New science standards and reform recommendations spanning grades K--16 focus on a limited set of key scientific concepts from each discipline that all students should know. They also emphasize the integration of these concepts with science practices so that students learn not only the "what" of science but also the "how" and "why." In line with this approach, we present an exercise that models the integration of fundamental evolutionary concepts with science practices. Students use Avida-ED digital evolution software to test claims from a study on mutated butterflies in the vicinity of the compromised Fukushima Daiichi Nuclear Power Plant complex subsequent to the Great East Japan Earthquake of 2011. This exercise is appropriate for use in both high school and undergraduate biology classrooms.