​Grade Level: Middle school (MS), grades 6–8. This lesson addresses the concepts and skills spelled out in A Framework for K–12 Science Education: Practices, Crosscutting Concepts, and Core Ideas (NRC, 2012). In particular, the activities of this lesson apply to the Crosscutting Concepts of Patterns and Scale and the Life Science Core Idea of Heredity: Inheritance and Variation of Traits (MS-LS3) and Biological Evolution: Unity and Diversity (MS-LS4).