Prelude to the Case

This “clicker case” is modified from Martin Kelly’s case study As the Worm Turns: Speciation and the Apple Maggot Fly published in 2003 on the National Center for Case Study Teaching in Science website. Classroom discussion of well understood cases of incipient speciation, such as the apple and hawthorn maggot fly Rhagoletis pomonella, can be an excellent tool for engaging students and teaching them about the mechanisms of speciation. Students learn about speciation, and then are presented with a case study in which the natural history of hawthorn and apple maggot flies is described. Students use various species concepts to decide if apple and hawthorn maggot flies should be considered separate species and decide what evidence is relevant to each species concept.

This case is called a clicker case because it was designed to be presented in a class that uses personal response systems, better known as “clickers.” The case study is presented in class via PowerPoint, with multiple-choice questions sprinkled throughout the “lecture.” Students are expected to answer the questions as they arise using their clickers. Many instructors allow students to consult with their neighbor before clicking in their answer. The entire approach encourages student participation even in the largest of classes. The use of clickers in combination with case studies is described in greater detail in the article “Clicker” Cases: Introducing Case Study Teaching Into Large Classrooms.

Go to the PowerPoint presentation (~8 MB)

Go to the teaching notes

Date Posted: November 4, 2009.