This activity guides the analysis of a published scientific figure from a study that investigated how gene duplication contributed to the evolution of electric fish.

Electric fish use electrical signals for navigating their environments, communicating with other electric fish, or even defending against predators and stunning prey. The fish produce electricity through a special organ that generates very fast action potentials. This ability may have evolved through the duplication and mutation of certain sodium channel genes. This figure compares the expression patterns of several sodium channel genes among three groups of fish, including two different groups of electric fish.
 
The “Educator Materials” document includes a captioned figure, background information, graph interpretation, and discussion questions. The “Student Handout” includes a captioned figure and background information.