Teaching Speciation Using Anole Lizards

This film explores how anole lizards have adapted to habitats across the islands of the Caribbean. It also shows the techniques used by scientists to study these lizards.

Use segments of the film throughout the playlist to introduce or complement different activities.

• Show 0:00–1:57 at the beginning of the first lesson to introduce the story of the anole lizards.
• Show 3:21–6:48 after students complete Module 1 of the Lizard Evolution Virtual Lab (resource 2 in this playlist) to illustrate the advantages and disadvantages of different body forms in different habitats.
• Show 9:51–14:28 before students start the “Using DNA to Explore Lizard Phylogeny” activity (resource 4 in this playlist) to motivate a discussion on the process of speciation and the role of reproductive barriers. This segment emphasizes how microevolution (evolutionary changes within a species) can lead to the formation of new species (macroevolution).
• Show 14:29–17:12 before students complete the “Activity for Lizards in the Evolutionary Tree” (resource 5 in this playlist).

Estimated Time: 15 minutes total for the film segments.

This interactive, modular lab explores the evolution of anole lizards in the Caribbean through data collection and analysis.

To use this resource as part of this playlist, have students complete only Modules 1 and 3 of the lab.

• In Module 1 (Ecomorphs), students explore the role of adaptations by collecting and analyzing data about the morphology and ecological niches of anole lizards.
• In Module 3 (Experimental Data), students perform an experiment designed to answer the question “What happens when lizards that represent one ecomorph are placed in a different habitat?” They also use statistical tools to analyze and interpret their data.

Estimated Time: Two 50-minute class periods.

In this activity, students formulate and evaluate a hypothesis about the amount of time necessary for natural selection by predation.

Have students complete the entire “Student Handout.” Use the suggestions in the “Educator Materials” to implement other parts of this activity, such as the video clip, with the following adjustments:

• Show the video from 0:00–1:34 between Part I and Part II of the activity.
• Show the remainder of the video (1:35–end) after Part IV, question 11.

Estimated Time: One to two 50-minute class periods.

In this activity, students build and interpret phylogenetic trees to make a claim about how certain adaptations evolved among anole lizard populations.

Have students complete the entire “Student Document.”

Estimated Time: Two 50-minute class periods.

This activity guides students through concepts covered in the film The Origin of Species: Lizards in an Evolutionary Tree (resource 1 in this playlist). It can be used to probe students’ understanding of key concepts addressed in the previous resources.

Use the questions in the “Student Handout” as assessment items for the concepts addressed by the following resources:

• Question 2: Module 1 of the Lizard Evolution Virtual Lab (resource 2 in this playlist)
• Questions 4 and 5: Module 3 of the Lizard Evolution Virtual Lab (resource 2 in this playlist)
• Questions 7–9: “Look Who’s Coming for Dinner: Selection by Predation” activity (resource 3 in this playlist)
• Questions 1, 3, 6, and 10–12: “Using DNA to Explore Lizard Phylogeny” activity (resource 4 in this playlist)

Estimated Time: Two 50-minute class periods.