To explore the similarities and differences of animal skulls.
In middle school, students should begin to extend their knowledge about animals from external anatomy to internal structures and functions. In this lesson, students explore skulls that are part of an online exhibit at the California Academy of Sciences.
The lesson could mention scientific classifications briefly, but mainly should be a precursor—a way to get students to see that the differences they can see in skulls might possibly be part of a classification system.
In earlier grades, students learned that plants and animals are alike in some ways and different in others, and that they have features that help them survive in their environments. Students learned to group organisms in different ways—by anatomy, behavior, habitat, and the like. In grades 6–8, it is important for students to move toward understanding the established classification systems, and in particular, the rationale biologists have used to establish them. It is important for students to describe the vast diversity and relationships between organisms and to pursue useful research questions.
Using the Skull Diversity student esheet, students should explore Skulls, on the California Academy of Sciences website. Give students an opportunity to guess the animals whose skulls are depicted and encourage them to provide reasons for their guesses. Then, pose the question, "What is a skull?" and ask students to devise their own definition.
Students should continue to use the Skull Diversity student esheet to explore these sections of the Skulls exhibit:
The esheet should lead students to reflect on the similarities and differences found in the skulls and also on the different types of things we can learn by studying and collecting skulls.
Possible answers to the questions posed in the esheet are listed below:
- What is the basic function of a skull? (Its basic function is to protect the brain and sensory organs in vertebrate animals.)
- How is a skull like a football helmet? (It protects the brain.)
- How does studying skulls help scientists to determine which animal species are closely related to others? (Since shared traits are often used to determine relatedness, similarities in skull architecture can help scientists make those determinations.)
After students have discussed the resources on the esheet, they should revisit their original definitions of skulls and reflect on how they would revise them based on what they have learned in the exhibit.
In order to assess student understanding, inform students that they should use their student esheet to visit the Academy Mission site. They should use the information from this site to write a paragraph explaining what can be learned from studying skulls. Students should list at least three different examples of how skulls are similar and three different examples of how skulls differ. Scientists examine skulls to determine how long individuals lived, how healthy they were, and how they died.
If they're interested in learning more about skulls, students could check out these resources:
The Science NetLinks lesson Classify That! can be used in conjunction with this lesson to develop students' understanding of animal classification.
These Web resources can be used to follow up on the ideas in this lesson: