Almost any lesson can be modified to better incorporate, reinforce, and make explicit the nature and process of science. To see how, visit Modifying your current lessons and our additional tips and strategies. The lesson below is an example of a modified biology lesson.
Lesson: Anolis lizards
Overview: Students “take a trip” to the Greater Antilles to figure out how the Anolis lizards on the islands might have evolved. They begin by observing the body structures and habitats of different species and then plot this data on a map of the islands to look for patterns in lizard distribution. From the patterns observed, students develop alternative hypotheses about how these lizards colonized the islands and evolved. To test their hypotheses, students are given an evolutionary tree which they color code according to their previous data. By combining both types of data, students generate a final hypothesis about how they think the lizards colonized the islands.
- Emphasize that science is done by people. In the original lesson, students are shown pictures of the lizards and a map of the islands, but they should also see pictures of the scientists who did this work. Help students connect the data with the activities of people in the field making lots and lots of observations.
- Be explicit about data representation. In the original lesson, students chart the lizard data on trees. They should recognize this as a form of data representation that makes it easier to see patterns. There is no one correct way to represent data. If students are experienced with it, you might even ask groups of students to come up with their own ways of representing the lizard data.
- Be explicit about hypotheses generating multiple expectations. In the original lesson, the class discussion on how different family trees can support different hypotheses is critical. During this discussion, you can emphasize the core logic of scientific testing: “If this idea is right, what would I expect to observe?” Encourage students to be specific about these expectations and to generate multiple expectations for each hypothesis.
- Be explicit about data interpretation and ambiguity in science. The lizard data generally support one hypothesis over the other, but they are not entirely consistent with it. One group of closely related lizards is an imperfect match. This is the sort of ambiguity that scientists face, and students should be encouraged to wrestle with it too. Don’t ignore results that don’t match your hypothesis!
- Be aware of misconceptions:
- Scientific ideas cannot be “read off” nature. In the original lesson, students receive an Anolis phylogeny. They should also be encouraged to ask how we know this set of relationships. This tree didn’t come from a book or from their teacher, but from people who collected lizard tissue samples, sequenced the DNA, and figured out which tree best fit the DNA evidence. Scientific knowledge is built!
- Experiment is not the only method of science. This activity exemplifies how we can test ideas without doing experiments. This is worth bringing out in post hoc discussion. A bulletin board might even be devoted to the topic of scientific testing/evidence, on which examples of different sorts of tests could be posted throughout the year.
- Apply the Science Flowchart. In the lesson, students made initial observations, asked questions, shared data, communicated with others, formed hypotheses, generated expectations, got more data, interpreted them, and concluded that they supported one hypothesis and opposed a different one. Have students trace their pathway through the flowchart to emphasize the nonlinearity of their activities. Ask students what some possible next steps would be. There are many possibilities!