Lesson 1

What’s the Story about How Plants and Animals Change Over Time?

Big Idea: In a population of plants or animals, physical traits may change over time.

Activity: Students examine “Many hundreds of years ago” and “Nowadays” images of 4 animal populations. Using these images as evidence that traits in populations of animals may change over time, students activate their initial ideas about how these changes might have happened.  They share and discuss each group’s initial ideas in preparation for learning about natural selection. Any mistaken preconceptions will be addressed later. 

Materials to Have Ready

  • Full-page copies of the 2-panel examples of change over time in the cane toad, guppies, owls, and soapberry bugs populations. Depending on your class size, you may need to print extra copies of the scenarios.

Video Overview (1:52)

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