Simulating Natural Selection

Level: Primary/Intermediate --- Content: Science

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Mr. Jones is a middle grades science teacher whose class is studying evolution and natural selection. This is a topic that is frequently difficult for his students to understand. After completing this unit, he wants his students to understand that naturally occurring variations in traits can allow some members of a species to survive while others perish. He wants them to distinguish between traits that can be inherited and those that are not.

The unit question is “Describe how changes in the environment effects whether or not animals survive.”

Because adaptation and natural selection are gradual processes occurring over many generations, they are difficult for students to observe. Therefore, Mr. Jones will ask students to explore the topic through the use of a simulation. The simulation allows students to select variations for rabbits and to see how these variations are inherited by future generations. It also allows students to introduce predators into the environment and to control the amount of food that is available for the rabbits. The simulation tracks changes in the population of rabbits over time for the conditions the students choose.

To begin the unit, Mr. Jones introduces students to the simulation, demonstrating how to introduce variations into the population and how to change the environment. He explains that their investigations will be easier to understand if they change just one thing at a time in the simulation and document the results.

Students work in pairs or small groups to investigate different questions, such as “How does the color of rabbits affect their survival?” They record population data from the simulation for each generation of rabbits, enter it into the Create a Graph Classic graphing tool, create a line graph,and post their graphs to a wiki created by their teacher so that they can compare the graphs generated by each small group. They then work on a research paper using a template provided by their teacher. In the paper, they describe their method and results, and discuss their results.

The final step in the research paper is to connect their research to existing theories and the work of real scientists, especially Charles Darwin. Mr. Jones uses Moodle to provide students Internet resources on Darwin and the topic of natural selection. Using these resources, the students write a literature review to add to their paper.

Mr. Jones then organizes the students into editorial boards that review all the research papers for presentation in a digital journal special issue on natural selection. He provides the editorial boards with a rubric and asks them to review all the papers of their classmates and provide feedback based on the rubric. Once these “editors” have completed their review, Mr. Jones averages the ratings for each paper from each editorial board and creates an online journal with the top three papers using a digital storybook tool called Tikatok

Tools used in this scenario
Natural Selection Simulation: http://phet.colorado.edu/simulations/sims.php?sim=Natural_Selection

Problem solving and data analysis: Create a Graph Classic: http://nces.ed.gov/nceskids/graphing/classic/

Creation and publication: Tikatok http://www.tikatok.com/  Mediawiki

Daily and professional practice: Moodle

Virtual collaboration: Mediawiki