Teddy Grahams and Natural Selection: A Tasty Simulation

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SWBAT describe the process of natural selection in relation to evolution.

Big Idea

Use Teddy Grahams with your students to investigate natural selection over multiple generations in this fun simulation!

Notes for the Teacher

This introductory activity into natural selection is a student favorite!  The activity itself is quite simple and fits easily into a 50 minute class period.  However, the discussion questions are more in depth and require students to spend time outside of class to reflect in a substantive way upon the week's work before the turn in date.  I also like that the activity requires students to revisit rules/norms for graph and data table construction.  Students tell me that they like that there is a snack at the end of this!

I typically buy two boxes of the snack for each class of 16 student pairs.  I fill solo cups up halfway and tell students that they can eat the contents after they have collected their data.  It is a good idea to have a few different flavor options just in case someone is allergic to chocolate.

Alternatively, you can use different colored buttons or other items you might have in the classroom if you don't' want/have time to buy snacks.  So long as there are two easily recognizable 'traits' to choose from, you can use many other snack or non food items for this activity.  But just to emphasize…kids love the snack part! 

This activity dovetails nicely with our doodle work, the Darwin/Lamarck scenario comparisons, and our upcoming peppered moth discussion and simulation.  By digging into the basics of natural selection numerous times and ways, students get a deeper understanding and broader picture of the main mechanisms of evolution.

The Classroom Flow: Introducing the Activity

10 minutes

1.  Tell students that today they will be exploring the concept of natural selection using Teddy Grahams.  

  • Note: Expect applause and immediate questions about if they will be able to eat them!

2.  Pass out the Teddy Graham activity document and give students a few minutes to read through the introductory paragraphs and directions.  

3.  Review with them the major points by asking the following questions from their brief reading:

  • How many bears do you start with? (12)
  • How many do you eat? (4)
  • What is your criteria for eating the two types of bears? (happy first, sad if no other choice)
  • How many generations do you collect data for and how many bears total in each generation? (5 generations, 12 bears total)


4.  Make sure students can differentiate between the happy and sad bears.

5.  Remind students they can eat their snacks after collecting data for five generations. Ask each pair of students to come up to get their cup of TGs and a plate/napkin for them to arrange the TGs for data collection.

The Classroom Flow: Collecting and Graphing Simulation Data

35 minutes

1.  Data collection will take approximately 10-15 minutes and you should expect very little need for clarification or oversight as students engage and work independently.

2.  When all student groups have collected their data, ask for the attention of the full class and pass out graph paper.

3.  Ask students to take out their graphing rules documents (full sheet and half sheet).

  • Note: Both documents contain the same information but bthe igger sheet has graphics while the half sheet is a brief reminder list.   Students typically prefer one representation over the other and I give out both at the start of the year.

4.  Tell students that their final assignment will contain the following three parts:

  • Discussion questions #1-5 on the activity document
  • A data table of collected data for five generations
  • A graph representing the data for those five generations

 5. Ask students to look over their direction sheet again and tell you the type of graph they will be making (line) and then how many lines will be represented on their graph (three:  happy, sad, total).

6.  Write up the graphing rules on the board again and emphasize that their graphs and data tables must adhere to the rule list in order to receive full credit for their work.

7.  Point out where students can find classroom rulers, colored pencils, and additional graph paper and let students get to work on their data representations!

  • Note:  I do not give assistance in the creation of the three lines graph with key.  At this point in the year, the rules for graphing should be very familiar to students and the process for determining the most appropriate way to number and label the axes is something I want them to experience for themselves.

The Classroom Flow: Following Up

5 minutes

1.  As the class session comes to an end, ask students to return their materials to their designated place in the classroom.

2.  Once students have cleaned up and returned to their seats, ask for any clarifying questions.

  • Note: Students will want to discuss discussion question #2 and 3.  Tell them that you will be happy to follow up with them in class later in the week before the assignment deadline, but that you want them to do some research on their own and together with their partner for the next day or so.  I find that this is a critical piece for student self-directed learning.  Almost every single student will get these questions right on the final assignment document without my help; however, if I had given that help on the first day, none of them would have had that experience of figuring it out on their own by looking at their resources independently. See the student work sample for a exemplary model for worked turned in after this activity. I especially like that this student adhered to the graphing rules, a year long quest of mine to create graphic representations of data made with the user/reader/grader in mind!