TEDDY

GRAHAM

NA

TU

RA

L SE

L EC

TI O

N L

AB

Sad Bear Happy Bear

Purpose:

The concept of natural selection will be demonstrated.

 

Materials:

Bears: Happy and Sad (Teddy Graham crackers)

Graph paper (attached on the back)

TEDDY GRAHAM STORY

You are a bear-eating monster from the land of Bear-Not-Friend. There are two kinds of bears that can be found naturally in your habitat: Happy Bears and Sad Bears. You can tell the difference between them by the way they hold their hands. Happy Bears hold their hands high in the air. They look like they have just scored a winning goal—if bears played football—real football—not American football. Sad bears hold their hands down low. They have not scored many goals in football—if bears played football. Happy Bears taste sweet and are easy to catch. Sad Bears taste bitter, are sneaky, and hard to catch. Because of this, you eat only Happy Bears. New bears are born every ‘year’ (during hibernation). The birth rate is one new bear for every old bear left from the last year.

Uh oh…why do I have to taste so good??

Good thing I don’t taste good..

PROCEDURE

1. Ready the story and follow instructions.

2. Obtain a population of bears (8-10), and record in table 1 the number of each: The Total Population, the Happy Bears, and the Sad Bears.

3. Eat three Happy Bears. If you don’t have three Happy Bears, then eat what you have in Happy Bears.

4. Get a new generation from the teacher. Repeat steps one and two.

5. Repeat for two more generations (total of four).

6. Determine the percentage of sad and happy bears for each generation (divide the number of that type of bear by the total number in that generation), record the percentages in table 2, and graph the population results. Driv

e Away!

Let’s get out of here!

Faster!!! Faster!!!

QUESTIONS

1. What happened to the percentage of each type of bear over time?• Happy• Sad

2. How does this compare with your hypothesis?

3. What is natural selection?

4. Describe the relationship of happy and sad bears to the concept of natural selection.

5. What is survival of the fittest?

6. How does this lab demonstrate this idea which Darwin hypothesized with survival of the fittest?

7.  How does this lab demonstrate what occurs during natural selection in the wild? Be sure to use Scientific terms, tie to Unity/Diversity and relate to genetic variation. Write at least one detailed paragraph summarizing your thoughts on this matter.