Natural Selection with Teddy Grahams Name:_________________________Core 1 2 3 4
Purpose:
The concept of natural selection will be demonstrated
Materials:
Bears: Happy and Sad (Teddy Graham crackers)
Graph paper (attached on the back)
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.
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 touchdowns 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.
Hypothesis:
What do you expect to happen to the number of Happy and Sad Bears over time?
Results:
Number of bears at the start? _________ This is generation one.
Generation
Table 1: The number of bears for each generation
Number of Happy
Bears
Number of Sad
Bears
Total Bears

Generation
Table 2: The percentage of bears for each generation
Percentage of
Happy Bears
Percentage of Sad
Bears
Total Bear
Percentages
Graph the data from Table 1 and 2.
1.
Graph what happens to the bear population over time.
2.
Remember to label axis and give it a title.
3.
Include a key on your graph like the one below. Distinguish between the bears with a different color of crayon, color pencil, marker, or pen.
4.
Create your graphs as a line graphs to show the change over time.
Key:
Graph Percentage of Happy Bears as:___________ (Use a color to distinguish)
Graph Percentage of Sad Bears as:_____________ (Use a color to distinguish)
Conclusion:
1.
How many bears did you get for each generation?
Generation 1 _____
Generation 2 _____
Generation 3 _____
Generation 4 _____
2.
What happened to the percentage of each type of bear over time? a.
Happy b.
Sad
3.
How does this compare with your hypothesis?
4.
What is natural selection?

5.
Describe the relationship of happy and sad bears to the concept of natural selection.
6.
What is survival of the fittest?
7.
How does this lab demonstrate this idea which Darwin hypothesized with survival of the fittest?
8.
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.