Natural Selection Lab
This is a kitchen lab, meaning you will conduct the lab in your home using Teddy Graham cookies that you supply. Read through all the directions before beginning. Submit your lab report according to the directions and grading rubric below.
Overview:
Students will simulate natural selection on a population of bear cookies by assuming the role of predator. Read the entire lab carefully before beginning.
Directions:
1. You are a bear-eating monster. You like happy bears because they taste sweet and are easy to catch. Sad bears are not part of your diet because they are bitter, sneaky, and impossible to catch. For this reason, you eat only Happy bears. New bears are born every 'year' (during hibernation) and the birth rate is one new bear for every old bear left from last year.
2. Form a hypothesis about what you expect to happen to the number of Happy and Sad bears over time. Include the hypothesis in your report.
Hypothesis:
3. Open the box of teddy crackers and randomly pull out 10 bears, this is your starting population. Record the number of Happy bears, the number of Sad bears, and the Total Population of bears you have in your Data Table.
4. Eat three Happy bears. If you don't have three Happy bears, then eat the number of Happy bears you have.
5. Determine the number of Happy bears and Sad bears that will be produced during hibernation (each remaining bear will produce one new bear), and then get the new generation from the teacher.
6. Repeat steps 4-5 for the second generation.
7. Repeat steps 4-5 for the third generation.
8. Determine the percentage of Happy and Sad bears for each generation and record the percentages in the Data Table.
Percentage Calculation: take the number of happy or Sad bears and divide by the total number of bears for that generation and multiply the answer by 100.
Example: Generation 1 has 2 Sad and 8 Happy Bears for a total of 10 bears.
To obtain the percentage of Sad bears you would divide 2 by 10 and then multiply the answer by 100. To obtain the percentage of Happy bears you would divide 4 by 10 and then multiply the answer by 100.
Results: Data Tables
Table 1. The number of bears for each generation
Generation
Number of Happy bears
Number of Sad bears
Total Population of Bears
Percentage of Happy Bears (#happy/#bears x 100)
Percentage of Sad Bears (#sad/#bears x 100)
1
2
3
( the graph picture will be sent btw PLEASE HELP ME WITH THIS I HAVE TO GET IT DONE BY THIS WEEK )
Results: Graph
Create a digital graph that displays what happens to the bear population over time. You may use any graphing tool you choose as long as it is digital. Graph the percentage data for both the Happy and Sad bears on the same graph. Use a different color for Happy and Sad. Percent will be on the y axis, time on the x axis
Discussion Questions:
Answer each question in thoughtful, detailed, and complete sentences.
1. Describe in detail what happened to the percentage of happy and sad bears over time by using the data present in your table and graph. Did the results support or refute your hypothesis?
2. Which type of bear has better "fitness" and why?
