Method
1. Students are divided evenly into groups, with an equal number of groups doing Simulation A, Simulation B, and Simulation C.
2. Each group will be given a coffee can containing 250 cubes with colored faces.
3. Members of each group will follow the instructions that specifically apply to their group.
Simulation A
1. Place 20 colored cubes in your can. Keep the rest of the cubes separate as your stockpile.
2. Record 20 as the population size for year 1 of the study.
3. Shake the can while holding it upright, and empty all of the cubes onto the lab table.
4. The color of the face of the cube facing upwards, determines what should be done with that cube.
- If the black face is facing up, that individual has died. Remove all black cubes from your population, and return them to your stockpile. Record the number of either in the data table.
- White or green faces represent females that have borne a child in that specific year. Count the number of white and green faces and add that number of cubes to your population.
- Record the number of births in the same row as you recorded the number of deaths for that year.
- Those with uncolored faces represent males and/or females who have not produced a child in that particular year.
5. Count the total number of cubes now on your lab table, and record this number in your data table in the same row as for other data for that year.
6. Return all cubes in your current population to the can.
7. Repeat steps 3-6 for 9 more years.
8. Return all cubes to the can, and plot the population growth for your population with a colored pencil, with years on the horizontal axis, and size of the population on the vertical axis.
Simulation B
Follow directions for Simulation A with the following exceptions:
- Black cubes represent individuals that have died. Count them and remove from your population, and return them to the stockpile.
- White cubes represent a female who have just borne a child. These should be counted, and for each white cube, add one more cube to your population from the stockpile.
- The cubes with green faces up represent a group of individuals in which only half of them bear a child. The other half are females who successfully have practiced birth control. Count the number of green cubes and divide by two. Also add this number of cubes to your total population. If there is an odd number of green cubes, flip a coin (heads=yes, tails=no) to determine whether or not the extra "green" female bears a child.
- All uncolored faces represent males in the population or females that are either not within the child-bearing years, or those who have not borne a child for some other reason.
Simulation C
Follow the directions for Simulation A with the following exceptions:
- Black cubes represent individuals that have died. They should be counted and removed from your population.
- White cubes represent a female who has successfully borne a child. These should be counted, and for each white cube another cube should be added to your population from the stockpile.
- A green cube represents a female who is successfully practicing birth control.
- Uncolored cubes are representatives of males or other non-reproducing females.
Results
Record all data in a table such as this.
Year
|
Number of Births
|
Number of Deaths
|
Population Size
|
2020
|
|
|
|
2021
|
|
|
|
2022
|
|
|
|
2023
|
|
|
|
2024
|
|
|
|
2025
|
|
|
|