What Forms of Growth Do Human Populations Show



What Forms of Growth Do Human Populations Show?

Many of the environmental problems we face are the result of the rapid growth in human populations. Global growth rate currently follows an exponential curve. In exponential growth, the growth rate may remain the same but the size of the population increases rapidly. To better deal with the environmental problems, we must better understand the consequences of exponential growth.

In this lab you will simulate the growth of a population in

(1) a typical underdeveloped nation

(2) a nation in which some people are practicing population control

(3) a nation with zero population growth. Individuals in your populations will be represented by wooden cubes with different-colored faces.

Procedure:

Part A:

1. Place 20 colored cubes in the can. In Data Table 1, record 20 as the population size for the year 2012.

2. Shake the can while holding it upright, and roll all the cubes onto the lab table so that all cubes lie flat.

3. Record in Data Table 1 all events affecting population size. Use the following key: If the cube pointing up is:

a. Black – the individual has died. Record the number of deaths in the next row of Data Table 1. Pick up all black cubes and return them to the stock box.

b. Yellow or green – the individual is a female who has just borne one child. Record the number of births in the same row of Data Table 1. For each birth, place a new cube from the stock box on the lab table, blank side up.

4. Count the total number of cubes now on the lab table and record the number as population size in the same row of Data Table 1. Return all cubes from the lab table to the can.

5. Repeat steps 2-4 through year 2019.

Data Table 1

|Year |Number of Births |Number of Deaths |Population Size |Annual Growth Rate |

|2012 |------------------------ |--------------------- | |-------------------------- |

|2013 | | | | |

|2014 | | | | |

|2015 | | | | |

|2016 | | | | |

|2017 | | | | |

|2018 | | | | |

|2019 | | | | |

Part B:

6. Record the number of cubes now in the can as population size on the first row in Data Table 2. In the “year column enter 2019, the last year for which you rolled cubes in Part A.

7. Shake the can while holding it upright, and roll the cubes onto the table.

8. Record in Data Table 2 all events affecting population size. Use the following key: If the face of cube pointing up is:

a. Black – the individual has died. Record the number of deaths in the next row of Data table 2. Pick up all “black” cubes and return them to the stock box.

b. Green – the individual is a female who has just borne a child. Record the number of births in the same row of Data Table 2. For each birth, place a new cube from the stock box on the lab table, blank side up.

c. Yellow – only one half are females who bear a child. The other half is females who successfully practice birth control. If there is an odd number of green cubes, flip a coin (heads = Yes, tails = No) to determine if the extra “green” female bears a child. For each birth, place a new cube from the stock box on the lab table, blank side up. Record the number of births in the same row in Data Table 2.

9. Without counting the total number of cubes now on the lab table, determine the present population size. Record this number as population size in the same row in Tat Table 2. Return all cubes from the lab table to the can.

10. Repeat 7-9 through year 2026.

Data Table 2

|Year |Number of Births |Number of Deaths |Population Size |Annual Growth Rate |

|2019 |----------------------- |------------------------- | |---------------------------- |

|2020 | | | | |

|2021 | | | | |

|2022 | | | | |

|2023 | | | | |

|2024 | | | | |

|2025 | | | | |

|2026 | | | | |

Part C:

11. Record the number of cubes now in the can as population size in the first row of Data Table 3. In the “year” column enter 2026.

12. Shake the can while holding it upright, and roll the cubes onto the lab table.

13. Record in Data Table 3, all events affecting population size. Use the following key: If the face of the cube pointing up is:

a. black – the individual has died. Record number of deaths in the next row of Data Table 3. Pick up all “black” cubes and return to the stock box.

b. Green – the individual is a female who has just borne one child. For each birth, place a new cube from the stock box on the lab table, blank side up. Record the number of births in the same row in Data Table 3.

c. Yellow – the individual is a female successfully practicing birth control. (do not add or remove cubes)

14. Without counting the total number of cubes now on the lab table, determine present population size. Record this number as population size in the same row in Data table 3. Return all cubes from the lab table to the can.

15. Repeat Steps 12-14 until year 2033.

Data Table 3

|Year |Number of Births |Number of Deaths |Population Size |Annual Growth Rate |

|2026 |----------------------- |------------------------ | |-------------------------- |

|2027 | | | | |

|2028 | | | | |

|2029 | | | | |

|2030 | | | | |

|2031 | | | | |

|2032 | | | | |

|2033 | | | | |

• Graph your results in Part A, plotting one point on the graph paper for each year for which you rolled cubes.

• Continuing the same graph, plot your results for Part B.

• Continuing the same graph, plot your results for Part C.

• Connect all points with straight lines.

• Use a dotted line to separate Part A, B, and C. Label the 1st section A, the 2nd B, and the 3rd C.

[pic]

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download