Lab 3: Demographics 

Fill this sheet out and submit via the link given in Blackboard.

· Begin by going to the following website: https://www.learner.org/courses/envsci/interactives/demographics/ 

· Then click the link labeled Open Simulator. 

· This will bring up a simulator, which is pre-loaded with demographic data from various countries. 

Part 1. Age Structure Diagrams

1. Using the tool provided on the website, examine the 2015 population, the growth rate, and the age structure diagram for each of the following countries. Match the overall profile of the age structure diagram to one of the shapes given below. 

Shape   1

Shape   2

Shape 3

Shape   4

Shape   5

Table of Age Structure Shapes to Match

2. Without changing any of the default settings for the country of interest, click the Step button 7 times, which advances the simulation to the year 2050. (Each click of the step button advanced the simulation 5 years). 

Write down the predicted population for 2050, as well as age structure shape that most closely matches the simulation. 

Enter all the data in the following data table: 

Table 1. 

Country

2015 

Population

2015 

Age Structure Shape 

2015 

Overall Growth Rate

2050 Population

2050 

Age Structure Shape 

2050

Overall Growth Rate

USA

Brazil

Nigeria

Questions:

3. What clues from the shape of the age structure diagram tell you whether a population has positive or negative growth rates? 

4. In our textbook, Figure 16.12 (p. 324) designates individuals in the ages of 0-14 as “pre-reproductive individuals”, and individuals between the ages of 15 and 44 as “reproductive individuals”.  Explain how we can get some idea of whether a population is growing or shrinking by comparing the population levels of pre-reproductive individuals to reproductive individuals. 

Part 2. Population Momentum

Call up the information for Nigeria (which is growing at a high rate). Enter the editing menu for the vital rates of birth by clicking on the pencil that is shown in the vital rates chart. When you get into the menu for editing the birth rates, look at the “Use rates from ______” feature. Use the pull down menu to select the values for the United States (which has a lower birth rate). 

Simulate what would happen if Nigeria were to suddenly have the birth rates of the United States. Click the Step button 7 times, which advances the simulation to the year 2050.

Questions:

5. What happens to the population immediately after the birth rate is abruptly dropped in this simulation? 

6. After the birth rate went down abruptly, in this simulation, at what point in the future did the simulation show that the population was leveling off or starting to decrease?

7. Why doesn’t the population level drop immediately when the birth rate is thus diminished?