Two Simulations

On the machines in the Anthropology computer room you will find in the Applications folder is a program called "Simulate5hypercard". Open this program.

There are two simulations. We looked at the first simulation in the lecture last Friday, and will look briefly at the second in the coming lecture on March 10th.

You should run these yourself to comment on assessment D.2. We are not looking for any right answers here, just evidence that you have examined the problems and have drawn some conclusions.

To run the first simulation, Population and Harvest, click . This resets the simulation to the start.

To run the simulation one time period at a time (a month in this case), click in the far right hand lower part of the window.

This is instructive at first, but can get tedious. To run continuously, tick . Untick to stop.

This simulation will run forever if permitted, but it will soon stop doing anything interesting. That is, each month will be very similar to the last. This is usually referred to as convergence. Stop by unticking again.

You should be able to draw conclusions just by watching the simulation. What does the population growth and decline relate to? What happens to food reserves. What happens if you put in a larger amount of food reserves? More land area under cultivation? Increase the annual harvest. Change the rate of population growth ?

You can examine this more systematically by clicking on . A dialog box will come up asking you where to save results. Make sure you look and see where this is!

Look at

it now looks like .

Now tick

and let it run to convergence. Now click .

If you look in the folder where you saved the results, you will see a file called "Population Harvest 1" (or 2 or 3 depending on how many times you do this). If you drag this file over Appleworks in the dock or in the Applications folder, Appleworks will import it as a spreadsheet. You can now select the whole table, or parts of it and make charts of how the simulation proceeded. (See Make Chart in the "Options" menu).

Questions to think about:

• What are the implications of this simulation regarding population growth?
• What are the implications for development projects?
• What are the implciation relating to food aid?

---

Now lets look a the other simulation.

We covered the second simulation in the lecture. To get to this simulation click on either of the arrows at the bottom. .

In this simulation only the and

and

{Step once} are useful. Nothting to graph.

The basic premise of this simulation is to see what impacts gender preference of children might have in conjunction with ideal family compositions and the use of some form of birth control to work towards this ideal.

There are two new controls. The first denotes the strategies:

This is used to select a particular idea about what ideal composition of the family might be. In the simulation we have simlified things so that each woman will have a maximum of four children, but will stop as soon as the idea conditions are reached. The simulation is male-biased, as this reflect the norm among human socieites where sex biases exist. However, these are not universal, and if you substitue boys for girls and vice versa the results apply to female focused biases.

The questions we want to investigate are:

• What will be the impact on sex ratios for each strategy? Will it result in more boys, girls, or the same? Try to answer before running the strategy.
• What will be the impact on population growth of each strategy? Will it result in high population growth, or medium, low, or negative population growth?

(remberer that we are assuming as many men as there are women, so replacement (0 growth) will be double the number of women.)

To run a strategy tick the appropriate choice in

Then click on

and then on .

Make notes on each run and try to deal with the questions above.

Now note there is another control, .

This should start off ticked. It simulates results for an infinite population. If you untick the box, you will not get the same result every time you run the same strategy.

If you increase the number of woment to 1000 in the blank "Total Adult Women" then the simulation will run with 1000 women. This will take longer, but be more representative of a real population, which will not achieve the theoretical 50/50 balance between boys and girls under any strategy,including no strategy. It will be slower!

Likewise 10000 women will be more like the results in , but very slow. 100000 women will be very close to the theoretical choice.

So the choice simply simulates the results of a very large population. Otherwise we have to either wait a long time, or run the simulation many times to assess the impact of each strategy.