Research Projects

Try the suggestion below, design your own, or write an essay using any of the questions throughout this unit as inspiration.

Suggested Project: Bring up the Deer program again. Change the parameters in the Control menu.

The Size of a Deer (in screen pixels) determines how big the field is: Smaller deer means smaller squares on a field of constant size, and so a field that can accommodate more steps, more grass plots, and more deer.

A deer dies if it fails to step on a green square for a number of steps greater than the setting of the Number of steps without food.

The Time of grass restoration is the number of steps required before grass is restored to an "eaten'' square.

The Breeding age of deer is the number of step-cycles after birth at which a live deer has an offspring. Every live deer has one offspring every time it takes this number of steps.

Your first task is to find a combination of these settings such that the population of deer reaches a constant value and stays there-more or less! This is called a stable population. Be systematic about the search, writing down in your notebook each setting and the population outcome. Is there more than one combination of settings that achieve this goal? If so, is there a pattern of such settings?

Your next tasks are to find (i) which changes in the settings from this stable condition result in a more or less steady increase in population, and (ii) which changes result in a more or less steady decrease in population. Is there a pattern to these changes? Can you find changes that lead to an oscillating population, one that increases and decreases rhythmically or erratically?

How would adding a predator complicate the problem and change the outcome? A predator, such as a wolf, eats deer, has baby predators, and dies if it does not meet a deer after a given number of steps.

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