Learning Exercise

COMPETENCE / NATURAL SELECTION

The Ecosimulator programme allows you to simulate the development of populations and some interspecific relationships in ecosystems, as well as some aspect of Natural Selection.

This time we are going to study interspecific competence as well as Natural Selection

Open the programme or the ECOSIMULATOR website. Go to Simulate > Data Entry.

In Standard Simulations choose "Competition 1", or enter data by hand:

Generations (sweeps) to graph:  50

Time for grass to grow: 0

RABBITS: Initial number=8  ; Maximum life=8  ; Points to eat=5  ; Distance when moving=10  ;

HARES: Initial number=8  ; Maximum life=8  ; Points to eat=6  ; Distance when moving=10;

Speed=average

Click "Start" and observe the populations development.

When the number of chosen sweeps is reached, click "Graph".

(To study Natural Selection here, you only have to think that the hare is nothing more than a mutant of the rabbit and not a different species.)

QUESTIONS to choose for your teacher:

1.      Draw in your notebook the graph obtained. And write down all the events or details that you find interesting.

2.      Describe in your own words the graph obtained. Do both species survive? What is the difference in data between both species? How can the data influence the graph obtained?

3.      Try now the "Competition 2" simulation. Copy in your notebook the graph obtained. How is it different from the previous simulation? What gives rabbits an advantage in this case?

4.      Do you know of any examples in which this type of graph is produced or could be produced?

5.      Define: competition, food chain, ecological niche.

6.      Search and copy in your notebook what the "Gause Exclusion Principle" says.  What does it have to do with your graphs? What beings did Gause experiment with?

7.      Now try the "Competition 3" simulation. Who are competing in this case?

8.      Try modifying the data to study other cases of competition, for example, could the size of the initial populations influence?

9.      Try in another simulation, also to modify between both just the maximum life. Does it have any effect?

10.   Write down the concept of mutation in your notebook. Debate: Could there be mutations in the human species that were affected by Natural Selection?