We did an experiment in science where we went outside and played a simulation. It was a game where there were one shark and four minnows and the rest of the class were seaweed. To survive, the shark has to eat two minnows, and to reproduce, it has to eat four minnows. The minnows have to eat one seaweed to survive and two seaweed to reproduce.
The first trial was really bad because we had no strategy. The shark died in the first round, same with one minnow. Then two of the three minnows ate way too much. They ate 9 seaweed each, which meant there were a lot more minnows then seaweed. Which meant that in a few rounds, the seaweed would be gone, which meant the minnows have nothing to eat which meant they go extinct.
The top image below shows the line graph of the bad run.
Then we figured out a strategy where the shark only ate 2 minnows and the minnows only ate 2 seaweed. We kept on doing that and we did really well. We ended with over 90 seaweed and 2 sharks and 8 minnows. We could do that forever and have over 1000 of each thing.
The bottom image below shows the line graph of the good run.
This teaches us that it is important to for each species to have enough to eat, and have a good balance between the numbers of them. That way, the cycle can just keep going without one of the species going extinct.