causal+patterns+in+ecology

Harvard University's Project Zero

Learning Ecology through Causal Patterns. Students look at models such as domino causality and cyclic causality and discuss the food web, food chain, and energy pyramid. The discussion moves away from memorizing and focuses on actual understanding. I have used this model in my study of chemistry and botany, as well.

Students can't stop playing the energy pyramid game.



Domino and Cyclic Causality

Below is a great page that explains the different causal patterns we have been discussing in class. We have only mentioned linear, domino, and cyclic causality so far this year. Later in the year, we will touch on the other causal patterns mentioned on this page. There are nice applications to literature, history, and science for these different causal patterns that were developed from research at Harvard University.

Different Causal Patterns


 * Below is a link that provides different videos. Guess whether these are examples of linear, cyclic, or domino causality. **

Causal Pattern Videos

The difference between linear and domino causality is that linear is when something is directly effected by something such as when a hawk eats a mouse. domino causality is less direct. an example is when a hawk population dies out and the mouse population grows. because the mice eat plants then the plant population would die down and so on.


 * Causal Patterns Questions **


 * 1. Give an example of Domino Causality in our Garden. Draw a picture or diagram and explain how the model works in the garden. **

The BEST example of domino causality in the garden following the route of the Sun that hits the garden during the day. The energy of the sun is used in the process of photosynthesis. Sugar is made and then used by the plant for growth. An animal may eat the plant (like the squirrel, rabbit, or deer). When plants and animals die they will be eaten by decomposers. Its domino because there is a clear beginning. You can not cycle back to the sun. The energy branches out in a food web like our text book domino demonstration.


 * 2. Give an example of Cyclic Causality in our Garden. Draw a picture or diagram and explain how the model works in the garden. **

An example of cylic causality is when the plant dies, the plant material is absorbed into the earth. The atoms (carbon, nitrogen, hydrogen, oxygen, etc.) from the dead plant are then available to be absorbed by another plant, which when it dies, starts the entire cycle again.

Another example is when a plant dies it is broken down by Bacteria and then it is made into other compounds (suger, Carbon dioxide) and reproduced to grow another plant. And the cycle would continue...... Or an animal would eat the plant and the energy would be past to the animal. and then to another animal. and so on.


 * 3. Would **ENERGY **in a Food web be illustrated best using a Domino Model or a Cyclic Model? **

It would best be illustrated in a Domino model because you can see that if one thing dies it really affects everything else.

The energy cycle would be best represented in a domino causality because the energy keeps branching out over the ecosystem in different animals and plants. This would also be good too because energy never comes back to the sun, or the first domino.

I know that energy can't go back to the sun but energy can only be changed and reused. That's why I think It should be a Cycle.


 * 3. Would **MATTER **(Atoms) in a Food web be illustrated best using a Domino Model or a Cyclic Model? **

It would best be illustrated in a Cyclic Model. there is no clear begining