Download “Mutualism” (PAGE 9)

N O T E
“Mutualism” (PAGE 9)
LESSON PLAN BY JEFFREY SPITZER
Can the animal world provide us with models of ethical behavior? Students
will explore the concept of mutualism as it appears in the animal world
and as it “seems” to appear in Rabbinic texts. They will learn that the
model of mutualism in the animal world is not exactly what the Rabbis had
in mind.
BABAGANEWZ TEACHERS’ GUIDE TISHREI 5763
CONCEPTS AND OBJECTIVES
k Students will examine a spectrum of different
kinds of “cooperative” behaviors and place animal
“mutualism” and “commensalism” on that spectrum in contrast with Jewishly motivated cooperative behaviors.
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MOTIVATION AND DEVELOPMENT
1. Carefully examine each of the three examples of
mutualism presented in the article. Describe the
benefits that each party gains from the relationship.
This can often be seen broadly as defense (the crocodile is defended by the plover against infection and
disease, and the dairying ants fight off insects threatening the plant lice), but can be seen more specifically as “hygiene” or “shelter “ or “sustenance.”
T E A C H I N G
How do the natural models fit with the texts’ reason for
why two are better than one?
3. Introduce the concept of commensalism.
Commensalism is a symbiotic relationship in which
one species benefits while the other species neither
benefits nor is harmed. Birds and the trees they nest
in are in a commensal relationship; the birds benefit and the trees are unharmed.
N O T E
Other examples of commensalism: Suckerfish attach
themselves to sharks and benefit from eating the crumbs
from the shark’s feeding. This neither benefits nor harms
the sharks. Clownfish, which are immune to sea anemones’
stings, get protection from the sea anemone (this is often
reported as mutualism, but research has shown that the
anemone really gets no benefit from the clownfish).
T I P
Ask the students to research other examples of mutualism:
e.g., termite ants and the cellulose-digesting protozoa they
carry around in their bellies; nutcracker birds and pine trees
(the birds get food and disperse the seeds); lichens that
consist of a fungus and an algae growing together (fungus
gets food from the photosynthesizing algae and the algae
gets a place to live). Determine what type of help each
party in the relationship receives.
2. Read the verses from Ecclesiastes 4:9–10 and the
accompanying commentary from Sefer H
. iddushei
Aggadot.
Ask the students if one relationship—mutualism or
commensalism—is “better” than the other, and why
they think so. Possible responses might include that
mutualism is better because both benefit while commensalism is “freeloading.” An (unlikely) alternative
response might be that commensalism is “better”
because the one gives freely without expecting anything in return.
If the students don’t come up with the second
response, raise it yourself and then ask:
Is it appropriate to judge animal behaviors?
If these were human behaviors, which relationship would
you think is “better”?
4. Instruct students to consider the following cases.
(The cases are available to print and distribute at
www.babaganewz.com.)
How does each compare to the cases you have already
assessed?
Identify whether any of the cases are analogous to either
mutualism or commensalism.
A. Ariel hates putting things away and Dani hates dusting and
vacuuming. Both are required to clean their rooms. Ariel and
Dani agree that Dani will straighten up both rooms, and Ariel
will dust and vacuum both rooms.
Sefer H
. iddushei Aggadot, vol. 3, p. 106,
Bava Batra
“Two are better than one,” for what is lacking in one is
found in the other.... For the one is not complete
(shalem), but when they are two, then creation is
complete and without lack....
Why are two better than one?
Is this an example of mutualism? If yes, how? If not, why
not?
How does the commentary elaborate on the original text?
The Hebrew word shalem, meaning “complete,” is related
to the word shalom. How is being whole and complete
related to peace?
Pirkei Avot 5:10
C. Ariel and Dani are siblings. Ariel has a lot of homework
tonight, and Dani has none. Ariel asks Dani to clean the
kitchen for him tonight, and he’ll clean it for her tomorrow
when it’s her chore. She says no.
One who says, “What is mine is mine and what is
yours is yours,” this is an average characteristic, but
there are those who say this is the characteristic of
Sodom. One who says, “What is mine is yours and
what is yours is mine” is a simpleton. [One who
says,] “What is mine is yours, and what is yours is
yours” is virtuous....
D. Ariel and Dani are on an airplane flight. They are hungry
and ask the attendant for a snack, and they get strawberries.
Ariel is allergic to berries. Dani asks him if she can have his.
He says yes.
Why is the first person described considered average? Why
might others call this model one of Sodom?
[The inhabitants of Sodom were infamous for their selfishness and their lack of concern for others.]
Case A is analogous to mutualism—both Ariel and
Dani benefit. Case B could be an example of either
mutualism or commensalism, depending upon
whether you think Ariel has benefited from giving
help. Case D is analagous to commensalism. One
benefits and the other is unharmed. Case C is also like
commensalism, but the unharmed persons refuses!
Which model of behavior most closely resembles mutualism?
Why is the model that suggests sharing attributed to a simpleton? How is this simplistic behavior?
Why is the third type of person in the mishnah described
as virtuous? How does this person exhibit behavior that is
beyond mutualism? Is this the behavior God expects from
us? Do you think that this is a fair standard? Explain.
Why did Dani say no in case C? Have you ever refused to
do something that would not harm you but would benefit
someone else?
FOLLOW-UP AND ENRICHMENT
Hold the following class discussion:
Should Ariel and Dani’s parent be able to force Dani to
switch nights for cleaning the kitchen?
Can models of animal behavior be models for human
ethics? Why or why not?
5. Study the text from Pirkei Avot. How does this
text help convey the idea that humans must behave
above and beyond the natural relationships
described in the article? According to this text, what
is appropriate behavior for people?
Symbiosis means living together. There are two other
models of symbiosis (in addition to mutualism and
commensalism), both of which are much more common. One is parasitism/predation in which one partner benefits and the other is harmed. The other is
competition, in which both species are harmed by the
presence or activities of the other. Humans engage in
predatory and competitive activities as well. Is this ethical? Is this inevitable? Why did BABAGANEWZ publish
an article in this issue on mutualism, and not one on
predation?
JEWISH TEXTS
Ecclesiastes 4:9–10
Two are better than one; because they have a good
reward for their labor. For if they fall, the one will lift
up his fellow....
BABAGANEWZ TEACHERS’ GUIDE TISHREI 5763
B. Dani can’t reach the hooks where she is supposed to store
her bike for the winter. Ariel, who is taller, puts her bike up for
her.
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