Transcript Relationships Research Project

Symbiosis Review
Relationships in Ecosystems
• There are many ways that organisms interact
with each other within ecosystems
• We have previously studied food webs as a
way to map the flow of energy through an
ecosystem from the sun to top consumers and
back to producers again
• There are more complex relationships that we
will explore next
Symbiosis
• Symbiosis describes any long-term relationship
between two organisms from different species
• These relationships usually benefit one organism
• The other organism may
– 1) benefit as well (mutualism)
– 2) be harmed by the relationship (parasitism)
– 3) neither benefit nor be harmed by the relationship
(commensalism)
Mutualism
• Mutualism describes a type of long-term
relationship between two organisms in which
BOTH organisms benefit
• Example:
– Clownfish and sea anemones
• Who benefits? Who is harmed?
– Bird eating ticks off of cow
• Who benefits? Who is harmed?
Commensalism
• Commensalism describes a type of long-term
relationship between two organisms in which
one organism benefits, and the other is
unaffected
• Example:
– Remora hitching a ride on a shark
• Who benefits? Who is harmed?
Parasitism
• Parasitism describes a type of long-term
relationship between two organisms in which
one organism benefits, and the other is
harmed
• Example:
– Parasitic fish “lice”
• Who benefits? Who is harmed?
What is ammensalism?
• Ammensalism is the ecological
interaction in which an individual
species harms another without
obtaining benefit.
• This type of symbiotic relationship is
common, but not considered an
important process structuring
communities because they are
“accidental” and do not benefit the
species doing the harm
• It is a 0/- relationship
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Examples of Ammensalism
• Elephants stepping on ants or leveling brush
does not benefit the elephant but causes
harm
Examples of Ammensalism
• Algal blooms can lead to the death of many
species of fish and other animals, however
the algae do not benefit from the deaths of
these individuals
Examples of Ammensalism
• One of the best examples of ammensalism is
the one established between humans and
other species under extinction due to human
actions like habitat devastation by fires,
ecological accidents, pollution of water, etc.
Examples of Ammensalism
• One way scientists have used ammensalism
to help humans can be found in the
relationship of the bread mold penicillium
with bacteria. Penicillium releases a
chemical called penicillin which kills
bacteria without benefiting the bread mold.
Luckily we use this secretion as medicine!
Unfortunately science is slow
• Rheumatic heart disease is a chronic (long-term) heart condition
caused by rheumatic fever
• Rheumatic fever is caused by a preceding group A streptococcal
(strep) infection
• Treating strep throat with antibiotics can prevent rheumatic fever
• Moreover, regular antibiotics (usually monthly injections) can
prevent patients with rheumatic fever from contracting further
strep infections and causing progression of valve damage.
• Rheumatic heart disease is known as a disease of poor people
because it leads to 15 million or more cases of heart disease that
requires open heart surgery, all in areas where antibiotics are
unavailable
A Summary of Symbiotic Interactions
Influence of Species B
Influence of species A
-
A
- (negative)
0 (neutral/null)
+ (positive)
+
0
+
+
Mutualism
B
A
-
B
Amensalism
A
Parasitism
A
+
B
A
B
0
0
Amensalism
Commensalism
0
-
+
B
A
+
Parasitism
B
+
0
A
B
+
Commensalism
A
+
Mutualism
B
Class Review
• Split into four groups, each with a different
colored marker
• You will rotate as the star board displays a
different task
• Each group will begin at a different type of
symbiosis (please label all four)
Class Review
• Task 1: What is the definition of your group’s
type of symbiosis?
• Task 2: What is an example (without
explanation) of your group’s type of symbiosis
• Task 3: Explain the example given by the
previous group
• Task 4: What is a second example WITH
explanation of your group’s type of symbiosis?
Review game
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•
•
•
Ring toss game
Four teams
You will answer questions as a team
If you get the answer correct
– Your team receives 1 point
– Your team may choose one person to throw for
bonus points
• If a team gets a question incorrect, the other
team may steal
For the quiz
• Be prepared to answer 4 open ended questions
that require:
• Identification of which species
benefits/harmed/neither for any situation
• Identification of which type of symbiosis is
observed supported by evidence
• Prediction of changes in population if the
population of one species from a symbiotic
relationship is altered
• Review the study guides on the class page