D.N.A
Objective: SWBAT propose an “Ecology Intervention” for
an ecological issue of their choosing and prepare a
statement to Congress
1. The organic and inorganic materials in all the organisms in the
diagram will eventually return to the environment by the action of
(A) decomposers
(B)
producers
(C)
primary consumers
(D)
secondary consumers
(E)
top carnivores
Use the diagram of the food web to identify the placement of each of
the following trophic levels
2.
3.
4.
5.
Primary producer
Omnivore
Decomposer
Top Carnivore
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D.N.A
Objective: SWBAT explain the relationship between
species richness, equability, and diversity.
1. An overlap in the niches of two species will most frequently result in
(A)
(B)
(C)
(D)
(E)
interspecific cooperation
a hybridization of species
a mutualistic symbiotic relationship
an increase in the biomass
interspecific competition
2. Competitive exclusion is most likely to occur between two
(A)
(B)
(C)
(D)
(E)
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closely related species occupying different niches
closely related species occupying the same niche
related species occupying different habitats
unrelated species occupying different niches
populations of the same species
organism
population
Community Ecology
community
ecosystem
biosphere
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Community Ecology
 Community

all the organisms that live together in a
place
 interactions
 Community Ecology

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study of
interactions
among all
populations
in a common
environment
To answer:
In what way do the
populations interact?
Four key characteristics of a
community
 1. Species diversity
 2. Dominant species
 3. Response to disturbances
 4. Trophic structure
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Niche
 An organism’s niche is its ecological role

habitat = address vs. niche = job
High tide
Competitive Exclusion
If Species 2 is removed,
then Species 1 will occupy
Low tide
whole tidal zone.
But at
lower depths Species 2
out-competes Species 1,
excluding it from its
potential (fundamental)
niche.
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Species 1
Chthamalus sp.
Species 2
Fundamental Realized
niches
niches
Semibalanus sp.
Niche & competition
 Competitive Exclusion

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No two similar species can occupy the
same niche at the same time
Interspecific interactions
 Symbiotic interactions

competition (-/-)
 compete for limited resource
 competitive exclusion!
predation / parasitism (-/+)
 mutualism (+/+)

 lichens (algae & fungus)

commensalism (+/0)
 barnacles attached
to whale
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Mutualism
OPEN WIDE: A cleaner
shrimp reaches into a
moray eel's mouth.
The shrimp uses its
claws to pick stuff off
the eel's body. That
can include dead
skin, tiny pieces of
food, and even little
creatures that can
hurt the fish.
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Mutualism
Example 2:
Bats get food from the flower. Seeds come out in bat poop.
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More examples of Commensalism
Clownfish hide in poisonous sea anemones which
protect them from larger fish. The clownfish
benefit, and nothing happens to the sea anemones.
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Parasitism
Female mosquito
feasting on human
blood.
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Predation drives evolution
 Predators adaptations

locate & subdue prey
 Prey adaptations

elude & defend Predation provides
horns, speed, coloration
a strong selection
pressure on both
prey & predator
spines, thorns, toxins
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Anti-predator adaptations
 Hide from predators
avoid detection
 camouflage

 Warn predators
advertise how undesirable
you are as prey
 aposematic coloration

 apo = away & sematic = sign/meaning
 Batesian mimicry
 Mullerian mimicry
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Defense mechanisms
 Camouflage

cryptic coloration
whipporwill
frog
lizard
lizard
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toad
Convergent evolution
Mimicry
Batesian mimicry
palatable or harmless species
mimics a harmful model
green parrot snake
hawkmoth larvae
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Hawkmoth larva puffs up to
look like poisonous snake
Convergent evolution
Batesian mimicry
Monarch male
Viceroy male
poisonous
edible
Which is the moth
bee?
fly vs.vs.
thethe
bee?
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fly
bee
moth
bee
Mullerian mimicry
two or more protected
species look like each other
Mullerian mimicry
- group defense?
- predators may evolve innate avoidance
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Common warning coloration
 Aposematic species come to resemble each other
black, red,
orange & yellow
means:
DON’T EAT ME!
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Coral snake
is poisonous
King snake is not
Red on yellow, poison fellow;
red on black, safe from attack
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Species diversity
greater diversity = greater stability
 Greater biodiversity
offers:
more food
resources
 more habitats
 more resilience
in face of
environmental
change

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