Download II. Community Interactions

II. Community Interactions (Chp 48)
Def. “all the populations of organisms inhabiting a
common environment and interacting with
one another”
Types of Interactions
A. Competition
1. Competitive exclusion - when two
species use the same limiting resource,
one is always eliminated
e.g. Paramecium caudatum and P. aurelia
2. Ecological niche - an organism’s role in the
environment (its profession, not its address)
a. Fundamental niche - determined by the
physiological limits of the organism
b. Realized niche - the portion of the
fundamental niche actually utilized due
to interactions with other species
•
e.g. Chthamalus and Balanus barnacles
c. Niche Partitioning – closely related
organisms that require the same resource will overlap
little to to allow competing species to coexist
•
e.g. five species of warblers
Think You Know Everything??????????
• The liquid inside young coconuts can be used as a substitute for blood plasma.
• No piece of paper can be folded in half more than seven (7) times.
• Donkeys kill more people annually than plane crashes.
• You burn more calories sleeping than you do watching television.
• Oak trees do not produce acorns until they are fifty (50) years of age or older.
• The first product to have a bar code was Wrigley's gum.
• The king of hearts is the only king without a mustache.
• American Airlines saved $40,000 in 1987 by eliminating one (1) olive from each salad
served in first-class.
• Venus is the only planet that rotates clockwise.
• Apples, not caffeine, are more efficient at waking you up in the morning.
B. Predation - eating of live organisms by
animals, plants, or fungi
1. Population control
2.Increases species diversity - keystone
predators maintain diversity by controlling
the number of potentially dominant species
Sea Stars (Pisaster) – control abundance of mussels
and barnacles
ii. Periwinkles (snails) – control diversity of algal species
i.
3. Drives evolution of predator and prey species
a. Speed, strength, teeth, intelligence
b. Defensive adaptations in plants
i. Structures - thorns and spines
ii. Chemicals - nicotine, morphine,
strychnine (poison), and cinnamon, cloves, or
peppermint (distasteful)
c. Defensive adaptation in animals
i. Concealment and camouflage - freezing,
burrows, protective coloration, warning
coloration, disguised appearance (walking
stick, peppered moth, frog looking like bird
dropping)
ii. Disagreeable taste, odor, or spray - stink
bug, monarch butterfly, bombardier
beetle
Bombardier beetles (Brachinus spp.) inject an explosive mixture of
hydroquinone, hydrogen peroxide plus several potent catalysts into
a reaction chamber in the abdomen. Catalase breaks down the
hydrogen peroxide into water and oxygen gas. Peroxidase oxidizes
hydroquinone into benzoquinone. The mixture of chemicals and
enzymes volatilizes instantly upon contact with the air, generating a
puff of "smoke"" and an audible popping sound. This caustic
flatulence is totally controlled by the beetle, otherwise it might
accidentally blow up its rear end. The explosive discharge
apparently discourages predators, either by chemical irritation, heat
or repugnance. The temperature of the explosive mixture of gasses
and fluids is over 100 degrees Celsius, the boiling point of water.
iii.
Mullerian mimicry - using similar
warning coloration
e.g. Yellow jacket, sandwasp
iv.
Batesian mimicry - harmless species
mimics unpalatable or dangerous species
e.g. viceroy and monarch butterflies, flies
and bees, hawkmoth larva and snake
Most dust particles in your house are made from dead skin.
The first owner of the Marlboro Company died of lung cancer. So did the first "Marlboro
Man."
Walt Disney was afraid of mice.
Pearls melt in vinegar.
It is possible to lead a cow upstairs...but not downstairs.
A duck's quack doesn't echo, and no one knows why.
Dentists have recommended that a toothbrush be kept at least six (6) feet away from a toilet
to avoid airborne particles resulting from the flush.
Richard Millhouse Nixon was the first U.S. president whose name contains all the letters
from the word "criminal." The second? William Jefferson Clinton.
Turtles can breathe through their butts
C. Symbiosis - close and long term
association between two species,
e.g. lichens = fungi + algae
1. Parasitism - one organism benefits, one is
harmed
- Plasmodium (malaria)
-mosquito
- tapeworm
2. Mutualism - beneficial to both organisms
- nitrogen-fixing bacteria
- PS algae in coral tissues
- acacias and ants
- protists in termite gut
- mycorrhiza = roots and fungi
- Leaf-cutter ant and fungus
3. Commensalism - beneficial to one, no effect
on other (hitchhikers)
- barnacles attached to whales
- worm in sea cucumber's anus
- clownfish and anemone