Download Predators and Prey • Predator – an organism that hunts and kills

Predation and Symbiosis | DAT
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Predators and Prey
• Predator – an organism that hunts
and kills other organisms for
food
• Prey – an organism that is hunted
• Predator-prey relationships are
one of the most selective
evolutionary forces
o Organisms that are welladapted to evade capture
will survive against
predation
Bright Coloration of Bees
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Evolutionary Adaptations of Prey
• Prey might evolve physical
obstacles to predation
o A porcupine’s quills
o A rose’s thorns
Their unique coloration helps
would-be predators recognize
them as poisonous
o After being stung, a
predator will resolve to
not prey upon bees
o The bees’ coloration
makes it easy for the
predator to recognize and
avoid other bees it
encounters
Mimicry
• In a phenomenon known as
mimicry, some species emulate
the appearance and behavior of
other species in order to protect
themselves against predation
• For example, some nonpoisonous flies have actually
adapted black/yellow striations
similar to those exhibited by bees
o Predators identify the
flies as bees, and don’t
prey upon them
Physical Protection for Prey
Prey might adapt physical barriers for protection
against predators.
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Some organisms, like bees, have
pursued the opposite
evolutionary route
o Rather than blend in with
their environment, they
exhibit bright coloration
Camouflage is a tactic employed
by prey to help them blend in
with the environment
o Such that predator’s don’t
see them
Camouflage
Camouflage allows prey to blend in with their
environment, aiding in their ability to evade
predation.
Mimicry
Some non-poisonous flies present themselves
with color similar to those of bees. Predators,
believing that the flies are unpalatable, do not
prey upon them.
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© 2017 J Co Review, Inc., Accessed by Guest on 04-30-2017
Predation and Symbiosis | DAT
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Coevolution
• There is an evolutionary backand-forth between predators and
prey
• Consider the Heliconius butterfly
and the passionfruit vine
This phenomenon, whereby a
palatable (non-poisonous)
organism mimics an unpalatable
(poisonous) one is called
Batesian mimicry
In another phenomenon, known
as Mullerian mimicry, two
unpalatable species emulate one
another
o This reinforces their
recognition among
predators
Heliconius Butterfly and Passionfruit Vine
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(a)
(b)
Mullerian Mimicry
The (a) Viceroy and (b) Monarch butterflies are
both poisonous independently. But, by
mimicking one another’s appearance, they
reinforce their recognition among predators; a
predator that has learned not to prey upon
Viceroy butterflies will also avoid preying upon
Monarch butterflies.
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Evolutionary Adaptations of
Predators
• Like prey, predators also adapt;
they refine their hunting abilities
o Venomous snakes use
poison to kill or
immobilize prey
o Cheetahs can outrun their
prey
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(a)
(b)
Evolutionary Advantages of Predators
(a) Venomous snakes can kill or immobilize
their prey. (b) Cheetahs are well-equipped to
outrun their prey.
The vines contain a toxin that
thwarts would-be predators
But butterfly larvae have evolved
tolerance to the toxin, making the
vines a good source of
sustenance for larvae
In response, the vines have
imprinted their leaves with spots
that look like butterfly eggs
o Butterflies, believing that
the vine’s leaves are
already inundated with
eggs, lay their eggs
elsewhere
They don’t want
to lay their eggs
on a leaf where
there will be
competition for
sustenance
This back-and-forth evolutionary
relationship is called coevolution
o The predator and prey
induce the evolution of
one another
Symbiotic Relationships
• There are several types of
observable interspecific
relationships
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© 2017 J Co Review, Inc., Accessed by Guest on 04-30-2017
Predation and Symbiosis | DAT
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o Known as symbiosis
Mutualism – benefits both
species in the relationship
Commensalism – benefits one
species and doesn’t affect the
other
Parasitism – benefits one species
and harms the other
Amensalism – doesn’t affect one
species and harms the other
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© 2017 J Co Review, Inc., Accessed by Guest on 04-30-2017