Transcript Chemical Mimicry

Chemical Mimicry
Submitted by:
Sean Brady
Matthew Forte
Michael Mourouzis
Lenora Overstreet
Dana Wilson
Chemical Mimicry
• The use of chemical signals may be the
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dominant form of communication in the insect
world.
Many insects have evolved highly complex and
specific chemical signals with which to
communicate within their own species.
It is not surprising that other organisms have
evolved the ability to exploit these
communication systems in order to fulfill their
own needs.
Chemical Mimicry
• One method of exploitation involves
mimicking the chemical signals used by
insects.
• In a system of chemical mimicry, a single
compound or a mixture of compounds is
produced by an organism to elicit a
specific behavioral response by an
organism of a different species.
Chemical Mimicry
• Chemical mimicry, which is used by vertebrates,
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invertebrates, plants and fungi, can be divided
into unique categories based on the outcome of
the relationship.
These different classes include aggressive
mimicry, reproductive mimicry, dispersal mimicry,
group mimicry, and predator mimicry.
Chemical Mimicry
• One of the most intriguing systems is the
use of chemical mimicry by plants in order
to attract insect pollinators.
• Most pollination systems have evolved as
mutualistic relationships in which both
organisms are rewarded:
Chemical Mimicry
• the insect obtaining pollen, nectar, waxes
or scents from the flower and the plant
achieving reproduction through the
transfer of its pollen by the insect.
Chemical Mimicry
• Chemical mimicry has evolved in
insect/flower systems where no reward is
received by the insect. The plant, which is
the sole benefactor, lures the insect to its
flower by producing specific scents. These
odors may mimic insect pheromones, food
sources, brood sites or prey odors.
Chemical Mimicry
• In addition to this, numerous examples of
pheromone and brood-site mimicry have been
observed. The similarities in compounds
produced by flowers and their insect pollinators
provides some possible explanations for
differences that have been found between insect
and plant-produced compounds. It is also true
that possible evolutionary patterns for various
classes of chemical mimicry exist.
Chemical Mimicry
• It is true that some flowers mimic the odors of
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dung and/or carrion to attract insects (mostly
beetles and flies) for pollination.
These systems are widespread in the plant
kingdom and have been extensively reported on.
This type of relationship is found in ten plant
families (Annonaceae, Araceae, Aristolochiaceae,
Asclepiadaceae, Burmanniaceae, Hydnoraceae,
Orchidaceae, Rafflesiaceae, Sterculiaceae, and
Taccaceae)
Chemical Mimicry
• In conclusion, many plants and animals use repellent
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chemicals to deter predation.
Millipedes secrete hydrocyanic acid when disturbed.
Some beetles squirt potential predators with such
mixtures as 85% acetic acid or 40% formic acid.
The discharge of the skunk is another familiar example.
But what if you have a powerful defensive weapon but
no potential predator notices until it has launched an
attack?
Examples
• Millipedes of the family Glomeridae, for
example, secrete a bitter substance (a
quinazoline) that repels birds;
Millipedes
• similar substances, differing only slightly in
molecular structure, are found in palms.
Ants
• Ants use specific mixtures of cuticular
hydrocarbons (CHCs) as recognition
labels, but this simple mechanism is
frequently circumvented by nest parasites
that engage in 'chemical mimicry' of their
host ants by producing or acquiring a
critical suite of these CHCs.
Ants
• Ants usually possess an elaborate
nestmate recognition system, which is
based on cuticular hydrocarbons and
allows them to distinguish nestmates from
non-nestmates through quantitative or
qualitative differences in the hydrocarbon
composition.
Ants
• Hence, living in a parabiotic association
probably necessitates changes of the
nestmate recognition system in both
species, since heterospecific ants have to
be accepted as nestmates.
Chemical Mimicry
• So, let’s think….
• Recall all that we have learned about the
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different types of mimicry presented in this
chapter…..
Describe the type of mimicry that you feel would
best analyze this situation….
Put this in your notes and ask questions if you
need to because this will be important on your
test….Good Luck!!!!