Biology 1001A Lecture 22:
29 Jan 2019
School
Department
Course
Prelecture:
On multiple choice exams, you should be able to identify...
How various types of interactions between species or between populations (predation,
parasitism, etc) affect each of the interacting parties
Meaning of coevolution
Meaning of commensalism, mutualism, and parasitism; and recognize examples of each
Why close mutualisms can be risky
Examples of adaptations evolved by plants or animals to avoid being eaten
Primary producers- supply energy (ex.plant)
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Primary consumers- eat primary producers (ex/rabbit)
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Secondary consumers- eat primary consumers
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Co-evolution: the evolution of genetically based, reciprocal adaptations in two or
more species that interact closely in the same ecological setting
Often involved more than two species
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Interaction
Balanc
e
Effects on Interacting Populations
Predation
+/-
Predators gain nutrients and energy; prey are killed or
injured
Parasitism
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Parasites gain nutrients and energy; plants are killed or
injured
Specialized predator-prey relationship
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Competition
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Both competing populations lose access to some
resources
Herbivory
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Herbivores gain nutrients and energy; plants are killed
Lecture 22
Wednesday, November 28, 2018
5:33 PM
tion,
ch
or
or
or
killed
or injured
Commensalism
-/0
One population benefits, the other is unaffected
Rare in nature
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Mutualism
+/+
Both populations benefit
Common (ex/ flowering plants and pollinating
animals)
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Symbiosis- when one species has a physically close ecological association with
another
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Endoparasites- live within a host
Ex/ tapeworms, flukes, and roundworms
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Generally complete their life cycle in one or two host individuals
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Ectoparasite- outside the host
Ex/ leeches, aphids, mosquitos
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Have elaborate sensory and behavioral mechanisms that allow them to
pinpoint a specific host
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Conspecifics- members of the same species
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Parasitoids- female lays her eggs in a larva or pupa of another insect species and h
young consume the tissues of the living host
Usually kills the host
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Blood feeders- animals that survive on the blood of other animals
Usually have chemicals in their saliva that stops clotting
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Must overcome clotting mechanisms once ingested and peripheral
vasoconstriction while removing
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Diseases can complicate
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Defense-
Size- too big to eat vs too small to be considered food
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Prey group- avoiding detection (safety of numbers)
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Camouflage
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Running away/hiding (tortoise)
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Offence
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Spines/Armour
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Chemical defense- can range from a bad taste to deadly
Milkweed- cardia glycosides
§
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Aposematic- bright patterns that "warn" predators about dangerous prey
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Mimicry- one harmless prey species disguising itself as a prey species that is
dangerous
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Document Summary
On multiple choice exams, you should be able to identify How various types of interactions between species or between populations (predation, parasitism, etc) affect each of the interacting parties. Meaning of commensalism, mutualism, and parasitism; and recognize examples of each. Examples of adaptations evolved by plants or animals to avoid being eaten. Co-evolution: the evolution of genetically based, reciprocal adaptations in two or more species that interact closely in the same ecological setting. Predators gain nutrients and energy; prey are killed or injured. Parasites gain nutrients and energy; plants are killed or injured. Both competing populations lose access to some resources. Herbivores gain nutrients and energy; plants are killed tion, ch or or or killed or injured. Symbiosis- when one species has a physically close ecological association with another. Generally complete their life cycle in one or two host individuals. Have elaborate sensory and behavioral mechanisms that allow them to pinpoint a specific host.
