lec 15 Flashcards
competitive exclusion principle
In reality this does not happen because
- when two species compete directly for the same limiting resources; the more efficient speies will eliminate the other
- no two species have exactly the same requirement
the competivie exclusion principle applies to what is called a _______ ______
population niche
niche
the sum total of the biotic and abiotic resources an organism uses
If the niche’s of two or more species are very similar then
one or more species may be driven out of the habitat by competitive exclusion
Symbiotic relationship: ____________
The three types are _________
- an interaction between two or more species in which one species lives in close association with another species
- (parasitism, commensalism, mutualsim
parasitism
a kind of predator-prey relationship in which one organism, the parasite, derives its food at the expense of its symbiotic associate, the host
parasitic relationship
one species(parasite) benefits and the other species (host) is harmed
parasites increase their fitness by
using the host for food, habitat, and a means of dispersal
Parasatoidism
kill the host
Hosts have adaptations that minimize the effect of parasites
immune responses: ________
behavioral defenses: _________
- common in micro-parasitic infection and less common in macro-parastic infection
- may help a host avoid infection
commensalism
a type of symbiosis in which one organism benefits and the other one is neither harmed nor helped
mutalism
is a positive interaction between two species that can be characterized by a number of benefits
Examples of mutualism: Provision of \_\_\_\_\_\_\_\_ \_\_\_\_\_ from predators, herbivores and parasites \_\_\_\_\_\_\_\_\_\_ with a third species enhanced \_\_\_\_\_\_\_\_\_
- essential resouces
- protection
- reduction of competition
- reproduction
obligate mutualists
cannot survive or reproduce without the interaction
faculative mutualist
can survive and reproduce without eachother
Competition is
an interaction between two or more individuals that attempt to use the same resource, such as food, water sunlight or living space
Intraspecific competition
competitive interactions between two or more individuals of the same species
Interspecific competition
competitive interactions between two different species
Exploitation
a type of competition where organisms are competing for the same resource but not directly interacting
Interference
a type of competition where there is direct competitive interactions
Interspecific interactions
Consumption, preemption, overgrowth, chemical interaction, territorial, encounter
consumption competition
individuals of one species inhibit individuals of another by consuming a shared resource
pre-emption competition
individuals of one species prevent occupation of an area by individuals of another by getting there first
overgrowth competition
individuals of one species grow over individuals of another species, inhibiting access to a resource
chemical interaction competition
individuals of one species release growth inhibitors or toxins that inhibit or kill other species
Allelopathy in plants
secretion of chemicals that inhibit germination of other species
Territorial competition
The behaviour of one species, excludes another species from a specific location that is defended as a territory
Encounter competition
non-territorial encounter between individuals of different species that affects one or more of the individuals involved
resource partitioning
Based on the fact that over time, natural selection favours
A reduction in competition among coexisting species,
individuals of each species, that avoid or at least reduce competition for limited environmental resources
competitive release __________________________
when ________________
or _______
- results in the expansion of species niche
- a competitor is no longer present
- when a species invades a habitat that is free of potential competitors
Parasties must __________ and __________ before host death but often cannot ________
leave one host
relocate to another
do this at will
To successfully migrate a parasite must
adapt its own life history with the hosts feeding, mating, and social behaviors
natural selection favours strains that _____ a host without ________
- infect
- killing
