lecture 23 Flashcards
competition
use or defense of a limiting resource by an individual that decreases resource availability to others
interspecific competition
between species
intraspecific competition
within a species
resources
factors used by an organism and affects pop growth rates
can 2 species that use resources exactly the same way coexist?
no because a species will extinct because of resource competition
gause principal is also called
competitive exclusion principal
competitive exclusion principal
two species cannot coexist in definitely on the same limiting resources, one species will die out
joseph grinnel idea of niche
the sum of the HABITAT requirement needed for a species survival and reproduction
charles elton idea of niche
the ROLE a species plays in a community
evelyn hutchinion idea of niche
combined these ideas
multidimensional hypervolume
allows a species to practice its way of life
dimension
environmental conditions/resources
fundamental niche
in the ABSENCE of biotic interactions like other species, this is where its capable of growing
realized niche
in the PRESCENCE of biotic interaction where it tends to grow with the other species present
two competitions can coexist but at
lower population densities
what are two ways species can minimize competition
partitioning resources and having a stronger competitor vs weaker competitor and predator-mediated coexistence
resource partitioning can cause
intraspecific competition to be greater than interspecific competition
two competitors will coexist when
the intraspecific competition is greater than the interspecific competition
rarity advantage
under these conditions a species gains a growth advantage, one species is at a low density and its competition is at a high density
the two outcomes of competition
- one competitor drives the other to extinction 2. both species coexist but at lower population densities, negative interaction
outcomes of other interspecific interactions
per capita growth rate of at least one species is modified and the avg pop density of at least one species differs
intraspecific competition causing evolution
goldilocks principal
goldilocks principal
individuals with optimal beak size will leave the most offspring, k will increase as birds that convert seeds into offspring come to pre dominate the pop
interspecific competition causing evolution
finches and insects presence, when bees are absent, finches are smaller and spend more time drinking nectar than when bees are absent
consumer resource interactions
leads to evolutionary arms race as prey continually evolve better defenses and predators continually evolve better offenses (red queen hypothesis)
