EXAM 2 Definitions Flashcards
surface-volume ratio
ratio which indicates the level of metabolic activity necessary, influencing “little r” and the life history strategies of an organism
Hutchinson’s niche
n-dimensional hypervolume that defines a range of conditions for which dN/dt > 0
isocline
the combination of abundances of N1 and N2 such that dN1/dt = 0
allopatry
species are living apart
sympatry
species are living together
intraspecific competition
competition for resources within a species (related to logistic growth model)
interspecific competition
competition for resources between species
exploitation competition
population growth rates (dN/dt) are suppressed indirectly through the use of shared resources
interference competition
behavior or an activity that directly reduces the exploitation efficiency of a competitor
neutral equilibrium
in relation to predation, relationship stays at starting place unless forced to move
stable equilibrium
in relation to competition stable coexistence (“case 3”), relationship eventually goes to a stable equilibrium point
unstable equilibrium
in relation to competition unstable coexistence (“case 4”), relationship eventually goes to favor one side
escape in numbers
prey avoid predation because predators are swamped by too many prey at one time (ex: periodical cicadas)
escape in size
prey avoid predation by ??? (ex: oaks producing acorns)
escape in time
prey avoid predation by being active at time that varies from/inhibits predator (ex: dessert mice)
escape in space
prey avoid predation by utilizing spacial refuges (ex: sea star and mussels)
senescence
aging and physiological deterioration of individuals in post-reproductive ages
rescue effect
the reduction in the probability of extinction that occurs when more population sites are occupied so more individuals are able to boost population size
metapopulation
a group of several local populations that are linked through immigration and emigration
lynx and snowshoe hare
originally was the standard example of the Lotka Volterra model until it was understood that the hares were cycling with vegetation, not their predator (the lynx)
sea star and mussel
example of escape by space coexistence strategy; mussels inhabit high tide zones where sea stars can’t reach them and are kept in check by the sea star population which preys on the mussels that try to expand downward
character displacement
shifts in the body size or morphology of a species in the presence of a competitor (usually a separation)
ecological assortment
extinctions lead to separation of species that are coexisting (population level process)
evolutionary adjustment
neither A nor B go extinct but they undergo changes in morphology that causes them to be in less direct competition with each other
