EXAM 2 Definitions

Question 1

surface-volume ratio

Answer 1

ratio which indicates the level of metabolic activity necessary, influencing “little r” and the life history strategies of an organism

Question 2

Hutchinson’s niche

Answer 2

n-dimensional hypervolume that defines a range of conditions for which dN/dt > 0

Question 3

isocline

Answer 3

the combination of abundances of N1 and N2 such that dN1/dt = 0

Question 4

allopatry

Answer 4

species are living apart

Question 5

sympatry

Answer 5

species are living together

Question 6

intraspecific competition

Answer 6

competition for resources within a species (related to logistic growth model)

Question 7

interspecific competition

Answer 7

competition for resources between species

Question 8

exploitation competition

Answer 8

population growth rates (dN/dt) are suppressed indirectly through the use of shared resources

Question 9

interference competition

Answer 9

behavior or an activity that directly reduces the exploitation efficiency of a competitor

Question 10

neutral equilibrium

Answer 10

in relation to predation, relationship stays at starting place unless forced to move

Question 11

stable equilibrium

Answer 11

in relation to competition stable coexistence (“case 3”), relationship eventually goes to a stable equilibrium point

Question 12

unstable equilibrium

Answer 12

in relation to competition unstable coexistence (“case 4”), relationship eventually goes to favor one side

Question 13

escape in numbers

Answer 13

prey avoid predation because predators are swamped by too many prey at one time (ex: periodical cicadas)

Question 14

escape in size

Answer 14

prey avoid predation by ??? (ex: oaks producing acorns)

Question 15

escape in time

Answer 15

prey avoid predation by being active at time that varies from/inhibits predator (ex: dessert mice)

Question 16

escape in space

Answer 16

prey avoid predation by utilizing spacial refuges (ex: sea star and mussels)

Question 17

senescence

Answer 17

aging and physiological deterioration of individuals in post-reproductive ages

Question 18

rescue effect

Answer 18

the reduction in the probability of extinction that occurs when more population sites are occupied so more individuals are able to boost population size

Question 19

metapopulation

Answer 19

a group of several local populations that are linked through immigration and emigration

Question 20

lynx and snowshoe hare

Answer 20

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)

Question 21

sea star and mussel

Answer 21

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

Question 22

character displacement

Answer 22

shifts in the body size or morphology of a species in the presence of a competitor (usually a separation)

Question 23

ecological assortment

Answer 23

extinctions lead to separation of species that are coexisting (population level process)

Question 24

evolutionary adjustment

Answer 24

neither A nor B go extinct but they undergo changes in morphology that causes them to be in less direct competition with each other