competition

Question 1

biological community

Answer 1

consists of all of the species that interact in a certain area.

Question 2

commensalism

Answer 2

occurs when one species benefits but the other species is unaffected (+/0).

Question 3

competition

Answer 3

occurs when individuals use the same resources – resulting in lower fitness for both (-/-).

Question 4

consumption

Answer 4

È including herbivory, predation, and parasitism; occurs when one organism eats or absorbed nutrients from another. The interaction increases the consumer’s fitness but decreases the victim’s fitness (+/-).

Question 5

mutualism

Answer 5

occurs when two species interact in a way that confers fitness benefits to both (+/+).

Question 6

coevolution

Answer 6

pattern of evolution where two species influence each other’s adaptations over time.

Question 7

coevolutionary arms race

Answer 7

repeating cycle of reciprocal adaptation.

Question 8

Intraspecific (“within species”) competition

Answer 8

competition that occurs between members of the same species. Competition for space, sunlight, food, and other resources intensifies as a population’s density increases. Major cause of density-dependent growth.

Question 9

Interspecific (“between species”) competition

Answer 9

occurs when individuals from different species using the same limiting resources. Occurs when the niches of two species overlap.

Question 10

niche

Answer 10

range of resources that the species is able to use, or the range of conditions it can tolerate.

Question 11

symmetric competition

Answer 11

both species experience a similar decrease in fitness due to the overlap of their niches. Both species may persist in the area of overlap, even if in reduced numbers.

Question 12

asymmetric competition

Answer 12

one species suffers a greater fitness decline than the other species does.

Question 13

competitive exclusion principle

Answer 13

Gause proposed that two species that occupy the same niche cannot coexist.

Question 14

fundamental niche

Answer 14

the total theoretical range of environmental conditions that a species can tolerate.

Question 15

realized niche

Answer 15

the portion of the fundamental niche that a species actually occupies, given limiting factors such as competition with other species.

Question 16

Common experimental strategy in competition studies:

Answer 16

one of the competitors is removed, and the response by the remaining species is observed.

Question 17

Because competition is a -/- interaction

Answer 17

there is strong natural selection on both species to avoid it. An evolutionary change in traits reduces the amount of niche overlap, and thus the amount of competition.

Question 18

Niche differentiation (resource partitioning)

Answer 18

an evolutionary change in resource use, caused by competition over generations.

Question 19

character displacement

Answer 19

the evolutionary change that occur in species’ traits, and that enables species to exploit different resources. Makes niche differentiation possible.