Deck 16: Species Diversity

Question 1

In a plot of species richness as a function of the number of samples taken

A) the asymptote represents species evenness.
B) additional samples after the asymptote will add little new information.
C) the slope of the line at the asymptote is a measure of beta diversity.
D) a bimodal curve indicates a high degree of endemism.
E) none of the above

Answer 1

B

Question 2

In a graph of the number of species as a function of their geometric abundance class,

A) rare species are found on the left tail of the curve.
B) rare species are found on the right tail of the curve.
C) species at the peak of the bell curve will be represented even in small samples.
D) a and c
E) b and c

Answer 2

A

Question 3

"Uncertainty" in the Shannon-Weiner Index

A) is a measure of species richness.
B) is a measure of species abundance.
C) is a measure of species richness and abundance.
D) refers to the variation inherent in sampling.
E) none of the above

Answer 3

C

Question 4

Which of the following are not regions with high species diversity?

A) ecotones
B) upland tropical forest
C) the deep ocean floor
D) peninsulas
E) none of the above

Question 5

In the species area equation S = cA^z ,

A) c is the competition coefficient
B) A is the area of the island
C) z is the tangent to the curve
D) the value of z is unknown for most islands
E) none of the above

Question 6

The global extinction rate began to increase

A) before humans migrated from Africa.
B) coincided with the development of agriculture.
C) began when humans became hunter-gatherers.
D) when the Pleistocene glaciers advanced.
E) none of the above

Question 7

The equilibrium number of species on an island

A) occurs when the extinction rate reaches zero.
B) is independent of island size.
C) occurs when immigration equals extinction.
D) occurs when no more species are able to immigrate.
E) none of the above

Question 8

On distant islands, the

A) extinction rate is higher.
B) equilibrium number of species is higher.
C) immigration rate is lower.
D) value of z is higher.
E) none of the above

Question 9

In the allopatric model of speciation,

A) hybrid matings are selected against.
B) species arise in the same region.
C) gene flow increases as speciation proceeds.
D) the populations must experience a single environment.
E) none of the above

Question 10

In the Court Jester model of diversity,

A) disturbances are predictable.
B) abiotic conditions change unpredictably.
C) biotic interactions are unimportant.
D) the geographic area is irrelevant.
E) none of the above

Question 11

In the lottery model of species diversity,

A) disturbance prevents species coexistence.
B) all species recolonize a site after disturbance.
C) after disturbance a subset of all possible species colonizes.
D) alpha and beta diversity are equal.
E) none of the above

Question 12

According to the intermediate disturbance hypothesis,

A) species diversity is highest when disturbance is rare.
B) species cannot colonize after intermediate disturbance.
C) competition eliminates species when disturbance is rare.
D) competition eliminates species when disturbance is common.
E) none of the above

Question 13

Which of the following does not depend on chance events?

A) the theory of island biogeography
B) the Court Jester model
C) the lottery model
D) keystone structures
E) none of the above

Question 14

Pre-mating reproductive barriers

A) generally arise before post-mating barriers.
B) are the result of local adaptation.
C) arise when hybrids are selected against.
D) facilitate gene flow.
E) none of the above

Question 15

In grasslands,

A) species diversity increased during drought.
B) species-poor communities were less affected by drought.
C) species-rich communities were less affected by drought.
D) evenness is correlated with drought resistance.
E) none of the above

Question 16

Which of the following was not a cause of mass extinctions in the fossil record?

A) tectonic movement
B) asteroids
C) changes in sea level
D) changes in solar output
E) none of the above

Question 17

When the habitat is complex, few species can survive.

Question 18

The Shannon-Weiner index of diversity measures gamma diversity.

Question 19

Species arise when gene flow between populations is inhibited.

Question 20

Biodiversity is the sum of alpha, beta, and gamma diversity.

Question 21

Islands have fewer species than the nearby mainland because there has not been sufficient time for species to colonize them.

Question 22

Habitats with moderate levels of disturbance have higher species diversity.

Question 23

In coral reefs, the Lottery Model results in low alpha diversity but high gamma diversity.

Question 24

In the Shannon-Weiner index (H = -∑ p_i ln p_i) the variable p_i represents the number of individuals in species i.

Question 25

The Yasuni forest in the Amazon is characterized by high but uniform species diversity.

Question 26

In Simberloff's experimental test of the theory of island biogeography, the same species were found on each island as had been present before the treatment.

Question 27

Ecological stability is the result of __________, the tendency of a system not to change when disturbed and __________, the ability of the system to recover.

Question 28

Define a species.

Question 29

Why do large islands have lower extinction than small islands?

Question 30

Explain why the immigration rate declines as a function of the number of species on an island.

Question 31

Explain why species diversity is low when disturbance is frequent in the Intermediate Disturbance hypothesis.

Question 32

How do the measures of diversity, species richness and evenness, differ?