Chapter 22

Question 1

A group of individuals that can exchange genetic material through interbreeding to produce fertile offspring.

Answer 1

Species

Question 2

As described by Ernst Mayr, the concept that “species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups.” The BSC is the most widely used and accepted definition of a species, but cannot be applied to Bacteria or Archaea.

Answer 2

biological species concept (BSC)

Question 3

Describes populations that have not yet diverged as separate species but whose genetic differences are extensive enough that the hybrid offspring they produce have reduced fertility or viability compared with offspring produced by crosses between individuals within each population.

Answer 3

partially reproductively isolated

Question 4

The idea that members of the same species usually look like each other more than like other species.

Answer 4

morphospecies concept

Question 5

Species that contain populations that are reproductively isolated from each other but can exchange genetic material through other, linking populations.

Answer 5

Ring Species

Question 6

Interbreeding between two different varieties or species.

Answer 6

Hybridization

Question 7

A complete description of the role a species plays in its environment.

Answer 7

Ecological Niche

Question 8

The concept that there is a one-to-one correspondence between a species and its niche.

Answer 8

ecological species concept (ESC)

Question 9

The idea that members of a species all share a common ancestry and a common fate.

Answer 9

phylogenetic species concept (PSC)

Question 10

Describes factors that prevent the fertilization of an egg.

Answer 10

pre-zygotic isolation

Question 11

Describes factors that cause the failure of the fertilized egg to develop into a fertile individual.

Answer 11

post-zygotic isolation

Question 12

Describes individuals that only mate with other individuals on the basis of specific courtship rituals, songs, and other behaviors.

Answer 12

behaviorally isolated

Question 13

Incompatibility between the gametes of two different species.

Answer 13

gametic isolation

Question 14

Structural configuration of the genitalia that prevents mating with another species.

Answer 14

mechanical incompatibility

Question 15

Pre-zygotic isolation between individuals that are reproductively active at different times.

Answer 15

temporal isolation

Question 16

Spatial segregation of individuals.

Answer 16

geographic isolation

Question 17

Pre-zygotic isolation between individuals that specialize ecologically in different ways

Answer 17

ecological isolation

Question 18

Describes populations that have not yet diverged as separate species but whose genetic differences are extensive enough that the hybrid offspring they produce have reduced fertility or viability compared with offspring produced by crosses between individuals within each population

Answer 18

partially reproductively isolated

Question 19

Describes populations that are geographically separated from each other.

Answer 19

Allopatric

Question 20

Allopatric populations that have yet to evolve even partial reproductive isolation but which have acquired population-specific traits.

Answer 20

Subspecies

Question 21

The process in which some individuals colonize a distant place far from the main source population.

Answer 21

Dispersal

Question 22

The process in which a geographic barrier arises within a single population, separating it into two or more isolated populations.

Answer 22

Vicariance

Question 23

A specific kind of allopatric speciation in which a few individuals from a mainland population disperse to a new location remote from the original population and evolve separately.

Answer 23

peripatric speciation

Question 24

The central population of a species.

Answer 24

mainland population

Question 25

An isolated population.

Answer 25

island population

Question 26

A period of unusually rapid evolutionary diversification in which natural selection accelerates the rates of both speciation and adaptation in a single lineage.

Answer 26

adaptive radiation

Question 27

A process in which two groups of organisms speciate in response to each other and at the same time, producing matching phylogenies.

Answer 27

co-speciation

Question 28

Describes populations that are in the same geographic location.

Answer 28

sympatric

Question 29

Speciation that occurs in a single generation.

Answer 29

instantaneous speciation

Question 30

The condition of having more than two complete sets of chromosomes in the genome.

Answer 30

Polyploidy

Question 31

The process by which diverging populations undergo natural selection in favor of enhanced pre-zygotic isolation to prevent the production of inferior hybrid offspring.

Answer 31

reinforcement of reproductive isolation (reinforcement)

Question 32

What are some different types of pre- and post-zygotic barriers and why are they important?

Answer 32

Pre-zygotic factors prevent fertilization from taking place, whereas post-zygotic factors result in the failure of the fertilized egg to develop into a fertile individual.

Question 33

Given a group of organisms, describe how you would test whether they all belong to one species or whether they belong to two separate species?

Answer 33

b

Question 34

Name two types of organisms that do not fit easily into the biological species concept. What species concept would work best for these organisms?

Answer 34

b

Question 35

Explain how ecological considerations can help inform whether or not a group of organisms represents a single species.

Answer 35

b

Question 36

Differentiate between allopatric and sympatric speciation, and state which is thought to be more common and why.

Answer 36

b

Question 37

Describe the random and nonrandom processes that result in speciation. Can both be considered evolution? Why or why not?

Answer 37

b