Deck 23: Species and Their Formation

Question 1

What did the experiments by Rice and Salt with fruit flies show?

A) Speciation can be studied in the lab.
B) The evolution of reproductive isolation requires more than one hundred generations.
C) Acetyldehyde can be used to keep flies from being species.
D) Both a and b
E) Both a and c

Answer 1

A

Question 2

Which of the following is often associated with higher rates of speciation?

A) Sexually dimorphic compared with sexually monomorphic birds
B) Insects with specialized diets compared with insects with generalized diets
C) Species with low dispersal ability compared with species with high dispersal ability
D) Plants with animal pollination compared with plants with wind pollination
E) All of the above

Answer 2

E

Question 3

The biological species concept defines a species as a group of

A) actually interbreeding natural populations that are reproductively isolated from other such groups.
B) potentially interbreeding natural populations that are reproductively isolated from other such groups.
C) actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.
D) actually or potentially interbreeding natural populations that are reproductively connected to other such groups.
E) actually interbreeding natural populations that are reproductively connected to other such groups.

Answer 3

actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

Question 4

Finches speciated in the Galápagos Islands because

A) the Galápagos Islands are not far from the mainland.
B) the Galápagos Islands are thought to promote sympatric speciation in birds.
C) hybridization across different island populations of finches led to high levels of polyploidy.
D) the islands of the Galápagos archipelago are sufficiently isolated from one another that there is little migration among them.
E) the islands of the Galápagos archipelago are close enough to one another that there is considerable migration among them.

Question 5

Which of the following is a major limitation of the morphological species concept?

A) It requires detailed knowledge of genetics and mating behavior.
B) Males and females of a single species do not necessarily look alike.
C) It is a very recent concept.
D) It is incompatible with the binomial system of classification.
E) It cannot be used in field guides.

Question 6

Even trained biologists have difficulty telling females of Drosophila melanogaster and D. sechellia apart, and yet these species are reproductively isolated. Thus, these species are considered _______ species.

A) lineage
B) morphological
C) cryptic
D) Coyne's
E) sympatric

Question 7

The content of most standard field guides reflects _______ species concept.

A) the biological
B) the lineage
C) Templeton's
D) the ecological
E) the morphological

Question 8

Which of the following is not a condition expected to favor allopatric speciation?

A) Continents drift apart and separate previously connected lineages.
B) A mountain range separates formerly connected populations.
C) Different environments on two sides of a barrier cause populations to diverge.
D) The range of a species is separated by loss of intermediate habitat.
E) Tetraploid individuals arise in one part of the range of a species.

Question 9

Which of the following is not a potential prezygotic reproductive barrier?

A) Temporal segregation of breeding seasons
B) Differences in chemicals that attract mates
C) Hybrid infertility
D) Spatial segregation of mating sites
E) Sperm that cannot penetrate an egg

Question 10

Speciation is an important component of evolution because it

A) generates the variation on which natural selection acts.
B) generates the variation on which genetic drift and mutations act.
C) enabled Charles Darwin to perceive the mechanisms of evolution.
D) generates the high extinction rates that drive evolutionary change.
E) has resulted in a world with millions of species, each adapted for a particular way of life.

Question 11

Which of the following species concepts would have great difficulty with the classification of cryptic species?

A) The morphological species concept
B) The lineage species concept
C) The biological species concept
D) Both b and c
E) None of the above

Question 12

Evolutionary radiations

A) happen often on continents but rarely on island archipelagoes.
B) characterize birds and plants but not other groups of organisms.
C) have happened on continents as well as on islands.
D) require major reorganizations of the genome.
E) never happen in species-poor environments.

Question 13

The binomial system of nomenclature, by which we still classify species, was originated by

A) Charles Darwin.
B) Thomas Malthus.
C) Carl Sagan.
D) Ernst Mayr.
E) None of the above

Question 14

Which statement about speciation is not true?

A) It always takes thousands of years.
B) Reproductive isolation may develop slowly between diverging lineages.
C) Among animals, it usually requires a physical barrier.
D) Among plants, it often happens as a result of polyploidy.
E) It has produced the millions of species living today.

Question 15

Which of the following statements about Cuatro Ciénegas is true?

A) Despite being a desert, it has many aquatic species.
B) It is home to species found nowhere else in the world.
C) It has always remained connected to the rest of northern Mexico.
D) Both a and b
E) Both b and c

Question 16

A common means of sympatric speciation is

A) polyploidy.
B) hybrid infertility.
C) temporal segregation of breeding seasons.
D) spatial segregation of mating sites.
E) imposition of a geographic barrier.

Question 17

Carolus Linnaeus

A) originated the binomial system of nomenclature.
B) differentiated species based on the biological species concept.
C) classified species based on morphology.
D) Both a and c
E) Both b and c

Question 18

Narrow hybrid zones may persist for long times because

A) hybrids are always at a disadvantage.
B) hybrids have an advantage only in narrow zones.
C) hybrid individuals never move far from their birthplaces.
D) individuals that move into the zone have not previously encountered individuals of the other species, so reinforcement of reproductive barriers has not occurred.
E) Narrow hybrid zones are artifacts because biologists generally restrict their studies to contact zones between species.

Question 19

The classification of organisms based on their appearance is known as _______ species concept.

A) the biological
B) Mayr's
C) the phylogenetic
D) the allopatric
E) the morphological

Question 20

What was the main reason that flies became reproductively isolated from one another in Rice and Salt's experiments?

A) Chromosomal changes
B) Gene flow
C) Genetic drift
D) Evolved preferences for different habitats
E) Reinforcement

Question 21

The biological species concept does not apply to which of the following groups of organisms?

A) Birds
B) Mammals that form monogamous pair bonds
C) Asexual fungi.
D) Fungi that engage in sexual reproduction
E) Cryptic species

Question 22

Which of the following factors led to the diversification of Darwin's finches?

A) Environmental conditions vary among the different islands.
B) Most of the islands are sufficiently distant from one another such that dispersal among populations on different islands is limited.
C) Because the Galápagos Islands are only 100 km from Ecuador, they receive a continual input of new genes from the mainland.
D) Both a and b
E) Both a and c

Question 23

Which of the following statements is false?

A) Darwin focused on the underlying causes of speciation.
B) Darwin lacked the tools of modern genetics.
C) The title of Darwin's most famous book reflected his recognition of the preeminent importance of the origin of new species in biological science.
D) The origin of new species involves the splitting and divergence of a single lineage into distinct species.
E) All of the above are true; none is false.

Question 24

Geographical speciation is also known as

A) reinforcement.
B) sympatric speciation.
C) Darwinian speciation.
D) the biological species concept.
E) allopatric speciation.

Question 25

Which of the following statements about Darwin's finches is true?

A) They arose from at least three different species from the South American mainland.
B) There are more species of Darwin's finches than of Hawaiian Drosophila.
C) Several, but not all, of Darwin's finches primarily eat seeds.
D) The finches show little differentiation in their beak shape and differ mainly in their size.
E) None of the above

Question 26

Which of the following does the Dobzhansky-Muller model of speciation necessarily require?

A) Natural selection
B) Reinforcement
C) Interaction between alleles at different loci
D) Chromosomal rearrangements, particularly centric fusions
E) Temporal isolation

Question 27

Which of the following is the most likely sequence of events in geographic speciation?

A) Geographic barrier, reproductive isolation, genetic divergence
B) Geographic barrier, genetic divergence, reproductive isolation
C) Genetic divergence, geographic barrier, reproductive isolation
D) Genetic divergence, reproductive isolation, geographic barrier
E) Reproductive isolation, genetic divergence, geographic barrier

Question 28

The biological species concept is most closely associated with which of the following scientists?

A) Charles Darwin
B) Ernst Mayr
C) Margaret Dayhoff
D) Alan Templeton
E) Carolus Linnaeus

Question 29

Which of the following statements about the evolution of reproductive isolation is false?

A) Reproductive isolation evolves at about the same rate in nearly all groups of organisms.
B) Reproductive isolation can gradually evolve in the lab, even if the researchers do not directly select for it.
C) Reproductive isolation gradually increases with increasing genetic distance.
D) Reproductive isolation is not "all-or-nothing": intermediate levels of reproductive isolation can be found.
E) All of the above are true; none is false.

Question 30

The _______ species concept holds that "species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups."

A) Darwinian
B) biological
C) morphological
D) Linnaean
E) natural populations

Question 31

Which of the following statements about speciation is true?

A) It is usually gradual.
B) It is the process by which one species splits into two daughter species.
C) Reproductive isolation is an important component.
D) All of the above
E) None of the above

Question 32

The Isthmus of Panama cut off gene flow between Atlantic and Pacific populations of a species of fish. The cessation of gene flow led to the accumulation of genetic differences between the populations, which led to reproductive isolation. Now Atlantic and Pacific populations of this fish are separate species that cannot interbreed, even if they were again to come into contact with each other. The process described is that of

A) sympatric speciation.
B) parapatric speciation.
C) allopatric speciation.
D) reinforcement.
E) temporal isolation.

Question 33

Which of the following statements about the Dobzhansky-Muller model of speciation is true?

A) It requires a phase in which some individuals are reproductively incompatible with other individuals in the same population.
B) It involves a single gene.
C) Empirical examples support the model.
D) All of the above
E) None of the above

Question 34

Which of the following statements about the Dobzhansky-Muller model of speciation is false?

A) It can involve combinations of single genes.
B) It can involve combinations of chromosomal rearrangements.
C) It requires different mutations occurring in each of the two populations.
D) It requires selection to act differently in the two populations.
E) All of the above are true; none is false.

Question 35

Which of the following adaptations is not found among any of the species of Darwin's finches?

A) Large bills for crushing large, hard seeds
B) Beaks that can open cactus fruits and extract the seeds
C) Long beaks for probing dead wood, crevices, and bark for insects
D) Heavy bills for twisting apart wood to reach larvae inside
E) None of the above; all of the adaptations are observed in these birds.

Question 36

Which of the following is believed to be the dominant mode of speciation among most groups of organisms?

A) Allopatric speciation
B) Sympatric speciation
C) Reinforcement
D) Hybrid speciation
E) Temporal speciation

Question 37

Which of the following situations is least likely to lead to geographic isolation, hence inhibiting allopatric speciation?

A) An eight-lane highway divides a population of snails with limited mobility.
B) A narrow, but deep, river divides a population of hummingbirds.
C) A narrow, but deep, river divides a population of white-footed mice (not known for their swimming ability).
D) A patch of land bisects a river and divides a population of minnows.
E) A mountain range divides a population of moths.

Question 38

The evolution of chromosomal rearrangements in Rhogeessa bats supports the role of _______ in speciation.

A) habitat isolation
B) autopolyploidy
C) the Dobzhansky-Muller model
D) gametic isolation
E) Both a and c

Question 39

Ginkgo trees grow in Asia and North America and thus are divided into two groups that are geographically separated. What aspect of Mayr's framing of the biological species concept classifies these populations as belonging to the same species?

A) They are reproductively isolated.
B) The two populations are potentially capable of exchanging genes.
C) They exchange genes across the Pacific Ocean.
D) They have different evolutionary ancestries.
E) They have formed a large hybrid zone.

Question 40

The notion of potentiality in Mayr's definition of "potentially interbreeding" species applies mainly to populations of organisms that are

A) sympatric.
B) existing in hybrid zones.
C) allopatric.
D) asexual.
E) experiencing an adaptive radiation.

Question 41

Crosses between the flour beetles Tribolium castaneum and T. freemani result in large numbers of hybrids that survive but are sterile. This is an example of

A) low hybrid zygote viability.
B) behavioral isolation.
C) low hybrid adult viability.
D) postzygotic reproductive isolation.
E) None of the above

Question 42

Which of the following statements about Rhagoletis pomonella is true?

A) Larvae learn the odor of the fruit in which they grew up, and they locate such plants for mating and laying their eggs.
B) The apple- and hawthorn-feeding types of Rhagoletis can be considered incipient species because they show partial polyploidy.
C) The apple- and hawthorn-feeding types of Rhagoletis emerge at approximately the same time.
D) All of the above
E) None of the above

Question 43

Before transferring sperm to the female during mating, the males of some species of beetles use their copulatory organs to remove the sperm of other males. In cases in which a female mated first with a male of a different species, the male of her own species is particularly adept at removing the other male's sperm. This is an example of _______ isolation.

A) geographical
B) behavioral
C) mechanical
D) postzygotic
E) precoital

Question 44

Despite inhabiting overlapping ranges, the western spotted skunk and the eastern spotted skunk do not interbreed. One reason for this lack of interbreeding is that the western species breeds in early fall and the eastern species breeds in late winter to early spring. This is an example of _______ isolation.

A) chemical
B) gametic
C) postzygotic
D) temporal
E) mechanical

Question 45

Which of the following is not a postzygotic isolation mechanism?

A) Abnormal meiosis following fertilization
B) Infertile hybrids
C) Reduced viability of hybrids
D) Abnormal mitosis following fertilization
E) Variation in mating pheromones

Question 46

Which of the following statements about hybrid zones is true?

A) They are excellent natural laboratories for speciation studies.
B) When they first appear, most hybrid zones contain mostly recombinant individuals.
C) They may result from human activity.
D) Both a and b
E) Both a and c

Question 47

What is the critical distinction between allopolyploidy and autopolyploidy?

A) Allopolyploidy involves disruptive selection.
B) Autopolyploidy involves disruptive selection.
C) If speciation is allopatric rather than sympatric, then the mode of speciation is allopolyploidy.
D) In autopolyploidy, one parental species makes up the polyploidy.
E) In allopolyploidy, two parental species make up the polyploidy.

Question 48

Which of the following statements about a hybrid zone is false?

A) It occurs where two different populations come into contact.
B) It may shift in location due to environmental changes.
C) Its habitat may differ from that favored by the parent populations.
D) It may narrow, or even disappear, if strong isolating mechanisms develop.
E) All of the above are true; none is false.

Question 49

Which of the following statements about Levin's studies with Phlox species is true?

A) The studies demonstrated the existence of reinforcement operating between these species.
B) The color pattern of Phlox drummondii influences the extent to which it will mate with other species.
C) P. drummondii and P. cuspidata are allopatric species.
D) Both a and b
E) Both a and c

Question 50

Suppose one incipient species of beetle prefers to live and mate in grassy areas and its sibling incipient species prefers sandy soils. This would be an example of _______ isolation.

A) temporal
B) habitat
C) prezygotic
D) both temporal and habitat
E) both habitat and prezygotic

Question 51

The hybrids between tetraploid and diploid plants of the same ancestral species

A) are usually fertile.
B) are triploid.
C) have chromosomes that usually segregate unevenly during meiosis.
D) Both a and b
E) Both b and c

Question 52

Studies of the columbines Aquilegia formosa and A. pubescens illustrate that

A) hybrids rarely form between these species because the two species are not interfertile.
B) hawkmoths prefer one species over the other because of differences between the species in the color of light that they emit.
C) hawkmoths show equal preference for the two species if the flowers of A. formosa are turned upright.
D) All of the above
E) None of the above

Question 53

Which of the following is not a prezygotic reproductive isolating barrier?

A) Behavioral isolation
B) Mechanical isolation
C) Hybrid infertility
D) Temporal isolation
E) None of the above

Question 54

Which of the following statements about polyploidy is true?

A) Autopolyploids may be produced when individuals of two different but closely related species hybridize.
B) Botanists estimate that 95 percent of fern species are polyploids.
C) Autopolyploids are often fertile because each of the chromosomes has a nearly identical partner with which to pair during meiosis.
D) Polyploidy is more common in animals than in plants.
E) A tetrapoloid individual usually can produce viable offspring by mating with a diploid.

Question 55

Which of the following was required for sympatric speciation in species like the apple maggot fly?

A) Genetic drift
B) Stabilizing selection
C) Disruptive selection
D) Allopatry
E) Polyploidy

Question 56

The most common means of sympatric speciation occurs via

A) geographic barriers.
B) the hawthorn process.
C) disruptive selection.
D) polyploidy.
E) reinforcement.

Question 57

Drosophila pseudoobscura and D. persimilis are two species of flies that live in the western United States. The geographic range of D. persimilis, which is much smaller than that of D. pseudoobscura, is enclosed within the range of D. pseudoobscura. Findings by Mohamed Noor and others show that D. pseudoobscura taken from areas that overlap with D. persimilis are less likely to mate with D. persimilis than are the D. pseudoobscura flies from populations that do not experience D. persimilis. What is the most likely explanation for these results?

A) Temporal isolation
B) The Dobzhansky-Muller model
C) Reinforcement
D) The Darwin effect
E) Adaptive radiation

Question 58

The sperm of one species of sea urchin is chemically incompatible with the eggs of a closely related species. This type of reproductive isolating barrier is called

A) postzygotic isolation.
B) gametic isolation.
C) low hybrid zygote viability.
D) temporal isolation.
E) behavioral isolation

Question 59

Natural selection would never directly favor the evolution of which of the following types of reproductive isolating barriers?

A) Mechanical isolation
B) Gametic isolation
C) Behavioral isolation
D) Hybrid infertility
E) None of the above

Question 60

Females of the species Drosophila pseudoobscura respond less well to courtship signals from males of their close relative D. persimilis than they do to those of males of their own species. This is an example of

A) gametic isolation.
B) hybrid infertility.
C) behavioral isolation.
D) adaptive radiation.
E) sympatric speciation.

Question 61

A biologist classifies two beetles as belonging to the same species because they look more similar to each other than they do to other beetles. This biologist is employing the _______ species concept.

Question 62

Which of the following statements about adaptive radiations is true?

A) They occur only on islands.
B) They frequently follow mass extinctions.
C) They begin when populations differentiate genetically in response to environmental differences.
D) Both b and c
E) All of the above

Question 63

Which of the following is the correct ranking with respect to number of species (from highest to lowest) of plants pollinated by wind (Wind), plants pollinated by animals that are generalist pollinators (Generalist), and plants pollinated by animals that are specialist pollinators (Specialist)?

A) Wind > Generalist > Specialist
B) Specialist > Generalist > Wind
C) Generalist > Specialist > Wind
D) Specialist > Wind > Generalist
E) Generalist > Wind > Specialist

Question 64

According to the Dobzhansky-Muller model, the evolution of reproductive isolation requires changes at (at least) _______ genetic loci.

Question 65

Which of the following statements best explains why the silverswords underwent an adaptive radiation and the tarweeds did not?

A) The ancestors of the silverswords had more ecological opportunities.
B) There were fewer trees in the areas in which the ancestors of the tarweeds settled.
C) Silverswords had a more behaviorally complex mating system, and thus there were more opportunities for the evolution of prezygotic reproductive isolation.
D) Stabilizing selection prevented the evolution of reproductive isolation in tarweeds.
E) None of the above.

Question 66

The _______ model explains the evolution of reproductive isolation as a consequence of interactions of alleles at different genetic loci.

Question 67

An evolutionary biologist makes decisions about whether to consider different populations of lacewings as separate species based on observations of the individuals with which these lacewings will mate. This biologist is most likely employing the _______ species concept.

Question 68

Which of the following statements about Hawaiian silverswords is true?

A) They are genetically diverse.
B) They exhibit extraordinary morphological diversity.
C) Their opportunities to exploit the "tree" way of life have been preempted.
D) They share a very distant common ancestor that currently lives in Asia.
E) All of the above

Question 69

Which of the following statements about the Hawaiian Islands is true?

A) Fewer than 100 species of insects inhabit the islands.
B) More than 100 species of amphibians are native to the islands.
C) More than 90 percent of the plant species found in the islands are endemic species.
D) There is only one species of land snail inhabiting the islands.
E) None of the above

Question 70

An evolutionary biologist makes decisions about whether to classify different salmon populations as separate species based on their phylogenies. This biologist is most likely employing the _______ species concept.

Question 71

Which of the following would likely lead to an increase in speciation rates?

A) Increased dispersal ability
B) A shift from animal to wind pollination
C) Complex sexually selected behaviors
D) A shift from plant-eating to insect-eating
E) None of the above

Question 72

The proliferation of a large number of daughter species from a single ancestor is known as

A) an evolutionary radiation.
B) an evolutionary explosion.
C) an adaptive explosion.
D) reinforcement.
E) Darwin's process.

Question 73

What is the main reason that there are so many species of land snails in the Hawaiian Islands?

A) They have complex social behaviors.
B) They have excellent dispersal ability.
C) They pollinate many flowers.
D) All of the above
E) None of the above

Question 74

Mayr's definition of species asserts that _______ isolation is the most important criterion for identifying species.

Question 75

When hybrid offspring are at a fitness disadvantage and reinforcement does not occur, which of the following is likely to occur?

A) The spreading of hybrids through both populations, resulting in the combining of both gene pools and no new species
B) An adaptive radiation
C) The formation of a new species via polyploidy
D) The formation of a hybrid zone
E) None of the above

Question 76

For which of the following reasons would we expect rapid speciation to occur among animals with complex sexually-selected behavior patterns?

A) The timing of reproduction is behaviorally mediated.
B) Behavioral differences usually reflect physiological differences.
C) They have difficulty in identifying members of their own species and often mate with members of other species.
D) They make sophisticated discriminations among potential mates.
E) They find mates more quickly and efficiently.

Question 77

Which of the following statements about speciation is true?

A) Wind-pollinated plants typically have higher speciation rates than animal-pollinated plants.
B) Species that move have higher rates of speciation than those with limited dispersal.
C) Sexual selection seems to decrease speciation rates.
D) Herbivorous insects typically have higher rates of speciation compared with insects that prey on other insects.
E) None of the above

Question 78

Which of the following statements about the hybrid zone in the European Bombina toads is false?

A) The hybrid zone is long and narrow.
B) Many of the hybrids are morphologically abnormal.
C) The fitness of the hybrids is only about half that of a purebred individual.
D) Adult toads are very adept at traveling long distances.
E) All of the above are true; none is false.

Question 79

Hybrid zones are likely to be narrow

A) in species that move around considerably during their lifetimes.
B) when reinforcement is occurring.
C) when there is strong selection against the hybrids.
D) when the hybrids are as fit as the original species.
E) when Muller's ratchet is operating.

Question 80

The Swedish biologist _______ developed the binominal classification system of nomenclature and classified organisms based on a(n) _______ species concept.