5) Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence?

C) genetic drift

6) In modern terminology, diversity is understood to be a result of genetic variation. Which of the following is a recognized source of variation for evolution?

E) recombination by crossing over in meiosis

7) A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of

A) a cline.

8) The higher the proportion of loci that are "fixed" in a population, the lower is that population's

E) nucleotide variability and average heterozygosity only.

9) Which statement about variation is true?

D) All new alleles are the result of nucleotide variability.

10) Rank the following one-base point mutations (from most likely to least likely) with respect to their likelihood of affecting the structure of the corresponding polypeptide:

B) 4, 3, 2, 1

11) Most invertebrates have a cluster of ten similar Hox genes, all located on the same chromosome. Most vertebrates have four such clusters of Hox genes, located on four nonhomologous chromosomes. The process that could have potentially contributed to the cluster's presence on more than one chromosome was ________.

D) nondisjunction

12) Which of the following is a true statement concerning genetic variation?

C) It must be present in a population before natural selection can act upon the population.

13) How many of these statements regarding populations are true?

D) Four of these statements are true.

14) Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus

A) the allele's frequency should not change from one generation to the next, but its representation in homozygous and heterozygous genotypes may change.

15) In the formula for determining a population's genotype frequencies, the 2 in the term 2pq is necessary because

B) heterozygotes can come about in two ways.

16) In the formula for determining a population’s genotype frequencies, the pq in the term 2pq is necessary because

C) the population is doubling in number.

17) Hardy-Weinberg equilibrium must occur in populations wherein

E) Only two of the responses above are correct.

18) In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the percentage of the population that is homozygous for this allele?

D) 9.0

19) In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the percentage of the population that is heterozygous for this allele?

E) 32.0

20) In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.1. What is the frequency of individuals with AA genotype?

D) 0.81

21) You sample a population of butterflies and find that 56% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population?

E) Allele frequency cannot be determined from this information.

22) In peas, a gene controls flower color such that R = purple and r = white. In an isolated pea patch, there are 36 purple-flowering plants and 64 white-flowering plants. Assuming Hardy-Weinberg equilibrium, what is the value of q for this population?

D) 0.80

23) Evolution

C) can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not met.

24) Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing

D) gene flow.

25) Swine are vulnerable to infection by bird flu virus and human flu virus, which can both be present in an individual pig at the same time. When this occurs, it is possible for genes from bird flu virus and human flu virus to be combined, thereby producing a genetically distinctive virus, which can subsequently cause widespread disease.

D) gene flow.

26) If the original finches that had been blown over to the Galápagos from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galápagos, this would have been an example of

E) both the first and third of these.

27) What is true of natural selection?

D) Mutations occur at random; natural selection can preserve and distribute beneficial mutations.

28) The restriction enzymes of bacteria protect the bacteria from successful attack by bacteriophages, whose genomes can be degraded by the restriction enzymes. The bacterial genomes are not vulnerable to these restriction enzymes because bacterial DNA is methylated. This situation selects for bacteriophages whose genomes are also methylated. As new strains of resistant bacteriophages become more prevalent, this in turn selects for bacteria whose genomes are not methylated and whose restriction enzymes instead degrade methylated DNA. The outcome of the conflict between bacteria and bacteriophage at any point in time results from

A) frequency-dependent selection.

29) The restriction enzymes of bacteria protect the bacteria from successful attack by bacteriophages, whose genomes can be degraded by the restriction enzymes. The bacterial genomes are not vulnerable to these restriction enzymes because bacterial DNA is methylated. This situation selects for bacteriophages whose genomes are also methylated. As new strains of resistant bacteriophages become more prevalent, this in turn selects for bacteria whose genomes are not methylated and whose restriction enzymes instead degrade methylated DNA. Over the course of evolutionary time, what should occur?

D) Methylated and nonmethylated strains should be maintained among both bacteria and bacteriophages, with ratios that vary over time.

30) Arrange the following from most general (i.e., most inclusive) to most specific (i.e., least inclusive):

C) 4, 2, 1, 5, 3

31) Sexual dimorphism is most often a result of

D) intersexual selection.

32) In the wild, male house finches (Carpodus mexicanus) vary considerably in the amount of red pigmentation in their head and throat feathers, with colors ranging from pale yellow to bright red. These colors come from carotenoid pigments that are found in the birds' diets; no vertebrates are known to synthesize carotenoid pigments. Thus, the brighter red the male's feathers are, the more successful he has been at acquiring the red carotenoid pigment by his food-gathering efforts (all other factors being equal). During breeding season, one should expect female house finches to prefer to mate with males with the brightest red feathers. Which of the following is true of this situation?

D) Three of the statements are correct.

33) During breeding season, one should expect female house finches to prefer to mate with males with the brightest red feathers. Which of the following terms are appropriately applied to this situation?

D) Three of the responses are correct.

34) Adult male humans generally have deeper voices than do adult female humans, which is the direct result of higher levels of testosterone causing growth of the larynx. If the fossil records of apes and humans alike show a trend toward decreasing larynx size in adult females and increasing larynx size in adult males, then

A) sexual dimorphism was developing over time in these species.

35) Adult male humans generally have deeper voices than do adult female humans, which is the direct result of higher levels of testosterone causing growth of the larynx. If one excludes the involvement of gender in the situation, then the pattern that is apparent in the fossil record is most similar to one that should be expected from

C) disruptive selection.

36) Which of the following statements best summarizes evolution as it is viewed today?

D) It is the differential survival and reproduction of the most-fit phenotypes.

37) Which of the following is most likely to produce an African butterfly species in the wild whose members have one of two strikingly different color patterns?

D) disruptive selection

38) Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more, than this have reduced fitness. Which of the following terms best describes this situation?

C) stabilizing selection

39) The recessive allele that causes phenylketonuria (PKU) is harmful, except when an infant's diet lacks the amino acid phenylalanine. What maintains the presence of this harmful allele in a population's gene pool?

C) diploidy

40) Heterozygote advantage should be most closely linked to which of the following?

B) stabilizing selection

41) In seedcracker finches from Cameroon, small- and large-billed birds specialize in cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population?

B) directional selection

42) When imbalances occur in the sex ratio of sexual species that have two sexes (i.e., other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of

E) frequency-dependent selection.

43) The same gene that causes various coat patterns in wild and domesticated cats also causes the cross-eyed condition in these cats, the cross-eyed condition being slightly maladaptive. In a hypothetical environment, the coat pattern that is associated with crossed eyes is highly adaptive, with the result that both the coat pattern and the cross-eyed condition increase in a feline population over time. Which statement is supported by these observations?

B) Phenotype is often the result of compromise.

44) A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do not seem to be optimally arranged because

D) natural selection is generally limited to modifying structures that were present in previous generations and in previous species.

45) There are those who claim that the theory of evolution cannot be true because the apes, which are supposed to be closely related to humans, do not likewise share the same large brains, capacity for complicated speech, and tool-making capability. They reason that if these features are generally beneficial, then the apes should have evolved them as well. Which of these provides the best argument against this misconception?

A) Advantageous alleles do not arise on demand.

46) Blue light is that portion of the visible spectrum that penetrates the deepest into bodies of water. Ultraviolet (UV) light, though, can penetrate even deeper. A gene within a population of marine fish that inhabits depths from 500 m to 1,000 m has an allele for a photopigment that is sensitive to UV light, and another allele for a photopigment that is sensitive to blue light. Which of the following graphs best depicts the predicted distribution of these alleles within a population if the fish that carry these alleles prefer to locate themselves where they can see best? (SEE IMAGE)

B) B

47) Anopheles mosquitoes, which carry the malaria parasite, cannot live above elevations of 5,900 feet. In addition, oxygen availability decreases with higher altitude. Consider a hypothetical human population that is adapted to life on the slopes of Mt. Kilimanjaro in Tanzania, a country in equatorial Africa. Mt. Kilimanjaro's base is about 2,600 feet above sea level and its peak is 19,341 feet above sea level. If the incidence of the sickle-cell allele in the population is plotted against altitude (feet above sea level), which of the following distributions is most likely, assuming little migration of people up or down the mountain?

B

48) If global warming permits mosquitoes to live at higher altitudes than they currently do, then in which direction should the entire plot in the correct distribution below be shifted?

A) to the right

49) What is true of the trait whose frequency distribution in a large population appears in the previous figure? It has probably undergone

B) stabilizing selection.

50) If the curve in the previous figure shifts to the left or to the right, there is no gene flow, and the population size consequently increases over successive generations. Which of the following is (are) probably occurring?

C) 2 and 3

51) Which of the following represents the treatment option most likely to avoid the production of drug-resistant HIV (assuming no drug interactions or side effects)?

D) using moderate doses of NA and two different PIs at the same time for several months

52) Within the body of an HIV-infected individual who is being treated with a single NA, and whose HIV particles are currently vulnerable to this NA, which of these situations can increase the virus' relative fitness?

B) 2 only

53) HIV has nine genes in its RNA genome. Every HIV particle contains two RNA molecules, and each molecule contains all nine genes. If, for some reason, the two RNA molecules within a single HIV particle do not have identical sequences, then which of these terms can be applied due to the existence of the nonidentical regions?

E) All but one of the responses are correct.

54) Every HIV particle contains two RNA molecules. If two genes from one RNA molecule become detached and then, as a unit, get attached to one end of the other RNA molecule within a single HIV particle, which of these is true?

E) One of the RNA molecules has experienced gene duplication as the result of translocation.

55) In a hypothetical population's gene pool, an autosomal gene, which had previously been fixed, undergoes a mutation that introduces a new allele, one inherited according to incomplete dominance. Natural selection then causes stabilizing selection at this locus. Consequently, what should happen over the course of many generations?

A) The proportions of both types of homozygote should decrease.

56) What is the most reasonable conclusion that can be drawn from the fact that the frequency of the recessive trait (aa) has not changed over time?

B) The two phenotypes are about equally adaptive under laboratory conditions.

57) What is the estimated frequency of allele A in the gene pool?

B) 0.50

58) What proportion of the population is probably heterozygous (Aa) for this trait?

C) 0.50

59) In which population would it be least likely that an accident would significantly alter the frequency of the brown allele?

B) population B

60) Which population is most likely to be subject to the bottleneck effect?

A) population A

61) What should be the proportion of heterozygous individuals in populations that live here?

D) 0.32

62) If the sickle-cell allele is recessive, what proportion of the population should be susceptible to sickle-cell anemia under typical conditions?

A) 0.04

63) In the United States, the parasite that causes malaria is not present, but African-Americans whose ancestors were from equatorial Africa are present. What should be happening to the sickle-cell allele in the United States, and what should be happening to it in equatorial Africa?

E) directional selection; stabilizing selection

64) With respect to the sickle-cell allele, what should be true of the β hemoglobin locus in U.S. populations of African-Americans whose ancestors were from equatorial Africa?

B) 1 and 3

65) Considering the overall human population of the U.S. mainland at the time when the slave trade brought large numbers of people from equatorial Africa, what was primarily acting to change the frequency of the sickle-cell allele in the overall U.S. population?

B) gene flow

66) The sickle-cell allele is pleiotropic (i.e., it affects more than one phenotypic trait). Specifically, this allele affects oxygen delivery to tissues and affects one's susceptibility to malaria. Under conditions of low atmospheric oxygen availability, individuals heterozygous for this allele can experience life-threatening sickle-cell "crises." Such individuals remain less susceptible to malaria. Thus, pleiotropic genes/alleles such as this can help explain why

C) adaptations are often compromises.

67) Which of these is closest to the allele frequency in the founding population?

A) 0.1 a, 0.9 A

68) If one assumes that Hardy-Weinberg equilibrium applies to the population of colonists on this planet, about how many people will have attached earlobes when the planet's population reaches 10,000?

A) 100

69) If four of the original colonists died before they produced offspring, the ratios of genotypes could be quite different in the subsequent generations. This would be an example of

C) genetic drift.

70) You are maintaining a small population of fruit flies in the laboratory by transferring the flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flies has decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to

A) cross your flies with flies from another lab.

71) The volcano is currently dormant, but in a hypothetical future scenario, satellite cones at the base of Mt. Kilimanjaro spew sulfurous gases and lava, destroying all life located between the base and 6,000 feet above sea level. As a result of this catastrophe, how should the frequency of the sickle-cell allele change in the remnant human population that survives above 6,000 feet, and which phenomenon accounts for this change in allele frequency?

E) decreases; bottleneck effect

72) Swine are vulnerable to infection by bird flu virus and human flu virus, which can both be present in an individual pig at the same time. When this occurs, it is possible for genes from bird flu virus and human flu virus to be combined. If the human flu virus contributes a gene for Tamiflu resistance (Tamiflu is an antiviral drug) to the new virus, and if the new virus is introduced to an environment lacking Tamiflu, then what is most likely to occur?

C) If the Tamiflu-resistance gene involves a cost, it will experience directional selection leading to reduction in its frequency.

73) Natural selection changes allele frequencies because some ________ survive and reproduce more successfully than others.

E) individuals

74) No two people are genetically identical, except for identical twins. The main source of genetic variation among human individuals is

C) the reshuffling of alleles in sexual reproduction.

75) Sparrows with average-sized wings survive severe storms better than those with longer or shorter wings, illustrating

E) stabilizing selection.

76) If the nucleotide variability of a locus equals 0%, what is the gene variability and number of alleles at that locus?

B) gene variability = 0%; number of alleles = 1

77) There are 40 individuals in population 1, all with genotype A1A1, and there are 25 individuals in population 2, all with genotype A2A2. Assume that these populations are located far from each other and that their environmental conditions are very similar. Based on the information given here, the observed genetic variation is most likely an example of

A) genetic drift.

78) A fruit fly population has a gene with two alleles, A1 and A2. Tests show that 70% of the gametes produced in the population contain the A1 allele. If the population is in Hardy-Weinberg equilibrium, what proportion of the flies carry both A1 and A2?

D) 0.42

1) What is true of macroevolution?

B) It is evolution above the species level.

2) What is true of the flightless cormorants of the Galápagos Islands?

D) Flightless cormorants on one island have restricted gene flow with those on other islands, which could someday lead to a macroevolutionary event.

3) Which of the following statements about species, as defined by the biological species concept, is (are) correct?

B) I and III

4) Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?

C) biological

5) There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little or no gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example?

D) biological

6) You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?

D) morphological

7) Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?

D) habitat isolation

8) Rank the following from most general to most specific:

B) 2, 4, 1, 3

9) Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate?

A) the postzygotic barrier called hybrid inviability

10) Theoretically, the production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) should

C) strengthen postzygotic barriers between horses and donkeys.

11) When male horses (stallions) and female donkeys (jennets) mate, they produce a sterile hybrid called a hinny. Hinnies occur much less frequently than do mules, but are just as healthy and robust as mules. Logically, which of the following best accounts for the relative rarity of hinnies, and what kind of prezygotic isolating mechanism is at work here?

D) Stallions and jennets are choosier about their mating partners than are mares and jacks; behavioral isolation.

12) Dogs (Canis lupus familiaris) and gray wolves (Canis lupus) can interbreed to produce viable, fertile offspring. These species shared a common ancestor recently (in geologic time) and have a high degree of genetic similarity, although their anatomies vary widely. Judging from this evidence, which two species concepts are most likely to place dogs and wolves together into a single species?

E) biological and phylogenetic

13) Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. If pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species, then which of these terms are applicable?

A) 1 and 2

14) Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. If pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species, then which of these terms is applicable?

B) mechanical isolation

15) What does the biological species concept use as the primary criterion for determining species boundaries?

C) gene flow

16) In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In rangelands of the western United States, pronghorns and cattle often associate with one another. If some of these fleas develop a strong preference for cattle blood and mate only with other fleas that prefer cattle blood, then over time which of these should occur, if the host mammal can be considered as the fleas' habitat?

E) 1 through 4

17) Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet?

C) They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations.

18) The difference between geographic isolation and habitat differentiation is the

A) relative locations of two populations as speciation occurs.

19) Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species?

D) 2 and 4

20) Beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it?

B) sympatric speciation; habitat differentiation

21) The origin of a new plant species by hybridization, coupled with accidents during nuclear division, is an example of

B) sympatric speciation.

22) The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and

D) an increasing number of viable, fertile hybrids is produced over the course of generations.

23) A hybrid zone is properly defined as

B) an area where mating occurs between members of two closely related species, producing viable offspring.

24) Which of these should decline in hybrid zones where reinforcement is occurring?

A) gene flow between distinct gene pools

25) The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is

A) sexual selection.

26) The most likely explanation for the recent decline in cichlid species diversity in Lake Victoria is

B) fusion.

27) A narrow hybrid zone separates the toad species Bombina bombina and Bombina variegata. What is true of those alleles that are unique to the parental species?

C) The alleles' heterozygosity should be higher among the hybrid toads there.

28) According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that

D) speciation occurred rapidly in geologic time.

29) According to the concept of punctuated equilibrium,

C) a new species accumulates most of its unique features as it comes into existence.

30) Speciation

E) can involve changes to a single gene.

31) Which of the following statements about speciation is correct?

E) Speciation is a basis for understanding macroevolution.

32) In order for speciation to occur, what must be true?

E) At least one gene, affecting at least one phenotypic trait, must change.

33) Which species is most closely related to species W?

A) V is most closely related to species W.

34) Which species is least expected to have a good record of transitional fossils; in other words, which species' fossils, if present at all, are expected only in relatively superficial (i.e., shallow) strata?

A) V

35) Which of these five species originated earliest and appeared suddenly in the fossil record?

B) W

36) Which conclusion can be drawn from this evolutionary tree?

D) A single clade (i.e., a group of species that share a common ancestor) can exhibit both gradualism and punctuated equilibrium.

37) Which of these five species is the extant (i.e., not extinct) species that is most closely related to species X, and why is this so?

A) V; shared a common ancestor with X most recently

38) The data in the previous graphs indicate that

D) two-way migration of squirrels occurred across the bridge, but without hybridization.

39) Which of the following reduces gene flow between the gene pools of the two species on Sao Tomé, despite the existence of hybrids?

C) hybrid sterility

40) The observation that island D. yakuba are more closely related to mainland D. yakuba than island D. yakuba are to D. santomea is best explained by proposing that D. santomea

D) descended from an original colony of D. yakuba, of which there are no surviving members. The current island D. yakuba represent a second colonization event from elsewhere.

41) If a speciation event occurred on Sao Tomé, producing D. santomea from a parent colony of D. yakuba, then which terms apply?

D) I and III

42) Using only the information provided in the paragraph, which of the following is the best initial hypothesis for how D. santomea descended from D. yakuba?

C) habitat differentiation

43) Which of these evolutionary trees represents the situation described in the previous paragraph (Note: Yakuba (I) represents the island population, and yakuba (M) represents the mainland population)?

A

44) If the low number of hybrid flies in the hybrid zone, relative to the number of D. santomea flies there, is due to the fact that hybrids are poorly adapted to conditions in the hybrid zone, and if fewer hybrid flies are produced with the passage of time, these conditions will most likely lead to

B) reinforcement.

45) Which two of the following have operated to increase divergence between mosquitofish populations on Andros?

E) 3 and 5

46) Which type of reproductive isolation operates to keep the mosquitofish isolated, even when fish from different ponds are reunited in the same body of water?

A) behavioral isolation

47) What is the best way to promote fusion between two related populations of mosquitofish, one of which lives in a predator-rich pond, and the other of which lives in a predator-poor pond?

A) Build a canal linking the two ponds that permits free movement of mosquitofish, but not of predators.

48) If one builds a canal linking a predator-rich pond to a predator-poor pond, then what type(s) of selection should subsequently be most expected among the mosquitofish in the original predator-rich pond, and what type(s) should be most expected among the mosquitofish in the formerly predator-poor pond?

C) less-intense directional selection; more-intense directional selection

49) The predatory fish rely on visual cues and speed to capture mosquitofish. Mosquitofish rely on speed and visual cues to avoid the predatory fish. Which adaptation(s) might help the predators survive in ponds that are home to faster mosquitofish?

E) 1, 3, or 4

50) Why should deepwater shrimp on different sides of the isthmus have diverged from each other earlier than shallow-water shrimp?

A) They have been geographically isolated from each other for a longer time.

51) In which habitat should one find snapping shrimp most closely related to shrimp that live in habitat A4?

C) B4

52) Which of these habitats is likely to harbor the youngest species?

E) A1

53) Which habitats should harbor snapping shrimp species with the greatest degree of genetic divergence from each other?

D) A5 and B5

54) Which factor is most important for explaining why there are equal numbers of snapping shrimp species on either side of the isthmus?

A) the relative shortness of time they have been separated

55) The Panama Canal was completed in 1914, and its depth is about 50 feet. After 1914, snapping shrimp species from which habitats should be most likely to form hybrids as the result of the canal?

C) A1 and B1

56) There are currently two, large, permanent bridges that span the Panama Canal. The bridges are about 8 miles apart. If snapping shrimp avoid swimming at night and avoid swimming under shadows, then what do these bridges represent for the snapping shrimp?

B) geographic barriers

57) The largest unit within which gene flow can readily occur is a

B) species.

58) Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?

C) behavioral isolation

59) According to the punctuated equilibria model,

C) most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species.

60) Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification?

A) The two forms interbreed often in nature, and their offspring have good survival and reproduction.

61) Which of the following factors would not contribute to allopatric speciation?

E) Gene flow between the two populations is extensive.

62) Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The diploid number for species C would probably be

D) 28.

63) Suppose that a group of male pied flycatchers migrated from a region where there were no collared flycatchers to a region where both species were present. Assuming events like this are very rare, which of the following scenarios is least likely?

E) The frequency of hybrid offspring would decrease.