Campbell Biology, 10e (Reece)
Chapter 24 The Origin of Species
Use the following information to answer the question(s) below.
Two populations of birds with somewhat different coloration live on opposite sides of a
peninsula. The habitat between the populations is not suitable for these birds. When birds from
the two populations are brought together, they produce young whose appearance is intermediate
between the two parents. These offspring will breed with each other or with birds from either
parent population, and all offspring of these pairings appear intermediate to various degrees.
1) What keeps the two populations separate?
A) temporal reproductive isolation
B) lack of hybrid viability
C) behavioral reproductive isolation
D) habitat isolation
2) The two populations are _____.
A) different subspecies, under the morphological species concept
B) different species, under the biological species concept
C) different species, under the phylogenetic species concept
3) Three populations of crickets look very similar, but the males have courtship songs that sound
different. What function would this difference in song likely serve if the populations came in
contact?
A) a temporal reproductive isolating mechanism
B) a postzygotic isolating mechanism
C) a behavioral reproductive isolating mechanism
D) a gametic reproductive isolating mechanism
4) Many songbirds breed in North America in the spring and summer and then migrate to Central
and South America in the fall. They spend the winter in these warmer areas, where they feed and
prepare for the spring migration north and another breeding season. Two hypothetical species of
sparrow, A and B, overwinter together in mixed flocks in Costa Rica. In spring, species A goes
to the east coast of North America, and species B goes to the west coast. What can you say about
the isolating mechanisms of these two species?
A) They must have strong postzygotic isolating mechanisms to spend winter in such close
proximity.
B) They must have strong prezygotic isolating mechanisms to spend winter in such close
proximity.
C) Their winter habitat has no bearing on their degree of reproductive isolation.
D) Reinforcement must be occurring when they winter together.
5) The peppered moth provides a well-known example of natural selection. The light-colored
form of the moth was predominant in England before the Industrial Revolution. In the mid-
nineteenth century, a dark-colored form appeared. The difference is produced by a dominant
allele of one gene. By about 1900, approximately 90% of the moths around industrial areas were
dark colored, whereas light-colored moths were still abundant elsewhere. Apparently, birds could
readily find the light moths against the soot-darkened background in industrial areas and,
therefore, were eating more light moths. Recently, use of cleaner fuels has greatly reduced soot
in the landscape, and the dark-colored moths have been disappearing. Should the two forms of
moths be considered separate species?
A) Yes, because natural selection has affected the frequency of the two different forms.
B) Yes, because they have completely different coloration.
C) Yes, because they are reproductively isolated based on habitat.
D) No.
3
Use the following information to answer the question(s) below.
About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting North and
South America) formed, dividing marine organisms into Pacific and Caribbean populations.
Researchers have examined species of snapping shrimp on both sides of the isthmus. Based on
the morphological species concept, there appeared to be seven pairs of species, with one species
of each pair in the Pacific and the other in the Caribbean. The different species pairs live at
somewhat different depths in the ocean. Using mitochondrial DNA sequences, the researchers
estimated phylogenies and found that each of these species pairs, separated by the isthmus, were
indeed each other’s closest relatives. The researchers investigated mating in the lab and found
that many species pairs were not very interested in courting with each other, and any that did
mate almost never produced fertile offspring. (N. Knowlton, L. A. Weigt, L. A. Solorzano, D. K.
Mills, and E. Bermingham. 1993. Divergence in proteins, mitochondrial DNA, and reproductive
incompatibility across the Isthmus of Panama. Science 260:1629-32.)
6) Refer to the paragraph about the formation of the Isthmus of Panama. The sister populations
on opposite sides of the isthmus are true species under which species concept?
A) the morphological species concept
B) the biological species concept
C) the phylogenetic species concept
D) the morpholoogical species, biological species, and phylogenetic species concepts
7) The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana
ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France
across central Europe to Russia. Both male and female hybrids exist, but when they mate among
themselves, they are rarely successful in producing offspring. What can you infer from this
information?
A) Postzygotic isolation exists between the two frog species.
B) Prezygotic isolation exists between the two frog species.
C) These two species are likely in the process of fusing back into one species.
D) The hybrids form a separate species under the biological species concept.
8) The approach to estimating phylogenetic trees is most like the approach of which species
concept?
A) morphological species concept
B) biological species concept
C) phylogenetic species concept
9) Macroevolution is _____.
A) the same as microevolution, but includes the origin of new species
B) evolution above the species level
C) defined as the evolution of microscopic organisms into organisms that can be seen with the
naked eye
D) defined as a change in allele or gene frequency over the course of many generations
10) Which of the various species concepts distinguishes two species based on the degree of
genetic exchange between their gene pools?
A) phylogenetic
B) ecological
C) biological
D) morphological
11) 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?
A) phylogenetic
B) ecological
C) morphological
D) biological
12) 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?
A) biological
B) phylogenetic
C) ecological
D) morphological
13) 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?
A) temporal isolation
B) behavioral isolation
C) habitat isolation
D) gametic isolation
14) Rank the following in order from most general to most specific:
1. gametic isolation
2. reproductive isolating mechanism
3. sperm-egg incompatibility in sea urchins
4. prezygotic isolating mechanism
A) 2, 3, 1, 4
B) 2, 4, 1, 3
C) 4, 1, 2, 3
D) 4, 2, 1, 3
15) Two species of frogs belonging to the same genus occasionally mate, but the embryos stop
developing after a day and then die. These two frog species separate by _____.
A) reduced hybrid viability
B) hybrid breakdown
C) reduced hybrid fertility
D) gametic isolation
16) The production of sterile mules by interbreeding between female horses (mares) and male
donkeys (jacks) is an example of _____.
A) reduced hybrid viability
B) hybrid breakdown
C) reduced hybrid fertility
D) mechanical isolation
17) 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?
A) ecological and morphological
B) ecological and phylogenetic
C) biological and morphological
D) biological and phylogenetic
18) Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma)
have overlapping ranges. 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. These two juniper species are kept separate by _____.
A) habitat isolation
B) temporal isolation
C) gametic isolation
D) behavioral isolation
19) What does the biological species concept use as the primary criterion for determining species
boundaries?
A) geographic isolation
B) niche differences
C) gene flow
D) morphological similarity
20) The largest unit within which gene flow can readily occur is _____.
A) a population
B) a species
C) the entire range of a genus
D) the hybrid zone
Use the following information to answer the question(s) below.
About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting North and
South America) formed, dividing marine organisms into Pacific and Caribbean populations.
Researchers have examined species of snapping shrimp on both sides of the isthmus. Based on
the morphological species concept, there appeared to be seven pairs of species, with one species
of each pair in the Pacific and the other in the Caribbean. The different species pairs live at
somewhat different depths in the ocean. Using mitochondrial DNA sequences, the researchers
estimated phylogenies and found that each of these species pairs, separated by the isthmus, were
indeed each other’s closest relatives. The researchers investigated mating in the lab and found
that many species pairs were not very interested in courting with each other, and any that did
mate almost never produced fertile offspring. (N. Knowlton, L. A. Weigt, L. A. Solorzano, D. K.
Mills, and E. Bermingham. 1993. Divergence in proteins, mitochondrial DNA, and reproductive
incompatibility across the Isthmus of Panama. Science 260:1629-32.)
21) Refer to the paragraph about the formation of the Isthmus of Panama. If the isthmus formed
gradually rather than suddenly, what pattern of genetic divergence would you expect to find in
these species pairs?
A) similar percentages of difference in DNA sequence between all pairs of sister species
B) greater percentage of difference in DNA sequence between species that inhabit deep water
than between species that inhabit shallow water
C) greater percentage of difference in DNA sequence between species that inhabit shallow water
than between species that inhabit deep water
22) Which of the following describes the most likely order of events in allopatric speciation?
A) genetic drift, genetic isolation, divergence
B) genetic isolation, divergence, genetic drift
C) divergence, genetic drift, genetic isolation
D) genetic isolation, genetic drift, divergence
23) You want to study divergence of populations, and you need to maximize the rate of
divergence to see results within the period of your grant funding. You will form a new
population by taking some individuals from a source population and isolating them so the two
populations cannot interbreed. What combination of characteristics would maximize your chance
of seeing divergence in this study?
1. Choose a random sample of individuals to form the new population.
2. Choose individuals from one extreme to form the new population.
3. Choose a species to study that produces many offspring.
4. Choose a species to study that produces a few, large offspring.
5. Place the new population in the same type of environment as the source population.
6. Place the new population in a novel environment compared to that of the source population.
A) 1, 3, and 6
B) 1, 4, and 6
C) 2, 3, and 5
D) 2, 3, and 6
24) How are two different species most likely to evolve from one ancestral species?
A) sympatrically, by a point mutation affecting morphology or behavior
B) sympatrically, due to extensive inbreeding
C) allopatrically, due to extensive inbreeding
D) allopatrically, after the ancestral species has split into two populations
25) House finches were found only in western North America until 1939, when a few individuals
were released in New York City. These individuals established a breeding population and
gradually expanded their range. The western population also expanded its range somewhat
eastward, and the two populations have recently come in contact. If the two forms were unable to
interbreed when their expanding ranges met, it would be an example of _____.
A) prezygotic isolation
B) reinforcement
C) allopatric speciation
D) sympatric speciation
26) Most causes of speciation are relatively slow, in that they may take many generations to see
changes, with the exception of _____.
A) polyploidy
B) reinforcement
C) colonization
D) natural selection
27) Two researchers experimentally formed tetraploid frogs by fertilizing diploid eggs from
Rana porosa brevipoda with diploid sperm from Rana nigromaculata. When they mated these
tetraploid frogs with each other, most of the offspring that survived to maturity were tetraploid,
with chromosome sets of both diploid parent species. Based on these results, if this type of
tetraploid formed in the wild, what would be the result? (Y. Kondo and A. Kashiwagi. 2004.
Experimentally induced autotetraploidy and allotetraploidy in two Japanese pond frogs. Journal
of Herpetology 38(3):381-92.)
A) The two parent species would interbreed and fuse into one species.
B) The two parent species would recognize each other as mates.
C) The tetraploids would be reproductively isolated from both parent species.
D) The tetraploids would be selected against.
28) A researcher notices that in a certain moth species, some females prefer to feed and lay eggs
on domesticated solanaceous plants like potatoes and tomatoes. Other females prefer to feed and
lay eggs on wild solanaceous plants like Datura. Both male and female moths primarily use
scent to find these plants from afar. Females tend to mate where they feed, and the researcher
finds a genetic basis for scent preference in these moths. Based on the above information, what
might be occurring in this moth species?
A) divergence in sympatry
B) divergence due to habitat fragmentation
C) postzygotic isolation
D) polyploidization
29) Two species of tree frogs that live sympatrically in the northeastern United States differ in
ploidy: Hyla chrysoscelis is diploid, and Hyla versicolor is tetraploid. The frogs are identical in
appearance, but their mating calls, which females use to find mates, differ. Which difference
most likely evolved first?
A) polyploidy
B) difference in mating calls
C) Polyploidy and different mating calls must have evolved at the same time.
30) In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In the
western United States, pronghorns and cattle often associate with one another in the same open
rangeland. Some of these fleas develop a strong preference for cattle blood and mate only with
other fleas that prefer cattle blood. The host mammal can be considered as the fleas’ habitat. If
this situation persists, and new species evolve, this would be an example of _____.
A) sympatric speciation and habitat isolation
B) sympatric speciation and temporal isolation
C) allopatric speciation and habitat isolation
D) allopatric speciation and gametic isolation
31) The difference between geographic isolation and habitat differentiation (isolation) is the
_____.
A) relative locations of two populations as speciation occurs
B) speed (tempo) at which two populations undergo speciation
C) amount of genetic variation that occurs among two gene pools as speciation occurs
D) identity of the phylogenetic kingdom or domain in which these phenomena occur
32) Among known plant species, which of these have been the two most commonly occurring
phenomena that have led to the origin of new species?
A) allopatric speciation and sexual selection
B) allopatric speciation and polyploidy
C) sympatric speciation and sexual selection
D) sympatric speciation and polyploidy
33) 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?
A) allopatric speciation; ecological isolation
B) sympatric speciation; habitat differentiation
C) allopatric speciation; behavioral isolation
D) sympatric speciation; allopolyploidy
Use the following description to answer the question(s) below.
On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist.
Drosophila yakuba inhabits the island’s lowlands, and is also found on the African mainland,
located about two hundred miles away. At higher elevations, and only on Sao Tomé, is found the
very closely related Drosophila santomea. The two species can hybridize, though male hybrids
are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly
outnumbered by D. santomea. Studies of the two species’ nuclear genomes reveal that D. yakuba
on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both
species). Sao Tomé rose from the Atlantic Ocean about fourteen million years ago.
34) 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?
A) allopolyploidy
B) autopolyploidy
C) habitat differentiation
D) sexual selection