Ch 15 Evolution Question and Answer

1
Ch 15 Evolution Question and Answer
2
True/FalseIndicate whether the statement is true
or false

• 1. A vestigial structure in one organism can be
  defined as a reduced form of a functional
  structure in another organism.

1. ANS T REF 425 TOP 15-5
3
True/FalseIndicate whether the statement is true
or false

• 2. Natural selection is based on the concepts of
  excess reproduction, variation, inheritance, and
  the advantages of certain traits.

2. ANS T REF 420 TOP 15-2
4
True/FalseIndicate whether the statement is true
or false

• 3. Darwin developed his theory of evolution
  exclusively from his work on the Galapagos
  Islands.

3. ANS F To develop his understanding of
evolution, Darwin used his studies on H.M.S.
Beagle and the work that he did later after his
return to England. REF 420422 TOP 15-1
5
True/FalseIndicate whether the statement is true
or false

• 4. According to Darwin, the process of natural
  selection could result in a new kingdom of
  organisms.

4. ANS F Natural selection can lead to new
species of organisms. REF 422 TOP 15-3
6
True/FalseIndicate whether the statement is true
or false

• 5. Fossils, although interesting, do not
  actually provide evidence of evolution.

5. ANS F Fossils provide strong evidence of
evolution. REF 423 TOP 15-4
7
True/FalseIndicate whether the statement is true
or false

• 6. Homologous structures indicate a shared
  ancestry, while vestigial structures do not.

6. ANS F Vestigial structures are homologous
structures and both indicate a shared
ancestry. REF 424425 TOP 15-5
8
True/FalseIndicate whether the statement is true
or false

• 7. Biochemical traits helped Darwin unravel his
  theory of evolution.

7. ANS F Darwin did not have any biochemical
information, but later scientists used
biochemical data to understand
evolution. REF 427 TOP 15-6
9
True/FalseIndicate whether the statement is true
or false

• 8. Biogeography is the study of why certain
  species live in certain areas.

8. ANS T REF 427 TOP 15-7
10
True/FalseIndicate whether the statement is true
or false

• 9. The Hardy-Weinberg principle describes the
  conditions within which evolution definitely
  occurs.

• ANS F
• The Hardy-Weinberg principle describes
• the conditions within which evolution does not
  occur.
• REF 431432 TOP 15-7

11
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 10. The theory of natural selection says that
  evolution will not occur in a population unless
  allelic frequencies are acted on by forces that
  cause change. _________________________

• ANS F, Hardy-Weinberg principle
• REF 431432 TOP 15-7

12
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 11. Any change in the allelic frequencies in a
  population that is due to chance is called
  founder effect. _________________________

• ANS F, genetic drift
• REF 433 TOP 15-7

13
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 12. A population of ants declines to a very low
  number. When the ants habitat is turned into a
  picnic area for humans, the additional food
  causes the population of ants to rebound. This is
  an example of natural selection.
  _________________________

• ANS F, a bottleneck
• REF 433 TOP 15-7

14
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 13. A mutation is a random change in genetic
  material. _________________________

13. ANS T REF 434 TOP 15-7
15
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 14. Humans born with either below-normal or
  above-normal birth weights have a lower chance of
  survival than those born with average birth
  weights. Consequently, birth weights vary little
  in human populations. This form of natural
  selection is called directional selection.
  _________________________

• ANS F, stabilizing selection
• REF 434 TOP 15-8

16
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 15. Inbreeding in a population leads to
  individuals that are heterozygous for many
  traits. _________________________

• ANS F, homozygous
• REF 434 TOP 15-7

17
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 16. Punctuated equilibrium and gradualism are two
  models that describe the cause of speciation.
  _________________________

• ANS F, rate
• REF 440441 TOP 15-9

18
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 17. Gradualism and punctuated equilibrium are
  similar models of evolution. _____________________
  ____

• ANS F, competing
• REF 441 TOP 15-9

19
Modified True/FalseIndicate whether the
statement is true or false. If false, change the
identified word or phrase to make the statement
true.

• 18. Embryos of different organisms exhibit
  homologous structures during certain phases of
  development that become totally different
  structures in adult forms. This indicates that
  organisms evolved from different ancestors.
  _________________________

• ANS F, common
• REF 426 TOP 15-5

20
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 19. Within a decade of the introduction of a new
  insecticide, nearly all of the descendants of the
  target insects are resistant to the usual-sized
  dose. What is the most likely explanation for
  this change in susceptibility to the insecticide?
• a. Eating the insecticide caused the insects to
  become more resistant to it.
• b. Eating the insecticide caused the insects to
  become less resistant to it.
• c. The pesticide destroyed organisms that cause
  disease in the insects, thus allowing them to
  live longer.
• d. The insects developed physiological
  adaptations to the insecticide.

• ANS D
• Over time, organisms often adapt to changes in
  the environment. In this case, the insects
  adapted to the insecticide and lost their initial
  susceptibility.
• REF 428430 TOP 15-3

21
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 20. Which answer best shows an animal's
  adaptation to the tropical rain forest?
• a. camouflage in a tree frog
• b. the long neck of a giraffe
• c. an elephant's long trunk
• d. migration of birds in winter

20. ANS A Some species have evolved
morphological adaptations that allow them to
blend in with their environments and therefore
survive. REF 428 TOP 15-5
22
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• Which combination of characteristics in a
  population would provide the greatest potential
  for evolutionary change?
• a. small population, few mutations
• b. small population, many mutations
• c. large population, few mutations
• d. large population, many mutations

21. ANS B Darwins theory of how traits change
in a population over time includes the idea that
variations can be inherited. Mutations in a small
population would be inherited and passed to the
next generation. The smaller the population and
the more mutations, the more changes would
happen in the population. REF 420 TOP 15-7
23
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 22. When investigating shell color of a species
  of snail found only in a remote area seldom
  visited by humans, scientists discovered the
  distribution of individuals that is shown in the
  graph in Figure 15-1. Based on the information
  shown in the graph, what form of selection is the
  snail population undergoing?
• a. stabilizing selection
• b. disruptive selection
• c. artificial selection
• d. directional selection

22. ANS D If an extreme version of a trait makes
an organism more fit, directional selection may
occur. This form of selection increases the
extreme versions of a trait in a
population. REF 435 TOP 15-7
24
Multiple Choice Identify the choice that best
completes the statement or answers the question.
Figure 15-2

• 23. What type of adaptation is shown in Figure
  15-2?
• a. Mimicry
• b. Camouflage
• c. artificial selection
• d .homologous structure

23. ANS B Camouflage is an adaptation that
allows species to blend in with the environment
and therefore survive. Camouflage is an
adaptation that allows species to
reproduce. REF 428 TOP 15-5
25
Multiple Choice Identify the choice that best
completes the statement or answers the question.
Figure 15-3

• 24. Which term best describes the structures
  shown in Figure 15-3?
• a. Homologous
• b. heterologous
• c. Analogous
• d. vestigial

24. ANS C Not all anatomically similar
structures are evidence of evolution. Analogous
structures are not inherited from a common
ancestor. REF 426 TOP 15-5
26
Multiple Choice Identify the choice that best
completes the statement or answers the question.
Figure 15-4

• 25. Which type of natural selection showed in
  Figure 15-4 favors average individuals?
• a. A
• b. B
• c. C
• d. D

25. ANS A Selected distribution would favor
average individuals because they would not have
extreme traits. REF 434 TOP 15-7
27
Multiple Choice Identify the choice that best
completes the statement or answers the question.
Figure 15-4

• 26. Which type of natural selection shown in
  Figure 15-4 would favor giraffes that need to
  reach the tallest branches to eat?
• a. A
• c. C
• b. B
• d. D

26. ANS C Natural selection acts to select the
individuals that are best adapted for survival
and reproduction. That concept is reflected in
C. REF 434 TOP 15-7
28
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 27. Which of the following is a correct statement
  about the relationship between natural selection
  and evolution?
• a. Natural selection results from evolution.
• b. Natural selection includes evolution as a part
  of it.
• c. Natural selection is one mechanism of
  evolution.
• d. Natural selection and evolution are the same
  thing.

27. ANS C Natural selection is one of several
processes, or mechanisms, that can lead to
evolutionary change. REF 422 TOP 15-3
29
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 28. How do fossils demonstrate evidence of
  evolution?
• They show that ancient species share similarities
  with species now on Earth.
• b. They show evidence of species that are now
  extinct.
• c. They are the primary source of evidence of
  natural selection.
• d. Fossils reveal that many species have remained
  unchanged for millions of years.

28. ANS A Fossils are the main evidence of
evolution because they show ancestors of modern
species. REF 423 TOP 15-4
30
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 29. Which of the following is an accurate
  comparison of derived traits and ancestral
  traits?
• a. Derived traits result from artificial
  selection ancestral traits result from natural
  selection.
• b. Derived traits appear in species ancestral
  traits appear in genera or higher taxa.
• c. Derived traits are primitive ancestral
  traits are contemporary.
• d. Derived traits are recent features ancestral
  traits are more primitive features.

29. ANS D Derived traits are recent features,
such as feathers in vertebrates ancestral
traits are more primitive features, such as teeth
in vertebrates. REF 424 TOP 15-5
31
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 30. Which of the following is the explanation of
  why bird wings and reptile forelegs are evidence
  of evolution?
• a. Similar functions point to a common ancestor.
• b. Analogous structures indicate a common
  ancestor.
• c. Vestigial structures point to a common
  ancestor.
• d. Homologous structures indicate a common
  ancestor.

30. ANS D Evolution predicts that an organisms
body parts are more likely to be modifications
of ancestral body parts than new
features. REF 424 TOP 15-5
32
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 31. Superficially similar features molded by
  natural selection in very different species are
  classified as what kind of structures?
• a. Vestigial
• b. Homologous
• c. Analogous
• d. comparative

31. ANS C Analogous structures are evidence of
convergent evolution through natural
selection. REF 426 TOP 15-5
33
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 32. According to Darwin, which of the following
  best explains why the mara is more similar to
  other South American mammals than it is to the
  rabbit?
• Its genotype is similar to the South American
  animals.
• It shares amino-acid sequences with other South
  American animals.
• It shares a closer ancestor with the South
  American animals.
• Its geographic distribution indicates very little
  variation over time.

32. ANS C Darwin recognized that South American
animals are more similar to each other than they
are to the similar species in Europe. He decided
that this is due to a common South American
ancestor. REF 427 TOP 15-6
34
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 33. Some features in organisms can be compared to
  spandrels in architecture in that, although they
  appear to have a function, they are really just
  there because of the evolution of other
  structures. This analogy is used as an argument
  for care in identifying what?
• a. homologous structures in organisms
• b. natural selection
• c. vestigial structures in organisms
• d. traits as adaptations

33. ANS D This analogy has been used to argue
the importance of being careful when saying that
a particular structure in an organism is an
adaptation, without evidence of natural
selection. REF 430 TOP 15-5
35
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 34. When allelic frequencies remain unchanged, a
  population is in genetic equilibrium. This
  statement expresses which of the following?
• genetic drift
• Hardy-Weinberg principle
• sympatric speciation
• prezygotic isolating mechanism

34. ANS B The Hardy-Weinberg principle showed
mathematically that evolution will not occur in
a population unless allelic frequencies are
acted upon by forces that cause
change. REF 431 TOP 15-7
36
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 35. A population diverges and becomes
  reproductively isolated. Which of the following
  is the best description of that phenomenon?
• a. speciation
• b. bottleneck
• c. postzygotic isolation
• d. sexual selection

35. ANS A REF 438 TOP 15-8
37
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 36. What is the term describing the process that
  occurs when a species evolves into a new species
  without a physical barrier separating
  populations?
• a. adaptive radiation
• c. sympatric speciation
• b. coevolution
• d. allopatric speciation

36. ANS C In this case, the ancestor species and
the new species live side-by-side during the
speciation process. REF 438 TOP 15-8
38
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 37. If a species is suddenly introduced into a
  new habitat, what might occur?
• a. habitat speciation
• b. coevolution
• c. adaptive radiation
• d. selective speciation

37. ANS C Adaptive radiation occurs when a
species is introduced to a new ecosystem or when
a species can survive in an environment that was
unreachable before. For example, Darwins
finches developed from a single species of
finches that reached the islands. REF 439 TOP 15
-7
39
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 38. Which of the following is biochemical
  evidence for evolution?
• a. Embryonic human hemoglobin is different from
  adult human hemoglobin.
• b. Hemoglobin in humans can vary between
  different individuals.
• c. Human hemoglobin is more similar to chimp
  hemoglobin than mouse hemoglobin.
• d. Human hemoglobin is different than mouse
  hemoglobin.

38. ANS C The structure of biochemical traits,
such as protein structure, reflects the degree
of relationship of different species in the same
way that anatomical traits do. REF 427 TOP 15-
40
Multiple Choice Identify the choice that best
completes the statement or answers the question.

• 39. On the islands of Hawaii there are a group of
  about 30 species of highly variable, but closely
  related, species of plant called silverswords.
  These species appear to be related to a small
  group of plants in North America. What are the
  silverswords an example of?
• a. mimicry
• b. analogous structures
• c. adaptive radiation
• d. vestigial structures

39. ANS C The silverswords are an example of an
adaptive radiation occurring after a single
species dispersed to new habitat in the Hawaiian
Islands. REF 439 TOP 15-7
41
CompletionComplete each statement.

• 40. Natural selection is the only mechanism of
  evolution that will lead to ____________________.

40. ANS adaptation REF 421422 TOP 15-2
42
CompletionComplete each statement.

• 41. Information on genetics and
  ____________________ now provide compelling
  evidence of evolution that was not available to
  Darwin.

• ANS biochemistry
• REF 427 TOP 15-6

43
CompletionComplete each statement.

• 42. Not all fossils of ____________________
  organisms have modern counterparts.

• ANS extinct
• REF 423 TOP 15-4

44
CompletionComplete each statement.

• 43. Imagine that you are a paleontologist and you
  have found a dinosaur fossil that is intermediate
  in form between species. You would classify this
  fossil as a ____________________ fossil.

• ANS transitional
• REF 424 TOP 15-4

45
CompletionComplete each statement.

• 44. Anatomically similar structures inherited
  from a common ancestor are called
  ____________________ structures.

• ANS homologous
• REF 424 TOP 15-5

46
CompletionComplete each statement.

• 45. The snake pelvis is an example of a
  ____________________ structure.

• ANS vestigial
• REF 425 TOP 15-5

47
SHORT ANSWER

• 46. How do changes in genetic equilibrium lead to
  speciation?

• ANS Answers will vary.
• Allele frequency is altered by genetic drift,
• natural selection, migration, mutation, or
  nonrandom mating.
• This results in a change in genetic equilibrium
• in a population that is evolving. Evolution leads
  
• eventually to speciation.
• REF 440 TOP 15-8

48
SHORT ANSWER

• 47. List and describe the indirect evidence
  available to support the theory of evolution.

47. ANS Fossils can show evolutionary changes
over time. Anatomical studies indicate
evolutionary relationships. Vestigial structures
indicate evolutionary pathways. Embryological
development and genetic comparisons show
evolution from a common ancestor. TOP 15-4
15-5 15-6
49
SHORT ANSWER

• 48. How is Darwin's theory of evolution by
  natural selection related to the origin of
  structural and physiological adaptations?

48. ANS Structural and physiological
adaptations occur at random within populations
because of adaptations. Darwin's theory explains
how these are fixed within populations. REF 420
TOP 15-2
50
SHORT ANSWER

• 49. Summarize Darwin's theory of evolution by
  natural selection.
• Figure 15-5

49. ANS Darwin's theory of evolution by natural
selection can be summarized by the following
four statements. First, variations exist within
populations. Second, some variations are more
advantageous for survival and reproduction than
others. Third, Organisms produce more offspring
than can survive. Finally, over time, offspring
of survivors will make up a larger proportion of
the population. REF 418421 TOP 15-2
51
SHORT ANSWER

• 50. A study of the squirrel population in a large
  northern city revealed that many of the squirrels
  inhabited large park areas that were also
  populated by numerous squirrel predators. The
  graph in Figure 15-5 reflects the data collected
  in regard to color and number of squirrels.
  Explain how this type of disruptive selection can
  lead to the separation of this population into
  two distinct species.

• 50. ANS
• After a long period of time, squirrels with the
  once-most-common phenotype, medium fur color,
  will produce fewer and fewer offspring and will
  gradually be eradicated. The light- and
  dark-colored individuals will live and reproduce
  successfully. After a while, disruptive selection
  will concentrate the color distribution at the
  two extremes. Eventually, the two groups may no
  longer recognize each other for mating purposes.
  This reproductive isolation could lead to the two
  types becoming separate species. Another
  possibility with the same end result is that
  these squirrels would tend to survive most
  successfully in areas where either dark or light
  coat color variation would be most advantageous.
  This would lead to geographic isolation.
• REF 436 TOP 15-7

52
Read this for an analogy to question 51.

• A biologist studying a variety of fly in the rain
  forest noticed that the types of foods the fly
  preferred were located either high in the trees
  or in the foliage on the ground. There didn't
  seem to be any of the preferred foods anywhere in
  between. An experiment was designed that would
  select for a genetically determined behavior
  known as geotaxis. If a fly shows positive
  geotaxis, it flies downward. If a fly shows
  negative geotaxis, it flies upward. To conduct
  the experiment, the flies being studied were
  marked and placed in a maze (illustrated in
  Figure 15-6). Each fly was placed in the "start"
  chamber. To exit from this area, the fly had to
  make a decision about which of the three exits to
  enter. One exit faced upward, indicating negative
  geotaxis, and another exit aimed downward,
  indicating positive geotaxis. A third exit
  permitted the fly to remain on middle ground.
  Each fly was placed in the maze 15 times and its
  choice of direction recorded. Some flies
  consistently went upward and entered the food
  vial at the end of the exit tube. Others
  consistently went downward and entered the food
  vial at the lower end. Some flies chose the
  upward and downward exits equal numbers of times
  others went for the middle exit.

Figure 15-6
53
SHORT ANSWER

• 51. A study of the squirrel population in a large
  northern city revealed that many of the squirrels
  inhabited large park areas that were also
  populated by numerous squirrel predators. The
  graph in Figure 15-5 reflects the data collected
  in regard to color and number of squirrels.
  Explain why the light- and dark-colored squirrels
  might be selected for and the medium-colored
  squirrels selected against.

51. ANS The light-colored squirrels blend in
well with the soil found in the area and with
the leaves that fall from the trees and cover
the ground in the autumn. The darker-colored
squirrels blend in well with the paved walkways
of the park area and also with the darkened tree
trunks. The medium-colored squirrels would be
more visible to predators and thus be selected
against. REF 435 TOP 15-5
54
SHORT ANSWER

• 52. Explain what might eventually happen if, in
  the wild, the flies developed into two
  populations with one showing positive geotaxis
  and the other showing negative geotaxis. Refer to
  Figure 15-6.

52. ANS Eventually, the two populations would
become reproductively isolated owing to their
height preferences. Two distinct species with
their separate gene pools would
result. REF 437 TOP 15-8
55
SHORT ANSWER

• 53. Explain what is occurring in the flies'
  environment to select for flies that do not
  exhibit a distinct preference for flying upward
  at every trial or downward at every trial. Refer
  to Figure 15-6.

• 53. ANS
• The preferred foods could ripen at different
  times so that at one point in the year, it would
  be beneficial to fly upward, and, at a different
  time of the year, it would be more productive to
  fly downward. It might be, for example, that they
  feed on the pollen or other product of a
  particular species of flower. The flower may open
  only in the evening. So at that time of the day,
  the fly would do better to fly upward toward the
  flower. At other times, the fly may do better
  moving downward. There could also be a variety of
  predators that feed on the flies. Perhaps some of
  these predators also have preferred niches that
  are related to height levels in the vegetation.
• REF 434436 TOP 15-7

56
SHORT ANSWER

• 54. If the selection of direction is a genetic
  trait, explain what should happen when flies
  consistently selecting the upward exit are mated
  and those selecting the downward exit are mated,
  and the "no preference" and middle-choice flies
  are discarded. Refer to Figure 15-6.

• 54. ANS
• You should end up with two different types of
  flies. One type will consistently fly only upward
  and the other will fly only downward.
• REF 434436 TOP 15-7

57
SHORT ANSWER

• 55. Assume the selection of direction is a
  genetic trait. Also assume flies consistently
  selecting the upward exit are mated together,
  those selecting the downward exit are mated
  together, and the "no preference" and middle
  choice flies are discarded. Describe what type of
  selection pressure is operating in this
  experiment. Use Figure 15-6 to explain your
  answer.

• 55. ANS
• Disruptive selection would be operating. The two
  extremes are being favored while the middle
  choice (sometimes positive geotaxis and sometimes
  negative) is being selected against. This is true
  because the middle flies are being discarded in
  the experiment while the two extremes are being
  retained and allowed to mate.
• REF 436 TOP 15-7

58
SHORT ANSWER

• 56. In terms of evolution and natural selection,
  decide why the researcher would suspect that the
  flies being studied would show geotaxis. Refer to
  Figure 15-6.

• 56. ANS
• It would be reasonable to expect that the flies
  would move either directly upward toward food or
  directly downward toward food because there
  wasn't anything for them to eat in between those
  areas.
• REF 434 TOP 15-7

59
SHORT ANSWER

• 57. The idea of punctuated equilibrium in
  evolutionary history was developed by two
  paleontologists as a way to explain their
  observations of certain fossil records. Explain
  what pattern in the fossil record the punctuated
  equilibrium model fits.

• 57. ANS
• Punctuated equilibrium is an explanation for
  fossil records in which an organism appears
  almost without change over many geological
  strata, or many years. Then there is a sudden
  change in the anatomy of the organism with no
  evidence of in-between stages.
• REF 440441 TOP 15-9

60
SHORT ANSWER

• 58. Compare allopatric and sympatric speciation.
  Begin your comparison with a definition of
  speciation.

• 58. ANS
• For speciation to occur, a population must
  diverge and then be reproductively isolated.
  There are two forms of speciation allopatric and
  sympatric. In allopatric speciation, a physical
  barrier divides two or more populations.
  Eventually, the populations will no longer be
  able to breed with one another. In sympatric
  speciation, a species evolves into a new species
  without a physical barrier. As a result, the
  species is no longer able to breed with the main
  population.
• REF 438 TOP 15-8

61
SHORT ANSWER

• 59. Describe what Darwin found about the finches
  on the Galapagos Islands and why it provided
  evidence for evolution.

• 59. ANS
• Darwin found several species of finch on the
  islands that were found nowhere else on Earth.
  Yet the finches on the Galapagos resembled
  finches from mainland South America. Darwin
  reasoned that a South American finch had come to
  the Galapagos Islands and over time had changed
  and given rise to new species on the islands that
  were different from each other and from the South
  American species.
• REF 418419 TOP 15-1

62
SHORT ANSWER

• 60. Discuss the important roles that the ideas in
  Lyells Principles of Geology and Malthus essay
  played in Darwins development of the theory of
  evolution by natural selection.

• 60. ANS
• Lyells book argued that Earth was very old,
  which gave selection enough time to produce all
  of the species seen on Earth and in fossils. It
  also influenced him as he observed and collected
  fossils on the trip. Malthus essay gave Darwin a
  key idea in evolution, the idea that populations
  have the potential for unlimited growth, but that
  limited resources will create a struggle for
  existence that will limit growth.
• REF 418 420 TOP 15-1

63
SHORT ANSWER

• 61. Why was artificial selection such an
  important form of evidence for the theory of
  evolution by natural selection proposed by Darwin?

• 61. ANS
• Artificial selection works, just like natural
  selection, by selecting certain inherited traits
  for greater representation in the next
  generation. Different traits are selected under
  artificial selection and natural selection, but
  if artificial selection works, which it does,
  then natural selection should also work.
• REF 420 TOP 15-1

64
SHORT ANSWER

• 62. Describe the importance of transitional
  fossils as evidence for evolution.

• 62. ANS
• Transitional fossils show organisms that have
  intermediate characters between one species and
  another, such as between an extinct fossil
  species and a modern species. They are important
  because evolution by natural selection predicts
  that the change from one species to another will
  be gradual. This is a prediction that
  transitional fossils should be found between very
  different, but related, species.
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65
SHORT ANSWER

• 63. Describe how the forelimbs of vertebrates
  illustrate homologous structures.

• 63. ANS
• Each limb is adapted for different uses, but all
  have similar bones.
• REF 424425 TOP 15-5

66
SHORT ANSWER

• 64. DNA is the molecule responsible for
  inheritance in all living organisms on Earth.
  What is this evidence of?

• 64. ANS
• The use of DNA by every living organism on Earth
  suggests that all living things share a common
  ancestor that used DNA as its hereditary
  molecule.
• REF 427 TOP 15-6

67
The End of Q and A for Ch 15