Deck 14: How Evolution Works

Question 1

In populations that have a high degree of genetic diversity,the fundamental cause of evolutionary change is

A) continental drift.
B) natural selection.
C) long-term climatic change.
D) mutation.

Answer 1

B

Question 2

Genetic variation is based on

A) the inheritance of alleles that are accumulated during an individual's lifetime.
B) differences in DNA sequences between the individuals in a population.
C) the accumulation of mutations in somatic cells (as opposed to gametes).
D) the formation of new combinations of alleles during asexual reproduction.

Answer 2

B

Question 3

Four mechanisms can change the composition of a population's gene pool,but only ________ does so by creating new alleles.

A) genetic drift
B) mutation
C) natural selection
D) gene flow

Answer 3

B

Question 4

For a population to evolve,there must be genetic differences between organisms in that population.These differences come from

A) mutation.
B) a change in an organism's behavior.
C) natural selection.
D) common descent.

Question 5

Before the industrial revolution,scholars believed that Earth was only 6,000 years old.What evidence first suggested that this belief might NOT be correct?

A) Scientists developed techniques to accurately determine the age of fossils.
B) Researchers saw bacteria undergoing natural selection at a rapid rate in the laboratory.
C) Geological studies showed that the slow action of rivers,glaciers,earthquakes,and volcanoes shapes Earth's surface over long periods of time.
D) Scholars observed that new species could evolve rapidly via artificial selection.

Question 6

One of the reasons why scientists have had so much difficulty finding a cure for HIV (human immunodeficiency virus)and AIDS is that the virus is quick to evolve resistance to the drugs that are used to treat it.What is the most likely mechanism for this type of evolution?

A) Certain versions of the virus are slower to die when exposed to a drug than others.Those viruses may survive drug treatment and pass their genes to their offspring.
B) Every time a person takes an HIV drug,it randomly kills off most of the virus particles but not all of them.Those that survive repopulate the body of their host.
C) Although all copies of a particular strain of HIV are identical,some are better at hiding in regions of the body that drugs cannot reach,and those viruses "teach" their offspring where to hide.
D) Some versions of HIV produce chemicals that break down the drugs before they can harm the virus.

Question 7

Biological evolution can be defined as

A) the process of direct observation.
B) adaptations to common descent.
C) the unchanging nature of life on Earth.
D) the change in allele frequencies in a population's gene pool over time.

Question 8

Species like the African cheetah,northern elephant seal,and Florida panther have all experienced a genetic bottleneck;what is the primary outcome of this experience?

A) Genetic mutation occurs at a higher frequency.
B) New genetic material arrives from individuals that join the population.
C) Natural selection becomes disruptive.
D) Genetic diversity is greatly reduced.

Question 9

Peppered moths in England evolved into a dark-colored form when soot darkened the bark of the trees they lived on and exposed the light-colored form to predation.However,air pollution control eventually restored the moths' habitat to its original condition.What would probably have happened to the peppered moth population if the light-colored alleles had been entirely lost from its gene pool during the period when dark-colored moths were selectively favored?

A) Mutations that would reestablish the light-colored allele in the gene pool would have occurred.
B) The moths would have evolved behaviorally and chosen to avoid trees with light-colored bark.
C) The moths would have changed their dietary preferences to foods that contain only light pigments.
D) The population would have become extremely small or possibly extinct after the loss of this adaptive trait.

Question 10

Many weeds have become resistant to the herbicides that were once used to control them.Which of the following statements best explains this observation?

A) The weeds have evolved to become different species.
B) The herbicides have evolved and are no longer effective against the weeds.
C) Continental drift has caused the evolution of weed resistance in the herbicides.
D) Natural selection has acted on the genetic variability in the weeds' genomes,enabling plants that have herbicide resistance to reproduce more successfully.

Question 11

Jean-Baptiste Lamarck proposed that changes in the characteristics of a population are a result of traits acquired during an organism's lifetime being inherited by that organism's offspring.What is wrong with this proposal?

A) Only changes in the DNA sequence of an organism can be inherited.Traits that are acquired throughout life generally do not alter DNA.
B) The environment chooses which traits are necessary for survival,rather than the individual.
C) Changes in a species occur at the individual level rather than the population level.
D) The inheritance of acquired traits would not lead to speciation,because it would cause all the individuals in a population to become more similar.

Question 12

One frequently observed example of evolution is

A) a chameleon changing colors as it moves from a leaf of one color to a leaf of another color.
B) bacteria developing increased resistance to an antibiotic that is used to kill them.
C) chimpanzees learning sign language.
D) humans teaching dogs to obey certain commands.

Question 13

In genetic drift,the events that affect the survival and reproduction of individuals in a population occur

A) primarily by chance.
B) in a predictable way.
C) rapidly and in close succession.
D) in close association with geological processes.

Question 14

A hurricane could cause genetic drift by

A) increasing the mutation rate of a population.
B) randomly killing more males than females in a population.
C) randomly killing more individuals of one genotype than another in a population.
D) relocating a population to a different habitat.

Question 15

Peppered moths are generally light in color and blend into the trunks of the trees they live on.Populations of peppered moths that are found in areas where soot has blackened the tree trunks are dark in color.This example demonstrates

A) artificial selection.
B) natural selection.
C) genetic drift.
D) vestigial coloration.

Question 16

Which of the following things is an example of gene flow?

A) an insecticide,like DDT,that improves reproductive success for only those individuals that have the genes for resistance
B) the selective removal of visually distinctive individuals via predation
C) the post-bottleneck expansion of a population after the restriction has been removed
D) pollen grains that can transport a gamete hundreds of miles to an isolated population

Question 17

Natural selection tends to

A) increase the commonality of characteristics that enhance survival and reproduction.
B) decrease the number of individuals in any given population.
C) lead to an increase in genetic drift.
D) decrease the likelihood of adaptation.

Question 18

The main conclusion Darwin reached after his return from the expedition aboard the HMS Beagle was that

A) the animals living on the Galápagos Islands were similar to those seen on other Pacific islands.
B) the animals living on the Galápagos Islands were closely related to those found in England.
C) animal species are stable over time and do not evolve.
D) plant and animal populations slowly change over time as beneficial characteristics become more widespread.

Question 19

Which of the following statements best describes what happens in gene flow?

A) Chance events alter a population's gene pool.
B) New individuals that join a population contribute their alleles to its gene pool.
C) Alleles that make an individual more successful move from one population to another.
D) Crossing-over creates new combinations of alleles during gamete formation.

Question 20

Which of the following statements about natural selection is true?

A) It is the principal cause of extinctions.
B) It is the principal cause of evolutionary change.
C) It occurs only in gametes.
D) It cannot occur without genetic drift.

Question 21

The most probable explanation for why two different species have similar features is

A) genetic drift.
B) gene flow.
C) artificial selection.
D) descent from a common ancestor.

Question 22

Many organisms are darker on their dorsal surface and lighter on their ventral surface.They are difficult to see from both above and below because of this ________,which is called countershading.

A) adaptation
B) pattern of resistance
C) selection pressure
D) fixation

Question 23

The fact that small,nonfunctioning hind legs are found in the skeletons of many snakes suggests that snakes

A) are in the process of evolving legs.
B) evolved from organisms with legs.
C) are really populations of lizards with one or more severe mutations in limb development.
D) evolved from eels (snakelike fishes).

Question 24

Which of the following statements about the evolutionary relatedness of organisms is FALSE?

A) Predictions of evolutionary relatedness that are based on the fossil record often agree with predictions that are based on continental drift.
B) Predictions of evolutionary relatedness that are based on fossil evidence often agree with those that are based on protein sequences.
C) Predictions of evolutionary relatedness that are based on DNA often contradict those that are based on anatomical evidence.
D) Predictions that are based on DNA sequences provide the strongest evidence that two organisms are related.

Question 25

Which of the following statements is an example of a behavioral adaptation?

A) Polar bears have white fur and are nearly invisible in their native habitat.
B) Pacific salmon spend the early part of their lives in fresh water but then migrate to the ocean to grow and mature.
C) Caterpillars that hatch on oak trees in the summer resemble twigs,whereas caterpillars that hatch in the spring resemble oak flowers.
D) Deer mice forage at night and are normally inactive during the day.

Question 26

Upon his return to England,Darwin realized that the species he had seen in the Galápagos Islands were distinctive to that locale.Which of the following statements best explains the uniqueness of the assemblage of species that Darwin observed?

A) Very little genetic drift was occurring,because the island populations were relatively large.
B) The islands were too remote for human occupancy;therefore,the habitat modification that humans introduce had not yet occurred.
C) No DNA mutation was occurring among the various island species.
D) Very little gene flow was occurring,because the islands were so distant from the mainland.

Question 27

It is quite common for species that are exposed to sexual selection to be sexually dimorphic.What best explains why the males of diverse species like the lion,elephant seal,and elk are so much larger than the females?

A) In these populations,the males fight one another for the privilege of breeding;therefore,larger males are more likely to be successful.
B) Only large,robust males survive long enough to reach the age of sexual maturity.
C) Large males are better able to defend their offspring;therefore,they make better mates.
D) Large males have superior predator avoidance skills;therefore,they make better mates.

Question 28

The number of different types of organisms found on Earth is primarily a result of

A) continental drift.
B) Darwin's theories.
C) natural selection and speciation.
D) common descent.

Question 29

The term sexual dimorphism refers to a species in which

A) the population consists of males and females.
B) males produce sperm and females produce ova.
C) the males and females differ in distinct anatomical ways,such as body size,coloration,or plumage.
D) natural selection produces a higher prereproduction mortality rate for one gender.

Question 30

The genus Lycopodium includes plants that evolved before the breakup of Pangaea.The genus Sequoiadendron (redwood trees)evolved after Pangaea split into separate landmasses.Which genus would you expect to have the widest distribution of living representatives across the modern continents?

A) Lycopodium
B) Sequoiadendron
C) Both should be equally distributed.
D) Both should be extinct.

Question 31

As embryos,baleen whales have teeth and also have two nostrils directly above their mouth.Before birth,however,the teeth are reabsorbed,and the nostrils migrate and fuse to become the blowhole.What does this observation suggest about the ancestry of these whales?

A) Baleen whales descended from an aquatic ancestor that breathed through an elongated snout,much like the modern alligator does today.
B) Baleen whale ancestors lived in habitats where the potential for mutation was relatively high;early abnormalities during embryonic development are later corrected before birth.
C) Baleen whales evolved from a terrestrial mammalian ancestor and share common inherited developmental features.
D) Modern terrestrial mammals are descended from the same marine mammal ancestors that gave rise to modern whales.

Question 32

Evolution is

A) not supported by scientific evidence.
B) strongly supported by scientific evidence.
C) not supported by the fossil record.
D) too obscure to study.

Question 33

Human embryos and fish embryos share a number of features.Why?

A) Humans and fishes share a common ancestor.
B) All embryos share a similar environment and have acquired similar features via directional selection.
C) Mutations in human and fish embryos have caused them to look alike.
D) Humans and all other vertebrates,including fishes,have identical sets of genes;the differences between the various species are caused by the patterns and timing of gene activation.

Question 34

Pangaea is

A) the component of plate tectonics that was formerly called continental drift.
B) the combined fossil record of ancient species.
C) an ancient supercontinent formed from the major landmasses that exist today as separate continents.
D) the result of natural selection.

Question 35

All mammals have hemoglobin,but the amino acid sequences are not identical.The human sequence differs from that of the baboon,dog,gorilla,and lemur by seven,ten,one,and seven amino acids,respectively.Based on this comparative DNA analysis,which of these animals most recently shared a common ancestor with humans?

A) the baboon
B) the dog
C) the lemur
D) the gorilla

Question 36

Which of the following statements about the fossil record is true?

A) It indicates that representatives of all known plant and animal groups originated on Earth at approximately the same time.
B) It contains strong evidence that major new groups of plants and animals were the descendants of previously existing organisms.
C) It indicates that humans date back as far as the first indications of life.
D) It is incomplete,disjointed,often contradictory,and generally uninterruptible with regard to the evolutionary history of life on Earth.

Question 37

Humans simulate the process of natural selection when they use ________ to develop new varieties of crop plants that better meet the needs of farmers.

A) artificial selection
B) cytochrome c
C) habitat changes
D) continental drift

Question 38

Flounder (a type of fish)generally match the color of the sandy bottoms of the bodies of water they inhabit.Their color functions like camouflage,making them difficult for predators to detect.This is an example of

A) speciation.
B) adaptation.
C) continental drift.
D) guided mutation.

Question 39

Which of the following statements about evolution is true?

A) It results only in the addition of traits to organisms.
B) It results only in the loss of traits from organisms.
C) It can result in the addition or loss of traits in organisms.
D) It has nothing to do with the addition or loss of traits.

Question 40

As terrestrial organisms,both insects and vertebrates evolved legs with joints,but the last common ancestor shared by these lineages existed long before vertebrates had evolved.This knowledge makes it possible to predict that

A) other aspects of leg anatomy,such as fingernails and the number of digits,will also be shared among the two lineages.
B) the DNA sequences that direct leg formation in insects and vertebrates will be very different.
C) future evolutionary developments in these lineages will also parallel one another.
D) the embryos of insects and vertebrates will share many additional developmental characteristics.

Question 41

Some highly successful biologists also have a strong religious faith.How do they reconcile their faith with the scientific evidence for evolution?

A) Most of them reject modern evolutionary theory because they believe it is biased by the ongoing conflict between religion and science.
B) They recognize that religion and evolution are distinct areas of inquiry that do not overlap with each other.
C) They note that the theory of evolution is flawed because it consistently fails to predict the patterns of mutations that are proposed to drive the process.
D) They recognize that evolution works only in nonsentient creatures and that human intelligence has limited the role of evolution.

Question 42

Some finches on the Galápagos Islands feed on insects,an unusual food for finches to eat.Which of the following statements about these finches is most likely to be true?

A) They could not survive if they were moved from their island.
B) They observed and learned this feeding style from local birds.
C) They switched their diet to insects because insects are nutritionally superior.
D) They gradually adapted to this feeding style because they had no competition from typical insect-eating birds.

Question 43

The fossils of organisms that existed when the continents were connected are distributed across ________ continents than the fossils of organisms that evolved after the continents separated.

Question 44

In ________ selection,success is related more to attracting a mate than to possessing adaptations that are beneficial for survival.

Question 45

Which of the following agricultural practices is supported by our current knowledge of the evolutionary process?

A) applying fertilizers and irrigation to newly established crops
B) periodically fallowing a field to give it time for nutrient accumulation
C) using a large variety of pest control methods on a rotating basis to retard the development of pesticide resistance
D) reducing a crop's genetic diversity,such as maturation or grain size,so that it becomes more uniform and easier to harvest and process

Question 46

One of the consequences of ________ is a change in the proportions of one or more of the inherited characteristics found in the next generation,compared with the original population.

Question 47

Suppose a population's gene pool consists of the A and a alleles in a ratio of 80:20.If the population has reached equilibrium,the next generation will consist of genotypes in a ratio of

A) 36AA:28Aa:36aa.
B) 36AA:48Aa:16aa.
C) 25AA:50Aa:25aa.
D) 64AA:32Aa:4aa.

Question 48

Genetic variation within a population is the result of the expression of the different ________ of a gene.

Question 49

Humans have bred cows that are specialized for milk production by mating female cows that produce large quantities of milk with male cows whose mothers also produced large quantities of milk.This is an example of ________ selection.

Question 50

Early scholars recognized that species change over time,either because of chance or because of changes imposed by their environment.

Question 51

Any characteristic that improves an organism's reproductive success in its environment is called a(n)________.

Question 52

After reading an essay written by ________,both Charles Darwin and Alfred Wallace became aware of the potential for populations to increase beyond their environment's capacity to provide for all individuals,resulting in competition for survival.

Question 53

Plate tectonics causes the ________ of Earth's landmasses over geologic time.

Question 54

A study by Charles and Mary Brown has documented a reduction in the wing length of cliff swallows that live near busy roadways;the study proposes that the need to avoid being hit by cars is the evolutionary driving force for the change.How would you evaluate this hypothesis if wing length had also shortened in cliff swallow populations that live in the desert Southwest where traffic is virtually nonexistent?

A) The hypothesis would still be valid.Natural selection is driven by local conditions;the two populations are probably evolving independently and they have coincidentally acquired the same characteristics.
B) The hypothesis would raise some doubts;perhaps aerial predators or another factor yet to be identified are creating the necessity for better flying skills in both populations.
C) The hypothesis would not be valid,because the probability of the same wing length mutation arising in geographically distinct populations is extremely low.
D) The hypothesis would not be valid;if the need to avoid vehicular collisions is driving natural selection,then no evolution should be occurring in the population that lives in the traffic-free environment.

Question 55

The need for new alleles to confront issues like environmental change has nothing to do with the specificity or rate of ________;the process is entirely random.

Question 56

Cliff swallows in southwestern Nebraska are experiencing a new natural selection pressure;the swallows that are less agile are more likely to be killed by ________.

Question 57

One result of ________ over evolutionary time spans is that the alleles that enable individuals to survive and reproduce at a higher rate than other individuals become more common in the population.

Question 58

________ are the preserved remains of formerly living organisms.

Question 59

The protein sequences and DNA sequences of organisms that share a recent common ancestor are likely to be ________ similar than those of organisms that do not share a recent common ancestor.

Question 60

The origin of many species of Galápagos finches from one original species is an example of

A) gene cascades.
B) mass extinctions.
C) adaptation and speciation.
D) genetic drift and emigration.

Question 61

The domestication of agricultural crops,such as corn and wheat,provides direct evidence for evolution.

Question 62

When scientists use the phrase theory of evolution,they are respecting the large segment of the scientific community that remains skeptical of the reality of evolution.

Question 63

All the individuals that constitute any given population will be genetically identical.

Question 64

Cliff swallows with long wings have an adaptive advantage over those with short wings when the selection pressure is related to agility during flight.

Question 65

Populations evolve over time because the individuals that form them are individually evolving.

Question 66

The evolution of the horse from an animal with five toes to an animal with one toe demonstrates one of the common evolutionary themes-that organisms become less complex over time.

Question 67

Scientists who believe in evolution are never religious.

Question 68

Darwin's ideas about natural selection were immediately accepted;this shows that the scientific community recognizes and accepts correct ideas as soon as they are presented.

Question 69

Humans have a reduced tailbone and the muscles to move a tail.This evidence indicates that we descended from an ancestor that had a tail.

Question 70

Continental drift predicts that fossils of species that evolved after Pangaea split apart should be found on only one or a few present-day continents.

Question 71

In the phrase survival of the fittest,the term fittest refers to the individual with the greatest physical strength.

Question 72

Nonheritable genetic variations typically account for only about 10 percent of the evolutionary change in a population.