Deck 15: The Origin of Species

Question 1

In the following figure,two populations of one species of fruit flies were raised for several generations on different nutrients (starch and maltose).Then the members of the two populations were reintroduced and the mating frequencies of flies from the two different populations were recorded.Which of the following is true?

A) After only a few generations, these two populations have undergone speciation because they no longer mate with each other at high levels.
B) The two populations are in the early stages of reproductive isolation because male flies are more likely to mate with female flies that were raised on the same medium.
C) Fruit flies grown on starch for several generations are no longer capable of consuming maltose.
D) The original population of fruit flies actually consisted of two different species of fruit flies. When hybridization occurred between the two populations, only sterile offspring were produced.

Answer 1

B

Question 2

Because alleles are only exchanged within species,each species is said to have a unique

A) habitat.
B) genetic heritage.
C) morphology.
D) allele frequency.

Answer 2

B

Question 3

Before the cultivation of the apple tree,apple maggot flies laid their eggs exclusively on the fruit of Hawthorne trees.As apple orchards became more prominent,apple maggot flies began to lay their eggs on both the fruit of the Hawthorne tree and the fruit of cultivated apple trees.Now,apple maggot flies that live on apple trees mate and lay their eggs at different times of the year than apple maggot flies that live on Hawthorne trees.Is this an example of reproductive isolation?

A) Yes; these two fly populations exhibit a postzygotic barrier that prevents hybrid individuals from developing properly.
B) No; although these two fly populations do not mate in nature, they can be forced to mate in a laboratory because their DNA sequences are still the same.
C) No; this is an example of speciation rather than reproductive isolation.
D) Yes; these two fly populations exhibit a temporal prezygotic barrier that prevents their gametes from encountering each other.

Answer 3

D

Question 4

Which of the following is an example of reproductive isolation?

A) Male deer with large branching antlers are more likely to mate.
B) A blue lizard washes away from a population of mostly green lizards during a hurricane and ends up on an island containing no other lizards to mate with.
C) One population of frogs mates in the deep water of a pond and another population of frogs mates on the shore of the same pond.
D) One individual from a population of fruit flies from an apple orchard is blown by heavy winds into another orchard where it mates with a different population of fruit flies.

Question 5

Which of the following is an example of a postzygotic barrier?

A) The gametes cannot join.
B) The zygote fails to develop.
C) The breeding seasons are different.
D) The courtship behaviors are different.

Question 6

Which of the following is NOT an example of a prezygotic barrier?

A) Two populations of plants produce flowers at different times of year.
B) The reproductive organ of the male of one species of damselfly is physically unable to deposit sperm in the reproductive receptacle of the female of another species of damselfly.
C) The hybrid produced by the mating of a lion and a tiger is reproductively sterile.
D) One population of frogs lives in the middle of a pond and the other lives exclusively on land.

Question 7

The primary difference between the prezygotic barriers and postzygotic barriers involved in reproductive isolation is that prezygotic barriers

A) are related to embryos and postzygotic barriers are related to gametes.
B) occur in species that undergo only asexual reproduction, whereas postzygotic barriers occur in species that undergo sexual reproduction.
C) occur in species undergoing allopatric speciation, whereas postzygotic barriers occur in species undergoing sympatric speciation.
D) prevent fertilization from occurring, whereas postzygotic barriers prevent offspring from developing or being reproductively successful.

Question 8

Speciation

A) can result from geographic isolation.
B) is directed.
C) occurs only in ring species.
D) reduces variation.

Question 9

For two populations to accumulate enough genetic differences to cause speciation,the factors that promote these differences

A) must operate in populations that are not physically separated.
B) must have a greater effect than does the amount of ongoing gene flow.
C) must prevent mutations.
D) should include polyploidy.

Question 10

Populations within a species are connected by

A) gene flow.
B) speciation.
C) continental drift.
D) genetic drift.

Question 11

Which of the following must take place for speciation to occur?

A) reproductive isolation
B) geographic isolation
C) polyploidy
D) hybridization

Question 12

Two species live in the same area but breed in different parts of their habitat.These species are

A) geographically isolated.
B) ecologically isolated.
C) artificially isolated.
D) likely to produce hybrids.

Question 13

Using reproductive isolation as a method of defining a species is NOT useful for

A) species whose ranges overlap.
B) species that cannot produce hybrids.
C) organisms known only from fossils.
D) organisms that reproduce sexually.

Question 14

The fossils of two adult birds are found in a nest containing several fossilized eggs.Physically,the bird fossils look very different from each other.What are scientists most likely to use to classify these species?

A) the biological species concept
B) the DNA-based species concept
C) the morphological species concept
D) the evidence of reproduction concept

Question 15

Individuals of the same species generally

A) experience prezygotic barriers to reproduction.
B) do not interbreed extensively.
C) share many common physical and behavioral characteristics.
D) vary only very slightly in appearance.

Question 16

The distance needed for geographic isolation is

A) larger for a crow than it is for a snail.
B) smaller for a crow than it is for a snail.
C) the same for both a crow and a snail.
D) impossible to determine because bird species cannot be geographically isolated.

Question 17

Which of the following is an example of a prezygotic barrier that can isolate two species living in the same geographic area?

A) The members of two populations of birds living in neighboring forests freely interbreed.
B) One species of cichlid has the same mating behavior as another cichlid species in the same lake.
C) The gametes of one species of orchid in a rainforest are unable to fuse with the gametes of another species of orchid in the same rainforest.
D) Two species of wildflowers mate and produce a hybrid that is capable of successfully breeding with either species.

Question 18

Geographic isolation limits the ________ between populations of a species.

A) genetic differences
B) adaptation
C) directional selection
D) gene flow

Question 19

Why have the two plant populations depicted in the following diagram become so different in the time they were separated by the ocean?

A) A small group of individuals carrying only the tall allele established a new population on the right side of the ocean.
B) The amount of gene flow between the two populations increased when the ocean separated the plants, so mutations moved from one population to another.
C) When sea levels rose, it killed all of the plants on the right side of the figure. A new species evolved from another plant species already existing in the mountains on the right.
D) The separated populations adapted to the different environments on each side of the ocean and became reproductively isolated.

Question 20

The willow flycatcher and the least flycatcher are similar in appearance,and in many regions of the United States,their ranges overlap.The two organisms do not interbreed.Based on this information,willow flycatchers and least flycatchers are

A) different species.
B) different populations of the same species.
C) hybrids.
D) reproductively isolated.

Question 21

The following pictures show a shark,which is a fish,and a dolphin,which is a mammal.The similar body types of these two species are due to

A) divergent evolution.
B) convergent evolution.
C) genetic drift.
D) adaptive radiation.

Question 22

Polyploidy can lead to very rapid speciation in plants because

A) polyploidy increases the amount of gene flow between polyploid plants and nonpolyploid plants.
B) the DNA sequences of essential genes are altered to such a degree that the polyploid plant can no longer mate with the original species.
C) the gametes of polyploid plants have too many chromosomes and cannot fuse to the gametes of the original species.
D) when a plant becomes polyploid, it often loses the ability to make gametes of any type.

Question 23

Grizzly bears,whales,mice,and humans are very different genotypically and phenotypically.However,they do share some genotypic and phenotypic traits because they

A) independently evolved the similar traits, even though they are not related to each other.
B) evolved from species that radiated from a common ancestral species millions of years ago.
C) occupy the same ecological niche where similar traits are selected.
D) are not reproductively isolated from each other.

Question 24

Sympatric speciation

A) occurs only in plants.
B) is impossible, because the populations of a species must be isolated from one another for speciation to occur.
C) is always a result of polyploidy.
D) occurs when a new species emerges from a population in the absence of a geographical barrier.

Question 25

Which of the following is NOT due to the common ancestry of related species?

A) homologous structures
B) vestigial structures
C) analogous structures
D) descendant structures

Question 26

Adaptive evolution

A) is large-scale movement of a single species over a new geographic area.
B) occurs when a more adapted species causes the extinction of a less adapted one.
C) is the process by which natural selection improves the match between an organism and its environment over time.
D) is an increase in the adaptiveness of many species that have already evolved.

Question 27

Mass extinctions frequently result in adaptive radiation because they lead to

A) allopatric speciation.
B) postzygotic barriers in other species.
C) mechanical isolation in other species.
D) ecological isolation in other species.

Question 28

In the following illustration of adaptive radiation of mammals,which is the ancestral species?

A) Grizzly bear
B) Brontotherium
C) Woolly mammoth
D) Morganucodon

Question 29

In general,geographical isolation occurs when

A) populations migrate to new environments.
B) gene flow is reduced by more than 75 percent due to climate change.
C) mutations overcome genetic drift across physical barriers.
D) populations are separated by a distance that is great enough to limit gene flow.

Question 30

The two squirrel species shown in the following figure arose from the same ancestor.The Kaibab squirrel lives on the north rim of the Grand Canyon and Abert's squirrel lives on the south rim.Which is the most likely explanation for their speciation?

A) The population of ancestral squirrel occupied only one of the rims of the Grand Canyon. As the population grew, some members of the population crossed the Grand Canyon to form a new population.
B) The population of the ancestral squirrel was split by the formation of the Grand Canyon. Since the habitats were different on each rim, the populations evolved differently and became reproductively isolated.
C) When the Grand Canyon formed, competition for food and shelter became fierce. The two species arose through sympatric speciation as some individuals gathered food on the north rim rather than the south rim.
D) The ancestral squirrel was actually a hybrid of two squirrel species. When the populations were separated and could no longer mate, the characteristics of the two species became more obvious.

Question 31

Adaptive evolution allows species to

A) reduce the mutation rate.
B) decrease genetic variation.
C) adjust to environmental changes.
D) hybridize.

Question 32

Adaptive radiation gives rise to

A) many descendent species.
B) many ancestral species.
C) a single descendent species.
D) many hybrid species.

Question 33

Vertebrates,animals with backbones,and arthropods,including insects,are only distantly related.The arthropod eye evolved independently of the vertebrate eye.Therefore,the arthropod eye and the vertebrate eye are ________ structures in relation to each other.

A) homologous
B) vestigial
C) analogous
D) hybrid

Question 34

Vertebrates are a group of related animals with a backbone.All vertebrates have basically the same eye structure.Therefore,the vertebrate eyes are

A) homologous structures.
B) vestigial structures.
C) analogous structures.
D) convergent structures.

Question 35

Which of the following does NOT provide an example of geographic isolation?

A) Two snail populations live in two valleys on opposite sides of a mountain range.
B) Two bird populations live on adjacent mountains with a narrow valley between them.
C) Two squirrel populations live on opposite sides of a wide, deep river.
D) Two fish populations live in different lakes.

Question 36

Polyploidy can lead to

A) a high rate of gene flow between populations.
B) geographic isolation.
C) fewer chromosomes.
D) reproductive isolation.

Question 37

Polyploidy in plants can lead to

A) prezygotic isolation.
B) reduced chromosome numbers.
C) reversed meiosis.
D) postzygotic isolation.

Question 38

A large population of animals is split in two by a physical barrier.Over time,the genetic makeup of the two resulting populations becomes more and more different,until each population becomes a separate species.This is an example of

A) sympatric speciation.
B) allopatric speciation.
C) genetic drift.
D) natural selection.

Question 39

Convergent evolution frequently occurs when two unrelated species

A) hybridize.
B) occupy different ecological niches.
C) have a predator-prey relationship.
D) live in similar habitats.

Question 40

Today's diversity of mammals originated with an adaptive radiation that occurred 65 million years ago.This adaptive radiation occurred because

A) ecological niches were opened up and predators were removed.
B) the evolution of a novel trait that gave the animals an advantage.
C) the ancestral species colonized a new continent.
D) increased competition led to rapid natural selection.

Question 41

A ________ species may exist when an organism's range loops around a geographic barrier.Neighboring populations in the range mate,but populations on opposite sides of the barrier cannot mate.

Question 42

Currently,the biggest factor having an effect on polar bear evolution is

A) convergent evolution.
B) polyploidy.
C) rapid environmental changes.
D) recent geographic isolation.

Question 43

Organisms with homologous traits

A) have undergone convergent evolution.
B) evolved the traits independently of each other.
C) are not related.
D) have speciated from a common ancestor.

Question 44

If a murky lake is stocked with a number of species of cichlid fish from Lake Victoria,what is most likely to happen?

A) The cichlid species will be very visible to the many predators in this area.
B) The colorful male cichlids will be very attractive to females in the lake.
C) The cichlid species will interbreed because the lake is so cloudy.
D) The cichlid species will have many offspring because they are so colorful.

Question 45

When speciation is caused by a rapid change in chromosomal number such as ________,new species form in a single generation.

Question 46

A biological species is a group of interbreeding populations that is ________ isolated from other species of organisms living in the same region.

Question 47

Two species live near each other but do not respond to each other's courtship displays.This is an example of ________ isolation,a type of prezygotic barrier.

Question 48

The only modern humans that exhibit Neanderthal genes are descended from non-African ancestors.This is because

A) hybrids produced by interbreeding between Neanderthals and African humans were not fertile.
B) the ancestors of African humans have the same ancestors as Neanderthals.
C) Neanderthals evolved outside of Africa, so only humans who lived outside of Africa could have interbred with them.
D) African humans evolved after Neanderthals went extinct.

Question 49

________ barriers cause speciation to occur by preventing fertilization when two individuals of different populations attempt to mate.

Question 50

Speciation as a result of geographic isolation generally occurs at a ________ rate than speciation as a result of polyploidy.

Question 51

A desert plant in North America and one in Africa both have similar spines that they did not inherit from a common ancestor.The spines are ________ to each other.

Question 52

The offspring of two individuals of different species that interbreed are known as ________.

Question 53

Which of the following does NOT contribute to the biodiversity seen on islands?

A) Islands allow for allopatric speciation.
B) The small populations on islands are susceptible to genetic drift.
C) Islands frequently provide microclimates that result in ecological isolation.
D) Species frequently undergo adaptive radiation when they migrate to remote islands.

Question 54

The great diversity of life on Earth is caused by ________,the formation of new species.

Question 55

The death of zygotes produced by the mating of individuals of two different populations is an example of how ________ barriers can lead to reproductive isolation.

Question 56

The formation of a new species

A) can occur slowly or rapidly.
B) takes at least 1 million years.
C) is evolutionarily insignificant.
D) never happens.

Question 57

Some scientists believe that amphibians may be the victims of the next mass extinction.If this does occur,other classes of animals may adapt to the ecological niches vacated by the amphibians in a process called ________.

Question 58

Speciation can occur when populations of a species are separated by a physical barrier becoming ________ isolated and subsequently reproductively isolated from one another.

Question 59

In the example below,two new species are created as a result of ________ speciation.

Question 60

________ speciation occurs when a new species arises in the absence of geographic isolation.

Question 61

Sympatric speciation can occur in the absence of geographic isolation.

Question 62

Geographic isolation can result in speciation but usually only over long periods of time.

Question 63

Gene flow prevents two populations from becoming genetically different.

Question 64

Sympatric speciation requires geographic isolation of populations.

Question 65

Two populations that are geographically isolated will always diverge into two species.

Question 66

Hair is an analogous feature in the different mammal species.

Question 67

Sympatric speciation always follows allopatric speciation.

Question 68

Evidence suggests that Neanderthals and humans are the same species.

Question 69

If organisms are categorized as a species by the morphological species concept,they will not be categorized as a species by the biological species concept.

Question 70

Speciation cannot occur without geographic isolation.

Question 71

Adaptive radiation can only take place in the presence of reproductive isolation.

Question 72

The fact that Neanderthal genes were found in the modern human genome suggests that these two species interbred at some point,creating human-Neanderthal ________.

Question 73

Terrestrial plants radiated onto land because of a mass extinction.

Question 74

Vestigial organs had a function in a previous ancestor but no longer have a function in the current species.

Question 75

The failure of the gametes to fuse is a prezygotic barrier to reproduction.

Question 76

The experiment diagrammed in the following image could lead to the reproductive isolation of fruit fly populations.