Deck 4: Speciation and Phylogeny

Question 1

According to the biological species concept, why do species tend to remain the same over long periods of time?

A) New mutations are usually maladaptive.
B) Environments change slowly.
C) Gene flow keeps individuals similar to each other.
D) Natural selection is a powerful process.

Answer 1

C

Question 2

Sympatric speciation occurs when two populations

A) experience different mutations.
B) living in the same location experience different selection pressures.
C) form fertile hybrids.
D) are physically separated from each other.

Answer 2

B

Question 3

According to the ecological species concept, species boundaries

A) cannot be maintained without good geographical separation.
B) are very flexible, so closely related species are easily confused.
C) are maintained by genetic drift.
D) are maintained by selection, even if they overlap in geography.

Answer 3

D

Question 4

What is microevolution?

A) the formation of new species
B) the extinction of a species
C) evolutionary change within a species
D) the death of individuals

Question 5

Which of the following does the ecological species concept emphasize?

A) the importance of allopatric barriers between species
B) the importance of gene flow within species
C) the importance of sympatry within species
D) the importance of selection pressures

Question 6

According to the biological species concept, a species is a group of organisms that

A) share a very similar morphology.
B) share the same geographical and environmental circumstances.
C) interbreed and are reproductively isolated from other like groups.
D) share genetic information.

Question 7

The biological species concept emphasizes

A) genetic drift within populations.
B) gene flow between populations.
C) the importance of mutations.
D) that the amount of genetic information that is exchanged within a population rarely changes.

Question 8

Why are biologists uncertain about how a species should be defined?

A) Biologists argue over how to incorporate behavior into species' definitions.
B) New species usually emerge too quickly to be observed by biologists.
C) Biologists are not in full agreement on the processes that give rise to new species.
D) Biologists have not figured out how to use DNA data to determine species' statuses.

Question 9

During allopatric speciation, ________ may amplify the initial differences between populations and lead to two new species.

A) microevolution and asexual reproduction
B) reinforcement and character displacement
C) blending and macroevolution
D) phylogeny and disequilibrium

Question 10

The existence of asexual species provides evidence that

A) species can be maintained through the biological species concept.
B) species can be maintained through the ecological species concept.
C) macroevolution is a stronger force than microevolution.
D) microevolution is a stronger force than macroevolution.

Question 11

Allopatric speciation can involve

A) recolonization without reproductive isolation.
B) gene flow.
C) genetic drift.
D) sharing a habitat.

Question 12

Which of the following statements is true of reproductive isolation?

A) It can occur because of changes in courtship behavior.
B) It requires long-term geographical separation.
C) It is enhanced by high rates of gene flow.
D) It only occurs on islands.

Question 13

________ occurs when members of a given group of organisms do NOT successfully mate with organisms of the same species outside of their group.

A) Monogamy
B) Gene flow
C) Reproductive isolation
D) Microevolution

Question 14

According to the ecological species concept, why do individuals within a species remain similar to each other?

A) Individuals in the same environment experience similar natural selection pressures.
B) Lack of gene flow prevents the mixing of genes.
C) Individuals in the same population share DNA.
D) Individuals in the same environment sometimes experience different selection pressures.

Question 15

Allopatric speciation occurs when

A) gene flow is maintained between two subgroups of a mother population.
B) two morphologically different subgroups of a species share the same habitat.
C) gene flow prevents genetic variants from being exchanged between subgroups.
D) a subgroup is physically isolated from the mother population and gene flow can no longer occur.

Question 16

Why are hybrids rare in the case of sympatric evolution and character displacement?

A) Hybrids scare the nonhybrids because of their uncanny appearance, and therefore rarely mate.
B) Hybrids usually move out of the region and thereafter undergo allopatric, not sympatric, evolution.
C) Sympatrically evolving species can't mate with each other and therefore can't produce hybrids.
D) Hybrids may have reduced ability to produce offspring and may be less able to compete with nonhybrids for food or other resources.

Question 17

Which of the following does sympatric speciation involve?

A) natural selection favoring different adaptations within a similar environment and within a population
B) natural selection favoring adaptations to a similar environment by geographically separated groups
C) a mother population divided into two physically separated populations, and adapting to distinct environments
D) a small subset of the population becoming isolated, followed by random genetic drift

Question 18

Allopatric speciation is most likely to occur in which of the following scenarios?

A) A large lake is divided into two smaller lakes by a geological process, dividing a single species of fish into two different groups.
B) All of the "parent" species of a new species go extinct, reducing gene flow between populations.
C) There are two distinct possible feeding strategies within a given population, causing the rise of two species living in the same geographic area.
D) A mutation changes the mating ritual followed by a subset of individuals in a population, and they end up forming an all-new species.

Question 19

What is macroevolution?

A) the formation of new species
B) the death of individuals
C) evolutionary change within a species
D) the extinction of a species

Question 20

On the Galápagos Islands, natural selection pressures maintain the boundaries between three species even though there is substantial gene flow between them. This example provides evidence that

A) neither the biological nor the ecological species concept applies to all situations.
B) multiple genes influence beak size.
C) these three species should be classified as a single species.
D) the medium ground finch (Geospiza fortis) has the optimal beak size.

Question 21

Parapatric speciation occurs when

A) selection causes a single species to develop different adaptations to a similar environment.
B) a population is divided into two reproductively isolated subgroups that form separate species.
C) a single species experiences a gradient of environmental differences within its geographic range, which result in partial genetic isolation.
D) a formerly isolated subpopulation recolonizes its home range and mates with the remaining individuals.

Question 22

Scientists use ________ to construct phylogenies.

A) systematics
B) taphonomy
C) macroevolution
D) character displacement

Question 23

When scientists use phylogenies to name species and classify them into hierarchical categories, they create

A) systematics.
B) taxonomies.
C) macroevolution.
D) character displacement.

Question 24

In order to conduct a meaningful comparative analysis, a researcher must

A) not take phylogeny into account.
B) only compare behavioral features.
C) only use independently evolved features.
D) compare absolutely everything about two taxa.

Question 25

Ancestral characters are traits that

A) characterize the last common ancestor that a particular collection of species share.
B) evolved after the last common ancestor that a particular collection of species share.
C) are less suited to the environment than derived characters.
D) are less specialized than derived characters.

Question 26

Which of the following statements is true of a properly done phylogeny?

A) It reflects developmental stages.
B) It can only be used for closely related species.
C) It reflects the evolutionary history of living species.
D) It does not help us understand evolutionary events.

Question 27

Which of the following statements correctly describes a hybrid zone?

A) It provides evidence for allopatric speciation.
B) It sometimes contains individuals that are less fit than those outside of hybrid zones.
C) It sometimes contains adaptive radiations.
D) It provides evidence for the ecological species concept.

Question 28

Consider the following amino acid sequence for three different species, A, B, and C. Each number is a different amino acid. The letter in each cell depicts the nitrogenous base that is associated with each amino acid. Which two species are most closely related based on this part of the genome? Amino Acid

A) Species A and C are most closely related.
B) Species A and B are most closely related.
C) Species B and C are most closely related.
D) All three species are equally related.

Question 29

Adaptive radiation occurs when

A) a mutation caused by solar radiation produces adaptations.
B) a population expands across a uniform habitat.
C) multiple new species are produced because subpopulations adapt to new environments.
D) a species loses adaptations through mutation.

Question 30

At the end of the Cretaceous era, mammals diversified to fill a broad range of ecological niches. This is an example of

A) reinforcement.
B) hybrid zones.
C) phylogeny.
D) adaptive radiation.

Question 31

Analogous characters are similar because of

A) similar DNA.
B) similar selection pressures acting on unrelated species.
C) common ancestry.
D) similar mutations.

Question 32

Consider species A, B, and C, who share a knuckle-walking common ancestor. Species A and B are bipedal. Species C is a knuckle walker. Which of the following is most likely to be true?

A) A and B are more closely related to each other than to C.
B) A and C are more closely related to each other than to B.
C) C and B are more closely related to each other than to A.
D) A, B and C most likely emerged at the same time from the common ancestor.

Question 33

Different species of baboons live all over Africa in very diverse habitats. This is an example of ________ speciation.

A) non-Darwinian
B) parapatric
C) sympatric
D) allopatric

Question 34

When daughter species first diverge from each other, they are most likely to differ in

A) morphological traits.
B) traits related to making a living or choosing mates.
C) features of their genome.
D) traits related to their life histories.

Question 35

Homologous characters are similar because of

A) convergent evolution.
B) similar selection pressures acting on unrelated species.
C) common ancestry.
D) similar environments in different parts of the world.

Question 36

________ speciation occurs when selection causes a single species to develop different adaptations to a similar environment.

A) Allopatric
B) Sympatric
C) Parapatric
D) Peripatric

Question 37

Closely related species are similar to each other because they

A) share a recent common ancestor.
B) have converged on some functional characteristic, such as flight.
C) live in close proximity to one another.
D) live in similar environments all over the world.

Question 38

Adaptive radiations are associated with

A) macroevolution.
B) microevolution.
C) taxonomy.
D) systematics.

Question 39

Derived characters are traits that

A) characterize the last common ancestor that a particular collection of species share.
B) evolved after the last common ancestor that a particular collection of species share.
C) are less suited to the environment than ancestral characters.
D) are more complicated than ancestral characters.

Question 40

Consider all three species of the genus Happy: the Eastern Mugwump, the Western Mugwump, and the Middle Mugwump. All of these species evolved from a six-legged common ancestor. The Eastern and Middle Mugwumps have six legs, and the Western Mugwumps have eight legs. For the genus Happy, six-leggedness is

A) ancestral.
B) derived.
C) convergent.
D) a mutation.

Question 41

For a given pair of closely related species, an ancestral character is

A) found in the common ancestor of the group, but is lost in both of the descendant species.
B) replaced by derived characters at the point of the split of the last common ancestor into two new species.
C) found in the last common ancestor of the pair, and may be present in one, both, or neither of the species.
D) found in the last common ancestor of the pair and at least one of the species.

Question 42

Scientists should only use derived traits to construct phylogenies because

A) many fossil species retain only derived traits.
B) derived traits are under greater genetic control than are analogous and homologous traits.
C) all organisms have homologous traits.
D) analogous and homologous traits do not tell us anything about close phylogenetic relationships.

Question 43

Cladistic systematics uses

A) only morphological similarity to classify organisms.
B) only descent to classify organisms.
C) both similarity and descent to classify organisms.
D) neither similarity nor descent to classify organisms.

Question 44

Closely related species may be grouped into ________ that may in turn be grouped into ________.

A) families; genera
B) genera; subspecies
C) genera; families
D) families; subspecies

Question 45

The term genetic distance refers to the

A) geographical distance between two genetically similar populations.
B) geographical distance between two genetically distinct populations.
C) distance an organism must go to find a mate that is genetically distinct from itself.
D) computed dissimilarity between two homologous genetic sequences.

Question 46

What is the biological species concept? Under what circumstances is this concept difficult to apply?

Question 47

The best evidence for a molecular clock that runs at a consistent rate is the fact that

A) we can't distinguish, genetically, between orangutans and the other great apes.
B) gorillas, humans, and chimpanzees are all the same distance, genetically, from orangutans.
C) humans evolved much faster than gorillas or chimpanzees.
D) humans and gorillas are more closely related to orangutans than are chimps.

Question 48

The limbs of all mammals contain three bones. This is an example of a(n) ________ trait.

A) analogous
B) derived
C) homologous
D) convergent

Question 49

Genetic distance data reveals that ________ are more genetically distant from humans than any of the other great apes.

A) gorillas
B) orangutans
C) chimpanzees
D) bonobos

Question 50

Give a hypothetical example of allopatric speciation.

Question 51

Explain the difference between ancestral and derived characters.

Question 52

Which of the following is true of proponents of the molecular-clock hypothesis?

A) They believe that most changes in DNA sequences produce clocklike change because they are controlled by drift and mutation.
B) They think the molecular clock is a result of natural selection.
C) They believe an organism's ability to track time is genetically encoded.
D) They use only derived traits in their analysis.

Question 53

How does speciation occur? After a speciation event, by what mechanisms do new species remain distinct?

Question 54

The comparative method, when considering phylogeny, forces us to consider

A) how many times an adaptation is found in the collection of species that make up a genus.
B) evolutionary relationships between species that do not share a common ancestor.
C) how many times a trait evolved, rather than how many species a trait is found in.
D) whether a given species should be classified in a particular genus.

Question 55

Evolutionary taxonomy uses

A) only morphological similarity to classify organisms.
B) only descent to classify organisms.
C) both similarity and descent to classify organisms.
D) neither similarity nor descent to classify organisms.

Question 56

The observation that chickens and humans are bipedal but not part of the same taxonomic group is an example of

A) gene flow.
B) ancestry.
C) systematics.
D) convergent evolution.

Question 57

Siamangs, gibbons, and orangutans are all members of the superfamily ________, but only the orangutan is a member of the family ________.

A) Pan; Hominidae
B) Pongidae; Hominidae
C) Hominoidae; Pongidae
D) Hominoidae; Pan

Question 58

Give a hypothetical example of parapatric speciation.

Question 59

Explain why shared ancestral characters do not yield good information about relationships between species.

Question 60

What is the ecological species concept? Is it applicable to asexual species?

Question 61

How do genetic distance measures work? How have genetic distance measurements been applied to the primate fossil record to reveal information about the divergence of primate groups?

Question 62

Compare and contrast cladistic and evolutionary systematics. Illustrate your answer by discussing the phylogeny of apes and humans.

Question 63

Explain the difference between homologous and analogous characters. Which of these should be used in phylogenetic analysis?