Question 1

A group of biologists primarily studying the evolutionary relationships of crickets also includes closely related grasshoppers to help determine which traits are ancestral in crickets.The grasshoppers are the
A) ingroup.
B) outgroup.
C) ancestral group.
D) derived group.
E) synapomorphy.

Accepted Answer

The grasshoppers are included as the outgroup, which is a taxon that is closely related to the ingroup (which in this case are crickets) but diverged from the common ancestor before the diversification of the ingroup. Studying the outgroup helps to determine which traits are ancestral in the ingroup.

Question 2

Refer to figure.  Shown are the phylogenetic relationships among eight species.Red dots show the appearance of derived traits.According to the phylogenetic tree, chimpanzee and perch share _______of the listed synapomorphies?
A) none
B) one
C) two
D) three
E) at least four

Accepted Answer

The answer of Refer to figure.  Shown are the...

Question 3

Several distantly related clades of a family of plants have smooth fleshy leaves, whereas most plants related to the plants with fleshy leaves do not have this trait.Without any further information, the least parsimonious explantation for this is that the fleshy leaves
A) evolved due to convergent evolution.
B) are a homologous feature within this family.
C) are a homoplastic trait within this family.
D) are examples of evolutionary reversals.
E) are due to a change in a single gene.

Accepted Answer

The least parsimonious explanation is that fleshy leaves are a homologous feature within this family, as it implies that this trait was present in a common ancestor and then lost in most related plants, which is less likely given the scattered distribution of the trait.

Question 4

Several distantly related lineages of vertebrates have shown decreases in size when they have adapted to living on islands.What is the most likely explanation for this decrease in size?
A) It is a synapomorphy.
B) It arose via convergent evolution.
C) It is a homologous trait.
D) It is an ancestral trait.
E) It is an evolutionary reversal.

Accepted Answer

Convergent evolution is the most likely explanation for the decrease in size in distantly related vertebrate lineages that have adapted to living on islands. This is because these lineages likely faced similar selective pressures in their island environments, leading to the evolution of similar traits such as smaller body size, even though they are not closely related.

Question 5

From a survey of Martian life, three hypothetical species have been found and nicknamed krons, furs, and pars.If krons and furs are sister species, the resulting phylogenetic tree will have 28 homoplasies.If krons and pars are sister species, the tree will have 22 homoplasies.Krons and pars have red body patches, whereas krons and furs have striped bodies.Based on the principles of parsimony, krons and _______ are sister species, _______ a synapomorphy.
A) pars; and striped bodies is likely
B) pars; and red body patches is likely
C) furs; and striped bodies is likely
D) furs; and red body patches is likely
E) furs; but neither trait can be

Accepted Answer

The principle of parsimony favors the hypothesis that requires the fewest evolutionary changes, in this case, the one with the least number of homoplasies. Since the tree with krons and pars as sister species has fewer homoplasies (22) compared to the tree with krons and furs as sister species (28), krons and pars are considered sister species. The shared trait of red body patches between krons and pars supports this relationship as a synapomorphy, making choice B correct.

Question 6

A group of biologists primarily studying the evolutionary relationships of crickets also include closely related grasshoppers to help determine which traits are ancestral in crickets.The crickets are the
A) ingroup.
B) outgroup.
C) ancestral group.
D) derived group.
E) synapomorphy.

Accepted Answer

The ingroup is the group of organisms being studied, in this case, the crickets. The grasshoppers are the outgroup as they are closely related but not part of the primary group being studied. Ancestral and derived groups refer to the characteristics of a particular clade rather than the organisms being studied. Synapomorphy refers to a shared derived character among a group of organisms, but is not a choice for this question.

Question 7

Which of the following cannot be a homologous trait?
A) A DNA sequence that evolves quickly
B) A DNA sequence that evolves slowly
C) A morphological trait that is entirely determined by the temperature regime under which an organism was raised
D) A highly heritable social behavior
E) The structure of the protein hemoglobin, which is used to transport oxygen throughout the circulatory system

Accepted Answer

Homologous traits are traits that are present in different species because they were inherited from a common ancestor. A DNA sequence that evolves quickly or slowly can still be homologous if it is shared among different species. A highly heritable social behavior can also be homologous if it is present in different species due to inheritance from a common ancestor. The structure of the protein hemoglobin is also homologous, as it is present in different vertebrate species and plays a similar role in each. However, a morphological trait that is entirely determined by the temperature regime under which an organism was raised could not be homologous because it is not inherited from a common ancestor but rather determined by the environment.

Question 8

Refer to the figure.  Based on this phylogenetic tree, we can conclude that gizzards
A) evolved after feathers.
B) were absent in the common ancestor of crocodiles and pigeons.
C) are a synapomorphy uniting pigeons and crocodiles.
D) evolved before scales.
E) were present in the common ancestor of lizards and pigeons.

Accepted Answer

The answer of Refer to the figure.  Based on...

Question 9

Four different phylogenetic trees of a group of salamanders have been proposed.Trees A and B each require 19 homoplasies, but tree A requires 16 synapomorphies, and tree B requires 15 synapomorphies.Tree C requires 15 homoplasies and 18 synapomorphies.Finally, tree D requires 22 homoplasies and 9 synapomorphies.According to the principle of parsimony, which tree or trees is/are the best?
A) Tree A
B) Tree B
C) Tree C
D) Tree D
E) Both tree A and tree B are equally good, and better than the others.

Accepted Answer

Tree C is the best according to the principle of parsimony because it requires the fewest homoplasies (15) while having a high number of synapomorphies (18), making it the most parsimonious or simplest explanation for the evolutionary relationships among the salamanders.

Question 10

Which statement about traits and phylogeny is true?
A) All similar traits are evidence of relatedness.
B) All shared traits are synapomorphies.
C) All synapomorphies are shared traits.
D) Homologous traits arise from reversals.
E) Homologous traits arise from convergent evolution.

Accepted Answer

A synapomorphy is a shared derived trait that is present in all members of a particular clade (group of organisms that share a common ancestor). Therefore, all synapomorphies are shared traits, but not all shared traits are synapomorphies. Additionally, not all similar traits are evidence of relatedness - this could also be due to convergent evolution. Homologous traits do not arise from reversals or convergent evolution, but rather from a common ancestor.

Question 11

Why are fossils useful for determining whether a trait is ancestral or derived?
A) Fossils can be dated, and thus we can know when a trait evolved.
B) Fossils can give us direct evidence of the character states of extinct lineages.
C) Maximum likelihood methods can be used with fossil structures.
D) With fossil information, we can know where animals actually lived in the past.
E) None of the above; fossils are not useful in determining whether a trait is ancestral or derived.

Accepted Answer

Fossils provide direct evidence of the character states of extinct lineages, which can help determine whether a trait is ancestral or derived. By examining the morphology of fossils, researchers can compare the characteristics of extinct organisms with those of living organisms, allowing them to infer the evolutionary relationships among different groups of organisms. Fossils can also provide information about the age of different rock layers, which can help to establish the temporal context in which different traits evolved. However, the other options (A, C, D, and E) are not as directly related to the usefulness of fossils for determining ancestral or derived traits.

Question 12

A trait that evolved by convergent evolution in more than one clade is
A) a homologous trait.
B) a homoplastic trait.
C) found in the common ancestor of these clades.
D) a synapomorphy.
E) an ancestral trait.

Accepted Answer

A homoplastic trait is a trait that evolved independently in different clades through convergent evolution, so this correctly describes the trait in question. A homologous trait, on the other hand, is one that is inherited from a common ancestor and may have different functions or forms in different organisms. The fact that the trait evolved convergently means it is not found in the common ancestor, so C and E are incorrect. Finally, a synapomorphy is a trait shared by two or more clades that evolved in their last common ancestor, which doesn't apply here.

Question 13

A lineage of ants evolved wings about 30 million years ago.A lineage within that lineage subsequently lost wings about 10 million years ago.The loss of wings is an example of a _______, which is a(n)______.
A) evolutionary reversal; homoplasy
B) evolutionary reversal; synapomorphy
C) convergent evolution; homoplasy
D) convergent evolution; synapomorphy
E) convergent evolution; evolutionary reversal

Accepted Answer

The loss of wings is an example of evolutionary reversal, as the lineage once had wings but subsequently lost them. It is also an example of homoplasy, as the loss of wings occurred independently in this lineage, rather than being inherited from a common ancestor.

Question 14

Two species of flies share traits, such as head morphology and the shape of their genitalia, traits that other related species do not have.These shared characteristics are called
A) homoplasies.
B) synapomorphies.
C) cladistics.
D) parsimonies.
E) ancestral traits.

Accepted Answer

Shared traits between two closely related species that are not found in more distantly related species are called synapomorphies. In contrast, homoplasies are shared traits that are not inherited from a common ancestor. Cladistics is a method of grouping organisms based on shared characteristics, while parsimony is a principle in which the simplest explanation or explanation with the fewest assumptions is favored. Ancestral traits are traits that are present in an organism's ancestor and are passed down to its descendants.

Question 15

Refer to the figure.  Which synapomorphies are shared by lizards and salamanders?
A) Lungs only
B) Lungs and jaws
C) Lungs, jaws, and claws/nails
D) Lungs and claws/nails
E) Jaws, lungs, and scales

Accepted Answer

The answer of Refer to the figure.  Which synapomorphies...

Question 16

"More complicated explanations are accepted only when the evidence requires them." Which does the preceding statement best summarize?
A) Taxonomy
B) Systematics
C) Parsimony
D) Synapomorphy
E) Homoplasy

Accepted Answer

The statement is referring to the principle of parsimony in phylogenetics, which states that the simplest explanation that is consistent with the data is usually the correct one. More complicated explanations should only be invoked when the data require them.

Question 17

Which is closest to the opposite of a homologous trait?
A) A synapomorphy
B) An ancestral trait
C) A heterologous trait
D) A homoplastic trait
E) A sister clade

Accepted Answer

The answer of Which is closest to the opposite of...

Question 18

The table shows the ancestral and derived traits of five species (A-E). In the table, the ancestral state of each trait is indicated by 0, and the derived state is indicated by 1.Which species (if any) is sister to species E? 
A) Species A
B) Species B
C) Species C
D) Species D
E) No species is sister to species E.

Accepted Answer

Species C shares two derived traits with species E (traits 2 and 4), indicating that they share a more recent common ancestor than any of the other species. None of the other species share more than one derived trait with species E. Therefore, species C is the sister to species E.

Question 19

Which statement is true?
A) All homoplasies are evolutionary reversals.
B) All evolutionary reversals are homoplasies.
C) All homologous features are evolutionary reversals.
D) All homoplasies are homologous features.
E) All derived characters are homoplasies.

Accepted Answer

Homoplasies refer to similarities that arise independently in different species, while evolutionary reversals refer to the reversion of a derived character back to the ancestral state. Evolutionary reversals can result in homoplasies, but not all homoplasies are evolutionary reversals. Therefore, statement B is correct.

Question 20

In its application to phylogenetics, parsimony is a method that
A) helps distinguish ingroups from outgroups.
B) helps distinguish synapomorphies from homoplasies.
C) helps distinguish convergent evolution from evolutionary reversals.
D) attempts to maximize the number of homoplasies.
E) attempts to minimize the number of synapomorphies.

Accepted Answer

Parsimony is a method used in phylogenetics to infer evolutionary relationships based on the principle that the simplest explanation is the most likely. This method aims to identify the minimum number of evolutionary changes (i.e., synapomorphies) required to explain the observed data. In this context, parsimony helps distinguish synapomorphies (shared derived traits that indicate a common ancestry) from homoplasies (similar traits that evolved independently). Therefore, the best choice is B, as the other options are incorrect.

Quiz 21: Reconstructing and Using Phylogenies

A group of biologists primarily studying the evolutionary relationships of crickets also includes closely related grasshoppers to help determine which traits are ancestral in crickets.The grasshoppers are the

Refer to figure. Shown are the phylogenetic relationships among eight species.Red dots show the appearance of derived traits.According to the phylogenetic tree, chimpanzee and perch share _______of the listed synapomorphies?

Several distantly related clades of a family of plants have smooth fleshy leaves, whereas most plants related to the plants with fleshy leaves do not have this trait.Without any further information, the least parsimonious explantation for this is that the fleshy leaves

Several distantly related lineages of vertebrates have shown decreases in size when they have adapted to living on islands.What is the most likely explanation for this decrease in size?

A group of biologists primarily studying the evolutionary relationships of crickets also include closely related grasshoppers to help determine which traits are ancestral in crickets.The crickets are the

Which of the following cannot be a homologous trait?

Refer to the figure. Based on this phylogenetic tree, we can conclude that gizzards

Which statement about traits and phylogeny is true?

Why are fossils useful for determining whether a trait is ancestral or derived?

A trait that evolved by convergent evolution in more than one clade is

A lineage of ants evolved wings about 30 million years ago.A lineage within that lineage subsequently lost wings about 10 million years ago.The loss of wings is an example of a _, which is a(n) .

Two species of flies share traits, such as head morphology and the shape of their genitalia, traits that other related species do not have.These shared characteristics are called

Refer to the figure. Which synapomorphies are shared by lizards and salamanders?

"More complicated explanations are accepted only when the evidence requires them." Which does the preceding statement best summarize?

Which is closest to the opposite of a homologous trait?

The table shows the ancestral and derived traits of five species (A-E) . In the table, the ancestral state of each trait is indicated by 0, and the derived state is indicated by 1.Which species (if any) is sister to species E?

Which statement is true?

In its application to phylogenetics, parsimony is a method that