Question 1

Which of the following cannot result in homoplasy?

Accepted Answer

Homoplasy refers to the development of similar traits in unrelated species due to convergent evolution or evolutionary reversals. However, descent from a common ancestor (option C) is the opposite of homoplasy as it refers to the development of shared traits due to common ancestry. Therefore, option C cannot result in homoplasy.

Question 2

Four different phylogenetic trees of a group of salamanders have been proposed. Trees A and B each require 12 homoplasies, but Tree A requires 14 synapomorphies and Tree B requires 13 synapomorphies. Tree C requires 15 homoplasies and 13 synapomorphies. Finally, Tree D requires 10 homoplasies and 15 synamorphies. According to the principle of parsimony, which tree or trees is the best?

Accepted Answer

According to the principle of parsimony, the tree with the fewest number of homoplasies and synapomorphies is favored. Among the four trees, Tree D requires the fewest number of homoplasies (10) and synapomorphies (15), making it the best choice according to the principle of parsimony.

Question 3

Which of the following kinds of data would be the most useful for distinguishing ancestral traits from derived traits?

Accepted Answer

Paleontological data, which includes fossil records, is most useful for distinguishing ancestral traits from derived traits because it provides direct evidence of the physical characteristics of ancient organisms, allowing scientists to trace the evolutionary history and changes over time.

Question 4

Shared derived traits are also known as

Accepted Answer

Shared derived traits are also known as synapomorphies, which are characteristics that are shared among a group of organisms and their common ancestor, but not present in more distantly related organisms. Homoplasies refer to traits that have evolved independently in different lineages and are not inherited from a common ancestor. Sympatries refer to organisms that are present in the same geographic area, while homologies refer to similarities in traits that are inherited from a common ancestor. Paraphylies refer to groups that do not include all descendants of a common ancestor.

Question 5

Homoplasies can arise via

Accepted Answer

Homoplasies are characteristics that are present in different taxa but are not derived from the same ancestral form. Convergent evolution and evolutionary reversals can both give rise to homoplasies. Synapomorphies, on the other hand, are characteristics that are present in different taxa and are derived from a common ancestor, and therefore do not give rise to homoplasies.

Question 6

In systematics and phylogeny, the fossil record is especially important because

Accepted Answer

The fossil record provides the absolute timing of evolutionary events, which is crucial in constructing phylogenetic trees and understanding the history of life on Earth. While there are limitations to using the fossil record (such as gaps in the record or biases in the preservation of certain organisms), it remains one of the most important sources of data for evolutionary biologists.

Question 7

Which of the following is a limitation of the use of morphology in phylogenetic analysis?

Accepted Answer

Morphological traits can be difficult to compare across distant taxa, and some taxa may not exhibit much morphological diversity, limiting their usefulness in phylogenetic analysis.

Question 8

Mitochondrial DNA is most useful for phylogenetic analysis

Accepted Answer

Mitochondrial DNA is most useful for phylogenetic analysis of closely related species because it evolves relatively quickly, allowing for the detection of recent evolutionary changes.

Question 9

Which of the following statements is true?

Accepted Answer

Synapomorphies are derived traits that are shared by a group of organisms and are used to infer evolutionary relationships.

Question 10

Humans and African apes (chimpanzees, bonobos, and gorillas) share traits, such as elongated skulls and shortened canine teeth, which other related species do not have. These shared characteristics are called

Accepted Answer

Synapomorphies are shared characteristics between species that are inherited from a common ancestor. In this case, humans and African apes share elongated skulls and shortened canine teeth as synapomorphies, indicating a close evolutionary relationship. Homoplasies, on the other hand, are shared characteristics that have evolved independently in unrelated species, while cladistics and parsimonies are methods used in evolutionary analysis.

Question 11

The antifreeze proteins found in fish that live in very cold waters has evolved independently in the Arctic and in the Antarctic, and not because of shared ancestry. Which of the following can be said about its evolution?

Accepted Answer

Homoplasy refers to the evolution of similar traits independently in different lineages. Since the antifreeze proteins in Arctic and Antarctic fish evolved independently and not because of shared ancestry, they are homoplasies. Homologous traits are similar due to shared ancestry, so choice A is incorrect. The fact that the proteins evolved independently also means that the Arctic and Antarctic fish do not form a clade, so choice C is incorrect. Therefore, the best choice is B.

Question 12

Information about which of the following types of behavior would be least useful in reconstructing phylogenies?

Accepted Answer

Learned behavior is least useful in reconstructing phylogenies because it is not inherited and can vary within a species or even within an individual's lifetime. In contrast, inherited behaviors, such as mating behaviors, foraging behaviors, and locomotion behaviors, can provide valuable information about the evolutionary relationships between species.

Question 13

Repetitive DNA sequences usually evolve very quickly. Based on this fact, molecules that have a rapid mutation rate are used to study relationships among

Accepted Answer

Repetitive DNA sequences that evolve quickly are most useful for studying relationships among very closely related species, as there may not be enough genetic variation in more slowly evolving DNA sequences to distinguish between them.

Question 14

Species A and B have long wings, whereas species C has short wings. Which of the following pieces of evidence would best support the hypothesis that long wings are a synapomorphy?

Accepted Answer

If the common ancestor had short wings, then the presence of long wings in species A and B would suggest that long wings evolved after the divergence from the common ancestor, supporting the idea that long wings are a synapomorphy for species A and B.

Question 15

The common ancestor of humans and the other "great apes" walked on all fours, while humans are bipeds. Bipedalism is thus the _______ trait.

Accepted Answer

Bipedalism is a derived trait that is unique to the human lineage and was not present in our common ancestor with the other great apes. An ancestral trait is one that was present in the common ancestor of a group of organisms, while a synapomorphic trait is a shared derived trait that evolved in the common ancestor of a group of organisms and is present in all of its descendants. Homoplasic traits are those that evolved independently in different lineages, often due to convergent evolution. Monophyletic refers to a group of organisms that includes an ancestor and all of its descendants.

Question 16

According to the principle of parsimony, the best phylogenetic hypothesis is the one that requires the

Accepted Answer

The principle of parsimony suggests that the best hypothesis is the one that requires the fewest homoplasies, which are evolutionary changes that arose independently in different lineages rather than being inherited from a common ancestor. This is because homoplasies can lead to incorrect grouping of organisms in a phylogenetic tree, and therefore the fewest possible homoplasies suggest the most accurate tree.

Question 17

Snakes, which lack limbs, evolved from vertebrates that had legs. This is an example of

Accepted Answer

The fact that snakes evolved from ancestors with legs means that they underwent an evolutionary reversal, where a trait that was present in their ancestors (legs) was lost in their descendants (snakes). Convergent evolution involves unrelated species evolving similar traits, a synapomorphy is a shared derived trait among a group of organisms, and homology refers to traits that are similar due to a shared ancestry. None of these options accurately describe the evolution of snakes losing their limbs.

Question 18

Some species in a hypothetical family of beetles are winged, and others are wingless. Which of the following would be most useful in determining whether having wings or being wingless was the ancestral trait?

Accepted Answer

An outgroup would be useful in determining the ancestral trait because it is a species that is closely related to the beetles but not a member of the family in question. By comparing the presence or absence of wings in the outgroup to the presence or absence in the family of beetles, scientists can determine whether winged or wingless is the ancestral trait.

Question 19

Which of the following findings led to the conclusion that sea squirts are more closely related to vertebrates than scientists had previously thought?

Accepted Answer

The finding that larvae have notochords led to the conclusion that sea squirts are more closely related to vertebrates than previously thought. The notochord is a defining characteristic of chordates, the phylum that encompasses vertebrates.

Question 20

As adaptions for flight, the wings of bats and the wings of birds are an example of

Accepted Answer

The wings of bats and birds are an example of convergent evolution, meaning that they evolved independently but ended up with similar features due to similar selective pressures (in this case, the need for flight).

Quiz 22: Reconstructing and Using Phylogenies