Question 1

Which of the following best describes the biological species concept?

Accepted Answer

A species is a group of populations that are reproductively isolated from other such groups.

Question 2

Which scenario would most likely result in allopatric speciation?

Accepted Answer

A population of birds is split by the formation of a new river, preventing gene flow between the two groups.

Question 3

Which of the following is a disadvantage of the morphospecies concept?

Accepted Answer

It is subjective and may fail to identify cryptic species.

Question 4

A botanist discovers a new plant species that is tetraploid ($$4n) $$and cannot produce viable offspring with the local diploid ($$2n) $$population. What mechanism of speciation is most likely responsible?

Accepted Answer

Sympatric speciation by polyploidy

Question 5

Which of the following best explains why polyploidy is a common mechanism of speciation in plants?

Accepted Answer

Polyploids can tolerate higher levels of self-fertilization and have increased genetic variation.

Question 6

Which of the following is an example of reinforcement during secondary contact?

Accepted Answer

Hybrid offspring have low fitness, leading to selection for traits that prevent interbreeding.

Question 7

A researcher uses DNA sequences from several populations of elephants to construct a phylogenetic tree. According to the phylogenetic species concept, how should species be defined?

Accepted Answer

As the smallest monophyletic groups on the tree.

Question 8

Which evolutionary process is most likely to counteract speciation by keeping populations genetically similar?

Accepted Answer

Gene flow

Question 9

In the case of apple maggot flies, what is the primary mechanism driving sympatric speciation?

Accepted Answer

Disruptive selection based on host fruit preference

Question 10

Which of the following is a limitation of the biological species concept?

Accepted Answer

It cannot be applied to asexual or fossil species.

Question 11

A population of birds is split by the formation of a new mountain range. Over time, the two populations diverge genetically and morphologically. Which process best describes this scenario?

Accepted Answer

Allopatric speciation by vicariance

Question 12

Which of the following is NOT a possible outcome when two populations that have undergone allopatric speciation come back into contact?

Accepted Answer

Immediate extinction of both populations

Question 13

Why might the phylogenetic species concept lead to the recognition of more species than the biological or morphospecies concepts?

Accepted Answer

It recognizes the smallest monophyletic groups, which can be very narrowly defined.

Question 14

Which of the following best explains why polyploidy can result in instant speciation?

Accepted Answer

Polyploid individuals are unable to mate with diploid individuals, resulting in immediate reproductive isolation.

Question 15

Which of the following is an example of speciation by dispersal?

Accepted Answer

A population of finches colonizes a new island and evolves into a new species.

Question 16

Which of the following is a key advantage of the ecological species concept?

Accepted Answer

It can be applied to asexual species.

Question 17

A hybrid zone forms between two species of warblers. Over time, the hybrid zone moves south as one species outcompetes the other. What is the most likely long-term outcome?

Accepted Answer

The outcompeted species may eventually go extinct in the region.

Question 18

Which of the following best describes the process of reinforcement?

Accepted Answer

Selection favors traits that prevent interbreeding between populations.

Question 19

Which of the following evolutionary mechanisms can cause two populations to diverge after they become genetically isolated?

Accepted Answer

Natural selection, genetic drift, and mutation

Speciation: Concepts, Mechanisms, and Outcomes

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