Question 1

Which of the following is an example of temporal reproductive isolation?

Accepted Answer

Two populations of frogs breed at different times of the year.

Question 2

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. What type of reproductive isolation is this?

Accepted Answer

Habitat isolation

Question 3

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. What type of reproductive isolation does this represent?

Accepted Answer

Behavioral isolation

Question 4

When two species of fungus—Neurospora crassa and Neurospora intermedia—are crossed, they produce fewer viable ascospores than either species produces when mating with their own species. What is this an example of?

Accepted Answer

Hybrid inviability

Question 5

A researcher finds that some moths prefer to feed and lay eggs on domesticated plants, while others prefer wild plants. Mating occurs where they feed, and there is a genetic basis for scent preference. What type of speciation might be occurring?

Accepted Answer

Sympatric speciation by disruptive selection

Question 6

There is an island in the middle of a large river that houses a large population of ants. Damming of the river causes the island to flood, isolating populations on high points. What type of speciation might be occurring?

Accepted Answer

Allopatric speciation by vicariance

Question 7

In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. Some fleas develop a strong preference for cattle blood and mate only with other fleas that prefer cattle blood. If new species evolve, this would be an example of:

Accepted Answer

Sympatric speciation by disruptive selection

Question 8

Palaeoloxodon falconeri was a species of dwarf elephant that inhabited Mediterranean islands. Mainland elephants migrated to the islands during a glacial period and became isolated. What speciation events led to this new population?

Accepted Answer

Allopatric speciation by dispersal followed by natural selection

Question 9

Which of the following best describes the morphological species concept?

Accepted Answer

Species are defined by differences in size, shape, or other morphological features.

Question 10

On a phylogenetic tree, a species is defined as:

Accepted Answer

The smallest monophyletic group sharing synapomorphies.

Question 11

Which of the following is a synapomorphy used to identify monophyletic groups?

Accepted Answer

Traits unique to a monophyletic group and shared by all its descendants.

Question 12

Which process is most likely to result in rapid speciation in plants due to chromosome-level mutations?

Accepted Answer

Sympatric speciation by polyploidization

Question 13

Which of the following equations represents the chromosome number in an autopolyploid formed by self-fertilization after nondisjunction in meiosis?

Accepted Answer

$$2n \rightarrow 2n$$ gametes \rightarrow $$4n$$ offspring$

Question 14

Which of the following is true about allopolyploid speciation?

Accepted Answer

It produces offspring with different sets of chromosomes from two species.

Question 15

What is the likely outcome when two populations come into contact and prezygotic isolation does NOT exist?

Accepted Answer

Populations may successfully interbreed and distinctions are erased (fusion).

Question 16

Which of the following is an example of reinforcement of divergence?

Accepted Answer

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

Question 17

Hybrid zones are best described as:

Accepted Answer

Areas where hybridization occurs and offspring have intermediate characteristics.

Question 18

Which of the following is NOT a mechanism of prezygotic isolation?

Accepted Answer

Hybrid sterility

Question 19

Which of the following scenarios would most likely result in extinction of one population after secondary contact?

Accepted Answer

One population is a better competitor for resources than the other.

Speciation: Mechanisms, Concepts, and Outcomes

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