$$n_{events} = \text{number of gene flow events detected by allele similarity}$$

Question 1

Which of the following best describes the biological species concept?

Accepted Answer

A group of populations whose members have the potential to interbreed and produce viable, fertile offspring.

Question 2

Which of the following is an example of a postzygotic reproductive barrier?

Accepted Answer

Reduced hybrid fertility

Question 3

A population of frogs is separated by a newly formed river, and over time, the two groups evolve independently. What type of speciation is this?

Accepted Answer

Allopatric speciation

Question 4

Which of the following is NOT a prezygotic barrier?

Accepted Answer

Reduced hybrid viability

Question 5

A mule is the offspring of a horse and a donkey. Mules are generally sterile. Which reproductive barrier does this illustrate?

Accepted Answer

Reduced hybrid fertility

Question 6

Which species concept is most useful for classifying fossil organisms?

Accepted Answer

Morphological species concept

Question 7

Polyploidy is a common mechanism of speciation in plants. Which of the following best describes autopolyploidy?

Accepted Answer

An individual with more than two chromosome sets derived from a single species.

Question 8

Which of the following equations represents the minimum number of gene flow events required to explain genetic patterns between two populations?

Accepted Answer

$$n_{events} = 	ext{number of gene flow events detected by allele similarity}$$

Question 9

Which of the following scenarios best illustrates reinforcement in a hybrid zone?

Accepted Answer

Hybrids are less fit than parent species, leading to stronger reproductive barriers.

Question 10

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

Accepted Answer

It cannot be applied to asexual organisms.

Question 11

Which of the following best describes the difference between gradualism and punctuated equilibrium?

Accepted Answer

Gradualism involves slow, steady change, while punctuated equilibrium involves periods of stasis interrupted by rapid change.

Question 12

Which of the following is an example of behavioral isolation?

Accepted Answer

Two species of birds have different mating dances.

Question 13

A hybrid plant is vigorous and fertile, but its offspring are weak and sterile. Which postzygotic barrier does this illustrate?

Accepted Answer

Hybrid breakdown

Question 14

Which of the following is a real-world example of gametic isolation?

Accepted Answer

Sea urchin sperm cannot fertilize eggs of a different species due to incompatible proteins.

Question 15

Which species concept defines a species as the smallest group of individuals on a phylogenetic tree?

Accepted Answer

Phylogenetic species concept

Question 16

Which of the following is most likely to drive sympatric speciation in cichlid fish in Lake Victoria?

Accepted Answer

Sexual selection for mates of different colors

Question 17

Which of the following best describes allopolyploidy?

Accepted Answer

A species with multiple sets of chromosomes derived from different species.

Question 18

Which of the following is a likely outcome if hybrids in a hybrid zone are as fit as the parent species?

Accepted Answer

Fusion of the two parent species into one

Question 19

Which of the following is a key factor in allopatric speciation?

Accepted Answer

A population is divided by a geographic barrier.

Question 20

Which of the following statements about speciation rates is supported by the fossil record?

Accepted Answer

Speciation can be rapid, occurring in as little as 4,000 years in some cases.

Speciation: Mechanisms and Patterns of Species Formation

Study Guide - Practice Questions