Chapter 12

Instructions

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Question 01

Are species natural units, into which organisms can be classified unambiguously?

a) Yes, this is true for all species.

b) This is true for some species, but not for all.

c) No, this is not true for any species.

Question 02

What is the decisive criterion according to the biological species concept (BSC)?

a) Sufficient similarity in morphology and behavior

b) Monophyly

c) Ability to interbreed

Question 03

Which one of the following phenomena is problematic for the BSC?

a) Asexual organisms and individuals so far apart that they will never meet.

b) Inter-species hybrids and individuals so far apart that they will never meet.

c) Asexual organisms and inter-species hybrids.

Question 04

The problem posed to the BSC by asexuality does not apply to bacteria, in which genetic exchange is possible by parasexual processes. True or false?

a) True

b) False

Question 05

What are cryptic species?

a) Species that cannot be distinguished on the basis of their phenotype.

b) Species which have not yet been discovered.

Question 06

A problem with the phylogenetic species concept (PSC) is that:

a) it tends to be too coarse, lumping closely related established species into a single species.

b) it tends to be too sensitive to high-resolution molecular characterization, splitting up a single established species into many different species.

Question 07

A possible reconciliation of different species concepts is by recognizing that:

a) a species is not constant in space, populations occupying different areas and facing different conditions may fulfill different species criteria.

b) a species is not constant in time, but goes through a succession of stages during its existence, each characterized by different species criteria.

Question 08

Which mechanisms are responsible for speciation?

a) There are no reasons to think that species originate by mechanisms different from those responsible for micro-evolution: natural selection and genetic drift.

b) Speciation requires mechanisms different from natural selection and genetic drift that drive changes within populations.

Question 09

The famous Darwin's finches on the Galapagos islands form a typical example of which type of speciation?

a) Competitive speciation

b) Allopatric speciation

c) Sympatric speciation

Question 10

What is competitive speciation?

a) Intense competition between two fairly similar species may promote further divergence.

b) Intraspecific competition may lead to divergence of coexisting populations and then through improved assortative mating to reproductive isolation.

Question 11

There are hundreds of species of fig wasps, each breeding on its own species of fig. What type of speciation is most likely at the basis of this pattern?

a) Sympatric speciation

b) Allopatric speciation

c) Parapatric speciation

Question 12

Speciation is always a gradual process that takes very long periods of time. True or false?

a) True

b) False

Question 13

What is the effect of secondary reinforcement of reproductive isolation?

a) It converts postzygotic isolation into prezygotic isolation.

b) It converts prezygotic isolation into postzygotic isolation.

Question 14

Secondary reinforcement is very important in causing reproductive isolation in hybrid zones. True or false?

a) True

b) False

Question 15

What is the potential role of sexual selection in speciation?

a) Once reproductive isolation has been established, the newly originated species will rapidly diverge due to sexual selection on male and female characteristics.

b) Changes in mating preferences in an early stage of speciation, brought about by sexual selection, may ultimately lead to reproductive isloation.