DC Biology Chapter 22 The Origin of Species

What is true of macroevolution?

• A) It is the same as microevolution, but includes the origin of new species. 
• B) It is evolution above the species level.
• C) It is defined as the evolution of microscopic organisms into organisms that can be seen with the naked eye. 
• D) It is defined as a change in allele or gene frequency over the course of many generations. 
• E) It is the conceptual link between irritability and adaptation.

What is true of the flightless cormorants of the Galápagos Islands? 

• A) They are descendants of the same common ancestor that gave rise to the unique finches of these islands. 
• B) They are close relatives of flightless cormorants from the Americas. 
• C) If they are still able to breed successfully with flying cormorants, it would probably be with North American cormorants, rather than with South American cormorants. 
• D) Flightless cormorants on one island have restricted gene flow with those on other islands, which could someday lead to a macroevolutionary event. 
• E) Their DNA has low levels of sequence homology with the DNA of flying American cormorants.

Which of the following statements about species, as defined by the biological species concept, is (are) correct? I. Biological species are defined by reproductive isolation. II. Biological species are the model used for grouping extinct forms of life. III. The biological species is the largest unit of population in which successful interbreeding is possible.

• A) I and II 
• B) I and III 
• C) II and III 
• D) I, II, and III

Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools? 

• A) phylogenetic 
• B) ecological 
• C) biological 
• D) morphological

There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little or no gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example? 

• A) phylogenetic 
• B) ecological 
• C) morphological 
• D) biological

You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use? 

• A) biological 
• B) phylogenetic 
• C) ecological 
• D) morphological

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms? 

• A) reduced hybrid fertility 
• B) hybrid breakdown 
• C) mechanical isolation 
• D) habitat isolation 
• E) gametic isolation

Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate? 

• A) the postzygotic barrier called hybrid inviability 
• B) the postzygotic barrier called hybrid breakdown 
• C) the prezygotic barrier called hybrid sterility 
• D) gametic isolation

Theoretically, the production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) should 

• A) result in the extinction of one of the two parental species. 
• B) cause convergent evolution. 
• C) strengthen postzygotic barriers between horses and donkeys. 
• D) weaken the intrinsic reproductive barriers between horses and donkeys. 
• E) eventually result in the formation of a single species from the two parental species.

When male horses (stallions) and female donkeys (jennets) mate, they produce a sterile hybrid called a hinny. Hinnies occur much less frequently than do mules, but are just as healthy and robust as mules. Logically, which of the following best accounts for the relative rarity of hinnies, and what kind of prezygotic isolating mechanism is at work here? 

• A) Most hinnies die during fetal development; reduced hybrid viability. 
• B) Most hinnies die soon after being born; hybrid breakdown. 
• C) Most hinnies are reproductively sterile; reduced hybrid fertility. 
• D) Stallions and jennets are choosier about their mating partners than are mares and jacks; behavioral isolation. 
• E) Stallions and jennets are choosier about their mating partners than are mares and jacks; gametic isolation.