Chapter 14 Quiz 1

Speciation, or the formation of new species, is

• responsible for the diversity of life
• an event that has occurred only a few times in the history of the planet
• necessary for natural selection and adaptation
• a form of microevolution

Which of the following would a biologist describe as microevolution?

• dramatic biological changes, such as the origin of flight within a taxon
• a change in the gene pool of a population from one generation to the next
• the formation of a new species
• the extinction of species

Under the biological species concept, a species is a group of organisms that

• share a common ancestor
• are physically similar
• live together in a location and carry out identical ecological roles
• have the potential to interbreed in nature and produce fertile offspring

The biological species concept is

• applicable to all forms of life, past, and present
• applicable to all present life forms, but not to fossil organisms whose reproductive behavior cannot be observed
• easy to apply to all present sexually reproducing organisms, but harder to apply to asexual organisms and fossils
• sometimes difficult to put into practice even for present sexual organisms, and useless for asexual organisms and fossils

True or False: The morphological species concept relies upon comparing the DNA sequences of organisms

• True 
• False

True or False: Under the biological species concept, the gap between species is maintained by reproductive isolation. 

• True
• False

True or False: The phylogenetic species concept defines a species as a set of organisms that shares a common ancestor and forms one branch on the tree of life. 

• True
• False

Which provides the most general and correct description of the idea of a reproductive barrier?

• a difference in behavior that keeps two species from interbreeding
• a biological difference between two species that prevents them from successfully interbreeding
• any feature (of geography, behavior, or morphology) that keeps one species from mating with another
• a geographic barrier that separates two species and prevents gene flow between them

Two populations of organisms belong to the same biological species when they

• encounter each other, mate, and produce viable, fertile offspring under natural conditions
• have anatomical features that make it difficult for organisms from the different populations to mate
• use different types of behaviors or physical features to attract mates
• can't mate with each other, because mating occurs at different times

Which of the following types of reproductive barriers separate a pair of species that could interbreed except that one mates at dusk and the other at dawn?

• behavioral isolation
• mechanical isolation
• habitat isolation
• temporal isolation