Chapter 17

___________is the original source of new alleles. a. Mutation b. Natural selection c. Genetic drift d. Gene flow e. All are original sources of new alleles

Which is required for evolution to occur in a population? a. random mating b. selection pressure c. gene flow d. none of the above

Match the modes of natural selection with their best descriptions. ________stabilizing \(\quad\)a. eliminates extreme forms of a trait. ________disruptive \(\quad\)b. eliminates midrange form of a trait

Sexual selection frequently influences aspects of body form and can lead to __________. a. a sexual dimorphism b. male aggression c. exaggerated traits d. all of the above

The persistence of sickle-cell anemia in a population with a high incidence of malaria is a case of ___________. a. bottlenecking b. inbreeding c. balanced polymorphism d. the founder effect e. frequency-dependent selection

__________tends to keep populations of a species similar to one another. a. Genetic drift b. Gene flow c. Mutation d. Natural selection

The theory of natural selection does not explain ____________. a. genetic drift b. the founder effect c. gene flow d. how mutations arise e. inheritance f. any of the above

Which of the following is not part of how we define a species? a. Its individuals appear different from other species. b. It is reproductively isolated from other species. c. Its populations can interbreed. d. Fertile offspring are produced.

Sex in many birds is typically preceded by an elaborate courtship dance. If a male's movements are unrecognized by the female, she will not mate with him. This is an example of ____________. a. reproductive isolation b. behavioral isolation c. sexual selection d. all of the above

The difference between sympatric and parapatric speciation is ____________. a. parapatric speciation occurs only in worms b. sympatric speciation requires a barrier to gene flow c. the extent of overlap in range d. reproductive isolation does not occur

A fire devastates all trees in a wide swath of forest. Populations of a species of tree-dwelling frog on either side of the burned area diverge to become separate species. This is an example of ____________. a. allopatric speciation b. parapatric speciation c. sympatric speciation d. adaptive radiation

Match the evolution concepts. $$ \text {________gene flow} \quad \quad\quad\quad\quad \text {a. can lead to interdependent species} $$ $$ \text {________sexual selection} \quad \quad\quad\quad\quad \text {b. changes in a population's allele frequencies due to chance alone} $$ $$ \text {________mutation} \quad \quad\quad\quad\quad \text {c. alleles enter or leave a population} $$ $$ \text {________genetic drift} \quad \quad\quad\quad\quad \text {d. adaptive traits make their bearers better at securing mates} $$ $$ \text {________coevolution} \quad \quad\quad\quad\quad \text {e. original source of new alleles} $$ $$ \text {________adaptive radiation} \quad \quad\quad\quad\quad \text {f. burst of divergences from one lineage into many} $$

Change in allele frequency of a population is called __________. a. macroevolution b. adaptive radiation c. inbreeding d. microevolution