Chapter 17

_______ is the original source of new alleles. a. Mutation b. Narural selection c. Gene flow d. Genetic drift

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

Match the modes of natural selection with their best descriptions. $$ \text { stabilizing} \quad \quad\quad\quad\quad \text {a. eliminates extreme forms of a trait} $$ $$ \text { directional} \quad \quad\quad\quad\quad \text { b. eliminates midrange forms of a trait \(r\) } $$ $$ \text { disruptive } \quad \quad\quad\quad\quad \text { c. shifts phenotypes in one direction } $$

Sexual selection frequently influences aspects of body form and can lead to ______ a. sister groups b. males and females c. exaggerated traits d. genetic equilibrium

The persistence of the sickle allele at high frequency in a population is an example of ______ a. bottlenecking b. inbreeding \(c\). the founder effect d. a balanced polymorphism

______ among populations can keep them similar to one another. a. Genetic drift b. Gene flow c. Mutation d. Natural selection

In many bird species, sex is preceded by a courtship dance. If a malés dance is 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

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

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

After fire devastates all of the 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 ______

______ is a way of reconstructing evolutionary history based on derived traits. a. Natural selection b. Coevolution c. Gene flow d. Cladistics

In evolutionary trees, each node represents a(n) ______ a. single lineage b. extinction c. divergence d. adaptive radiation

Match the evolutionary concepts. $$ \text {gene flow} \quad \quad\quad\quad\quad \text {a. can lead to interdependent species} $$ $$ \text {sexual selection} \quad \quad\quad\quad\quad \text {b. changes in a population's allele frequencies due to chance alone} $$ $$ \text { extinct} \quad \quad\quad\quad\quad \text {c. alleles enter or leave a population} $$ $$ \text { genetic drift} \quad \quad\quad\quad\quad \text { d. evolutionary history} $$ $$ \text { phylogeny } \quad \quad\quad\quad\quad \text {e. operates on variation in shared traits} $$ $$ \text { adaptive radiation} \quad \quad\quad\quad\quad \text { f. adaptive traits make their bearers better at securing mates} $$ $$ \text { derived trait } \quad \quad\quad\quad\quad \text {g. no more living members} $$ $$ \text {coevolution} \quad \quad\quad\quad\quad \text {h. diagram of sets within sets } $$ $$ \text { natural selection} \quad \quad\quad\quad\quad \text {burst of divergences from one lineage into many} $$ $$ \text { cladogram} \quad \quad\quad\quad\quad \text {j. present in a group, but not in any of the groups ancestors} $$

The evolution of wings helped the insect clade to be very successful. In this example, wings are a(n) ________ a. derived trait b. adaptive trait c. key innovation d. all of the above