Chapter 12

__________ 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

Individuals don't evolve; __________ do.

Match the modes of natural selection with their best descriptions. a. eliminates extreme forms of a trait b. eliminates midrange forms of a trait c. shifts allele frequencies in one direction _____stabilizing _____directional _____disruptive

Sexual selection, such as competition between males for access to fertile females, frequently influences aspects of body form and can lead to ____________ . a. male/female differences b. male aggression c. exaggerated traits d. all of the above

The persistence of the sickle allele at high frequency in a population is a case of _______________ . a. bottlenecking b. balanced polymorphism c. natural selection d. inbreeding e. both b and \(\mathrm{d}\)

___________ tends to keep different 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

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. adaptive radiation c. sympatric speciation d. an evolutionary bottleneck

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

Cladistics ___________. a. is a way of reconstructing evolutionary history b. may involve parsimony analysis c. is based on derived traits d. all of the above are correct

In cladistics, the only taxon that is always correct as a clade is the ____________ a. genus b. family c. species d. kingdom

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

In cladograms, sister groups are __________ . a. inbred b. the same age c. represented by nodes d. members of the same family

Match the evolution concepts. a. can lead to interdependent species b. changes in a population's allele frequencies due to chance alone c. alleles enter and leave a population d. evolutionary history e. adaptive traits make their bearers better at securing mates f. burst of divergences from one lineage into many g. no more living members h. diagram of sets within sets gene flow sexual selection extinct genetic drift cladogram adaptive radiation coevolution phylogeny