17

Question 1

Directional selection

Answer 1

Mode of natural selection in which phenotypes at one end of a range of variation are favored

Question 2

Stabilizing selection

Answer 2

Mode of natural selection in which intermediate forms of a trait are favored over extremes

Question 3

disruptive selection

Answer 3

Mode of natural selection that favors forms of a trait at the extremes of a range of variation

Question 4

sexual selection

Answer 4

some individuals of a population out-reproduce others because they are better at securing mates

Question 5

genetic drift

Answer 5

Change in allele frequencies in a population due to chance alone

Question 6

fixed

Answer 6

Refers to an allele for which all members of a population are homozygous

Question 7

bottleneck

Answer 7

Drastic reduction in population size so severe that it reduces genetic diversity

Question 8

gene flow

Answer 8

The movement of alleles into and out of a population

Question 9

speciation

Answer 9

One of several processes by which new species arise

Question 10

reproductive isolation

Answer 10

Absence of gene flow between populations

Question 11

exaptation

Answer 11

Adaptation of an existing structure for a completely different purpose; a major evolutionary novelty

Question 12

stasis

Answer 12

no change over time