Ch 12

Question 1

fitness values before such standardization are values

Answer 1

absolute fitness

Question 2

metaphor for the relationship between mean fitness of a population and the allele frequencies at one or more loci that affect fitness. possible populations with allele frequencies that max mean fitness are represented as peaks on the metaphorical landscape

Answer 2

adaptive landscape

Question 3

allele frequency, or combination of allele frequencies at two or more loci, at which the mean fitness of a population has a (local) max. also the mean phenotype that max mean fitness
valley is when it has a min.

Answer 3

adaptive peak/valley

Question 4

source of natural selection that opposes another source of selection on a trait

Answer 4

antagonistic selection

Question 5

elimination of deleterious mutations in a region of the genome; may explain low levels of neutral sequence variaiton

Answer 5

background selection

Question 6

form of natural selection that maintains polymorphism at a locus within a population

Answer 6

balancing selection

Question 7

proportion by which the avg fitness of individuals of one genotype differs from that of a reference genotype

Answer 7

coefficient of selection

Question 8

selection for a value of a character that is higher or lower than its current mean value

Answer 8

directional selection

Question 9

selection in favor of two or more modal phenotypes and against those intermediate between them

Answer 9

diversifying selection

Question 10

success of an entity in reproducing; hence the avg contribution of an allele or genotype to the next generation or to succeeding generation

Answer 10

fitness

Question 11

mode of natural selection in which the fitness of each genotype varies as a function of its frequency in the population

Answer 11

frequency-dependent selection

Question 12

manifestation of higher fitness by heterozygotes than by homozygotes at a specific locus

Answer 12

heterozygote (dis)advantage

Question 13

test for selection at a locus by comparing DNA sequence variation within species with the variation among species

Answer 13

McDonald-Kreitman test

Question 14

arithmetic avg fitness of all individuals in a population, usually relative to some standard

Answer 14

mean fitness

Question 15

stable variation at a locus owing to superior fitness of different genotypes under different conditions of a varying environment

Answer 15

multiple-niche polymorphism

Question 16

constancy; more often in this book, the propensity to return to a condition or to one several such conditions

Answer 16

multiple stable equilibria

Question 17

expression by two alleles in heterozygous condition of a phenotypic value for some character that lies outside the range of the two corresponding homozygotes

Answer 17

overdominance

Question 18

change in the allele frequency within a population from one to another local maximum of mean fitness by passage through states of lower mean fitness

Answer 18

peak shift

Question 19

elimination of deleterious alleles from a population

Answer 19

purifying selection

Question 20

fitness of a genotype relative to the fitness of a reference genotype, which is often set at 1.0;

Answer 20

relative fitness

Question 21

fitness of a genotype or other biological entity, often measured by the avg per capita number of offspring that a newly formed zygote will have, or by similar measures

Answer 21

reproductive success

Question 22

increment in fitness provided by an allele or a character state

Answer 22

selective advantage

Question 23

reduction or elimination of DNA sequence variation in the vicinity of a mutation that has been fixed by natural selection relatively recently

Answer 23

selective sweep

Question 24

selection that maintains the mean of a character at or near a constant intermediate value in a population

Answer 24

stabilizing selection

Question 25

lower fitness of a heterozygote than of both of the homozygotes for the same allele

Answer 25

underdominance