Chapter 20: Evolution

Question 1

species

Answer 1

a group of individuals capable, through reproduction, of sharing alleles with one another

Question 2

Gene pool

Answer 2

consists of all the alleles present in all the individuals in the species

Question 3

populations

Answer 3

interbreeding groups of organisms of the same species living in the same geographical area

Question 4

What are the two sources of genetic variation?

Answer 4

Mutation and recombination

Question 5

Recombination

Answer 5

a process by which pieces of DNA are broken and recombined to produce new combinations of alleles

Question 6

Neutral mutation

Answer 6

a mutation that has little to no effect (most of the genome consists of noncoding DNA so most mutations are neutral)

Question 7

deleterious mutation

Answer 7

when a large population of mutations occurs in protein-coding regions of the genome

Question 8

advantageous mutation

Answer 8

a mutation occurs that has a beneficial effect to the carriers’ chances of survival or reproduction

Question 9

evolution

Answer 9

a change in the frequency of alleles or genotype in a population over time

Question 10

What are the conditions of the Hardy-Weinberg Equilibrium model?

Answer 10

no migration, no mutation, large population, no mate choice, and no differential survival or reproductive success of individuals (natural selection)

Question 11

what is p^2 +2pq +q^2 = 1 used for?

Answer 11

to find the predicted genotype frequencies for a population

Question 12

Stabilizing selection

Answer 12

selects against the extremes

Question 13

directional selection

Answer 13

selects against one of the two extremes

Question 14

disruptive selection

Answer 14

selects against the mean

Question 15

natural selection

Answer 15

the change in an allele’s frequency over time base on that particular allele’s impact on survival and reproduction

Question 16

fitness

Answer 16

a measure of the extent to which the individual’s genotype is represented in the next generation

Question 17

the modern synthesis

Answer 17

a synthesis between Darwin’s theory of natural selection and Mendelian genetics

Question 18

intrasexual selection

Answer 18

members of one sex compete with one another for access to the other sex

Question 19

intersexual selection

Answer 19

a form of sexual selection involving interaction between males and females as when females choose form among males

Question 20

artificial selection

Answer 20

selection by a breeder rather than by natural selection

Question 21

What are the nonadaptive mechanisms of evolution?

Answer 21

migration, mutation, genetic drift, and non-random mating

Question 22

molecular evolution

Answer 22

a change in DNA or amino acid sequences over time

Question 23

What evolutionary factor leads to adaptations?

Answer 23

natural selection

Question 24

How do we measure evolutionary change?

Answer 24

gel electrophoresis, observable physical traits, and DNA sequencing