Test 1

Question 0

Assumptions of HWE

Answer 0

• no selection
• no genetic drift ( infinitely large Pop size)
• no mutation
• no migration
• random mating (no sexual selection)

Question 1

How to calculate allele frequencies (not from hardy Weinberg)

Answer 1

p = (2NAA + NAG) / 2Ntotal

p = f(AA) + .5f(AG)

Question 2

Evolutionary mechanisms

Answer 2

• selection
• finite population (genetic drift)
• mutation
• migration
• non-random mating

Question 3

Hardy Weinberg equilibrium

Answer 3

p2 + 2pq + q2 = 1

p+q=1

Question 4

Cline

Answer 4

A gradual change in character or allele frequency over a geographic distance

Question 5

Fitness

Answer 5

Ability to survive and reproduce in a particular environment

Alleles with higher fitness in a given environment will become more common over time (fixation)

Max is 1

Question 6

Rate to reach fixation depends on …

Answer 6

• selection strength
• whether the Allele is dominant or recessive
• frequency

Question 7

Homozygote advantage (genotype)
Phenotype ?
Fitness direction ?
Genetic variation ?
Example?

Answer 7

Waa = 1

Directional selection
Fitness goes up
Genetic variation goes down
Example is Dawson’s flies, Enders guppies

Question 8

Heterozygote Adv
Phenotype?
Genetic variation?
Example?

Answer 8

WAa = 1

Stabilizing selection
Fitness increases
Genetic variation stays the same
Eg sickle cell anemia, births weight

Question 9

Heterozygous disadvantage
Phenotype 
Fitness 
Genetic variation 
Example

Answer 9

WAa<1

Diversifying/disruptive selection
Fitness increases
Genetic variation decreases in a given pop, stays the same across different pops
Eg. Birds with diff sized beaks that depend on diet

Question 10

Negative frequency dependent selection ; fitness change, genetic variation?

Answer 10

(Is a phenotype; less common more fit, more common less fit)
Fitness goes up
Genetic variation stays the same
(Batesian mimicry, no poisonous butterfly mimics pattern of poisonous one)

Question 11

positive frequency dependent selection

Answer 11

More common more fit, less common less fit
(Mullerian mimicry - butterflies that are poisonous look alike)
Fitness increases
Genetic variation goes down in a given pop, same across pop

Question 12

Founder effect

Answer 12

Form of genetic drift in which a change in allele frequency after a population is founded by a few individuals

Question 13

Population bottleneck (effect)

Answer 13

Form of genetic drift in which there is a change in allele frequency due to loss of population (usually a freak event)

Question 14

Sources of genetic variation in bacteria

Answer 14

ONLY mutation (NOT recombination)

Question 15

Is selection stronger in large or small populations?

Answer 15

Large (in smaller sometimes it can go to loss)

Question 16

Mutation/Selection Balance

Answer 16

An equilibrium at which rate of addition of deleterious allele by mutation is balanced by the rate of removal by natural selection

Question 17

Is migration (gene flow) stronger in large or small populations?

Answer 17

Small populations (One-Island model)

Question 19

Advantages and disadvantages of inbreeding

Answer 19

advantages: ecological, genetic
disadvantages: inbreeding depression, increase frequency of homozygotes (likely to be deleterious)

does NOT change allele frequencies
measured by F (inbreeding coefficient, min is 0 (no inbreeding) max is 1)