Weeks 1 and 2

Question 1

Genetic drift
Natural selection
Mutation
Migration

Answer 1

evolutionary forces that can cause change in allele frequency from one generation to another

Question 2

Population genetics looks at

Answer 2

changes in gene frequency within and between populations

Question 3

Microevolution

Answer 3

evolution within a species

Question 4

Ho for population genetics

Answer 4

no evolution

Question 5

P =

Answer 5

relative frequency of A1A1 genotype (normal homozygotes)

of A1A1 individuals / total population number

Question 6

H =

Answer 6

relative frequency of A1A2 genotype (heterozygotes)

of A1A2 individuals / total population number

Question 7

Q =

Answer 7

relative frequency of A2A2 genotype (recessive)

of A2A2 individuals / total population number

Question 8

Relative frequency of A1 allele

Answer 8

p = P + 1/2H

Question 9

Relative frequency of A2 allele

Answer 9

q = Q + 1/2H

Question 10

When is a locus being in HWE?

Answer 10

when no forces of evolution influence allele frequencies at a single gene locus.

Question 11

Consequences of being in HWE?

Answer 11

a gene locus is said to be in HEW
allele frequencies will predict genotype frequencies
genotype frequencies will remain stable
allelic variation is NOT lost between generations
Rare alleles are maintained in heterozygotes

Question 12

HWE is a property of

Answer 12

a gene NOT an individual or a population

Question 13

Genes are acted upon

Answer 13

by evolutionary forces

Question 14

In a population some genes are in HWE and some are not

Answer 14

True

Question 15

Assumptions of HWE

Answer 15

1. Large population size (insures no genetic drift)
2. No external forces ( no nat. sel, mutation, migration)
3. Random mating (no assortive mating, sexual selection or inbreeding)

Question 16

What genes tend to be in HWE

Answer 16

those with phenotypes that have no positive or negative effects

Called selectively neutral loci

Question 17

When is the frequency of heterozygotes the highest

Answer 17

When p and q are equal (each at 0.5)

Question 18

How quickly can a locus reach HWE?

Answer 18

within one generation of random mating

Question 19

Multiple alleles with HWE

Answer 19

(p+q+r)2

Question 20

Sex-linked traits with HWE

Answer 20

in males p=P and q=Q because males are hemizygous

Use male values to find females:
Females: p2=P, 2pq=H, q2=Q

Question 21

When looking at numerical values, what indicates a population is NOT in HWE?

Answer 21

deviations of observed genotype from expected genotype = evolution

Question 22

Why is HWE important to genetics?

Answer 22

Provides a starting point to test for evolution within a population.

If locus is not in HWE, then evolution must be acting on that locus

Next step….determine which evolutionary force is at work

Question 23

Evolution acts on what

Answer 23

natural variation within a population

Question 24

define selection

Answer 24

directed variation in survival and reproduction of different types.

Can be beneficial or harmful (causes directional selection)

Question 25

Define genetic drift

Answer 25

Random variation due to segregation and independent assortment

Question 26

Macroevolution

Answer 26

speciation. phenotypes become so different that species cannot reproduce together

Question 27

What are the geologic pieces of evidence supporting evolution?

Answer 27

Fossil layers
Radiometric dating
Principle of superposition
Principle of cross - cutting relationships
Principle of faunal succession

Question 28

What evidence for evolution comes from the fossil record

Answer 28

extinction
succession
transitional forms

Question 29

What evidence for evolution comes from common ancestry

Answer 29

Homologous structures: arise from common origin / common embryonic development

Homologies that are NOT analogies provide strongest support

Genetic homology

Vestigial structures

Question 30

Convergent evolution leads to

Answer 30

Analogous structures. NOT evidence of a common ancestor. Evolve independently due to similar environmental pressures.