Unit 2 Exam

Question 1

Hitchhiking

Answer 1

when a non beneficial allele increases in frequency because it’s linked to a beneficial trait

Question 2

Selective Sweep

Answer 2

fixation of a beneficial allele

Question 3

Balancing Selection

Answer 3

genetic diversity by keeping both alleles present

Question 4

Overdominants

Answer 4

heterozygotes with higher fitness than either homozygotes

Question 5

Negative Frequency Dependent Selection

Answer 5

favors rare allele

Question 6

Multiple Niche Polymorphism

Answer 6

different genotypes maintained in different environments

Question 7

Selection favoring dominant alleles

Answer 7

results in a loss of genetic variation

Question 8

Underdominance

Answer 8

heterozygotes have a disadvantage

Question 9

Positive Frequency Dependent Selection

Answer 9

favors the more common allele

Question 10

Adaptive landscape

Answer 10

how populations evolve, selection will move uphill

Question 11

Neutral Theory

Answer 11

Not under selection constraints

Question 12

dn/ds ratio

Answer 12

measures the difference between nonsynonymous mutation and synonymous mutations

Question 13

local adaptation

Answer 13

sites in the genome with high divergence in isolated populations

Question 14

Quantitative Trait Loci

Answer 14

region of the genome that affects a quantitative trait and can be used to examine genetically variable loci in disparate populations

Question 15

Disruptive Selection

Answer 15

selection of a quantitative trait which shifts the mean towards both extremes and away from the mean

Question 16

Heritability

Answer 16

a measure of likeness between parental and offspring for a specific trait

Question 17

Stabilizing Selection

Answer 17

selection of a quantitative trait which shifts the population towards the mean

Question 18

Directional Selection

Answer 18

selection of a quantitative trait which shifts the mean towards one extreme

Question 19

Coalescence

Answer 19

the period in the past in which two lineages converge on a shared common ancestor

Question 20

Inbreeding Load

Answer 20

fixation of deleterious alleles in a small population, resulting in overall decreased fitness

Question 20

Founder Event

Answer 20

when a small population becomes isolated from the original population, drastically reducing the gene pool

Question 21

Bottleneck

Answer 21

short term reduction in population size which likely results in a drastic mis-sampling of the gene pool

Question 22

Effective Population Size

Answer 22

the realized number of individuals in a population which are contributing genetic material to the subsequent generation

Question 23

Cline

Answer 23

Smooth change in allele frequency or the mean of a character across a geographic transect

Question 24

QTL

Answer 24

Changes in the genome can be detected in different populations and mapped to adaptive environmental traits

Question 25

Mechanical Isolation

Answer 25

Prezygotic, Reproductive structures are incompatible

Question 26

Sexual Isolation/Assortive Mating

Answer 26

Prezygotic, do not recognize other individuals due to a m ismatch in body size

Question 27

Ecological Inviability

Answer 27

Postzygotic, Hybrid offspring have lower rates of survivorship than parents

Question 28

Temporal

Answer 28

Prezygotic, mating occurs at different times of the year (cicadas)

Question 29

β>0

Answer 29

positive selection

Question 30

β<0

Answer 30

negative selection

Question 31

β=0

Answer 31

no directional selection

Question 32

Fsub st= 0

Answer 32

genetically the same

Question 33

Fsub st= 1

Answer 33

genetically distinct

Question 34

var (p)

Answer 34

variation in allele frequency

Question 35

(1-p̄)

Answer 35

is pretty much q, mean allele frequency of Allele 2

Question 36

Plasticity

Answer 36

ability of an organism to develop phenotypic difference to adapt to environment

Question 37

gene flow

Answer 37

movement of alleles to one population or another, equalizes allele frequency; will introduce new alleles

Question 38

migration rate

Answer 38

proportion of individuals in a population that arrives from another each generation

Question 39

o^2

Answer 39

variance

Question 40

Allele swamping

Answer 40

s<

Question 41

Bergmann's Rule

Answer 41

cline in mammals/birds where population in cooler climates have higher body mass

Question 42

Underdominance

Answer 42

heterozygotes have disadvantage over both homozygotes

Question 43

tension zone

Answer 43

area that is an abrupt distinction in phenotype; maintained by underdominance

Question 44

Dispersal

Answer 44

Movement