Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Principals of Evolution > Population Genetics I: Natural Selection > Flashcards

Population Genetics I: Natural Selection Flashcards

(73 cards)

Start Studying
1
Q

Hardy-Weinberg Equation

A

(p + q)^2 = p^2 + 2pq + q^2 = 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

within a population, do allele frequencies change from generation to generation?

A

no, allele frequencies will not change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what happens if the random mating assumption is violated?

A

genotype frequencies will change but allele frequencies will not

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

evolutionary processes

A
  • infinite population size
  • no migration
  • no mutation
  • no natural selection
  • mating is random
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how many rounds of random mating is required to reestablish HW equilibrium?

A

one round of random mating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how to find the frequency of the A allele

A

p^2 + (1/2) 2pq

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how to calculate the expected number of individuals with a genotype given allele frequencies

A

p^2
2pq
q^2
then total the answers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

steps to a statistical test

A
  • have a hypothesis
  • define the expectation under the null hypothesis of no effect
  • collect data
  • compute a test statistic
  • find the probability of your test statistic
  • interpret your results
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

chi squared test

A

X^2 = sum (observed - expected)^2 / expected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

critical value of X^2 distribution

A

3.84

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

absolute fitness

A

the average lifetime reproductive success of individuals with that phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

fitness component

A

an individual score on a measure of performance expected to correlate strongly with the genetic contribution to the next generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

examples of fitness components

A
  • survival
  • fecundity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

natural selection

A

a consequence of differences in fitness between individuals that differ in phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

symbol for relative fitness

A

W

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

relative fitness

A

the fitness of a phenotype compared with others in the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the maximum relative fitness typically equal to

A

1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how to calculate relative fitness

A

absolute fitness / maximum absolute fitness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how to calculate the allele frequencies at time t0

A

p = AA / total t0 + 0.5 (Aa / total t0)
q = aa / total t0 + 0.5 (Aa / total t0)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how to calculate the expected # of individuals at time t1

A

AA = p^2 + total t1
Aa = 2pq + total t1
aa = q + total t1
add all together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how to calculate absolute fitness

A

observed at time t1 / # expected at time t1
- done for all genotypes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how to calculate relative fitness

A

all fitnesses / maximum absolute fitness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how to see there was evolution?

A

delta q = q1 - q0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

fitness is a _________, not an _________

A

description, explanation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
how did Herbert Spenser define natural selection?
- he defined natural selection as survival of the fittest - this is not an accurate definition
26
how does an advantageous trait contribute to an organisms?
the organisms survival and reproductive success
27
what does the phenotype of an organism in relation to the environment it inhabits determine?
how fit that organism is
28
fitness is...
context dependent
29
the general selection model equation
delta q = pq [q (W3 - W2) + P (W2 - W1)] / W
30
how to calculate average effect of an allele substitution
[q (W3 - W2) + p (W2 - W1)]
31
what does the general selection model quanify?
the relationship between allele frequencies and fitness
32
the greater the difference between the relative fitnesses...
the greater the rate of evolution
33
S
selection coefficient
34
AA
W1 = 1
35
Aa
W2 = 1a
36
aa
W3 = 1 - S
37
how to calculate selection with dominance
delta q = -spq^2 / 1 - sq^2
38
directional selection
a mode of natural selection in which a phenotype is consistently favored, causing allele frequencies to shift over time in the direction of that phenotype
39
the rate of change in allele frequencies
a function of the allele frequencies, the relative fitness values, and the mean population fitness in the population
40
does the directional selection always increase mean population fitness?
yes
41
how to calculate the selection with dominance when the fitness of the homozygous recessive = 0
qn = q0 / 1 + nq0
42
eugenics
the study and practice of control over the evolution of human populations in an effort to decrease the frequency of undesirable traits
43
cystic fibrosis
cell surface protein expressed in the mucus lining of the intestines and lungs
44
what does CTFR enable?
cells to ingest and destroy the bacterium
45
how does cystic fibrosis form?
homozygotes for loss-of-function mutations suffer chronic infections with the bacterium
46
how to calculate heterozygote advantage
p = S2 / S1 + S2 q = S1 / S1 + S2
47
balancing selection
forms of natural selection that maintain variation within a population
48
Hb^A
normal allele in hemoglobin
49
Hb^S
sickle cell allele in hemoglobin
50
what are homozygotes for the Hb^A allele susceptible to?
malaria in West Africa
51
what is malaria caused by?
protozoan Alveolata
52
symptoms and effects of malaria and sickle cell anemia
- invades red blood cells & eats the hemoglobin - malaria causes severe fevers - infected blood cells clump up and cause dangerous clots
53
Hb^S allele anemia
- the red blood cells do not carry oxygen well and form a sickle shape when they do not have oxygen - the blocks blood vessels and eventually leads to death - when sickle cells pass through the spleen they are detected by white blood cells as defective and destroyed
54
Hb^A Hb^S heterozygotes
resistant to malaria but suffer mild anemia
55
is S positive or negative in underdominance?
negative
56
mutation
- fundamental to evolutionary theory - the raw material of the evolutionary process
57
mutation includes
- point mutations - indels - gene duplication - transposable elements - chromosomal mutations - genome level mutations
58
is mutation planned or random?
mutation has causes, but is random with respect to adaptive needs
59
the environment doe snot induce adaptive mutations
no "inheritance of acquired characters"
60
what prevents mutations?
developmental constraints prevent many mutations from ever being expressed at the phenotypic level
61
purifying selection
selection against deleterious mutation
62
how is purifying selection removed?
removed by selection if dominant or codominant
63
u = A --> a
forward mutation rate
64
v = a --> A
backward mutation rate
65
how does mutation change the frequency of allele a?
if deltaqm is the per generation change in q, due to mutation, then detlaqm = pu -qv
66
mutation without selection will...
increase the frequency of the a allele
67
what happens when there is a selection against the aa genotype?
the frequency of the a allele declines
68
selection without mutation will...
decrease the frequency of the a allele
69
what happens at mutation selection balance?
a allele will achieve an equilibrium
70
what kind of disease is spinal muscular atropy?
neurodegenerative disease
71
neurodegenerative disease
degeneration of the muscles that control voluntary movement
72
what causes neurodegenerative disease?
deletions at one locus
73
what maintains neurodegenerative disease?
mutation/selection balance

Principals of Evolution (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions