1. Deviations from HWE
I. Mutation
II. Migration
III. Non-Random Mating
IV. Genetic Drift - Sampling Error
V. Selection

2. Deviations from HWE
I. Mutation
II. Migration
III. Non-Random Mating
IV. Genetic Drift - Sampling Error
V. Selection
1. Measuring “fitness” – differential reproductive success

3. IV. Genetic Drift - Sampling Error V. Selection
Deviations from HWE
I. Mutation
II. Migration
III. Non-Random Mating
IV. Genetic Drift - Sampling Error
V. Selection
1. Measuring “fitness” – differential reproductive success
a. The mean number of reproducing offspring (or females)/female

4. IV. Genetic Drift - Sampling Error V. Selection
Deviations from HWE
I. Mutation
II. Migration
III. Non-Random Mating
IV. Genetic Drift - Sampling Error
V. Selection
1. Measuring “fitness” – differential reproductive success
a. The mean number of reproducing offspring (or females)/female
b. Components of fitness:

5. IV. Genetic Drift - Sampling Error V. Selection
Deviations from HWE
I. Mutation
II. Migration
III. Non-Random Mating
IV. Genetic Drift - Sampling Error
V. Selection
1. Measuring “fitness” – differential reproductive success
a. The mean number of reproducing offspring (or females)/female
b. Components of fitness
- probability of female surviving to reproductive age

6. IV. Genetic Drift - Sampling Error V. Selection
Deviations from HWE
I. Mutation
II. Migration
III. Non-Random Mating
IV. Genetic Drift - Sampling Error
V. Selection
1. Measuring “fitness” – differential reproductive success
a. The mean number of reproducing offspring (or females)/female
b. Components of fitness
- probability of female surviving to reproductive age
- number of offspring the female produces

7. IV. Genetic Drift - Sampling Error V. Selection
Deviations from HWE
I. Mutation
II. Migration
III. Non-Random Mating
IV. Genetic Drift - Sampling Error
V. Selection
1. Measuring “fitness” – differential reproductive success
a. The mean number of reproducing offspring (or females)/female
b. Components of fitness
- probability of female surviving to reproductive age
- number of offspring the female produces
- probability that offspring survive to reproductive age

8. IV. Genetic Drift - Sampling Error V. Selection
Deviations from HWE
I. Mutation
II. Migration
III. Non-Random Mating
IV. Genetic Drift - Sampling Error
V. Selection
1. Measuring “fitness” – differential reproductive success
a. The mean number of reproducing offspring (or females)/female
b. Components of fitness
- probability of female surviving to reproductive age
- number of offspring the female produces
- probability that offspring survive to reproductive age
c. With a limited energy budget, selection cannot maximize all three
components… there will necessarily be TRADE-OFFS.

9. 5. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets

10. 1. Measuring “fitness” – differential reproductive success
5. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets
GROWTH
METABOLISM
REPRODUCTION

11. 1. Measuring “fitness” – differential reproductive success
5. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets
Maximize probability of survival
Maximize reproduction
GROWTH
METABOLISM
GROWTH
REPRODUCTION
METABOLISM
REPRODUCTION

12. 1. Measuring “fitness” – differential reproductive success
5. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets
Trade-offs within reproduction
METABOLISM
REPRODUCTION
REPRODUCTION
METABOLISM
A few large, high prob of survival
Lots of small, low prob of survival

13. 5. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets
3. Modeling Selection

14. Selection for a Dominant Allele
5. Modeling Selection
Selection for a Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00

15. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.2

16. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.2
Relative Fitness (ω) 1
0.25

17. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.2
Relative Fitness (ω) 1
0.25
Survival to Reproduction
0.09

18. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.2
Relative Fitness 1
0.25
Survival to Reproduction
0.09
= 0.73
This = “mean fitness of the population” (ω)

19. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.2
Relative Fitness 1
0.25
Survival to Reproduction
0.09
= 0.73
Geno. Freq., breeders
0.22
0.66
0.12

20. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.2
Relative Fitness 1
0.25
Survival to Reproduction
0.09
= 0.73
Geno. Freq., breeders
0.22
0.66
0.12
Gene Freq's, gene pool
p = 0.55
q = 0.45

21. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.2
Relative Fitness 1
0.25
Survival to Reproduction
0.09
= 0.73
Geno. Freq., breeders
0.22
0.66
0.12
Gene Freq's, gene pool
p = 0.55
q = 0.45
Genotypes, F1
0.3025
0.495
0.2025
= 100

22. 3. Modeling Selection
Selection for a Dominant Allele
Δp declines with each generation.

23. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
Δp declines with each generation.
BECAUSE: as q declines, a greater proportion of q alleles are present in heterozygotes (and invisible to selection). As q declines, q2 declines more rapidly...

24. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
Δp declines with each generation.
So, in large populations, it is hard for selection to completely eliminate a deleterious allele....

25. Selection for a Dominant Allele
3. Modeling Selection
Selection for a Dominant Allele
Δp declines with each generation.
Also, this means that in different populations with different gene frequencies, the rate at which p changes will vary (even though the relative fitness differences are the same)

26. 3. Modeling Selection
Selection for a Dominant Allele
Δp declines with each generation.
Rate of change also depends on the strength of selection; the difference in reproductive success among genotypes.

27. 3. Modeling Selection
Selection for a Dominant Allele
Selection for an Incompletely Dominant Allele

28. Selection for an Incompletely Dominant Allele
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.4
0.2
Relative Fitness 1
0.5
0.25
Survival to Reproduction
0.24
0.09
= 0.49
Geno. Freq., breeders
0.33
0..50
0.17
Gene Freq's, gene pool
p = 0.58
q = 0.42
Genotypes, F1
0.34
0.18
= 100

29. Selection for an Incompletely Dominant Allele
- deleterious alleles can no longer hide in the heterozygote; its presence always causes a reduction in fitness, and so it can be eliminated from a population.
In this case, the beneficial allele is said to have an ‘additive’ effect, because one dose is ‘good’ but two doses in the homozygote is ‘better’.

30. Heterosis - selection for the heterozygote
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.4
0.8
0.2
Relative Fitness
0.5 (1-s) 1
0.25 (1-t)
Survival to Reproduction
0.08
0.09
= 0.65
Geno. Freq., breeders
0.12
0.74
0.14
Gene Freq's, gene pool
p = 0.49
q = 0.51
Genotypes, F1
0.24
0.50
0.26
= 100
Maintains both genes in the gene pool
peq = t/s+t
= 0.75/1.25 = 0.6
AA Aa aa

31. Maintains both genes in the gene pool
peq = t/s+t
= 0.75/1.25 = 0.6

32. Heterosis - selection for the heterozygote
Sickle cell caused by a SNP of valine for glutamic acid at the 6th position in the beta globin protein in hemoglobin (147 amino acids long).
The malarial parasite (Plasmodium falciparum) cannot complete development in red blood cells with this hemoglobin, because O2 levels are too low in these cells.
NN NS SS

33. Selection Against the Heterozygote
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.4
0.6
Relative Fitness 1
0.5
0.75
Corrected Fitness
1.0
formulae
1 + s
1 + t

34. Selection Against the Heterozygote - peq = t/(s + t)
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.4
0.6
Relative Fitness 1
0.5
0.75
Corrected Fitness
1.0
formulae
1 + s
1 + t

35. Selection Against the Heterozygote - peq = t/(s + t)
- here = .25/( ) = .33
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.4
0.6
Relative Fitness 1
0.5
0.75
Corrected Fitness
1.0
formulae
1 + s
1 + t

36. Selection Against the Heterozygote - peq = t/(s + t)
- here = .25/( ) = .33
- if p > 0.33, then it will keep increasing to fixation.
p = 0.4, q = 0.6 AA Aa aa
Parental "zygotes"
0.16
0.48
0.36
= 1.00
prob. of survival (fitness)
0.8
0.4
0.6
Relative Fitness 1
0.5
0.75
Corrected Fitness
1.0
formulae
1 + s
1 + t

37. Selection Against the Heterozygote
- peq = t/(s + t)
- here = .25/( ) = .33
- if p > 0.33, then it will keep increasing to fixation.
- However, if p < 0.33, then p will decline to zero... AND THERE WILL BE FIXATION FOR A SUBOPTIMAL ALLELE....'a'... !! UNSTABLE EQUILIBRIUM!!!!

38. E. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets
3. Modeling Selection
4. Types of Selection

39. E. Selection
4. Types of Selection - Directional

40. E. Selection
4. Types of Selection - Directional

41. E. Selection
4. Types of Selection - Stabilizing

42. 4. Types of Selection - Disruptive
E. Selection
4. Types of Selection - Disruptive
Lab experiment – “bidirectional selection” – create two lines by directionally selecting for extremes. Populations are ‘isolated’ and don’t reproduce.

43. 4. Types of Selection - Disruptive
E. Selection
4. Types of Selection - Disruptive
African Fire-Bellied Seed Crackers

44. E. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets
3. Modeling Selection
4. Types of Selection
5. Frequency-Dependent Selection
The selective value depends on the frequency of the allele/phenotype in the population.
“rare mate phenomenon” = negative frequency dependence

45. Elderflower orchids:
- don’t produce nectar
- bumblebees visit most common flower color and get discouraged, try the other color…. Back and forth.
- visit equal NUMBERS of the two colors, but that means that a greater proportion of the rarer flower color is visited.
As phenotype gets rare, fitness increases. Maintains alleles in population

46. (of yellow flowers)

48. - Morphs of Heliconius melpomene and H. erato
Mullerian complex between two distasteful species... positive frequency dependence in both populations to look like the most abundant morph in a given area

49. E. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets
3. Modeling Selection
4. Types of Selection
5. Interactive Effects

50. E. Selection
1. Measuring “fitness” – differential reproductive success
2. Relationships with Energy Budgets
3. Modeling Selection
4. Types of Selection
5. Interactive Effects
- antagonistic pleiotropy

51. Pleiotropy
Ester1 allele: confers resistance to insecticide, but increases risk of predation.
Increased in frequency along coast of France, where spraying occurred (benefit > cost)
Did not increase inland much (did increase due to migration), as cost > benefit and selected against

52. Ester1 was eventually replaced by the Ester4 allele, which conferred a weaker benefit for pesticide resistance BUT had no negative effects inland… so the net benefit was greater.

53. E. Selection
5. Interactive Effects
- mutation-selection balance
A deleterious allele (selectively disadvantageous) can be maintained in a population by mutation:
Δq = m – sq2 = rate they are added by mutation – rate lost by selection against the homozygous genotype.
qeq = √m/s

54. E. Selection
5. Interactive Effects
- mutation-selection balance
- selection and drift

55. Deterministic Effects of Selection > Random Effects of Drift
At small sizes, it is possible to lose an adaptive allele.
However, just by chance, adaptive alleles can become fixed – rapidly increasing the reproductive success of population