1. Modern Evolutionary Biology I. Population Genetics
A. Overview
B. The Genetic Structure of a Population
C. The Hardy-Weinberg Equilibrium Model
D. Deviations From HWE: 
1. Mutation
2. Migration
3. Non-Random Mating:
4. Populations of Finite Size and Sampling Error - "Genetic Drift"
5. Natural Selection: “differential reproductive success”
we measure reproductive success as ‘fitness’
1. Fitness Components:

2. D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
Fitness = The mean number of reproducing offspring / genotype
- probability of surviving to reproductive age
- number of offspring
- probability that offspring survive to reproductive age

3. D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
Fitness = The mean number of reproducing offspring / genotype
- probability of surviving to reproductive age
- number of offspring
- probability that offspring survive to reproductive age
2. Constraints:
i. finite energy budgets and necessary trade-offs:

4. GROWTH METABOLISM REPRODUCTION D. Deviations From HWE:
5. Natural Selection
Fitness Components:
Fitness = The mean number of reproducing offspring / genotype
- probability of surviving to reproductive age
- number of offspring
- probability that offspring survive to reproductive age
2. Constraints:
i. finite energy budgets and necessary trade-offs:
GROWTH
METABOLISM
REPRODUCTION

5. Maximize probability of survival
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
2. Constraints:
finite energy budgets and necessary trade-offs:
TRADE OFF #1: Survival vs. Reproduction
Maximize probability of survival
GROWTH
METABOLISM
REPRODUCTION
Maximize reproduction

6. Lots of small, low prob of survival A few large, high prob of survival
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
2. Constraints:
finite energy budgets and necessary trade-offs:
TRADE OFF #1: Survival vs. Reproduction
TRADE OFF #2: Lots of small offspring vs. few large offspring
METABOLISM
REPRODUCTION
Lots of small, low prob of survival
A few large, high prob of survival
METABOLISM

7. Photosynthetic potential
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
2. Constraints:
finite energy budgets and necessary trade-offs:
Contradictory selective pressures:
Leaf Size
Photosynthetic potential
Water Retention

8. Photosynthetic potential
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
2. Constraints:
finite energy budgets and necessary trade-offs:
Contradictory selective pressures:
Leaf Size
Photosynthetic potential
Water Retention
Rainforest understory – dark, wet
Big leaves adaptive

9. Photosynthetic potential
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
2. Constraints:
finite energy budgets and necessary trade-offs:
Contradictory selective pressures:
Leaf Size
Photosynthetic potential
Water Retention
Desert – sunny, dry
Small leaves adaptive

10. prob. of survival (fitness) 0.8 0.4 0.2
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
Constraints:
Modeling Selection:
a. Calculating relative fitness
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
0.8/0.8=1
0.4/0.8 = 0.5
0.2/0.8=0.25
Calculate relative fitness by dividing all fitness values by the LARGEST value.

11. prob. of survival (fitness) 0.8 0.4 0.2
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
Constraints:
Modeling Selection:
a. Calculating relative fitness
b. Modeling Selection
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
Multiply the initial genotypic frequency by relative fitness.
Of course, not all organisms have survived, so these new frequencies do not sum to 1 any more.

12. prob. of survival (fitness) 0.8 0.4 0.2
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
Constraints:
Modeling Selection:
a. Calculating relative fitness
b. Modeling Selection
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
Freq’s in Breeding Adults
0.16/0.49 = 0.33
0.24/0.49 = 0.49
0.09/0.49 = 0.18
But we need to know what FRACTION of these SURVIVORS has each genotype. So, divide each frequency by the total. THESE are the genotypic frequencies in the survivors that have reached reproductive age and will breed.

13. prob. of survival (fitness) 0.8 0.4 0.2
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
Constraints:
Modeling Selection:
a. Calculating relative fitness
b. Modeling Selection
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
Freq’s in Breeding Adults
0.16/0.49 = 0.33
0.24/0.49 = 0.49
0.09/0.49 = 0.18
Gene Frequencies
F(A) = 0.575
F(a) = 0.425
Freq’s in F1 (p2, 2pq, q2)
0.33
0.49
0.18
Calculate the gene frequencies, and compute genotypes in offspring (assuming all other HWE conditions are met, like random mating.)

14. D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
Constraints:
Modeling Selection:
4. Types of Selection

15. Intrasexual – competition within a sex for access to mates.
D. Deviations From HWE: 
5. Natural Selection
Fitness Components:
Constraints:
Modeling Selection:
4. Types of Selection
Sexual Selection
Some traits that decrease survival may be selected for because they have a direct and disproportional benefit on probability of mating.
Intrasexual – competition within a sex for access to mates.
Intersexual – mates are chosen by the opposite sex.

16. Sources of Variation Agents of Change Mutation Natural Selection
Modern Evolutionary Biology
I. Population Genetics
A. Overview
B. The Genetic Structure of a Population
C. The Hardy-Weinberg Equilibrium Model
D. Deviations From HWE
E. Summary; The Modern Synthetic Theory of Evolution
Sources of Variation Agents of Change
Mutation Natural Selection
Recombination Genetic Drift
- crossing over Migration
- independent assortment Mutation
Non-random Mating
VARIATION