Natural Selection Simulation Worksheet

Biol 1441- Principles of Biology II

Microevolution
Simulating Natural Selection using the Hardy-Weinberg Principle

Natural Selection Worksheet - Effects of Cryptic Coloration on Allele Frequency

Type of Predator: Visual_x___ Blind_____

Complete the calculations of the missing data.

Generation 1
Allele frequency
Step 1. Given, or select allele frequencies for simulation.
Hardy Weinberg Eq. (p + q)² = p² + 2(p)(q) + q² = 1

freq. A (p)	freq. a (q)
0.5	0.5

Genotype Frequency (decimal value)
Step 2. Calculate genotype frequencies by multiplying the appropriate allele frequencies.

Red, AA = p²	Mottle, Aa = 2(p)(q)	White, aa = q²
0.25		0.25

No. of each phenotype in population, N=60
Step 3. Multiply each genotype frequency by 60 to get the number of each phenotype.

Red	Mottle	White
15	30

No. of each phenotype removed by predator
Step 4. Remove and count predator's selection

Red	Mottle	White
4	13	7

No. of each phenotype that survived
Step 5. Subtract to find number of survivors.

Red	Mottle	White
11

Sum all surviving phenotypes to calculate the Total Survival
Total survival =_36_

Step 6. From step 5, calculate the total of alleles/genotype surviving by multiplying each surviving pheontype by 2.
Total number of alleles surviving: 36 total phenotypes x 2 = 72

Red	Mottle	White
	34

Step 7. Total the number of each allele surviving to the next generation is:
A= #Red + 0.5(#Mottle) = 22 + 17 = 39 a= #white + 0.5(#Mottle) = _______

Step 8. Allele frequency of survivors entering the next generation:

Allele frequency p = A / Total #alleles surviving (Step 6) = A / 72 =______

Allele frequency q = a / Total #alleles surviving (Step 6) = A / 72 =_0.46_

These frequencies are then transfered to the Allele frequency box for Generation 2.

Repeat steps 1 through 8 for Generation 2
Allele frequency

freq. A (p)	freq. a (q)
	0.46

Genotype Frequency (decimal value)

Red, AA = p²	Mottle, Aa = 2(p)(q)	White, aa = q²
	0.50	0.21

No. of each phenotype in population, N=60

Red	Mottle	White
17

No. of each phenotype removed by prey

Red	Mottle	White
5	14	8

Total of all phenotype that survived
Total survival =_33_

Red	Mottle	White
		5

No. of Alleles/genotype surviving

Red	Mottle	White
	32

Total the number of each allele surviving to the next generation is:
A= #Red + 0.5(#Mottle) = __40__ a= #white + 0.5(#Mottle) = _______

Allele frequency of survivors entering the next generation:

Allele frequency p = A / Total #alleles surviving =__0.61__

Allele frequency p = a / Total #alleles surviving =______