15.3 PDQ

1. Fill out the chart Hardy Weinberg Equations P + Q =1 P2 + 2PQ + Q2 = 1 Required Conditions for HW Equilibruim No net mutations No natural selection No gene flow Large population size Random Mating

2. What is the significance of the HW equilibrium? It allows us to see if evolution is occurring in a population

3. If all of the above conditions hold, how many generations are required for a population to reach HW equilibrium? 1

4. What do deviations from HW equilibrium indicate? That evolution is occurring!

5. p. 299 Calculate the allele and genotype frequencies of Ldh in this newly founded population? Allele frequency of A = 10/20 = 0.5 = p Allele frequency of a = 10/20 = 0.5 = q AA Genotype frequency = 4/10 = 0.4 = P2 Aa Genotype frequency = 2/10 = 0.2 = 2pq aa Genotype frequency = 4/10 = 0.4 = q2

5. p. 299 #b No because P2 does not equal 0.4, it equals 0.25. and Q2 does not equal 0.2, it equals 0.25.

5. #c Same Allele frequencies: p = 0.5, q = 0.5 (unchanged)   Genotype frequencies: Frequency of aa = p2 = 0.25 Frequency of Aa = 2pq = 0.5 Frequency of AA = q2 = 0.25

#5 d Small population (only 10) Gene flow could occur (it happened before due to the hurricane!) Random mating is not possible Selection for or against a trait could occur

Summarize the effect of the following on allele frequencies Mutations If dominant mutation, p goes up; If recessive mutation, p goes down etc. Gene Flow Emmigration would lower p and q; Immigration would increase p and q Genetic Drift Random – p and q would change either way Non-Random mating Chosen traits (dominant or recessive) would go up Natural Selection Best fit traits for survival (dominant or recessive) would go up