BIOL 201 1st Edition Lecture 5Outline of Previous LectureI. Self-incompatibility in plantsII. Heterozygote Advantagea. Sickle CellIII. Alternative equilibriaa. Positive frequency-dependent selectionb. Heterozygote disadvantageIV. Selection and Quantitative TraitsV. 3 modes of Selectiona. Directional Selectionb. Stabilizing Selectionc. Disruptive SelectionVI. Detecting Selectiona. Correlation across populationsb. Comparing survivors to non-survivorsc. Functional selectiond. Convergent Evolutione. Molecular methodsVII. Measuring selection and responses to selectiona. Selection differentialb. Response to selectionc. Connecting the two + heritabilityd. Selection gradientOutline of Current LectureI. Mutation-selection balance/equilibriumII. Chart of frequenciesIII. EquationsIV. Cystic fibrosisV. Example ProblemCurrent LectureI. Mutation-selection balance/equilibriumi. Mutation generates new deleterious alleles while selection removes them.ii. The equilibrium frequency of a harmful mutation depends on the rates of the two processesII. Chart of frequencies- - Genotype - Expected Frequency- Fitness- - A1A1- p2- 1- - A1A2- 2pq - 1- - A2A2- q2- 1-sIII. Equationsi. p= frequency of one allele and q= frequency of the otherii. s= penalty paid in terms of fitness for expressing deleterious alleleiii. rate of mutation occurring: μ(p) where mu= coefficient of mutation rateiv. selection rate (against homozygous recessive)= -q2(s)v. allele frequencies have to be between 0 and 1.1. If q really close to 0 then the change in q is equal to the mutation rate and the change is positive  q will increase2. If q is really close to 1 then p is almost 0 so you can ignore the mutation rate and the change in q will be negative  q will decreasevi. = qμ2svii. q2 = μ/sIV. Cystic fibrosis: caused by a mutation in the gene for the CFTR protein, mutation occurs when an individual doesn’t have any of the functional alleles for the proteini. Allele for the mutation is recessiveii. With no working protein, secretions like mucus becomes thick and sticky  clogging of ducts and passageways in lungs and pancreasiii. Impairs lungs and digestive system, makes breeding ground forbacteria and scarring that can lead to respiratory failureV. Example Problem – Rates of Cystic Fibrosisi. You can get the q= mutation rate from the values belowii. European Caucasian mutation rate: 1/2500 = 0.0004iii. Hawaii’s mutation rate: 1/90,000 = 1.1 x 10-5iv. Japan’s mutation rate: 1/350,000 = 2.9 x 10-6v. Mutations that cause changes in phenotype of a human typically happen at a rate of 10-5 or 10-6 per new gamete. European’s rate is unusually high.vi. Mutation-selection equilibrium doesn’t explain what’s happening here. People have proposed that the CF allele used to help people survive against other diseases in the