Please answer the following questions: 1. What is positive selection? 2. What is the cause of WBS, William Beuren syndrome? Solution 1. Positive selection is the process in which new favourable and advantageous genetic variants sweep the population. It is that selection which was described by darwin , wherein an extreme phenotype is favoured over the other phenotypes causing the frequency of allele to shift in that direction over the course of time. This is called as directional selection im population genetics..