Medical Genetics Why study Populations and Gene Frequencies 1. Genetic variability necessary for evolutionary successi 2. Measuring genetic variability at many loci can characterize a population; 3. Variability of phenotypic and molecular traits are analyzed.Medical Genetics Why Study Populations and Gene Frequencies 1. Genetic variability necessary for evolutionary success; 2. Measuring genetic variability at many loci can characterize a population; 3. Variability of phenotypic and molecular traits are analyzed