Explore the fundamentals of quantitative genetics in this comprehensive lecture from the Third Bangalore School on Population Genetics and Evolution. Delve into the multifactorial model of genotype/phenotype relationships, examining key concepts from Hard & Clark 2007. Learn about the cornerstone of evolutionary biology through population genetics, integrating mathematical and statistical concepts with fundamental biological principles. Gain insights into evolutionary processes, genetic inheritance, mutation, and selection. Discover how quantitative genetics allows for predictions of evolutionary changes in populations, connecting various biological disciplines. Ideal for students and researchers in biology, mathematics, medicine, physics, and statistics interested in evolutionary theory and its applications.