Today's poultry genetic principles and applications of breeding programs are guided by Mendel's milestone work on inheritance and Darwin's selection principles. Their foundational work was brought to poultry by Robinson (1912). He detailed principles of poultry selection, breeding applications and mating strategies in his work. Around the same time, Raymond Pearl (1911) conducted extensive work on the heritability of egg quality traits such as egg weight, egg shape, albumen height and shell quality. His work helped us to understand the genetic bases of today's egg quality traits, their relationships with other traits and the genetic basis of egg production. J. L. Lush (1945) laid the foundation for modern genetic selection in animals. He applied principles of population genetics, statistics and biometrics to improve traits in livestock. I. M. Lerner (1950) used poultry both as an animal model and as a commercial species to test use of part-year laying records on sibs to replace progeny testing of males and to reduce generation interval and increase selection intensity. His work outlines genetic and population genetic principles and practices. During the mid-twentieth-century, breeding companies pioneered the application of genetics to egg production and egg quality to select breeding lines. Their advancement has led to a signifcant period of progress in understanding and selecting egg quality traits in poultry programs.