Mendel performed his experiments on pea plants, i.e. Pisum sativum. After eight years of tedious experiments with pea plants, he proposed three fundamental principles of inheritance. These principles eventually assisted clinicians in human disease research, e.g. after a few years of the discovery of Mendel's work, Archibald Garrod applied Mendel's principles to his study of alkaptonuria. Today, whether we talk about pea plants or humans, genetic traits that follow the rules of inheritance that Mendel proposed are called Mendelian principles.
