Classical genetics genetics is often referred to as the oldest form of genetics, and began with Gregor Mendel's experiments that formulated and defined a fundamental biological concept known as Mendelian Inheritance. Mendelian Inheritance is the process in which genes and traits are passed from a set of parents to their offspring. These inherited traits are passed down mechanistically with one gene from one parent and the second gene from another parent in sexually reproducing organisms. This creates the pair of genes in diploid organisms. Gregor Mendel started his experimentation and study of inheritance with phenotypes of garden peas and continued the experiments
Johann Karl Nestler stock animals and their offspring Nestler hoped to explain the (genetic history). Examination of the records of the ancestors of the best breeding animals, called by Nestler "developmental history" () was for him the reverse side of the same coin. According to Wood and Orel the search for rules of heredity in sheep created an atmosphere of enquiry about heredity in general, which had influence on later work of Gregor Johann Mendel, himself a student at the Faculty of Philosophy in 1840–43. Nestler was also a very active member of the "Moravian-Silesian Society for Advancement of Agriculture" (, in which