Gregor Mendel both his professors at the Palacký University, Olomouc (Friedrich Franz and Johann Karl Nestler), and his colleagues at the monastery (such as Franz Diebl) to study variation in plants. In 1854, Napp authorized Mendel to carry out a study in the monastery's experimental garden, which was originally planted by Napp in 1830. Unlike Nestler, who studied hereditary traits in sheep, Mendel used the common edible pea and started his experiments in 1856. After initial experiments with pea plants, Mendel settled on studying seven traits that seemed to be inherited independently of other traits: seed shape, flower color, seed coat tint,
Plant genetics put forth by Mendel. W.E. Castle discovered that while individual traits may segregate and change over time with selection, that when selection is stopped and environmental effects are taken into account, the genetic ratio stops changing and reach a sort of stasis, the foundation of Population Genetics. This was independently discovered by G.H. Hardy and W. Weinberg, which ultimately gave rise to the concept of Hardy-Weinberg equilibrium published in 1908. For a more thorough exploration of the history of population genetics, see History of Population Genetics by Bob Allard. Around this same time, genetic and plant breeding experiments in maize