Around 1923 the soon-to-be famous Soviet mathematician and probabilist Sergei N. Bernstein started to construct an axiomatic foundation of a theory of heredity. He began from the premise of stationarity (constancy of type proportions) from the first generation of offspring. https://www.bekindtopets.com/top-price-Ratch-A-Pull-Double-Action-Calf-Puller-super-grab/