History of genetics established the concept of dominance, recognizing that when some plant varieties are crossed, certain characteristics (present in one parent) usually appear in the offspring; he also found that some ancestral characteristics found in neither parent may appear in offspring. However, plant breeders made little attempt to establish a theoretical foundation for their work or to share their knowledge with current work of physiology, although Gartons Agricultural Plant Breeders in England explained their system. In breeding experiments between 1856 and 1865, Gregor Mendel first traced inheritance patterns of certain traits in pea plants and showed that they obeyed simple statistical rules
Genetics and the Origin of Species that give them a competitive advantage, and they have the best chance of surviving and procreating. The main element lacking in the theory was any mechanism that would allow organisms to pass on these favorable variations. Lacking such a mechanism, the theory of evolution faced competition from theories such as neo-Lamarckism, in which the environment acted directly on organisms, changing their structures. Darwin did not know that the monk Gregor Mendel was already working on experiments that would explain inheritance in terms of units of heredity that we now call genes. When Mendelian genetics was rediscovered by several scientists, it