<P> In the 18th century, with increased knowledge of plant and animal diversity and the accompanying increased focus on taxonomy, new ideas about heredity began to appear . Linnaeus and others (among them Joseph Gottlieb Kölreuter, Carl Friedrich von Gärtner, and Charles Naudin) conducted extensive experiments with hybridization, especially species hybrids . Species hybridizers described a wide variety of inheritance phenomena, include hybrid sterility and the high variability of back - crosses . </P> <P> Plant breeders were also developing an array of stable varieties in many important plant species . In the early 19th century, Augustin Sageret 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 . </P> <P> 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 with some traits being dominant and others being recessive . These patterns of Mendelian inheritance demonstrated that application of statistics to inheritance could be highly useful; they also contradicted 19th century theories of blending inheritance as the traits remained discrete through multiple generation of hybridization . </P> <P> From his statistical analysis Mendel defined a concept that he described as a character (which in his mind holds also for "determinant of that character"). In only one sentence of his historical paper he used the term "factors" to designate the "material creating" the character: "So far as experience goes, we find it in every case confirmed that constant progeny can only be formed when the egg cells and the fertilizing pollen are of like character, so that both are provided with the material for creating quite similar individuals, as is the case with the normal fertilization of pure species . We must therefore regard it as certain that exactly similar factors must be at work also in the production of the constant forms in the hybrid plants ." (Mendel, 1866). </P>

Who carried out the first genetic study in history