Forward genetics a bare minimum for the appearance of specific phenotypes. However, such initial screens were either incomplete as they were missing redundant loci and epigenetic effects, and such screens were difficult to undertake for certain phenotypes that lack directly measurable phenotypes. Additionally a classical genetics approach takes significantly longer. Gregor Mendel experimented with pea plant phenotypes and published his conclusions about genes and inheritance in 1865. Around the early 1900s Thomas Hunt Morgan was mutating Drosophila using radium and attempting to find heritable mutations Alfred Sturtevant later began mapping genes of Drosophila with mutations they had been following. In the 1990s
Catholic Church and evolution development of evolutionary theory included those of the Jesuit-educated French scientist Jean-Baptiste Lamarck (1744-1829) and of the Augustinian monk Gregor Mendel (1822-1884). Lamarck developed Lamarckism, the first coherent theory of evolution, proposing in "Philosophie Zoologique" (1809) and other works his theory of the transmutation of species. He constructed a genealogical tree to show the genetic connection of organisms. Mendel entered the Brno Augustinian monastery in 1843, but also trained as a scientist at the Olmutz Philosophical Institute and at the University of Vienna. The Brno monastery was a centre of scholarship, with an extensive library and tradition of scientific research.