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
Gregor Mendel next thirty-five years. His paper was criticized at the time, but is now considered a seminal work. Notably, Charles Darwin was not aware of Mendel's paper, and it is envisaged that if he had been aware of it, genetics as we know it now might have taken hold much earlier. Mendel's scientific biography thus provides an example of the failure of obscure, highly original, innovators to receive the attention they deserve. Mendel began his studies on heredity using mice. He was at St. Thomas's Abbey but his bishop did not like one of his friars studying animal sex, so Mendel