Editing Forward genetics (section)

==Classical forward genetics==

By the [[classical genetics]] approach, a researcher would locate (map) the gene on its chromosome by [[crossbreeding]] with individuals that carry other unusual traits and collecting statistics on how frequently the two traits are inherited together. Classical geneticists would have used phenotypic traits to map the new mutant alleles. Eventually the hope is that such screens would reach a large enough scale that most or all newly generated mutations would represent a second hit of a locus, essentially saturating the genome with mutations. This type of saturation mutagenesis within classical experiments was used to define sets of genes that were a bare minimum for the appearance of specific phenotypes.<ref>{{cite book | first1 = Greg | last1 = Gibson | first2 = Spencer V. | last2 = Muse | name-list-style = vanc | date = 2009 | title = A Primer of Genome Science | edition = Third | publisher = Sinauer Press }}</ref> 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.