Editing Genetics (section)

=== Mendelian genetics ===
[[File:Sexlinked inheritance white.jpg|thumb|Morgan's observation of [[Sex linkage|sex-linked inheritance]] of a mutation causing white eyes in ''[[Drosophila]]'' led him to the hypothesis that genes are located upon chromosomes.]]

{{main|Mendelian inheritance}}

Modern genetics started with Mendel's studies of the nature of inheritance in plants. In his paper "''Versuche über Pflanzenhybriden''" ("[[Experiments on Plant Hybridization]]"), presented in 1865 to the ''Naturforschender Verein'' (Society for Research in Nature) in [[Brno]], Mendel traced the inheritance patterns of certain traits in pea plants and described them mathematically. Although this pattern of inheritance could only be observed for a few traits, Mendel's work suggested that heredity was particulate, not acquired, and that the inheritance patterns of many traits could be explained through simple rules and ratios.<ref name="mendel">{{cite web |title=Mendel's Paper in English |url=http://www.mendelweb.org/Mendel.html | vauthors = Blumberg RB |url-status=live |archive-url=https://web.archive.org/web/20160113051202/http://www.mendelweb.org/Mendel.html |archive-date=13 January 2016}}</ref>

The importance of Mendel's work did not gain wide understanding until 1900, after his death, when [[Hugo de Vries]] and other scientists rediscovered his research. [[William Bateson]], a proponent of Mendel's work, coined the word ''genetics'' in 1905.<ref>genetics, ''n.'', [[Oxford English Dictionary]], 3rd ed.</ref><ref>{{cite web |url=http://www.jic.ac.uk/corporate/about/bateson.htm |title=Letter from William Bateson to Alan Sedgwick in 1905 |publisher=The John Innes Centre |access-date=15 March 2008 |vauthors=Bateson W |url-status=dead |archive-url=https://web.archive.org/web/20071013020831/http://www.jic.ac.uk/corporate/about/bateson.htm |archive-date=13 October 2007}} The letter was to an Adam Sedgwick, a zoologist and "Reader in Animal Morphology" at [[Trinity College, Cambridge]]</ref> The adjective ''genetic'', derived from the Greek word ''genesis''—γένεσις, "origin", predates the noun and was first used in a biological sense in 1860.<ref>genetic, ''adj.'', Oxford English Dictionary, 3rd ed.</ref> Bateson both acted as a mentor and was aided significantly by the work of other scientists from Newnham College at Cambridge, specifically the work of [[Edith Rebecca Saunders|Becky Saunders]], [[Nora Darwin Barlow]], and [[Muriel Wheldale Onslow]].<ref>{{cite journal | vauthors = Richmond ML | title = Opportunities for women in early genetics | journal = Nature Reviews. Genetics | volume = 8 | issue = 11 | pages = 897–902 | date = November 2007 | pmid = 17893692 | doi = 10.1038/nrg2200 | url = http://www.nature.com/reviews/genetics | url-status = live | s2cid = 21992183 | df = dmy-all | archive-url = https://web.archive.org/web/20080516070928/http://www.nature.com/reviews/genetics/ | archive-date = 16 May 2008 | url-access = subscription }}</ref> Bateson popularized the usage of the word ''genetics'' to describe the study of inheritance in his inaugural address to the Third International Conference on Plant Hybridization in [[London]] in 1906.<ref name="bateson_genetics">{{cite conference |vauthors=Bateson W |title=The Progress of Genetic Research |editor=Wilks, W |book-title=Report of the Third 1906 International Conference on Genetics: Hybridization (the cross-breeding of genera or species), the cross-breeding of varieties, and general plant breeding|publisher=Royal Horticultural Society |location=London |year=1907}} :Initially titled the "International Conference on Hybridisation and Plant Breeding", the title was changed as a result of Bateson's speech. See: {{Cite book|vauthors=Cock AG, Forsdyke DR |year=2008|title=Treasure your exceptions: the science and life of William Bateson|url=https://archive.org/details/treasureyourexce00cock |url-access=limited |publisher=Springer|isbn=978-0-387-75687-5|page=[https://archive.org/details/treasureyourexce00cock/page/n265 248]}}</ref>

After the rediscovery of Mendel's work, scientists tried to determine which molecules in the cell were responsible for inheritance. In 1900, Nettie Stevens began studying the mealworm.<ref name="net">{{cite web |title=Nettie Stevens: A Discoverer of Sex Chromosomes |url=https://www.nature.com/scitable/topicpage/nettie-stevens-a-discoverer-of-sex-chromosomes-6580266/ |website=Scitable |publisher=Nature Education |access-date=8 June 2020}}</ref> Over the next 11 years, she discovered that females only had the X chromosome and males had both X and Y chromosomes.<ref name="net" /> She was able to conclude that sex is a chromosomal factor and is determined by the male.<ref name="net" /> In 1911, [[Thomas Hunt Morgan]] argued that genes are on [[chromosome]]s, based on observations of a sex-linked [[White (mutation)|white eye]] mutation in [[Drosophila melanogaster|fruit flies]].<ref>{{cite journal |doi=10.1093/icb/23.4.855 |title=Thomas Hunt Morgan – The Geneticist |year=1983 | vauthors = Moore JA |journal=Integrative and Comparative Biology |volume=23 |pages=855–865 |issue=4|doi-access= }}</ref> In 1913, his student [[Alfred Sturtevant]] used the phenomenon of [[genetic linkage]] to show that genes are arranged linearly on the chromosome.<ref>{{cite journal |vauthors=Sturtevant AH |year=1913 |title=The linear arrangement of six sex-linked factors in Drosophila, as shown by their mode of association |journal=Journal of Experimental Biology |volume=14 |issue=1 |pages=43–59 |url=http://www.esp.org/foundations/genetics/classical/holdings/s/ahs-13.pdf |doi=10.1002/jez.1400140104 |bibcode=1913JEZ....14...43S |url-status=live |archive-url=https://web.archive.org/web/20080227183131/http://www.esp.org/foundations/genetics/classical/holdings/s/ahs-13.pdf |archive-date=27 February 2008 |citeseerx=10.1.1.37.9595 |s2cid=82583173}}</ref>