Editing Hybrid (biology) (section)

===Genetics===
[[File:Gruppenweise artbildung unter spezieller berücksichtigung der gattung Oenothera (Taf. II) (7164908226).jpg|thumb|upright|''[[Oenothera lamarckiana]]'' is a permanent natural hybrid, studied intensively by the geneticist [[Hugo de Vries]]. Illustration by De Vries, 1913.]]

From the point of view of genetics, several different kinds of hybrid can be distinguished.<ref name="Rieger">{{cite book |last1=Rieger |first1=R. |last2=Michaelis |first2=A. |last3=Green |first3=M. M. |date=1991 |title=Glossary of Genetics: Classical and Molecular |edition=5th |publisher=Springer-Verlag |isbn=9780387520544 |page=[https://archive.org/details/glossaryofgeneti0000rieg/page/256 256] |url= https://archive.org/details/glossaryofgeneti0000rieg/page/256}}</ref><ref name="A2007">{{cite book |last=Allendorf |first=Fred |title=Conservation and the Genetics of Populations |date=2007 |publisher=Blackwell |page=534}}</ref>
A genetic hybrid carries two different [[allele]]s of the same [[gene]], where for instance one allele may code for a lighter coat colour than the other.<ref name="Rieger" /><ref name="A2007" /> A structural hybrid results from the fusion of [[gamete]]s that have differing structure in at least one chromosome, as a result of [[Chromosome abnormality#Structural abnormalities|structural abnormalities]].<ref name="Rieger" /><ref name="A2007" /> A numerical hybrid results from the fusion of gametes having different [[Ploidy|haploid numbers of chromosomes]].<ref name="Rieger" /><ref name="A2007" /> A permanent hybrid results when only the heterozygous [[genotype]] occurs, as in ''[[Oenothera lamarckiana]]'',<ref name="Sirks2013" /> because all homozygous combinations are lethal.<ref name="Rieger" /><ref name="A2007" /> In the early history of genetics, [[Hugo de Vries]] supposed these were [[Mutationism|caused by mutation]].<ref>{{cite book |last=De Vries |first=Hugo |author-link=Hugo de Vries |date=1901–1903 |title=Die mutationstheorie |volume=I and II |language=de |publisher=Von Veit |location=Leipzig}}</ref><ref>{{cite journal |last=de Vries |first=Hugo |author-link=Hugo de Vries |date=January 1919 |title=''Oenothera rubrinervis'': A Half Mutant |journal=Botanical Gazette |volume=67 |issue=1 |pages=1–26 |jstor=2468868 |doi=10.1086/332396 |s2cid=83752035 |url= https://zenodo.org/record/1431405 |access-date=23 August 2020 |archive-date=18 January 2021 |archive-url= https://web.archive.org/web/20210118204356/https://zenodo.org/record/1431405 |url-status=live}}</ref>