Examine individual changes

'{{Short description|State of having just one sex in any individual organism}} {{Distinguish|sexual dimorphism}} In [[biology]], '''gonochorism''' is a [[sexual system]] where there are two [[Sex|sexes]] and each individual organism is either [[male]] or [[female]].<ref>{{Cite book |url=https://www.oxfordreference.com/view/10.1093/acref/9780195307610.001.0001/acref-9780195307610-e-2626 |title=A Dictionary of Genetics |vauthors=King RC, Stansfield WD, Mulligan PK |date=2006-07-27 |publisher=Oxford University Press |isbn=978-0-19-976957-5 |pages=187 |language=en |chapter=Gonochorism |url-access=subscription |access-date=2021-06-11 |archive-date=2021-06-11 |archive-url=https://web.archive.org/web/20210611220101/https://www.oxfordreference.com/view/10.1093/acref/9780195307610.001.0001/acref-9780195307610-e-2626 |url-status=live }}</ref> The term gonochorism is usually applied in animal species, the vast majority of which are gonochoric.<ref name="Kliman2016">{{Cite book |url=https://books.google.com/books?id=_r4OCAAAQBAJ |title=Encyclopedia of Evolutionary Biology |vauthors=Kliman RM |date=2016 |publisher=Academic Press |isbn=978-0-12-800426-5 |veditors=Schärer L, Ramm S |volume=2 |chapter=Hermaphrodites |archive-url=https://web.archive.org/web/20240328080956/https://books.google.com/books?id=_r4OCAAAQBAJ |archive-date=2024-03-28 |access-date=2021-08-05 |url-status=bot: unknown }}</ref>{{rp|212–222}} Gonochorism contrasts with [[simultaneous hermaphroditism]] but it may be hard to tell if a species is gonochoric or [[Sequential hermaphroditism|sequentially hermaphroditic]] e.g. [[parrotfish]], ''[[Patella ferruginea]]''.<ref>{{Cite book |url=https://www.toddkshackelford.com/downloads/Holub-Shackelford-Gonochorism-EACB-2021.pdf |title=Encyclopedia of Animal Cognition and Behavior |vauthors=Holub AM, Shackelford TK |author-link2=Todd K. Shackelford |date=2020 |publisher=Springer International Publishing |isbn=978-3-319-47829-6 |veditors=Vonk J, Shackelford TK |location=Cham |pages=1–3 |language=en |chapter=Gonochorism |doi=10.1007/978-3-319-47829-6_305-1 |s2cid=240938739 |access-date=2021-05-02 |archive-date=2021-04-26 |archive-url=https://web.archive.org/web/20210426192450/https://www.toddkshackelford.com/downloads/Holub-Shackelford-Gonochorism-EACB-2021.pdf |url-status=live }}</ref> However, in gonochoric species individuals remain either male or female throughout their lives.<ref>{{Cite book |author-link=Stuart West |url=https://books.google.com/books?id=HeCZBO8J9IYC |title=Sex Allocation |vauthors=West S |date=2009-09-28 |publisher=Princeton University Press |isbn=978-1-4008-3201-9 |pages=1 |language=en}}</ref> Species that reproduce by [[Thelytokous|thelytokous parthenogenesis]] and do not have males can still be classified as gonochoric.<ref>{{Cite book |url=https://books.google.com/books?id=AKGsDwAAQBAJ&q=gonochoric+the+biology+of+reproduction |title=The Biology of Reproduction |vauthors=Fusco G, Minelli A |date=2019-10-10 |publisher=Cambridge University Press |isbn=978-1-108-49985-9 |pages=116–117 |language=en}}</ref>{{clarify|date=June 2021|reason=This needs an explanation for why this is the case. This claim may also need more research.}} ==Terminology == {{wiktionary|gonochorism|gonochory|unisexualism}} The term is derived from [[Greek language|Greek]] (''gone'', generation) + (''chorizein,'' to separate).<ref>{{Cite book |last=Winn |first=Philip |url=https://books.google.com/books?id=OEMSWCeeSPYC&dq=gonochorism+dictionary&pg=PA698 |title=Dictionary of Biological Psychology |date=2003-09-02 |publisher=Routledge |isbn=978-1-134-77815-7 |pages=698 |language=en |access-date=2021-11-30 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002313/https://books.google.com/books?id=OEMSWCeeSPYC&dq=gonochorism+dictionary&pg=PA698#v=onepage&q=gonochorism%20dictionary&f=false |url-status=live }}</ref> The term gonochorism originally came from German ''Gonochorismus''.<ref>{{Cite web |title=Definition of GONOCHORISM |url=https://www.merriam-webster.com/dictionary/gonochorism |access-date=2021-09-29 |website=www.merriam-webster.com |language=en |archive-date=2021-09-29 |archive-url=https://web.archive.org/web/20210929141705/https://www.merriam-webster.com/dictionary/gonochorism |url-status=live }}</ref> Gonochorism is also referred to as unisexualism or gonochory. == Evolution == {{Main|Evolution of sexual reproduction}} {{For|evolution of dioecy in plants|Dioecy#Evolution of dioecy}}Gonochorism has [[Convergent evolution|evolved independently]] multiple times.<ref name="Bachtrog-2014">{{cite journal |display-authors=6 |vauthors=Bachtrog D, [[Judith Mank | Mank JE]], Peichel CL, [[Mark Kirkpatrick | Kirkpatrick M]], [[Sarah Otto | Otto SP]], Ashman TL, Hahn MW, Kitano J, Mayrose I, Ming R, Perrin N, Ross L, Valenzuela N, Vamosi JC |date=July 2014 |title=Sex determination: why so many ways of doing it? |journal=PLOS Biology |volume=12 |issue=7 |pages=e1001899 |doi=10.1371/journal.pbio.1001899 |pmc=4077654 |pmid=24983465 |doi-access=free}}</ref> It is very evolutionarily stable in animals.<ref name="Leonard2016">{{Cite journal |last=Leonard |first=Janet L. |date=2013-10-01 |title=Williams' Paradox and the Role of Phenotypic Plasticity in Sexual Systems |journal=Integrative and Comparative Biology |volume=53 |issue=4 |pages=671–688 |doi=10.1093/icb/ict088 |issn=1540-7063 |pmid=23970358 |doi-access=free}}</ref> Its stability and advantages have received little attention.<ref>{{Cite book |url=https://books.google.com/books?id=0rWZDwAAQBAJ&q=sexual+system |title=Transitions Between Sexual Systems: Understanding the Mechanisms of, and Pathways Between, Dioecy, Hermaphroditism and Other Sexual Systems |vauthors=Leonard JL |date=2019-05-21 |publisher=Springer |isbn=978-3-319-94139-4 |language=en |access-date=2021-07-12 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002409/https://books.google.com/books?id=0rWZDwAAQBAJ&q=sexual+system#v=snippet&q=sexual%20system&f=false |url-status=live }}</ref>{{Rp|page=46}} Gonochorism owes its origin to the evolution of [[anisogamy]],<ref>{{Cite book |last=Barnes |first=R. S. K. |url=https://books.google.com/books?id=L_UETIhX2sAC&dq=gonochorism+evolution&pg=PA202 |title=An Introduction to Marine Ecology |last2=Hughes |first2=R. N. |date=1999-06-02 |publisher=John Wiley & Sons |isbn=978-0-86542-834-8 |pages=202 |language=en |access-date=2021-11-30 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002434/https://books.google.com/books?id=L_UETIhX2sAC&dq=gonochorism+evolution&pg=PA202#v=onepage&q=gonochorism%20evolution&f=false |url-status=live }}</ref> but it is unclear if the evolution of anisogamy first led to hermaphroditism or gonochorism.<ref name="Kliman2016" />{{rp|213}} Gonochorism is thought to be the ancestral state in [[Polychaete|polychaetes]],<ref name="Leonard2016" />{{Rp|page=126}} [[hexacorallia]],<ref>{{Cite book |last=Dubinsky |first=Zvy |url=https://books.google.com/books?id=4hI5XCcYzUgC&dq=gonochorism+ancestral&pg=PA74 |title=Coral Reefs: An Ecosystem in Transition |last2=Stambler |first2=Noga |date=2010-12-02 |publisher=Springer Science & Business Media |isbn=978-94-007-0114-4 |language=en |access-date=2022-07-27 |archive-date=2023-04-19 |archive-url=https://web.archive.org/web/20230419094504/https://books.google.com/books?id=4hI5XCcYzUgC&dq=gonochorism+ancestral&pg=PA74 |url-status=live }}</ref>{{Rp|page=74}} [[Nematode|nematodes]],<ref>{{Cite book |last=Schmidt-Rhaesa |first=Andreas |url=https://books.google.com/books?id=FJfoBQAAQBAJ&dq=gonochorism+evolved+independently+10+times&pg=PA62 |title=Nematoda |date=2013-12-18 |publisher=Walter de Gruyter |isbn=978-3-11-027425-7 |language=en |access-date=2022-07-27 |archive-date=2023-04-19 |archive-url=https://web.archive.org/web/20230419094458/https://books.google.com/books?id=FJfoBQAAQBAJ&dq=gonochorism+evolved+independently+10+times&pg=PA62 |url-status=live }}</ref>{{Rp|page=62}} and hermaphroditic [[Fish|fishes]]. Gonochorism is thought to be ancestral in hermaphroditic fishes because it is widespread in [[Basal (phylogenetics)|basal]] [[Clade|clades]] of fish and other vertebrate lineages.<ref>{{Cite journal |vauthors=Erisman BE, Petersen CW, Hastings PA, Warner RR |date=October 2013 |title=Phylogenetic perspectives on the evolution of functional hermaphroditism in teleost fishes |journal=Integrative and Comparative Biology |volume=53 |issue=4 |pages=736–54 |doi=10.1093/icb/ict077 |pmid=23817661 |doi-access=free}}</ref> Two papers from 2008 have suggested that transitions between hermaphroditism and gonochorism or vice versa have occurred in animals between 10 and 20 times.<ref>{{Cite journal |last=Weeks |first=Stephen C. |date=18 June 2012 |title=The Role of Androdioecy and Gynodioecy in Mediating Evolutionary Transitions Between Dioecy and Hermaphroditism in the Animalia |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2012.01714.x |journal=Evolution |language=en |volume=66 |issue=12 |pages=3670–3686 |doi=10.1111/j.1558-5646.2012.01714.x |pmid=23206127 |s2cid=3198554 |access-date=12 July 2022 |archive-date=15 June 2022 |archive-url=https://web.archive.org/web/20220615211222/https://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2012.01714.x |url-status=live }}</ref> In a 2017 study involving 165 taxon groups, more evolutionary transitions from gonochorism to hermaphroditism were found than the reverse.<ref>{{Cite journal |vauthors=Sasson DA, Ryan JF |date=December 2017 |title=A reconstruction of sexual modes throughout animal evolution |journal=BMC Evolutionary Biology |volume=17 |issue=1 |pages=242 |bibcode=2017BMCEE..17..242S |doi=10.1186/s12862-017-1071-3 |pmc=5717846 |pmid=29207942 |doi-access=free}}</ref> ==Use across species== === Animals === The term is most often used with animals, in which the species are usually gonochoric. Gonochorism has been estimated to occur in 95% of [[animal]] species.<ref>{{Cite journal |vauthors=Muyle A, Bachtrog D, Marais GA, Turner JM |date=June 2021 |title=Epigenetics drive the evolution of sex chromosomes in animals and plants |journal=Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences |volume=376 |issue=1826 |pages=20200124 |doi=10.1098/rstb.2020.0124 |pmc=8059572 |pmid=33866802}}</ref> It is very common in [[vertebrate]] species, 99% of which are gonochoric.<ref>{{Cite book |author-link=Michael Skinner (biologist) |title=Encyclopedia of Reproduction |vauthors=Skinner M |date=2018-06-29 |publisher=Academic Press |isbn=978-0-12-815145-7 |veditors=Pan Q, Guiguen Y, Herpin A |pages=168 |language=en |chapter=Evolution of Sex Determining Genes in Fish |chapter-url=https://books.google.com/books?id=m4RlDwAAQBAJ&pg=RA5-PA168 |access-date=2021-06-01 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002506/https://books.google.com/books?id=m4RlDwAAQBAJ&pg=RA5-PA168#v=onepage&q&f=false |url-status=live }}</ref><ref>{{Cite journal |vauthors=Kuwamura T, Sunobe T, Sakai Y, Kadota T, Sawada K |date=2020-07-01 |title=Hermaphroditism in fishes: an annotated list of species, phylogeny, and mating system |journal=Ichthyological Research |language=en |volume=67 |issue=3 |pages=341–360 |bibcode=2020IchtR..67..341K |doi=10.1007/s10228-020-00754-6 |issn=1616-3915 |doi-access=free}}</ref> 98% of fishes are gonochoric.<ref>{{Cite book |last=Pandian |first=T. J. |author-link=Thavamani Jegajothivel Pandian |url=https://books.google.com/books?id=eAjSBQAAQBAJ&dq=gonochorism+estimates&pg=PA8 |title=Sex Determination in Fish |date=2011-09-02 |publisher=CRC Press |isbn=978-1-4398-7919-1 |pages=8 |language=en |access-date=2021-11-30 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002517/https://books.google.com/books?id=eAjSBQAAQBAJ&dq=gonochorism+estimates&pg=PA8#v=onepage&q=gonochorism%20estimates&f=false |url-status=live }}</ref> [[Mammal|Mammals]] (including [[Human|humans]]<ref>{{Cite book |url=https://books.google.com/books?id=z4pXRaZAkdkC&q=humans+are+dioecious+genetics&pg=PA75 |title=Genetics: A Conceptual Approach |vauthors=Pierce BA |date=2012 |publisher=Macmillan |isbn=978-1-4292-3252-4 |pages=75 |language=en |access-date=2021-07-12 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002532/https://books.google.com/books?id=z4pXRaZAkdkC&q=humans+are+dioecious+genetics&pg=PA75#v=snippet&q=humans%20are%20dioecious%20genetics&f=false |url-status=live }}</ref><ref>{{Cite book |url=https://books.google.com/books?id=1VXX1jkhPH8C&q=humans+are+dioecious+biology&pg=PT57 |title=Human Evolutionary Biology |vauthors=Muehlenbein MP |date=2010-07-29 |publisher=Cambridge University Press |isbn=978-0-521-87948-4 |veditors=Jones J |pages=74 |language=en |access-date=2021-07-12 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002509/https://books.google.com/books?id=1VXX1jkhPH8C&q=humans+are+dioecious+biology&pg=PT57#v=snippet&q=humans%20are%20dioecious%20biology&f=false |url-status=live }}</ref>) and [[Bird|birds]] are solely gonochoric.<ref>{{Cite book |url=https://books.google.com/books?id=g4teDwAAQBAJ&q=mammal+gonochorism&pg=PA290 |title=Reproductive and Developmental Strategies: The Continuity of Life |vauthors=Kobayashi K, Kitano T, Iwao Y, Kondo M |date=June 2018 |publisher=Springer |isbn=978-4-431-56609-0 |pages=290 |language=en |access-date=2021-05-05 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002524/https://books.google.com/books?id=g4teDwAAQBAJ&q=mammal+gonochorism&pg=PA290#v=snippet&q=mammal%20gonochorism&f=false |url-status=live }}</ref> [[Tardigrade|Tardigrades]] are almost always gonochoric.<ref>{{Cite book |last=Thorp |first=James H. |url=https://books.google.com/books?id=iOI9ifbikoQC&dq=gonochorism+invertebrates&pg=PA468 |title=Ecology and Classification of North American Freshwater Invertebrates |last2=Covich |first2=Alan P. |date=2010 |publisher=Academic Press |isbn=978-0-12-374855-3 |pages=468 |language=en |access-date=2021-11-30 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002541/https://books.google.com/books?id=iOI9ifbikoQC&dq=gonochorism+invertebrates&pg=PA468#v=onepage&q=gonochorism%20invertebrates&f=false |url-status=live }}</ref> 75% of [[Snail|snails]] are gonochoric.<ref>{{Cite book |url=https://books.google.com/books?id=_r4OCAAAQBAJ&q=gonochorism+encyclopedia |title=Encyclopedia of Evolutionary Biology |date=2016-04-14 |publisher=Academic Press |isbn=978-0-12-800426-5 |volume=4 |pages=50 |language=en |access-date=2021-11-30 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002538/https://books.google.com/books?id=_r4OCAAAQBAJ&q=gonochorism+encyclopedia#v=snippet&q=gonochorism%20encyclopedia&f=false |url-status=live }}</ref> Most [[Arthropod|arthropods]] are gonochoric.<ref>{{Cite book |last=Giribet |first=Gonzalo |url=https://books.google.com/books?id=anetDwAAQBAJ&dq=gonochorism+invertebrates&pg=PA249 |title=The Invertebrate Tree of Life |last2=Edgecombe |first2=Gregory D. |date=2020-03-03 |publisher=Princeton University Press |isbn=978-0-691-19706-7 |pages=249 |language=en}}</ref> For example a majority of [[Crustacean|crustaceans]] are gonochoric.<ref>{{Cite book |last=Subramoniam |first=Thanumalaya |url=https://books.google.com/books?id=ztUCDAAAQBAJ&q=evolution+of+hermaphroditism |title=Sexual Biology and Reproduction in Crustaceans |date=2016-09-27 |publisher=Academic Press |isbn=978-0-12-809606-2 |pages=57–58 |language=en |access-date=2021-11-30 |archive-date=2024-04-17 |archive-url=https://web.archive.org/web/20240417002541/https://books.google.com/books?id=ztUCDAAAQBAJ&q=evolution+of+hermaphroditism#v=snippet&q=evolution%20of%20hermaphroditism&f=false |url-status=live }}</ref> In animals, sex is most often genetically determined, but may be determined by other mechanisms. For example, [[alligator]]s use [[temperature-dependent sex determination]] during egg incubation. === Plants === [[Plantae|Plants]] which have single-sex individuals are typically called [[dioecy|dioecious]] ([[vascular plants]])<ref>{{Cite book |last=Beentje |first=Henk |title=The Kew Plant Glossary |publisher=[[Royal Botanic Gardens, Kew]] |year=2016 |isbn=978-1-84246-604-9 |edition=2 |location=Richmond, Surrey}}</ref> or [[dioicy|dioicous]] ([[bryophyte]]s)<ref>{{Cite journal |last=Villarreal |first=Juan Carlos |last2=Renner |first2=Susanne S. |date=2013 |title=Correlates of monoicy and dioicy in hornworts, the apparent sister group to vascular plants |journal=BMC Evolutionary Biology |volume=13 |issue=1 |pages=239 |bibcode=2013BMCEE..13..239V |doi=10.1186/1471-2148-13-239 |pmc=4228369 |pmid=24180692 |doi-access=free}}</ref> instead of gonochoric. In [[flowering plant]]s, individual flowers may be hermaphroditic (i.e. with both stamens and ovaries) or dioecious (unisexual), having either no stamens (i.e. no male parts) or no ovaries (i.e. no female parts). Among flowering plants with unisexual flowers, some also produce [[Hermaphrodite#Plants|hermaphrodite]] flowers, and the three types may occur in different arrangements on the same or separate plants. Plant species can thus be hermaphrodite, [[Monoecious (botany)|monoecious]], [[Dioecy|dioecious]], [[Trioecy|trioecious]], [[polygamomonoecious]], [[polygamodioecious]], [[Andromonoecy|andromonoecious]], or [[Gynomonoecious (botany)|gynomonoecious]]. [[File:Schistosome_Parasite_SEM.jpg|right|thumb|Unlike most [[Platyhelminthes|flatworms]], [[Schistosoma|schistosomes]] are gonochoric. The narrow female can be seen emerging from the thicker male's gynecophoral canal below his ventral sucker.]] Examples of species with gonochoric or dioecious [[pollination]] include [[holly|hollies]] and [[kiwifruit]]. In these plants the male plant that supplies the [[pollen]] is referred to as the [[pollenizer]]. == Other reproductive strategies == Gonochorism stands in contrast to other [[reproductive strategy|reproductive strategies]] such as [[asexual reproduction]] and [[hermaphrodite|hermaphroditism]]. Closely related taxa can have differing sexual strategies – for example, the genus ''[[Ophryotrocha]]'' contains species that are gonochoric and species that are hermaphrodites.<ref>{{Cite journal |vauthors=Prevedelli D, N'Siala GM, Simonini R |date=January 2006 |title=Gonochorism vs. hermaphroditism: relationship between life history and fitness in three species of Ophryotrocha (Polychaeta: Dorvilleidae) with different forms of sexuality |journal=The Journal of Animal Ecology |volume=75 |issue=1 |pages=203–12 |bibcode=2006JAnEc..75..203P |doi=10.1111/j.1365-2656.2006.01040.x |pmid=16903057 |doi-access=free}}</ref> The sex of an individual may also change during its lifetime{{snd}}this [[sequential hermaphroditism]] can, for example, be found in [[parrotfish]]<ref>{{Cite web |title=Stoplight parrotfish |url=http://www.flmnh.ufl.edu/fish/Gallery/Descript/Sparrotfish/SParrotfish.html |url-status=dead |archive-url=https://web.archive.org/web/20091206221521/http://www.flmnh.ufl.edu:80/fish/Gallery/Descript/SParrotfish/SParrotfish.html |archive-date=6 December 2009 |access-date=15 December 2009 |website=Florida Museum of Natural History, Ichthyology Department |vauthors=Bester C}}</ref><ref>{{Cite journal |vauthors=Afonso P, Morato T, Santos RS |date=2008 |title=Spatial patterns in reproductive traits of the temperate parrotfish Sparisoma cretense. |journal=Fisheries Research |volume=90 |issue=1–3 |pages=92–99 |doi=10.1016/j.fishres.2007.09.029}}</ref> and [[Cockle (bivalve)|cockles]]. == See also == {{portal|Biology}} *[[Diclinous]] *[[Monoclinous]] *[[Plant sexuality]] == References == {{reflist|1=30em}} [[Category:Reproduction]] [[Category:Pollination]] [[Category:Sexual system]]'