Gonochorism#Evolution

{{wiktionary|gonochorism|gonochory|unisexualism}}

The term is derived from Greek gone 'generation' + chorizein 'to separate'.{{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 }} The term gonochorism originally came from German Gonochorismus.{{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 }}

Gonochorism is also referred to as unisexualism or gonochory.

{{Main|Evolution of sexual reproduction}}

{{For|evolution of dioecy in plants|Dioecy#Evolution of dioecy}}Gonochorism has evolved independently multiple times.{{cite journal |display-authors=6 |vauthors=Bachtrog D, Mank JE, Peichel CL, Kirkpatrick M, 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}} It is very evolutionarily stable in animals.{{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}} Its stability and advantages have received little attention.{{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 }}{{Rp|page=46}} Gonochorism owes its origin to the evolution of anisogamy,{{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 }} but it is unclear if the evolution of anisogamy first led to hermaphroditism or gonochorism.{{rp|213}}

Gonochorism is thought to be the ancestral state in polychaetes,{{Rp|page=126}} Hexacorallia,{{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 }}{{Rp|page=74}} nematodes,{{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 }}{{Rp|page=62}} and hermaphroditic fishes. Gonochorism is thought to be ancestral in hermaphroditic fishes because it is widespread in basal clades of fish and other vertebrate lineages.{{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}}

Two papers from 2008 have suggested that transitions between hermaphroditism and gonochorism or vice versa have occurred in animals between 10 and 20 times.{{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 |url-access=subscription }} In a 2017 study involving 165 taxon groups, more evolutionary transitions from gonochorism to hermaphroditism were found than the reverse.{{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}}

The term gonochorism is most often used for animal species, an estimated 95% of which are gonochoric.{{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}} It is very common in vertebrate species, 99% of which are gonochoric.{{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 }}{{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}} Ninety-eight percent of fishes are gonochoric.{{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 }} Mammals (including humans{{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 }}{{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 }}) and birds are solely gonochoric.{{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 }} Tardigrades are almost always gonochoric.{{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 }} Seventy-five percent of snails are gonochoric.{{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 }} Most arthropods including a majority of crustaceans are gonochoric.{{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}}{{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 }}

In animals, sex is most often genetically determined, but may be determined by other mechanisms. For example, alligators use temperature-dependent sex determination during egg incubation.

The term gonochorism is not usually applied to plants. Vascular plants which have single-sex individuals are called dioecious,{{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}} while bryophytes with single-sex individuals are dioicous.{{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}} In flowering plants, 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 flowers, and the three types may occur in different arrangements on the same or separate plants. Plant species can thus be hermaphrodite, monoecious, dioecious, trioecious, polygamomonoecious, polygamodioecious, andromonoecious, or gynomonoecious.

File:Schistosome_Parasite_SEM.jpg, 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 hollies and kiwifruit. In these plants the male plant that supplies the pollen is referred to as the pollenizer.

Gonochorism stands in contrast to other reproductive strategies such as asexual reproduction and hermaphroditism. Closely related taxa can have differing sexual strategies – for example, the genus Ophryotrocha contains species that are gonochoric and species that are hermaphrodites.{{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}}

The sex of an individual may also change during its lifetime{{snd}}this sequential hermaphroditism can, for example, be found in parrotfish{{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}}{{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}} and cockles.{{citation needed|date=November 2024}}

{{portal|Biology}}

• Diclinous
• Monoclinous
• Plant sexuality
• Gynogenesis

{{reflist|1=30em}}

Category:Reproduction

Category:Pollination

Category:Sexual system