Hermaphrodite#Plants

{{Short description|Sexually reproducing organism that produces both male and female gametes}}

{{Distinguish|Intersex{{!}}Intersex people|Intersex (biology)}}

A hermaphrodite ({{IPAc-en|h|ər|ˈ|m|æ|f|r|ə|ˌ|d|aɪ|t}}) is a sexually reproducing organism that produces both male and female gametes.{{Cite book| vauthors = Avise JC |url=https://books.google.com/books?id=jqiR8C0lEckC&q=Sex+is+defined+by+gametes&pg=PA1|title=Hermaphroditism: A Primer on the Biology, Ecology, and Evolution of Dual Sexuality|date=2011-03-18|publisher=Columbia University Press|isbn=978-0-231-52715-6|pages=1–7|language=en}} Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic.{{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|date=2020|publisher=Springer International Publishing|isbn=978-3-319-47829-6|veditors=Vonk J, Shackelford TK|place=Cham|pages=1–3|language=en|chapter=Gonochorism|doi=10.1007/978-3-319-47829-6_305-1|s2cid=240938739|author-link2=Todd K. Shackelford}}

The individuals of many taxonomic groups of animals, primarily invertebrates, are hermaphrodites, capable of producing viable gametes of both sexes. In the great majority of tunicates, mollusks, and earthworms, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male. Hermaphroditism is also found in some fish species, but is rare in other vertebrate groups. Most hermaphroditic species exhibit some degree of self-fertilization. The distribution of self-fertilization rates among animals is similar to that of plants, suggesting that similar pressures are operating to direct the evolution of selfing in animals and plants.{{cite journal | vauthors = Jarne P, Auld JR | title = Animals mix it up too: the distribution of self-fertilization among hermaphroditic animals | journal = Evolution; International Journal of Organic Evolution | volume = 60 | issue = 9 | pages = 1816–24 | date = September 2006 | pmid = 17089966 | doi = 10.1554/06-246.1 | s2cid = 23849389 }}

A rough estimate of the number of hermaphroditic animal species is 65,000, about 5% of all animal species, or 33% excluding insects. Insects are almost exclusively gonochoric.{{cite book| vauthors = Royer M |chapter=Hermaphroditism in Insects. Studies on Icerya purchasi |date=1975 | veditors = Reinboth R | title=Intersexuality in the Animal Kingdom |pages=135–145 |publisher=Springer |location=Berlin, Heidelberg |doi=10.1007/978-3-642-66069-6_14 |isbn=978-3-642-66071-9 }} There are no known hermaphroditic species among mammals{{Cite book| vauthors = Gorshkov V |url=https://books.google.com/books?id=xaO1BwAAQBAJ&q=No+cases+of+hermaphroditism+or+parthenogenesis+are+found+among+birds+and+mammals.&pg=PT165|title=Physical and Biological Bases of Life Stability: Man, Biota, Environment|date=2012-12-06|publisher=Springer Science & Business Media|isbn=978-3-642-85001-1|language=en}} or birds.{{cite journal|vauthors=Schärer L|date=February 2017|title=The varied ways of being male and female|journal=Molecular Reproduction and Development|volume=84|issue=2|pages=94–104|doi=10.1002/mrd.22775|pmid=28032683|quote=Of note, the otherwise well-studied insects, birds, and mammals are strikingly absent here—with not a single species among these groups showing hermaphroditism (for details on a supposedly hermaphroditic scale insect, however, see Gardner and Ross, 2011).|doi-access=free}}

About 94% of flowering plant species are either hermaphroditic (all flowers produce both male and female gametes) or monoecious, where both male and female flowers occur on the same plant. There are also mixed breeding systems, in both plants and animals, where hermaphrodite individuals coexist with males (called androdioecy) or with females (called gynodioecy), or all three exist in the same species (called trioecy). Sometimes, both male and hermaphrodite flowers occur on the same plant (andromonoecy) or both female and hermaphrodite flowers occur on the same plant (gynomonoecy).

Hermaphrodism is not to be confused with ovotesticular syndrome in mammals, which is a separate and unrelated phenomenon. While people with the condition were previously called "true hermaphrodites" in medical literature, this usage is now considered to be outdated as of 2006 and misleading,{{cite web| vauthors = Herndon A |title=Getting Rid of "Hermaphroditism" Once and For All|url=http://www.isna.org/node/979|url-status=live|archive-url=https://web.archive.org/web/20110927013509/http://www.isna.org/node/979|archive-date=27 September 2011|access-date=2 October 2011|publisher=Intersex Society of North America}}{{Cite web |title=Is a person who is intersex a hermaphrodite? |url=https://isna.org/faq/hermaphrodite/ |access-date=2024-01-20 |website=Intersex Society of North America |quote=The mythological term “hermaphrodite” implies that a person is both fully male and fully female. This is a physiologic impossibility. The words “hermaphrodite” and “pseudo-hermaphrodite” are stigmatizing and misleading words.}} as people with ovotesticular syndrome do not have functional sets of both male and female organs.{{Citation| vauthors = Rosenfield KA |title=Hermaphrodite |date=2018 |encyclopedia=Encyclopedia of Animal Cognition and Behavior|pages=1–2| veditors = Vonk J, Shackelford T |place=Cham |publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-47829-6_329-1|isbn=978-3-319-47829-6 }}{{Cite book |url=https://books.google.com/books?id=bLhcDwAAQBAJ&q=term+hermaphrodite+misleading+biology+of+sex&pg=PA309 |title=Biology of Sex |vauthors=Mills A |date=2018-01-01 |publisher=University of Toronto Press |isbn=978-1-4875-9337-7 |pages=309 |language=en |quote=In the past, the term hermaphrodite was widely applied in such cases, but humans are not hermaphroditic. In a truly hermaphroditic species, individuals have functional sets of male and female organs.}}

Etymology

The term hermaphrodite derives from the {{langx|la|hermaphroditus}}, from {{langx|grc|ἑρμαφρόδιτος|hermaphroditos}},{{cite web|title=Definition of hermaphroditus|publisher=Numen: The Latin Lexicon|url=http://latinlexicon.org/definition.php?p1=2025388|access-date=19 July 2013|url-status=live|archive-url=https://web.archive.org/web/20141106082854/http://latinlexicon.org/definition.php?p1=2025388|archive-date=6 November 2014}} which derives from Hermaphroditus (Ἑρμαφρόδιτος), the son of Hermes and Aphrodite in Greek mythology. According to Ovid, he fused with the nymph Salmacis resulting in one individual possessing physical traits of male and female sexes.Ovid, Metamorphoses, Book IV: The story of Hermaphroditus and Salmacis. According to the earlier Diodorus Siculus, he was born with a physical body combining male and female sexes.{{cite book | url=https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Diodorus_Siculus/4A*.html#6.5|title= The Library of History of Diodorus Siculus | volume = IV | chapter = Chapters 1–7 | page = 361 | via = penelope.uchicago.edu}} The word hermaphrodite entered the English lexicon as early as the late fourteenth century.{{cite web|title= Hermaphrodite | work = Online Etymology Dictionary|url=http://www.etymonline.com/index.php?term=hermaphrodite|access-date=3 June 2012|url-status=live|archive-url=https://web.archive.org/web/20131105230942/http://www.etymonline.com/index.php?term=hermaphrodite|archive-date=5 November 2013}}

Animals

=Sequential hermaphrodites=

File:Crepidula fornicata.JPG (common slipper shell)]]

File:Ocellaris clownfish.JPG are initially male; the largest fish in a group becomes a female.]]File:Parrotfish Timor.jpg start life as females and later change into males.]]

Sequential hermaphrodites (dichogamy) occur in species in which the individual first develops as one sex, but can later change into the opposite sex.{{cite book |title=Animal behavior desk reference: a dictionary of animal behavior, ecology, and evolution |url=https://archive.org/details/animalbehaviorde00barr_955 |url-access=limited | vauthors = Barrows EM |edition=2nd |year=2001 |publisher=CRC Press |location= Boca Raton, Fla|isbn=978-0-8493-2005-7|oclc=299866547 |page= [https://archive.org/details/animalbehaviorde00barr_955/page/n329 317]}} (Definitions differ on whether sequential hermaphroditism encompasses serial hermaphroditism; for authors who exclude serial hermaphroditism, a sequential hermaphrodite is also stipulated to only change sex once.{{cite book|url=https://books.google.com/books?id=eAjSBQAAQBAJ&pg=PA164|title=Sex Determination in Fish | vauthors = Pandian TJ |date=2 September 2011|publisher=CRC Press|via=Google Books|url-status=live|archive-url=https://web.archive.org/web/20171107033127/https://books.google.co.uk/books?id=eAjSBQAAQBAJ&pg=PA164|archive-date=7 November 2017|isbn=978-1-4398-7919-1}}) This contrasts with simultaneous hermaphrodites, in which an individual possesses fully functional male and female genitalia. Sequential hermaphroditism is common in fish (particularly teleost fish) and many gastropods (such as the common slipper shell). Sequential hermaphroditism can best be understood in terms of behavioral ecology and evolutionary life history theory, as described in the size-advantage mode{{cite journal | vauthors = Warner RR | title = Sex change and the size-advantage model | journal = Trends in Ecology & Evolution | volume = 3 | issue = 6 | pages = 133–6 | date = June 1988 | pmid = 21227182 | doi = 10.1016/0169-5347(88)90176-0 | bibcode = 1988TEcoE...3..133W }} first proposed by Michael T. Ghiselin{{cite journal | vauthors = Ghiselin MT | title = The evolution of hermaphroditism among animals | journal = The Quarterly Review of Biology | volume = 44 | issue = 2 | pages = 189–208 | date = June 1969 | pmid = 4901396 | doi = 10.1086/406066 | s2cid = 38139187 }} which states that if an individual of a certain sex could significantly increase its reproductive success after reaching a certain size, it would be to their advantage to switch to that sex.

Sequential hermaphrodites can be divided into three broad categories:

Protandry: Where an organism develops as a male, and then changes sex to a female.
Example: The clownfish (genus Amphiprion) are colorful reef fish found living in symbiosis with sea anemones. Generally one anemone contains a 'harem', consisting of a large female, a smaller reproductive male, and even smaller non-reproductive males. If the female is removed, the reproductive male will change sex and the largest of the non-reproductive males will mature and become reproductive. It has been shown that fishing pressure can change when the switch from male to female occurs, since fishermen usually prefer to catch the larger fish. The populations are generally changing sex at a smaller size, due to natural selection.
Protogyny: Where the organism develops as a female, and then changes sex to a male.
Example: Wrasses (Family Labridae) are a group of reef fish in which protogyny is common. Wrasses also have an uncommon life history strategy, which is termed diandry (literally, two males). In these species, two male morphs exists: an initial phase male and a terminal phase male. Initial phase males do not look like males and spawn in groups with females. They are not territorial. They are, perhaps, female mimics (which is why they are found swimming in group with females). Terminal phase males are territorial and have a distinctively bright coloration.{{Cite book | vauthors = Bagemihl B |title=Biological exuberance : animal homosexuality and natural diversity |publisher=St. Martin's Press |year=1999 |isbn=978-0-312-25377-6 |edition=2nd |location=New York}} Individuals are born as males or females, but if they are born males, they are not born as terminal phase males. Females and initial phase males can become terminal phase males. Usually, the most dominant female or initial phase male replaces any terminal phase male when those males die or abandon the group.
Bidirectional sex changers: Where an organism has female and male reproductive organs, but may act either as a female or as a male during different stages in life.
Example: Lythrypnus dalli (Family Lythrypnus) are a group of coral reef fish in which bidirectional sex change occurs. Once a social hierarchy is established a fish changes sex according to its social status, regardless of the initial sex, based on a simple principle: if the fish expresses subordinate behavior then it changes its sex to female, and if the fish expresses dominant or non-dominant superior behavior then it changes its sex to male.{{cite journal| vauthors = Rodgers EW, Early RL, Grober MA |title=Social status determines sexual phenotype in the bi-directional sex changing bluebanded goby Lythrypnus dalli|journal=J Fish Biol|year=2007|volume=70|issue=6|pages=1660–1668|doi=10.1111/j.1095-8649.2007.01427.x|bibcode=2007JFBio..70.1660R }}

Dichogamy can have both conservation-related implications for humans, as mentioned above, as well as economic implications. For instance, groupers are favoured fish for eating in many Asian countries and are often aquacultured. Since the adults take several years to change from female to male, the broodstock are extremely valuable individuals.

=Simultaneous hermaphrodites=

File:Mating Pseudobiceros bedfordi.pngns mating by penis fencing. Each has two penises on the undersides of their heads which they use to inject sperm.]]File:Mating earthworms.jpgs are simultaneous hermaphrodites, having both male and female reproductive organs.]]

Simultaneous hermaphrodites (or homogamous hermaphrodites) are individuals in which both male and female sexual organs are present and functional at the same time. Self-fertilization often occurs.

Pulmonate land snails and land slugs are perhaps the best-known kinds of simultaneous hermaphrodites, and are the most widespread of terrestrial animals possessing this sexual polymorphism. Sexual material is exchanged between both animals via spermatophores, and is then stored in the spermatheca. After exchange of spermatozoa, both animals will lay fertilized eggs after a period of gestation. The eggs will proceed to hatch after a development period. Snails typically reproduce from early spring through late autumn.{{cite journal | vauthors = Janssen R, Baur B | title = Seasonal effects on egg production and level of paternity in a natural population of a simultaneous hermaphrodite snail | journal = Ecology and Evolution | volume = 5 | issue = 14 | pages = 2916–28 | date = July 2015 | pmid = 26306176 | pmc = 4541995 | doi = 10.1002/ece3.1560 | bibcode = 2015EcoEv...5.2916J }}
Banana slugs are an example of a hermaphroditic gastropod. Mating with a partner is more desirable biologically than self-fertilization, as the genetic material of the resultant offspring is varied, but if mating with a partner is not possible, self-fertilization is practiced. The male sexual organ of an adult banana slug is quite large in proportion to its size, as well as compared to the female organ. It is possible for banana slugs, while mating, to become stuck together. If a substantial amount of wiggling fails to separate them, the male organ will be bitten off (using the slug's radula), see apophallation. If a banana slug has lost its male sexual organ, it can still mate as a female, making hermaphroditism a valuable adaptation.{{cite journal| vauthors = Leonard JL, Pearse JS, Harper AB |title=Comparative reproductive biology of Ariolimax californicus and A. dolichophallus (Gastropoda; Stylommiatophora)|journal=Invertebrate Reproduction & Development|date=2002|volume=41|issue=1–3|pages=83–93|doi=10.1080/07924259.2002.9652738|bibcode=2002InvRD..41...83L |s2cid=83829239}}
The species of colourful sea slugs Goniobranchus reticulatus is hermaphroditic, with both male and female organs active at the same time during copulation. After mating, the external portion of the penis detaches, but is able to regrow within 24 hours.{{cite news | url = https://www.bbc.co.uk/news/science-environment-21431678 | title = Sea slug's 'disposable penis' surprises | author = Morelle R | author-link=Rebecca Morelle |date = 12 February 2013 | work=BBC News}}{{cite journal | vauthors = Sekizawa A, Seki S, Tokuzato M, Shiga S, Nakashima Y | title = Disposable penis and its replenishment in a simultaneous hermaphrodite | journal = Biology Letters | volume = 9 | issue = 2 | pages = 20121150 | date = April 2013 | pmid = 23407499 | pmc = 3639767 | doi = 10.1098/rsbl.2012.1150 }}
Earthworms are another example of a simultaneous hermaphrodite. Although they possess ovaries and testes, they have a protective mechanism against self-fertilization. Sexual reproduction occurs when two worms meet and exchange gametes, copulating on damp nights during warm seasons.
The free-living hermaphroditic nematode Caenorhabditis elegans reproduces primarily by self-fertilization, but infrequent out-crossing events occur at a rate of approximately 1%.{{cite journal | vauthors = Barrière A, Félix MA | title = High local genetic diversity and low outcrossing rate in Caenorhabditis elegans natural populations | journal = Current Biology | volume = 15 | issue = 13 | pages = 1176–84 | date = July 2005 | pmid = 16005289 | doi = 10.1016/j.cub.2005.06.022 | arxiv = q-bio/0508003 | s2cid = 2229622 | bibcode = 2005CBio...15.1176B }}
Hamlets do not practice self-fertilization, but a pair will mate multiple times over several nights, taking turns between which one acts as the male and which acts as the female.{{Cite book| vauthors = Russell PJ, Hertz PE, McMillan B |chapter-url=https://books.google.com/books?id=bLgaCgAAQBAJ&q=simultaneous+hermaphroditism+mammals&pg=PT1192|title=Biology: The Dynamic Science|date=2016-01-01|publisher=Cengage Learning|isbn=978-1-305-85610-3|pages=1151|language=en|chapter=Animal Reproduction}}{{Failed verification|date=June 2021}}
The mangrove killifish (Kryptolebias marmoratus) are simultaneous hermaphrodites, producing both eggs and sperm and routinely reproducing by self-fertilization. Each individual normally fertilizes itself when an egg and sperm produced by an internal organ unite inside the fish's body.{{cite journal | vauthors = Sakakura Y, Soyano K, Noakes D, Hagiwara A |date=2006 |title=Gonadal morphology in the self-fertilizing mangrove killifish, Kryptolebias marmoratus |journal=Ichthyological Research |volume=53 |issue=4 |pages=427–430 |doi=10.1007/s10228-006-0362-2 |bibcode=2006IchtR..53..427S |hdl=10069/35713 |s2cid=9474211 |hdl-access=free }} This species is also regarded as the only known vertebrate species that can reproduce by self fertilization.{{cite journal | vauthors = Kanamori A, Yamamura A, Koshiba S, Lee JS, Orlando EF, Hori H | title = Methyltestosterone efficiently induces male development in the self-fertilizing hermaphrodite fish, Kryptolebias marmoratus | journal = Genesis | volume = 44 | issue = 10 | pages = 495–503 | date = October 2006 | pmid = 17029221 | doi = 10.1002/dvg.20240 | s2cid = 13639701 }}

=Pseudohermaphroditism=

When spotted hyenas were first scientifically observed by explorers, they were thought to be hermaphrodites. Early observations of wild spotted hyenas led researchers to believe that all spotted hyenas, male or female, were born with what looked to be a penis. A female spotted hyena's apparent penis is in fact an enlarged clitoris, which contains an external birth canal.{{cite web|url=http://www.livescience.com/699-painful-realities-hyena-sex.html|title=The Painful Realities of Hyena Sex|website=Live Science|date=26 April 2006|url-status=live|archive-url=https://web.archive.org/web/20121119124756/http://www.livescience.com/699-painful-realities-hyena-sex.html|archive-date=2012-11-19}}{{cite web|url=http://www.eurekalert.org/multimedia/pub/716.php|title=Hyena Graphic|website=EurekAlert!|url-status=dead|archive-url=https://web.archive.org/web/20110310230213/http://www.eurekalert.org/multimedia/pub/716.php|archive-date=2011-03-10|access-date=2011-03-20}} It can be difficult to determine the sex of spotted hyenas until sexual maturity, when they may become pregnant. When a female spotted hyena gives birth, she passes the cub through the cervix internally, but then passes it out through the elongated clitoris.{{cite web|url=http://www.bellaonline.com/articles/art27509.asp|title=Hermaphrodite Hyenas?|url-status=dead|archive-url=https://web.archive.org/web/20101123173312/http://www.bellaonline.com/articles/art27509.asp|archive-date=2010-11-23|access-date=2011-03-19}}

Plants

{{Main|Sexual reproduction in plants|Plant reproductive morphology#Bisexual|Monoicy}}

File:Hylocereus undatus 1.jpg, a hermaphrodite plant with perfect flowers that have both functional carpels and stamens.]]

The term hermaphrodite is used in botany to describe, for example, a perfect flower that has both staminate (male, pollen-producing) and carpellate (female, ovule-producing) parts. The overwhelming majority of flowering plant species are hermaphroditic.{{Cite book| vauthors = Soni NK |url=https://books.google.com/books?id=RvBe_bCQAukC&q=hermaphrodite+or+bisexual+flower&pg=PA87|title=Fundamentals of Botany|date=2010-04-01|publisher=Tata McGraw-Hill Education|isbn=978-0-07-068177-4|pages=87|language=en}}

= Monoecy =

Flowering plant species with separate, imperfect, male and female flowers on the same individual are called monoecious. Monoecy only occurs in about 7% of flowering plant species.{{cite web | vauthors = Molnar S |title= Plant Reproductive Systems|url= http://www.geocities.com/we_evolve/Plants/breeding_sys.html|date= 17 February 2004|work= Evolution and the Origins of Life|publisher= Geocities.com |access-date=12 September 2009 |archive-url=https://web.archive.org/web/20091022174814/http://geocities.com/we_evolve/Plants/breeding_sys.html |archive-date=2009-10-22}} Monoecious plants are often referred to as hermaphroditic because they produce both male and female gametes. However, the individual flowers are not hermaphroditic if they only produce gametes of one sex.{{Cite book| vauthors = Glover B |url=https://books.google.com/books?id=uXMVDAAAQBAJ&q=Monoecy&pg=PA139|title=Understanding Flowers and Flowering | edition = Second|date=February 2014|publisher=Oxford University Press|isbn=978-0-19-966159-6|pages=138–139|language=en}} 65% of gymnosperm species are dioecious, but conifers are almost all monoecious.{{cite journal| vauthors = Walas Ł, Mandryk W, Thomas PA, Tyrała-Wierucka Ż, Iszkuło G |date=2018|title=Sexual systems in gymnosperms: A review|journal=Basic and Applied Ecology|volume=31|pages=1–9|doi=10.1016/j.baae.2018.05.009|bibcode=2018BApEc..31....1W |s2cid=90740232|url=http://keele-repository.worktribe.com/previewfile/457433/29052018_1-s2.0-S1439179117304498-main.pdf}} Some plants can change their sex throughout their lifetime, a phenomenon called sequential hermaphroditism.{{citation needed|date=July 2021}}

= Andromonoecy =

In andromonoecious species, the plants produce perfect (hermaphrodite) flowers and separate fertile male flowers that are sterile as female.{{Cite book|url=https://books.google.com/books?id=AKGsDwAAQBAJ&q=The+Biology+of+Reproduction+PAGE+112|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=111–113|language=en|author-link2=Alessandro Minelli (biologist)|access-date=29 March 2021|archive-url=https://web.archive.org/web/20210401100101/https://books.google.com/books?id=AKGsDwAAQBAJ&newbks=0&printsec=frontcover&dq=The+Biology+of+Reproduction+PAGE+112&hl=en|archive-date=1 April 2021|url-status=live}}{{cite journal | vauthors = Kouonon LC, Jacquemart AL, Bi AI, Bertin P, Baudoin JP, Dje Y | title = Reproductive biology of the andromonoecious Cucumis melo subsp. agrestis (Cucurbitaceae) | journal = Annals of Botany | volume = 104 | issue = 6 | pages = 1129–39 | date = November 2009 | pmid = 19671577 | pmc = 2766191 | doi = 10.1093/aob/mcp196 }} Andromonoecy occurs in about 4000 species of flowering plants (2% of flowering plants).{{cite journal | vauthors = Vallejo-Marín M, Rausher MD | title = The role of male flowers in andromonoecious species: energetic costs and siring success in Solanum carolinense L | journal = Evolution; International Journal of Organic Evolution | volume = 61 | issue = 2 | pages = 404–12 | date = February 2007 | pmid = 17348949 | doi = 10.1111/j.1558-5646.2007.00031.x | s2cid = 781464 }}

= Gynomonoecy =

In gynomonoecious species, the plants produce hermaphrodite flowers and separate male-sterile pistillate flowers. One example is the meadow saxifrage, Saxifraga granulata.{{cite journal | vauthors = Stevens D, Richards A |date=1985 |title=Gynodioecy in Saxifraga granulata L. |journal=Plant Systematics and Evolution |volume=151 |pages=43–54 |doi=10.1007/BF02418018 |s2cid=21632274 }} Charles Darwin gave several other examples in his 1877 book "The Different Forms of Flowers on Plants of the Same Species".{{cite book | vauthors = Charles D |date=1877 |title=The different forms of flowers on plants of the same species |publisher=John Murray |location =London }}

About 57% of moss species and 68% of liverworts are unisexual, meaning that their gametophytes produce either male or female gametes, but not both.{{cite book | veditors = Shaw AJ, Goffinet B | title = Bryophyte biology | vauthors = Shaw AJ, Goffinet B |date=2000 |chapter= Chapter 12: Population ecology, population genetics, and microevolution |pages=369–402 |publisher=Cambridge University Press |location=Cambridge, UK |isbn=978-0-521-66794-4 }}{{rp|377}}

Sequential hermaphroditism is common in bryophytes and some vascular plants.{{citation needed|date=April 2023}}

Use regarding humans

File:Hermaphroditus lady lever.jpg, the "son" of the Greek god Hermes and the goddess Aphrodite, origin of the word "hermaphrodite"]]

File:Fertilityobandojf.JPG in the Philippines, before becoming a Catholic festival, was initially an Anitist ritual dedicated to the hermaphrodite deity, Lakapati, who presided over fertility.{{Cite web|url=https://www.aswangproject.com/lakapati-the-transgender-tagalog-deity/|title=LAKAPATI: The "Transgender" Tagalog Deity? Not so fast…|website=THE ASWANG PROJECT|date=29 November 2018|language=en-US|access-date=2019-07-03}}]]

File:Nadar - "Hermaphrodite" (Seventh Gallica image).jpg of a person displaying ambiguous genitalia, one of a nine-part series. The series may be the earliest medical photographic documentation of an intersex person.{{cite journal | vauthors = Schultheiss D, Herrmann TR, Jonas U | title = Early photo-illustration of a hermaphrodite by the French photographer and artist Nadar in 1860 | journal = The Journal of Sexual Medicine | volume = 3 | issue = 2 | pages = 355–60 | date = March 2006 | pmid = 16490032 | doi = 10.1111/j.1743-6109.2005.00157.x }} {{subscription required}}

{{rp|358}}]]

Historically, the term hermaphrodite was used in law to refer to people whose sex was in doubt. The 12th-century {{lang|la|Decretum Gratiani}} states that "Whether an hermaphrodite may witness a testament, depends on which sex prevails" ("Hermafroditus an ad testamentum adhiberi possit, qualitas sexus incalescentis ostendit.").Decretum Gratiani, C. 4, q. 2 et 3, c. 3{{cite web | url = http://geschichte.digitale-sammlungen.de/decretum-gratiani/kapitel/dc_chapter_1_1585 | title = Decretum Gratiani (Kirchenrechtssammlung) | work = Bayerische StaatsBibliothek (Bavarian State Library) | date = February 5, 2009 | url-status=live | archive-url = https://web.archive.org/web/20161220084841/http://geschichte.digitale-sammlungen.de/decretum-gratiani/kapitel/dc_chapter_1_1585 | archive-date = December 20, 2016 }}

Alexander ab Alexandro (1461–1523) stated, using the term hermaphrodite, that the people who bore the sexes of both man and woman were regarded by the Athenians and the Romans as monsters, and thrown into the sea at Athens and into the Tiber at Rome.{{Cite journal| vauthors = chevalier de Jaucourt L |title=Hermaphrodite |journal = Encyclopedia of Diderot & d'Alembert |volume=8 |pages=165–167 |date=1765 |url=http://quod.lib.umich.edu/d/did/did2222.0000.208/--hermaphrodite?rgn=main;view=fulltext;q1=hair|access-date=13 April 2023 }} Similarly, the 17th-century English jurist and judge Edward Coke (Lord Coke), wrote in his Institutes of the Lawes of England on laws of succession stating, "Every heire is either a male, a female, or an hermaphrodite, that is both male and female. And an hermaphrodite (which is also called Androgynus) shall be heire, either as male or female, according to that kind of sexe which doth prevaile."{{cite book | vauthors = Coke E | title = The First Part of the Institutes of the Laws of England, Institutes 8.a. | edition = 1st Am. | date = 1812 }}{{Cite journal| volume = 41| vauthors = Greenberg J | title = Defining Male and Female: Intersexuality and the Collision Between Law and Biology| journal = Arizona Law Review| date = 1999| ssrn = 896307|pages = 277–278}}

During the Victorian era, medical authors attempted to ascertain whether or not humans could be hermaphrodites, adopting a precise biological definition to the term.{{Cite book| publisher = Johns Hopkins University Press| isbn = 978-0-8018-9155-7| vauthors = Reis E | title = Bodies in Doubt: an American History of Intersex| location = Baltimore| pages = 55–81| date = 2009}} From that period until the early 21st century, individuals with ovotesticular syndrome were termed true hermaphrodites if their gonadal tissue contained both testicular and ovarian tissue, and pseudohermaphrodites if their external appearance (phenotype) differed from sex expected from internal gonads. This language has fallen out of favor due to misconceptions and stigma associated with the terms,{{cite journal | vauthors = Dreger AD, Chase C, Sousa A, Gruppuso PA, Frader J | title = Changing the nomenclature/taxonomy for intersex: a scientific and clinical rationale | journal = Journal of Pediatric Endocrinology & Metabolism | volume = 18 | issue = 8 | pages = 729–733 | date = August 2005 | pmid = 16200837 | doi = 10.1515/JPEM.2005.18.8.729 | url = http://www.aissg.org/PDFs/Dreger-Nomenclature-2005.PDF | access-date = 27 July 2016 | url-status = dead | s2cid = 39459050 | archive-url = https://web.archive.org/web/20161220154642/http://www.aissg.org/PDFs/Dreger-Nomenclature-2005.PDF | archive-date = 20 December 2016 }}{{cite journal | vauthors = Vilain E, Achermann JC, Eugster EA, Harley VR, Morel Y, Wilson JD, Hiort O | title = We used to call them hermaphrodites | journal = Genetics in Medicine | volume = 9 | issue = 2 | pages = 65–66 | date = February 2007 | pmid = 17304046 | doi = 10.1097/GIM.0b013e31802cffcf | quote = use of the words “hermaphrodite,” “pseudohermaphrodite,” and “intersex” should be abandoned, as they either are confusing or have a negative social connotation that may be perceived as harmful by some patients and parents. | doi-access = free }} and a shift to nomenclature based on genetics.

The term "intersex" described a wide variety of combinations of what are ambiguous biological characteristics. Intersex biology may include, for example, ambiguous-looking external genitalia, karyotypes that include mixed XX and XY chromosome pairs (46XX/46XY, 46XX/47XXY or 45X/XY mosaic). Clinically, medicine currently uses the terminology "disorders of sex development" {{Cite journal|url=http://www.emeraldinsight.com/books.htm?chapterid=1943090 | vauthors = Georgiann D |author-link=Georgiann Davis| date =2011|title =DSD is a Perfectly Fine Term": Reasserting Medical Authority through a Shift in Intersex Terminology | veditors = McGann PJ, Hutson DJ |journal=Sociology of Diagnosis (Advances in Medical Sociology)|series=Advances in Medical Sociology |volume =12|pages=155–182|doi=10.1108/S1057-6290(2011)0000012012 |isbn=978-0-85724-575-5 |url-access=subscription }} (also known as variations in sex characteristics.){{Cite web |title=Information about the standard for gender, sex, and variations of sex characteristics {{!}} Stats NZ |url=https://www.stats.govt.nz/methods/information-about-the-standard-for-gender-sex-and-variations-of-sex-characteristics |access-date=2024-03-12 |website=www.stats.govt.nz}} This is particularly significant because of the relationship between medical terminology and medical intervention.{{Citation|title=Darlington Statement|date=March 2017|url=https://oii.org.au/darlington-statement/|archive-url=https://web.archive.org/web/20170322204013/https://oii.org.au/darlington-statement/|access-date=March 21, 2017|archive-date=2017-03-22|author1-link=Androgen Insensitivity Syndrome Support Group Australia|author2-link=Intersex Trust Aotearoa New Zealand|author3-link=Organisation Intersex International Australia|author6-link=Tony Briffa (politician)|author7-link=Morgan Carpenter|vauthors=((Androgen Insensitivity Support Syndrome Support Group Australia)), ((Intersex Trust Aotearoa New Zealand)), ((Organisation Intersex International Australia)), Black E, Bond K, Briffa T, Carpenter M, Morgan, Cody C, David A, Driver B, Hannaford C, Harlow E, Hart B, Hart P, Leckey D, Lum S, Mitchell MB, Nyhuis E, O'Callaghan B, Perrin S, Smith C, Williams T, Yang I, Yovanovic|author17-link=Mani Mitchell|first24=Georgie|author14-link=Phoebe Hart|author13-link=Bonnie Hart|url-status=dead}}

Intersex civil society organizations, and many human rights institutions,{{Citation | author1 = UN Committee against Torture | author1-link = United Nations Convention against Torture#Committee against Torture | author2 = UN Committee on the Rights of the Child | author2-link = Committee on the Rights of the Child | author3 = UN Committee on the Rights of People with Disabilities | author3-link = Committee on the Rights of Persons with Disabilities | author4 = UN Subcommittee on Prevention of Torture and other Cruel, Inhuman or Degrading Treatment or Punishment | author5 = Méndez J | author5-link = Juan E. Méndez | author6 = Pῡras D | author7 = Šimonoviæ D | author8 = Santos Pais M | author9 = African Commission on Human and Peoples' Rights | author9-link = African Commission on Human and Peoples' Rights | author10 = Council of Europe Commissioner for Human Rights | author10-link = Commissioner for Human Rights | author11 = Inter-American Commission on Human Rights | author11-link = Inter-American Commission on Human Rights | work = Office of the High Commissioner for Human Rights | title = Intersex Awareness Day – Wednesday 26 October. End violence and harmful medical practices on intersex children and adults, UN and regional experts urge | date = October 24, 2016 | url = http://www.ohchr.org/EN/NewsEvents/Pages/DisplayNews.aspx?NewsID=20739&LangID=E | url-status = live | archive-url = https://web.archive.org/web/20161121185256/http://ohchr.org/EN/NewsEvents/Pages/DisplayNews.aspx?NewsID=20739&LangID=E | archive-date = November 21, 2016 }}{{Citation| author1 = Council of Europe| author2 = Commissioner for Human Rights| author1-link = Council of Europe| author2-link = Commissioner for Human Rights| title = Human rights and intersex people, Issue Paper| date = April 2015| url = https://wcd.coe.int/ViewDoc.jsp?Ref=CommDH/IssuePaper(2015)1&Language=lanEnglish&Ver=original| url-status = dead| archive-url = https://web.archive.org/web/20160106203349/https://wcd.coe.int/ViewDoc.jsp?Ref=CommDH%2FIssuePaper%282015%291&Language=lanEnglish&Ver=original| archive-date = 2016-01-06| access-date = 2018-06-10}} have criticized medical interventions designed to make bodies more typically male or female.

In some cases, variations in sex characteristics are caused by unusual levels of sex hormones, which may be the result of an atypical set of sex chromosomes.{{medical citation needed|date=July 2023}} One common cause of variations in sex characteristics traits is the crossing over of the testis-determining factor (SRY) from the Y chromosome to the X chromosome during meiosis. The SRY is then activated in only certain areas, causing development of testes in some areas by beginning a series of events starting with the upregulation of the transcription factor (SOX9), and in other areas not being active (causing the growth of ovarian tissues). Thus, testicular and ovarian tissues will both be present in the same individual.{{cite journal | vauthors = Margarit E, Coll MD, Oliva R, Gómez D, Soler A, Ballesta F | title = SRY gene transferred to the long arm of the X chromosome in a Y-positive XX true hermaphrodite | journal = American Journal of Medical Genetics | volume = 90 | issue = 1 | pages = 25–8 | date = January 2000 | pmid = 10602113 | doi = 10.1002/(SICI)1096-8628(20000103)90:1<25::AID-AJMG5>3.0.CO;2-5 }} Of all total recorded cases of ovotesticular DSD, in only 8% percent of all cases was SRY present, leaving the rest of cases that could be explained to other or less common causes, with the vast majority simply being currently unexplainable.

Fetuses were previously thought to be phenotypically female before the sexual differentiation stage;{{cite book| vauthors = Leyner M, Goldberg B |author-link1=Mark Leyner |title=Why Do Men Have Nipples?: Hundreds of Questions You'd Only Ask a Doctor After Your Third Martini|year=2005|publisher=Three Rivers Press|location=New York|isbn=978-1-4000-8231-5|oclc=57722472|url=https://archive.org/details/whydomenhavenipp00leyn}} however, this is now known to be incorrect, as humans are simply undifferentiated before this stage and possess a paramesonephric duct, a mesonephric duct, and a genital tubercle.{{cite book | vauthors = Rey R, Josso N, Racine C |title=Endotext [Internet] |date=2020-05-27 |publisher=MDText.com, Inc. |location=South Dartmouth, Mass. |chapter=Sexual Differentiation |pmid=25905232 |access-date=28 Mar 2023 | veditors = Feingold KR, Anawalt B, Blackman MR, Boyce A, Chrousos G, Corpas E, de Herder WW, Dhatariya K, Dungan K, Hofland J, Kalra S, Kaltsas G, Kapoor N, Koch C, Kopp P, Korbonits M, Kovacs CS, Kuohung W, Laferrère B, Levy M, McGee EA, McLachlan R, New M, Purnell J, Sahay R, Shah AS, Singer F, Sperling MA, Stratakis CA, Trence DL, Wilson DP | display-editors = 6 |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK279001/ |via=National Institutes of Health |orig-year=first published 2000 }}{{cite journal | vauthors = Hughes IA | title = Minireview: sex differentiation | journal = Endocrinology | volume = 142 | issue = 8 | pages = 3281–3287 | date = August 2001 | pmid = 11459768 | doi = 10.1210/endo.142.8.8406 | doi-access = free }}

Evolution

{{For|evolution of sexual systems with hermaphodites|Trioecy#Evolution of trioecy|Androdioecy#Evolution of androdioecy|Gynodioecy#Evolution}}The evolution of anisogamy may have contributed to the evolution of simultaneous hermaphroditism and sequential hermaphroditism,{{cite journal |vauthors=Schärer L |date=February 2017 |title=The varied ways of being male and female |journal=Molecular Reproduction and Development |volume=84 |issue=2 |pages=94–104 |doi=10.1002/mrd.22775 |pmid=28032683 |quote= |doi-access=free}} it remains unclear if the evolution of anisogamy first led to hermaphroditism or gonochorism.{{cite book | vauthors = Kliman R |url=https://books.google.com/books?id=_r4OCAAAQBAJ |title=Encyclopedia of Evolutionary Biology |date=2016 |publisher=Academic Press |isbn=978-0-12-800426-5 |volume=2 |location= |pages=212–224 |access-date=2021-09-29 |archive-url=https://web.archive.org/web/20210506205920/https://www.google.com/books/edition/Encyclopedia_of_Evolutionary_Biology/_r4OCAAAQBAJ?hl=en&gbpv=0&kptab=overview |archive-date=2021-05-06 | url-status = live }}{{rp|213}}

A 2023 study argued that hermaphroditism can evolve directly from mating types under certain circumstances, such as if the fertilization is well organized and the average size of groups is small.{{cite journal | vauthors = Henshaw JM, Bittlingmaier M, Schärer L | title = Hermaphroditic origins of anisogamy | journal = Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences | volume = 378 | issue = 1876 | pages = 20220283 | date = May 2023 | pmid = 36934747 | pmc = 10024982 | doi = 10.1098/rstb.2022.0283 }} Simultaneous hermaphroditism that exclusively reproduces through self-fertilization has evolved many times in plants and animals, but it might not last long evolutionarily.{{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 |pages= |language=en}}{{Rp|page=14}}

= In animals =

Joan Roughgarden and Priya Iyer argued that the last common ancestor for animals was hermaphroditic and that transitions from hermaphroditism to gonochorism were more numerous than the reverse. Other scientists have criticized this argument; saying it’s based on paraphyletic Spiralia, assignments of sexual modes for the phylum level than the species level, and methods exclusively based on maximum parsimony.{{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}}

Hermaphroditism is polyphyletic in invertebrates where it evolved from gonochorism{{Rp|page=97}} and gonochorism is also ancestral to hermaphroditic fishes.{{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}} According to Nelson Çabej simultaneous hermaphroditism in animals most likely evolved due to a limited number of mating partners.{{Cite book | vauthors = Cabej NR |url=https://books.google.com/books?id=THz_-R8BSs0C&q=The+most+plausible+hypothesis+on+the+evolution+of+simultaneous+hermaphroditism+is+the+limited+availability+of+mating+partners.&pg=PA101 |title=Building the Most Complex Structure on Earth: An Epigenetic Narrative of Development and Evolution of Animals |date=2013-04-01 |publisher=Newnes |isbn=978-0-12-401729-0 |pages=101 |language=en}}

= In plants =

{{See also|Monoecy#Evolution|Andromonoecy#Evolution|Gynomonoecy#Evolution}}

It is widely accepted that the first vascular plants were outcrossing hermaphrodites.{{Cite book| vauthors = Orton TJ |url=https://books.google.com/books?id=rte_DwAAQBAJ&q=Horticultural+Plant+Breeding|title=Horticultural Plant Breeding|date=2019-11-21|publisher=Academic Press|isbn=978-0-12-815570-7|pages=176|language=en}} In flowering plants, hermaphroditism is ancestral to dioecy.{{Cite book| vauthors = Núñez-Farfán J, Valverde PL |url=https://books.google.com/books?id=iF70DwAAQBAJ&q=consensus+dioecy&pg=PA177|title=Evolutionary Ecology of Plant-Herbivore Interaction |date=2020-07-30|publisher=Springer Nature|isbn=978-3-030-46012-9|pages=177|language=en}}

Hermaphroditism in plants may promote self fertilization in pioneer populations.{{Cite book| vauthors = Burns KC |url=https://books.google.com/books?id=wbOQDwAAQBAJ&q=evolution+of+hermaphroditism+in+plants|title=Evolution in Isolation: The Search for an Island Syndrome in Plants|date=2019-05-16|publisher=Cambridge University Press|isbn=978-1-108-42201-7|pages=21–22|language=en}} However, plants have evolved multiple different mechanisms to avoid self-fertilization in hermaphrodites, including sequential hermaphroditism, molecular recognition systems and mechanical or morphological mechanisms such as heterostyly.{{cite book | vauthors = Judd WS, Campbell CS, Kellogg EA, Stevens PF, Donoghue MJ |title=Plant systematics, a phylogenetic approach |edition=2 |date=2002 |publisher=Sinauer Associates Inc. |location=Sunderland MA, US |isbn=0-87893-403-0 }}{{rp|73,74}}

References

External links

[https://www.britannica.com/EBchecked/topic/263151/hermaphroditism Britannica Online Encyclopedia: hermaphroditism (biology)]
[http://www.cell.com/current-biology/abstract/S0960-9822%2805%2901105-X Current Biology – Gender trading in a hermaphrodite]
[http://www.plosbiology.org/article/info:doi%2F10.1371%2Fjournal.pbio.0030030 The Evolution of Self-Fertile Hermaphroditism: The Fog Is Clearing] {{Webarchive|url=https://web.archive.org/web/20140116131052/http://www.plosbiology.org/article/info:doi%2F10.1371%2Fjournal.pbio.0030030 |date=2014-01-16 }}
[https://www.angelfire.com/ca2/BornHermaphrodite/ "Born True Hermaphrodite – Pictorial Profile", about Lynn Edward Harris]

Category:Sexual reproduction

Category:Reproductive system

Category:Intersex history

Category:Supernumerary body parts