# Male > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Male > Markdown URL: https://mediated.wiki/source/Male.md > Source: https://en.wikipedia.org/wiki/Male > Source revision: 1347047910 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Sex of an organism which produces sperm}} {{About|the male sex|the capital of the Maldives|Malé|other uses}} {{redirect|Males}} {{pp-vandalism|small=yes}} {{Use dmy dates|date=July 2025}} [[File:Mars symbol.svg|thumb|The symbol of the Roman god [Mars](/source/Mars_(mythology)) (god of war) is often used to represent the male sex. It also stands for the planet [Mars](/source/Mars) and is the [alchemical symbol](/source/alchemical_symbol) for [iron](/source/iron).]] '''Male''' ([symbol](/source/Planet_symbols): [♂](/source/%E2%99%82)) is the [sex](/source/sex) of an [organism](/source/organism) that produces, or is organized to produce, the [gamete](/source/gamete) (sex cell) known as [sperm](/source/sperm), which fuses with the larger [female](/source/female) gamete,{{Cite journal |last1=Lehtonen |first1=Jussi |last2=Parker |first2=Geoff A. |author-link2=Geoff Parker |date=1 December 2014 |title=Gamete competition, gamete limitation, and the evolution of the two sexes |url=https://academic.oup.com/molehr/article/20/12/1161/1062990 |journal=Molecular Human Reproduction |language=en |volume=20 |issue=12 |pages=1161–1168 |doi=10.1093/molehr/gau068 |issn=1360-9947 |pmid=25323972 |doi-access=free}}{{Cite book|last1=Fusco|first1=Giuseppe|url=https://books.google.com/books?id=AKGsDwAAQBAJ&q=the+biology+of+reproduction+define+sex|title=The Biology of Reproduction|last2=Minelli|first2=Alessandro|date=10 October 2019 |publisher=Cambridge University Press|isbn=978-1-108-49985-9|pages=111–113|language=en}}{{Cite book |last1=Hine |first1=Robert |url=https://books.google.com/books?id=gMf9CAAAQBAJ&pg=PA354 |title=A Dictionary of Biology |last2=Martin |first2=Elizabeth |date=2015 |publisher=Oxford University Press |isbn=978-0-19-871437-8 |page=354 |language=en}}{{Cite journal |last=Bhargava |first=Aditi |last2=Arnold |first2=Arthur P |last3=Bangasser |first3=Debra A |last4=Denton |first4=Kate M |last5=Gupta |first5=Arpana |last6=Hilliard Krause |first6=Lucinda M |last7=Mayer |first7=Emeran A |last8=McCarthy |first8=Margaret |last9=Miller |first9=Walter L |last10=Raznahan |first10=Armin |last11=Verma |first11=Ragini |date=2021-05-25 |title=Considering Sex as a Biological Variable in Basic and Clinical Studies: An Endocrine Society Scientific Statement |url=https://academic.oup.com/edrv/article/42/3/219/6159361 |journal=Endocrine Reviews |language=en |volume=42 |issue=3 |pages=3 |doi=10.1210/endrev/bnaa034 |issn=0163-769X |pmc=8348944 |pmid=33704446}} or [ovum](/source/Egg_cell), in the process of [fertilisation](/source/fertilisation). A male organism cannot [reproduce sexually](/source/sexual_reproduction) without access to at least one ovum from a female, but some organisms can reproduce both sexually and [asexually](/source/Asexual_reproduction).{{Cite journal|last=Lively|first=Curtis M.|date=1 March 2010 |title=A Review of Red Queen Models for the Persistence of Obligate Sexual Reproduction|url=https://academic.oup.com/jhered/article/101/suppl_1/S13/757712|journal=Journal of Heredity|language=en|volume=101|issue=suppl_1|pages=S13–S20|doi=10.1093/jhered/esq010|pmid=20421322|issn=0022-1503|doi-access=free}} Most male [mammal](/source/mammal)s, including male humans, have a [Y chromosome](/source/Y_chromosome),{{Cite web|last=Reference|first=Genetics Home|title=Y chromosome|url=https://medlineplus.gov/genetics/chromosome/y/|access-date=22 July 2020 |website=Genetics Home Reference|language=en}}{{Cite web|title=Y Chromosome|url=https://www.genome.gov/genetics-glossary/Y-Chromosome|access-date=7 September 2020 |website=Genome.gov|language=en}} which codes for the production of larger amounts of [testosterone](/source/testosterone) to develop [male reproductive organs](/source/male_reproductive_organs). In humans, the word ''male'' can also be used to refer to [gender](/source/gender), in the social sense of [gender role](/source/gender_role) or [gender identity](/source/gender_identity).{{Cite web |date=4 February 2025 |title=Definition of MALE |url=https://www.merriam-webster.com/dictionary/male |access-date=10 February 2025 |website=www.merriam-webster.com |language=en}} == Overview == The existence of separate sexes has evolved independently at different times and in different [lineages](/source/lineage_(evolution)), an example of [convergent evolution](/source/convergent_evolution).{{Cite web |last=Berrill |first=N.J. |title=Sex |url=https://www.britannica.com/science/sex |access-date=22 July 2020 |website=Encyclopedia Britannica |language=en}}{{Cite news |last1=Klymkowsky |first1=Michael W. |last2=Melanie M. |first2=Cooper |date=4 June 2016 |title=4.9: Sexual dimorphism |language=en |website=Biology LibreTexts |url=https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_Biofundamentals_(Klymkowsky_and_Cooper)/04%3A_Social_evolution_and_sexual_selection/4.09%3A_Sexual_dimorphism |access-date=22 July 2020}} The repeated pattern is sexual reproduction in [isogamous](/source/isogamy) species with two or more [mating type](/source/mating_type)s with gametes of identical form and behavior (but different at the molecular level) to [anisogamous](/source/anisogamy) species with [gamete](/source/gamete)s of male and [female](/source/female) types to [oogamous](/source/oogamy) species in which the female gamete is very much larger than the male and has no ability to move. There is a good argument that this pattern was driven by the physical constraints on the mechanisms by which two gametes get together as required for [sexual reproduction](/source/sexual_reproduction).{{Cite book |last=Dusenbery |first=David B. |url=https://archive.org/details/livingatmicrosca0000duse |title=Living at Micro Scale |publisher=Harvard University Press |year=2009 |isbn=978-0-674-03116-6 |location=Cambridge, Massachusetts |at=Chapter 20 |url-access=registration}}.{{Page needed|date=August 2021}}. But in some species males can reproduce by themselves asexually, for example via [androgenesis](/source/androgenesis).{{cite journal |last1=Hedtke |first1=Shannon M. |last2=Stanger-Hall |first2=Kathrin |last3=Baker |first3=Robert J. |last4=Hillis |first4=David M. |author-link4=David Hillis |date=May 2008 |title=All-Male Asexuality: Origin and Maintenance of Androgenesis in the Asian Clam Corbicula |journal=Evolution |volume=62 |issue=5 |pages=1119–1136 |doi=10.1111/j.1558-5646.2008.00344.x |pmid=18266987 |bibcode=2008Evolu..62.1119H }}{{cite journal|first1=Tanja |last1=Schwander |first2=Benjamin P |last2=Oldroyd |date=28 September 2008|title=Androgenesis: where males hijack eggs to clone themselves|journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=371 |issue=1706 |doi=10.1098/rstb.2015.0534 |pmid=27619698 |pmc=5031619 }} Accordingly, sex is defined across species by the type of gametes produced (i.e.: spermatozoa vs. ova) and differences between males and females in one lineage are not always predictive of differences in another.{{Cite news|last=Wilcox|first=Christie|title=Why Sex? Biologists Find New Explanations.|url=https://www.quantamagazine.org/why-sex-biologists-find-new-explanations-20200423/|access-date=22 July 2020|website=Quanta Magazine|date=23 April 2020|language=en}}{{Citation|last=Lehtonen|first=Jussi|title=Gamete Size|date=2017|encyclopedia=Encyclopedia of Evolutionary Psychological Science|pages=1–4|editor-last=Shackelford|editor-first=Todd K.|place=Cham|publisher=Springer International Publishing|language=en|doi=10.1007/978-3-319-16999-6_3063-1|isbn=978-3-319-16999-6|editor2-last=Weekes-Shackelford|editor2-first=Viviana A.}} [Male/female dimorphism](/source/sexual_dimorphism) between organisms or reproductive organs of different sexes is not limited to animals; male gametes are produced by [chytrid](/source/chytrid)s, [diatom](/source/diatom)s and land [plant](/source/plant)s, among others. In land plants, ''female'' and ''male'' designate not only the female and male gamete-producing organisms and structures but also the structures of the [sporophyte](/source/sporophyte)s that give rise to male and female plants.{{citation needed|date=May 2021}} == Evolution == {{See also|Evolution of sexual reproduction|Sex#Evolution of sex}} The [evolution of anisogamy](/source/Anisogamy) led to the evolution of male and female function. Before the evolution of anisogamy, [mating type](/source/mating_type)s in a species were [isogamous](/source/Isogamy): the same size and both could move, catalogued only as "+" or "-" types.{{rp|216}} In anisogamy, the mating type is called a gamete. The male gamete is smaller than the female gamete, and usually mobile.{{Cite encyclopedia|entry=Anisogamy|encyclopedia=Encyclopedia of Animal Cognition and Behavior|publisher=Springer International Publishing|place=Cham |date=2019|pages=1–5|doi=10.1007/978-3-319-47829-6_340-1|isbn=978-3-319-47829-6 |vauthors=Kumar R, Meena M, Swapnil P|title=Anisogamy |veditors=Vonk J, Shackelford T}} Anisogamy remains poorly understood, as there is no fossil record of its emergence. Numerous theories exist as to why anisogamy emerged. Many share a common thread, in that larger female gametes are more likely to survive, and that smaller male gametes are more likely to find other gametes because they can travel faster. Current models often fail to account for why isogamy remains in a few species.{{Cite book |last1=Togashi |first1=Tatsuya |url=https://books.google.com/books?id=5eOvRTIuLXMC&pg=PA1 |title=The Evolution of Anisogamy: A Fundamental Phenomenon Underlying Sexual Selection |last2=Cox |first2=Paul Alan |date=14 April 2011 |publisher=Cambridge University Press |isbn=978-1-139-50082-1 |pages=1–15 |language=en}} Anisogamy appears to have evolved multiple times from isogamy; for example, female [Volvocales](/source/Volvocales) (a type of green algae) evolved from the plus mating type.{{Cite book |last1=Sawada |first1=Hitoshi |url=https://books.google.com/books?id=Adm6BQAAQBAJ&pg=PA222 |title=Sexual Reproduction in Animals and Plants |last2=Inoue |first2=Naokazu |last3=Iwano |first3=Megumi |date=7 February 2014 |publisher=Springer |isbn=978-4-431-54589-7 |language=en}}{{rp|222}} Although sexual evolution emerged at least 1.2 billion years ago, the lack of anisogamous fossil records make it hard to pinpoint when males evolved.{{cite journal|last=Butterfield|first=Nicholas J.|date=2000|title=Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes|url=https://mr.crossref.org/iPage?doi=10.1666%2F0094-8373%282000%29026%3C0386%3ABPNGNS%3E2.0.CO%3B2|journal=[Paleobiology](/source/Paleobiology_(journal))|volume=26|issue=3|page=386|doi=10.1666/0094-8373(2000)026<0386:BPNGNS>2.0.CO;2|bibcode=2000Pbio...26..386B |s2cid=36648568 |access-date=12 April 2021|url-access=subscription}} One theory suggests male evolved from the dominant mating type (called mating type minus).{{Cite journal|last1=Togashi|first1=Tatsuya|last2=Bartelt|first2=John L.|last3=Yoshimura|first3=Jin|last4=Tainaka|first4=Kei-ichi|last5=Cox|first5=Paul Alan|date=21 August 2012 |title=Evolutionary trajectories explain the diversified evolution of isogamy and anisogamy in marine green algae|journal=Proceedings of the National Academy of Sciences of the United States of America|volume=109|issue=34|pages=13692–13697|doi=10.1073/pnas.1203495109|issn=0027-8424|pmc=3427103|pmid=22869736|bibcode=2012PNAS..10913692T|doi-access=free}} == Symbol, etymology, and usage == === Symbol === A common [symbol](/source/gender_symbol) used to represent the male sex is the [Mars symbol](/source/Mars_symbol) ♂, a circle with an arrow pointing [northeast](/source/Ordinal_direction). The [Unicode](/source/Unicode) code-point is: :{{unichar|2642|MALE SIGN|html=}} The symbol is identical to the planetary symbol of [Mars](/source/Mars). It was first used to denote sex by [Carl Linnaeus](/source/Carl_Linnaeus) in 1751. The symbol is sometimes seen as a stylized representation of the shield and spear of the Roman god [Mars](/source/Mars_(mythology)). According to [William T. Stearn](/source/William_T._Stearn), however, this derivation is "fanciful" and all the historical evidence favours "the conclusion of the French classical scholar [Claude de Saumaise](/source/Claude_de_Saumaise) (Salmasius, 1588{{ndash}}1683)" that it is derived from ''θρ'', the contraction of a Greek name for the planet Mars, which is ''Thouros''.{{Cite journal |jstor = 1217734|title = The Origin of the Male and Female Symbols of Biology|journal = Taxon|volume = 11|issue = 4|pages = 109–113|last1 = Stearn|first1 = William T.|year = 1962|doi = 10.2307/1217734 | bibcode=1962Taxon..11..109S }} === Etymology === Borrowed from [Old French](/source/Old_French) ''masle'', from [Latin](/source/Latin) ''masculus'' ("masculine, male, worthy of a man"), diminutive of ''mās'' ("male person or animal, male").{{cite web |title=male {{!}} Etymology, origin and meaning of male by etymonline |url=https://www.etymonline.com/word/male#etymonline_v_6731 |website=www.etymonline.com |publisher=[Etymonline](/source/Etymonline) |access-date=23 July 2023 |language=en}} === Usage === In humans, the word ''male'' can be used in the context of [gender](/source/gender), such as for gender role or gender identity of a [man](/source/man) or [boy](/source/boy).{{cite book |last1=Palazzani |first1=Laura |url=https://books.google.com/books?id=w8bbP6D7U2UC&pg=PA5 |title=Gender in Philosophy and Law |last2=Bailes |first2=Victoria |last3=Fella |first3=Marina |publisher=Dordrecht : Springer |year=2012 |isbn=978-94-007-4991-7 |series=SpringerBriefs in law |page=v |quote='gender' means human gender, male/female gender}} (eBook) For example, according to Merriam-Webster, "male" can refer to "having a gender identity that is the opposite of female".{{Cite web |title=Definition of MALE |url=https://www.merriam-webster.com/dictionary/male |access-date=2023-03-22 |website=Merriam-Webster |language=en}} According to the Cambridge Dictionary, "male" can mean "belonging or relating to men".{{Cite web |title=male |url=https://dictionary.cambridge.org/us/dictionary/english/male |website=Cambridge Dictionary}} ''Male'' can also refer to [a shape of connectors](/source/gender_of_connectors_and_fasteners).{{cite book| author =J. Richard Johnson | title= How to Build Electronic Equipment | year =1962 | page=167 | quote=To minimize confusion, the connector portions with projecting prongs are referred to as the 'male' portion, and the sockets as the 'female' portion.| publisher = Rider | location = New York}}{{cite book | author =Richard Ferncase | title =Film and Video Lighting Terms and Concepts | year=2013 | page=96 | quote= female[:] Refers to a socket type connector, which must receive a male connector | isbn= 978-0-240-80157-5 | publisher = Hoboken Taylor and Francis}} == Sex determination == {{Main|Sex-determination system}} [[File:Anterior view of human female and male, with labels 2.png|thumb|Photograph of an adult male human, with an adult [female](/source/female) for comparison. Both models have partially shaved body hair; e.g. clean-shaven pubic regions.]] The sex of a particular organism may be determined by a number of factors. These may be genetic or environmental, or may naturally change during the course of an organism's life. Although most species have only two sexes (either male or female), [hermaphroditic](/source/Hermaphrodite) animals, such as [worm](/source/worm)s, have both male and female reproductive organs.{{Cite web|title=hermaphroditism {{!}} Definition, Types, & Effects|url=https://www.britannica.com/science/hermaphroditism|access-date=22 July 2020|website=Encyclopedia Britannica|language=en}} Species that are divided into females and males are classified as [gonochoric](/source/Gonochorism) in animals, as [dioecious](/source/Dioecy) in [seed plants](/source/seed_plants) and as [dioicous](/source/Dioicy) in [cryptogam](/source/cryptogam)s.{{cite book |author=Buck WR |url=https://books.google.com/books?id=fuOKCOlRngkC |title=Bryophyte Biology |last2=Goffinet |first2=B |date=August 2000 |publisher=Cambridge University Press |isbn=978-0-521-66794-4 |editor=Shaw AJ & Goffinet B |location=New York |chapter=Morphology and classification of mosses}}{{rp|82}} Males can coexist with hermaphrodites, a [sexual system](/source/sexual_system) called [androdioecy](/source/androdioecy). They can also coexist with females and hermaphrodites, a sexual system called [trioecy](/source/trioecy).{{Cite book |last=Leonard |first=Janet L. |url=https://books.google.com/books?id=0rWZDwAAQBAJ&pg=PA1 |title=Transitions Between Sexual Systems: Understanding the Mechanisms of, and Pathways Between, Dioecy, Hermaphroditism and Other Sexual Systems |date=2019-05-21 |publisher=Springer |isbn=978-3-319-94139-4 |pages=1–3 |language=en}} Not all species share a common [sex-determination system](/source/sex-determination_system). In most [animal](/source/animal)s, including [humans](/source/Homo_sapiens), sex is determined [genetically](/source/genetics); however, species such as ''[Cymothoa exigua](/source/Cymothoa_exigua)'' change sex depending on the number of females present in the vicinity.{{Cite journal |last1=Ruiz-L |first1=A. |last2=Madrid-V |first2=J. |date=6 March 1992 |title=Studies on the biology of the parasitic isopod Cymothoa exigua Schioedte and Meinert, 1884 and it's relationship with the snapper Lutjanus peru (Pisces: Lutjanidae) Nichols and Murphy, 1922, from commercial catch in Michoacan |url=https://cienciasmarinas.com.mx/index.php/cmarinas/article/view/885 |journal=Ciencias Marinas |language=en |volume=18 |issue=1 |pages=19–34 |doi=10.7773/cm.v18i1.885 |bibcode=1992CiMar..18...19R |issn=2395-9053|doi-access=free }} === Genetic determination === Most [mammal](/source/mammal)s, including [human](/source/human)s, are genetically determined as such by the [XY sex-determination system](/source/XY_sex-determination_system) where males have XY (as opposed to XX in females) [sex chromosomes](/source/sex_chromosomes). It is also possible in a variety of species, including humans, to be [XX male](/source/XX_male) or have other [karyotypes](/source/karyotypes). During [reproduction](/source/reproduction), a male can give either an X sperm or a Y sperm, while a female can only give an X egg. A Y sperm and an X egg produce a male, while an X sperm and an X egg produce a [female](/source/female).{{Cite web|date=17 July 2018|title=43.1C: Sex Determination|url=https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_General_Biology_(Boundless)/43%3A_Animal_Reproduction_and_Development/43.1%3A_Reproduction_Methods/43.1C%3A_Sex_Determination|access-date=2020-07-22|website=Biology LibreTexts|language=en}} The part of the Y-chromosome which is responsible for maleness is the sex-determining region of the Y-chromosome, the [SRY](/source/SRY).{{Cite web|last=Reference|first=Genetics Home|title=SRY gene|url=https://medlineplus.gov/genetics/gene/sry/|access-date=22 July 2020|website=Genetics Home Reference|language=en}} The SRY activates [Sox9](/source/Sox9), which forms feedforward loops with [FGF9](/source/FGF9) and [PGD2](/source/PGD2) in the [gonad](/source/gonad)s, allowing the levels of these genes to stay high enough in order to cause male development;{{cite journal | last1=Moniot | first1=Brigitte | last2=Declosmenil | first2=Faustine | last3=Barrionuevo | first3=Francisco | last4=Scherer | first4=Gerd | last5=Aritake | first5=Kosuke | last6=Malki | first6=Safia | last7=Marzi | first7=Laetitia | last8=Cohen-Solal | first8=Ann | last9=Georg | first9=Ina | last10=Klattig | first10=Jürgen | last11=Englert | first11=Christoph | last12=Kim | first12=Yuna | last13=Capel | first13=Blanche | last14=Eguchi | first14=Naomi | last15=Urade | first15=Yoshihiro | last16=Boizet-Bonhoure | first16=Brigitte | last17=Poulat | first17=Francis | year=2009 | title=The PGD2 pathway, independently of FGF9, amplifies SOX9 activity in Sertoli cells during male sexual differentiation| journal=Development| volume=136| issue=11| pages=1813–1821| pmid = 19429785 | doi=10.1242/dev.032631| pmc=4075598 }} for example, Fgf9 is responsible for development of the [spermatic cord](/source/spermatic_cord)s and the multiplication of [Sertoli cell](/source/Sertoli_cell)s, both of which are crucial to male sexual development.{{Cite journal | last1 = Kim | first1 = Y. | last2 = Kobayashi | first2 = A. | last3 = Sekido | first3 = R. | last4 = Dinapoli | first4 = L. | last5 = Brennan | first5 = J. | last6 = Chaboissier | first6 = M. C. | last7 = Poulat | first7 = F. | last8 = Behringer | first8 = R. R. | last9 = Lovell-Badge | first9 = R. | doi = 10.1371/journal.pbio.0040187 | last10 = Capel | first10 = B. | title = Fgf9 and Wnt4 Act as Antagonistic Signals to Regulate Mammalian Sex Determination | journal = PLOS Biology | volume = 4 | issue = 6 | article-number = e187 | year = 2006 | pmid = 16700629 | pmc =1463023 | doi-access = free }} The [ZW sex-determination system](/source/ZW_sex-determination_system), where males have ZZ (as opposed to ZW in females) sex chromosomes, may be found in [bird](/source/bird)s and some [insect](/source/insect)s (mostly [butterflies and moths](/source/Lepidoptera)) and other organisms. Members of the insect order [Hymenoptera](/source/Hymenoptera), such as [ant](/source/ant)s and [bee](/source/bee)s, are often determined by [haplodiploidy](/source/haplodiploidy),{{cite journal |vauthors=Bachtrog D, [Mank JE](/source/Judith_Mank), Peichel CL, [Kirkpatrick M](/source/Mark_Kirkpatrick), [Otto SP](/source/Sarah_Otto), 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 |article-number=e1001899 |doi=10.1371/journal.pbio.1001899 |pmc=4077654 |pmid=24983465 |doi-access=free}} where most males are [haploid](/source/haploid) and females and some sterile males are [diploid](/source/diploid). However, fertile diploid males may still appear in some species, such as ''[Cataglyphis cursor](/source/Cataglyphis_cursor)''.{{cite journal |last1=Doums |first1=Claudie |title=Fertile diploid males in the ant Cataglyphis cursor: a potential cost of thelytoky? |url=https://link.springer.com/article/10.1007/s00265-013-1606-6 |journal=Behavioral Ecology and Sociobiology |year=2013 |volume=67 |issue=12 |pages=1983–1993 |access-date=2 October 2021 |doi=10.1007/s00265-013-1606-6|bibcode=2013BEcoS..67.1983D |s2cid=18141328 |hdl=10261/88167 |hdl-access=free }} === Environmental determination === In some species of reptiles, such as [alligator](/source/alligator)s, sex is determined by the temperature at which the egg is incubated. Other species, such as some [snail](/source/snail)s, practice sex change: adults start out male, then become female.{{Cite journal|last1=Cahill|first1=Abigail E.|last2=Juman|first2=Alia Rehana|last3=Pellman-Isaacs|first3=Aaron|last4=Bruno|first4=William T.|date=December 2015|title=Physical and Chemical Interactions with Conspecifics Mediate Sex Change in a Protandrous Gastropod Crepidula fornicata|journal=The Biological Bulletin|volume=229|issue=3|pages=276–281|doi=10.1086/bblv229n3p276|pmid=26695826|s2cid=22783998|issn=0006-3185}} In tropical [clown fish](/source/clown_fish), the dominant individual in a group becomes female while the other ones are male.{{Cite journal|last=Bull|first=J. J.|date=March 1980|title=Sex Determination in Reptiles|journal=The Quarterly Review of Biology|volume=55|issue=1|pages=3–21|doi=10.1086/411613|s2cid=85177125|issn=0033-5770}} == Secondary sex characteristics == {{Main|Secondary sex characteristic}} Male animals have evolved to use secondary sex characteristics as a way of displaying traits that signify their [fitness](/source/Fitness_(biology)). [Sexual selection](/source/Sexual_selection) is believed to be the driving force behind the development of these characteristics. Differences in physical size and the ability to fulfill the requirements of sexual selection have contributed significantly to the outcome of secondary sex characteristics in each species.{{cite book |vauthors=Campbell B|title=Human Evolution: An Introduction to Man's Adaptations|publisher=[Routledge](/source/Routledge)|isbn=978-1-351-51441-5|year=2017|pages=392–393|url=https://books.google.com/books?id=ctwzDwAAQBAJ&pg=PT392}} In many species, males differ from females in more ways than just the production of sperm. For example, in some insects and fish, the male is smaller than the female. In seed plants, the [sporophyte sex organ](/source/flower) of a single organism includes both the male and female parts. In mammals, including humans, males are typically larger than females. This is often attributed to the need for male mammals to be physically stronger and more competitive in order to win mating opportunities. In humans specifically, males have more body hair and muscle mass than females.{{Cite book|last1=Ellis|first1=Lee|url=https://books.google.com/books?id=Skw2mezpvO4C&q=sex+differences+in+size&pg=PA21|title=Sex Differences: Summarizing More than a Century of Scientific Research|last2=Hershberger|first2=Scott|last3=Field|first3=Evelyn|last4=Wersinger|first4=Scott|last5=Pellis|first5=Sergio|last6=Geary|first6=David|last7=Palmer|first7=Craig|last8=Hoyenga|first8=Katherine|last9=Hetsroni|first9=Amir|date=13 May 2013|publisher=Psychology Press|isbn=978-1-136-87493-2|language=en}}{{Page needed|date=August 2021}}{{Cite book|last1=Richards|first1=Julia E.|url=https://books.google.com/books?id=MUw0eHzuH2AC&q=secondary+sex+characteristics&pg=PA277|title=The Human Genome|last2=Hawley|first2=R. Scott|date=12 December 2010|publisher=Academic Press|isbn=978-0-08-091865-5|language=en}}{{Page needed|date=August 2021}} Birds often exhibit colorful [plumage](/source/plumage) that attracts females.{{Cite book|last1=switze|first1=International Conference on Comparative Physiology 1992 Crans|url=https://books.google.com/books?id=zunYrumtsR8C&q=sex+differences+in+birds&pg=PA303|title=The Differences Between the Sexes|last2=Bassau|first2=Short &|date=4 August 1994|publisher=Cambridge University Press|isbn=978-0-521-44878-9|language=en}}{{Page needed|date=August 2021}} This is true for many species of birds where the male displays more vibrant colors than the female, making them more noticeable to potential mates. These characteristics have evolved over time as a result of sexual selection, as males who exhibited these traits were more successful in attracting mates and passing on their genes. == See also == * [Boy](/source/Boy) * [Man](/source/Man) * [Masculinity](/source/Masculinity) * [Lord](/source/Lord) * [Gentleman](/source/Gentleman) == References == {{Reflist|30em}} == Further reading == {{commons category|Males|lcfirst=yes}} {{Wiktionary}} * {{cite journal|last=Wedgwood|first=Hensleigh|author-link=Hensleigh Wedgwood|title=On False Etymologies|journal=Transactions of the Philological Society|url=https://babel.hathitrust.org/cgi/pt?id=uc1.b3924121;view=1up;seq=78|year=1855|issue=6|page=68}} {{Sex (biology)}} {{Sexual identities}} {{Authority control}} Category:Male Category:Terms for men Category:Sex Category:Boys --- Adapted from the Wikipedia article [Male](https://en.wikipedia.org/wiki/Male) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Male?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.