View source for Homininae

{{short description|Subfamily of mammals}}
{{For|an explanation of very similar terms|Hominidae|Hominini}}
{{Automatic taxobox
| fossil_range = {{fossilrange|12.5|0|earliest=14}}
| image = Secretary_Leonard_Carmichael.jpg
| image_caption = Three hominines – an adult [[human male]] ([[Leonard Carmichael]]) holding a juvenile [[gorilla]] (left) and a juvenile [[chimpanzee]] (right).
| taxon = Homininae
| authority = [[John Edward Gray|Gray]], 1825
| type_species = ''[[Homo sapiens]]''
| type_species_authority = Linnaeus, 1758
| subdivision_ranks = Tribes
| subdivision = * †[[Dryopithecini]] (?)
* [[Gorillini]]
* [[Hominini]]
}}

'''Homininae''' (the '''hominines''') is a [[subfamily]] of the family [[Hominidae]] (hominids). The Homininae {{IPAc-en|h|ɒ|m|ᵻ|ˈ|n|aɪ|n|iː}} encompass humans, and are also called "'''African hominids'''" or "'''African apes'''". <ref>{{cite journal | vauthors = Grabowski M, Jungers WL | title = Evidence of a chimpanzee-sized ancestor of humans but a gibbon-sized ancestor of apes | language = En | journal = Nature Communications | volume = 8 | issue = 1 | article-number = 880 | date = October 2017 | pmid = 29026075 | pmc = 5638852 | doi = 10.1038/s41467-017-00997-4 | bibcode = 2017NatCo...8..880G }}</ref><ref>{{cite journal | vauthors = Fuss J, Spassov N, Begun DR, Böhme M | title = Potential hominin affinities of Graecopithecus from the Late Miocene of Europe | journal = PLOS ONE | volume = 12 | issue = 5 | article-number = e0177127 | date = 2017-05-22 | pmid = 28531170 | pmc = 5439669 | doi = 10.1371/journal.pone.0177127| bibcode = 2017PLoSO..1277127F | doi-access = free }}</ref> This subfamily includes two tribes, [[Hominini]] and [[Gorillini]], both having [[extant taxon|extant]] (or living) species as well as [[extinct]] species.

Tribe [[Hominini]] includes: the extant genus ''[[Homo]]'', which comprises only one extant species — modern [[human]] (''Homo sapiens''), and numerous extinct human species; and the extant genus ''[[Pan (genus)|Pan]]'', which includes two extant species, [[chimpanzee]]s and [[bonobo]]s. Tribe [[Gorillini]] ([[gorilla]]s) contains one extant genus, ''Gorilla'', with two extant species, with variants, and one known extinct genus. Alternatively, the genus ''Pan'' is considered by some to belong, instead of to a subtribe [[Panina]], to its own separate tribe, (''so-called'') "Panini," which would be a third tribe for Homininae.

Some classification schemes provide a more comprehensive account of extinct groups (see section "Taxonomic Classification" below). For example, tribe Hominini shows two subtribes: subtribe [[Hominina]], which contains at least two extinct [[genera]]; and subtribe Panina, which presents only the extant genus, ''Pan'' (chimpanzees/bonobos), as fossils of extinct chimpanzees/bonobos are very rarely found.

The Homininae comprise all [[hominid]]s that arose after the subfamily [[Ponginae]] ([[orangutan]]s) split from the line of the [[great ape]]s. The Homininae [[cladogram]] has three main branches leading to gorillas (via the tribe Gorillini), to humans, and to chimpanzees (via the tribe Hominini and subtribes Hominina and Panina, see graphic "Evolutionary tree" below). There are two living species each of Panina, chimpanzees and bonobos, and two living and one extinct species of gorillas. Traces of extinct ''Homo'' species, including ''[[Homo floresiensis]]'', have been found with dates as recent as 40,000 years ago. Individual members of this subfamily are called '''hominine''' or '''hominines''' — not to be confused with the terms [[hominin]]s or [[Hominini]].<ref group="Note" name="CommonNames">A ''hominin'' is a member of the tribe Hominini, a ''hominine'' is a member of the subfamily Homininae, a ''hominid'' is a member of the family Hominidae, and a ''hominoid'' is a member of the superfamily Hominoidea.</ref>

==History of discoveries and classification==
{{See also|List of human evolution fossils}}
[[File:Homininae.svg|left|frame|[[Evolutionary tree]] of the superfamily [[Hominoidea]], emphasizing the subfamily Homininae: after an initial separation from the main line (some 18 million years ago) of [[Hylobatidae]] (current [[gibbon]]s), the line of subfamily [[Ponginae]] broke away—leading to the current orangutan; and later the Homininae split into the tribe [[Hominini]] (with subtribes Hominina and Panina), and the tribe [[Gorillini]].]]
Until 1970, the family (and term) Hominidae meant humans only; the non-human [[great ape]]s were assigned to the then-family [[Pongidae]].<ref name=Goodman>{{cite book | vauthors = Goodman M |author-link=Morris Goodman (scientist) |chapter = Man's place in the phylogeny of the primates as reflected in serum proteins |pages = 204–234 | veditors = Washburn SL |title=Classification and Human Evolution |chapter-url=https://books.google.com/books?id=8NHbEwLkYmQC&pg=PA204 |publisher=Transaction Publishers |isbn=978-0-202-36487-2 |year=1964}}</ref> Later discoveries led to revised classifications, with the great [[ape]]s then united with humans (now in subfamily Homininae)<ref name="GBIF">{{GBIF |title=Homininae Gray, 1825 |id=113406995 |access-date=2024-08-02}}</ref> as members of family Hominidae<ref name=Goodman1>{{cite journal | journal = Annual Review of Anthropology | volume = 3 | pages = 203–228 | year = 1974 | doi = 10.1146/annurev.an.03.100174.001223 | title = Biochemical Evidence on Hominid Phylogeny | vauthors = Goodman M}}</ref> 
By 1990, it was recognized that [[gorilla]]s and [[chimpanzee]]s are more closely related to [[human]]s than they are to [[orangutan]]s, leading to their (gorillas' and chimpanzees') placement in subfamily Homininae as well.<ref name=Goodman2>{{cite journal | vauthors = Goodman M, Tagle DA, Fitch DH, Bailey W, Czelusniak J, Koop BF, Benson P, Slightom JL | title = Primate evolution at the DNA level and a classification of hominoids | journal = Journal of Molecular Evolution | volume = 30 | issue = 3 | pages = 260–6 | date = March 1990 | pmid = 2109087 | doi = 10.1007/BF02099995| bibcode = 1990JMolE..30..260G | s2cid = 2112935 }}</ref>

The subfamily Homininae can be further subdivided into three branches, the tribe [[Gorillini]] (gorillas), the tribe [[Hominini]] with subtribes [[Pan (genus)|Panina]] (chimpanzees/bonobos) and [[Hominina]] (humans and their extinct relatives), and the extinct tribe [[Dryopithecini]]. The [[Late Miocene]] fossil ''[[Nakalipithecus nakayamai]]'', described in 2007, is a [[basal (evolution)|basal]] member of this [[clade]], as is, perhaps, its contemporary ''[[Ouranopithecus]]''; that is, they are not assignable to any of the three extant branches. Their existence suggests that the Homininae tribes diverged not earlier than about 8 million years ago (see [[Human evolutionary genetics]]).

Today, chimpanzees and gorillas live in [[tropical forest]]s with acid soils that rarely preserve fossils. Although no fossil gorillas have been reported, four chimpanzee teeth about 500,000 years old have been discovered in the East-African rift valley ([[Kapthurin]] Formation, Kenya), where many fossils from the human lineage (hominins)<ref group="Note" name="CommonNames" /> have been found.<ref>{{cite journal | vauthors = McBrearty S, Jablonski NG | title = First fossil chimpanzee | journal = Nature | volume = 437 | issue = 7055 | pages = 105–8 | date = September 2005 | pmid = 16136135 | doi = 10.1038/nature04008| bibcode = 2005Natur.437..105M | s2cid = 4423286 }}</ref> This shows that some chimpanzees lived close to ''Homo'' (''[[H. erectus]]'' or ''[[H. rhodesiensis]]'') at the time; the same is likely true for gorillas.<ref name="GBIF" />

==Taxonomic classification==
{{Human timeline}}
{{clade
       |1={{clade|label1=[[Hylobatidae]] (Gibbons)|1={{clade
         |label1=
}}
       |label2=[[Hominidae]] (Great apes)
       |2={{clade|label1=[[Ponginae]] |1={{clade
         |label1= (Orangutans)           |1={{clade
           }} }}
         |label2=Homininae
          |2={{clade|label1=[[Gorillini]]  |1={{clade
             |label1=(Gorilla)
             |1={{clade
             }} }}
             |label2=[[Hominini]]
             |2={{clade
                |label1=[[Panina]]
                |1={{clade|label1=(chimpanzees)|1={{clade
                }} }}
                |2={{clade|label1=[[Hominina]] (Humans)|1={{clade
                }} }}
             }}         
         }}
      }}               
   }}|style1=font-size:80%; line-height:80%|label1=[[Hominoidea]] (Apes) }}


{{clade
       |1={{Clade
      |label1=Homininae (7)|1={{clade
      |1={{clade
        |1={{clade
          |1=[[Hominina]]
          |2=''[[Pan (genus)|Pan]]''
          |state3=dashed
          }}
}}
      |label3=[[Gorillini]]
      |2={{Clade
        |1=[[Gorillini|Crown Gorillini]]
        |2=''[[Chororapithecus]]'' (†)
     }}
    }}
    |state3=dashed
    |3=''[[Nakalipithecus]]'' (†10)
    |4=[[Dryopithecini]] (†)
  }}|style1=font-size:80%; line-height:80%|label1=[[Hominidae]] (Great apes) }}

'''Homininae'''
* Tribe [[Dryopithecini]][[†]] (?)
** ''[[Kenyapithecus]] (?)''
*** ''Kenyapitheus wickeri''
** ''[[Ouranopithecus]]''
*** ''Ouranopithecus macedoniensis''
** ''[[Otavipithecus]]''
*** ''Otavipithecus namibiensis''
** ''[[Oreopithecus]] (?)'' 
*** ''Oreopithecus bambolii''
** ''[[Nakalipithecus]]''
*** ''Nakalipithecus nakayamai''
** ''[[Anoiapithecus]]''
*** ''Anoiapithecus brevirostris''
** ''[[Dryopithecus]]'' 
*** ''Dryopithecus fontani''
** ''[[Hispanopithecus]] (?)'' 
*** ''Hispanopithecus laietanus''
*** ''Hispanopithecus crusafonti''
** ''[[Pierolapithecus]]''
*** ''Pierolapithecus catalaunicus''
** ''[[Rudapithecus]] (?)''
*** ''Rudapithecus hungaricus''
** ''[[Samburupithecus]]''
*** ''Samburupithecus kiptalami''
** ''[[Danuvius guggenmosi|Danuvius]]''
*** ''Danuvius guggenmosi''
* Tribe [[Gorillini]]
** ''[[Chororapithecus]]'' [[†]]
*** ''Chororapithecus abyssinicus''
** Genus ''[[Gorilla]]''
*** [[Western gorilla]], ''Gorilla gorilla''
**** [[Western lowland gorilla]], ''Gorilla gorilla gorilla''
**** [[Cross River gorilla]], ''Gorilla gorilla diehli''
*** [[Eastern gorilla]], ''Gorilla beringei''
**** [[Mountain gorilla]], ''Gorilla beringei beringei''
**** [[Eastern lowland gorilla]], ''Gorilla beringei graueri''
* Tribe [[Hominini]]
** Subtribe [[Pan (genus)|Panina]]
*** Genus ''[[Pan (genus)|Pan]]''
**** [[Common chimpanzee|Chimpanzee]] (common chimpanzee), ''Pan troglodytes''
***** [[Central chimpanzee]], ''Pan troglodytes troglodytes''
***** [[Western chimpanzee]], ''Pan troglodytes verus''
***** [[Nigeria-Cameroon chimpanzee]], ''Pan troglodytes ellioti''
***** [[Eastern chimpanzee]], ''Pan troglodytes schweinfurthii''
**** [[Bonobo]] (pygmy chimpanzee), ''Pan paniscus''
** Subtribe [[Hominina]]
*** ''[[Sahelanthropus]] (?)''[[†]]<ref>{{Cite journal |last1=Sevim-Erol |first1=Ayla |last2=Begun |first2=D. R. |last3=Sözer |first3=Ç Sönmez |last4=Mayda |first4=S. |last5=van den Hoek Ostende |first5=L. W. |last6=Martin |first6=R. M. G. |last7=Alçiçek |first7=M. Cihat |date=2023-08-23 |title=A new ape from Türkiye and the radiation of late Miocene hominines |journal=Communications Biology |language=en |volume=6 |issue=1 |page=842 |doi=10.1038/s42003-023-05210-5 |issn=2399-3642 |pmc=10447513 |pmid=37612372}}</ref> 
**** ''Sahelanthropus tchadensis''
*** ''[[Orrorin]]''[[†]]
**** ''Orrorin tugenensis''
**** ''Orrorin praegens''
*** ''[[Ardipithecus]]''[[†]]
**** ''[[Ardipithecus ramidus]]''
**** ''[[Ardipithecus kadabba]]''
*** ''[[Kenyanthropus]]''[[†]]
**** ''Kenyanthropus platyops''
*** ''[[Australopithecus]]''[[†]]
**** ''[[Australopithecus bahrelghazali]]''
**** ''[[Australopithecus anamensis]]''
**** ''[[Australopithecus afarensis]]''
**** ''[[Australopithecus africanus]]''
**** ''[[Australopithecus garhi]]''
**** ''[[Australopithecus sediba]]''
*** ''[[Paranthropus]]''[[†]]
**** ''[[Paranthropus aethiopicus]]''
**** ''[[Paranthropus robustus]]''
**** ''[[Paranthropus boisei]]''
*** ''[[Homo]]'' – immediate ancestors of modern [[human]]s
**** ''[[Homo gautengensis]]''[[†]] (probable ''H. habilis'' specimens)
**** ''[[Homo rudolfensis]]''[[†]]
**** ''[[Homo habilis]]''[[†]]
**** ''[[Homo floresiensis]]''[[†]]
**** ''[[Homo erectus]]''[[†]]
**** ''[[Homo ergaster]]''[[†]]
**** ''[[Homo antecessor]]''[[†]]
**** ''[[Homo heidelbergensis]]''[[†]]
**** ''[[Homo cepranensis]]''[[†]] (probable early ''H. sapiens'' specimens)
**** [[Denisova hominin|Denisovans]] (scientific name has not yet been assigned)[[†]]
**** ''[[Neanderthal|Homo neanderthalensis]]''[[†]]
**** ''[[Homo rhodesiensis]]''[[†]] (probable late ''H. heidelbergensis'' specimens)
**** ''[[Homo sapiens]]''
***** [[Anatomically modern human]], ''Homo sapiens sapiens''
****** ''[[Anatomically modern human|Archaic Homo sapiens]]'' ([[Cro-Magnon]])[[†]]
****** [[Red Deer Cave people]][[†]] (scientific name has not yet been assigned)
***** ''[[Homo sapiens idaltu]]''[[†]] (classification not widely accepted)

==Evolution==
{{see also|Human evolution|Human evolutionary genetics}}
The age of the subfamily Homininae (of the [[Orangutan–human last common ancestor|Homininae–Ponginae last common ancestor]]) is estimated at some 14<ref name=Hill&Ward1988>{{Cite journal |date=1988 | first1 = Andrew | last1 = Hill | first2 = Steven | last2 = Ward | name-list-style = vanc |title=Origin of the Hominidae: The Record of African Large Hominoid Evolution Between 14 My and 4 My|journal=Yearbook of Physical Anthropology |volume=31 |issue=59 |pages=49–83 |doi=10.1002/ajpa.1330310505| bibcode = 1988AJPA...31S..49H |doi-access=free }}</ref> to 12.5 million years (''[[Sivapithecus]]'').<ref name="FinarelliClyde2004">{{Cite journal | vauthors = Finarelli JA, Clyde WC | title = Reassessing hominoid phylogeny: Evaluating congruence in the morphological and temporal data | journal = Paleobiology | volume = 30 | issue = 4 | pages = 614–651 | year = 2004 | doi = 10.1666/0094-8373(2004)030<0614:RHPECI>2.0.CO;2 | bibcode = 2004Pbio...30..614F | s2cid = 86034107 | url = http://earth.unh.edu/clyde/PDF%20of%20Papers/Finarelli_Clyde_2004.pdf | access-date = 2017-12-04 | archive-url = https://web.archive.org/web/20100721142855/http://earth.unh.edu/clyde/PDF%20of%20Papers/Finarelli_Clyde_2004.pdf | archive-date = 2010-07-21 }}</ref><ref name="Chaimanee_etal2004">{{cite journal | vauthors = Chaimanee Y, Suteethorn V, Jintasakul P, Vidthayanon C, Marandat B, Jaeger JJ | title = A new orang-utan relative from the Late Miocene of Thailand | journal = Nature | volume = 427 | issue = 6973 | pages = 439–41 | date = January 2004 | pmid = 14749830 | doi = 10.1038/nature02245 | bibcode = 2004Natur.427..439C | s2cid = 4349664 | url = http://www.scienceinschool.org/repository/docs/issue5_nature_chaimanee2004.pdf | access-date = 2017-12-04 | archive-date = 2012-01-17 | archive-url = https://web.archive.org/web/20120117153522/http://www.scienceinschool.org/repository/docs/issue5_nature_chaimanee2004.pdf }}</ref> 
Its separation into Gorillini and Hominini (the "gorilla–human last common ancestor", GHLCA) is estimated to have occurred at about {{Mya|8|10}} (T<sub>GHLCA</sub>) during the late [[Miocene]], close to the age of ''[[Nakalipithecus|Nakalipithecus nakayamai]]''.<ref>{{cite news |last=Jha |first=Alok | name-list-style = vanc |date=March 7, 2012 |title= Gorilla genome analysis reveals new human links |url=https://www.theguardian.com/science/2012/mar/07/gorilla-genome-analysis-new-human-link |newspaper=The Guardian |access-date=May 8, 2015}}
{{cite news |last=Jha |first=Alok | name-list-style = vanc |date=March 9, 2012 |title=Scientists unlock genetic code for gorillas - and show the human link |url=http://www.smh.com.au/environment/animals/scientists-unlock-genetic-code-for-gorillas--and-show-the-human-link-20120308-1unam.html |newspaper=The Sydney Morning Herald |access-date=May 8, 2015}}
{{cite news |last=Hansford |first=Dave |date=November 13, 2007 |title=New Ape May Be Human-Gorilla Ancestor |url=http://news.nationalgeographic.com/news/2007/11/071113-ape-fossil.html |newspaper=National Geographic News |access-date=May 8, 2015}}</ref>

There is evidence there was interbreeding of Gorillas and the Pan–Homo ancestors until right up to the Pan–Homo split.<ref>{{Cite journal|last1=Popadin|first1=Konstantin|last2=Gunbin|first2=Konstantin|last3=Peshkin|first3=Leonid|last4=Annis|first4=Sofia|last5=Fleischmann|first5=Zoe|last6=Kraytsberg|first6=Genya|last7=Markuzon|first7=Natalya|last8=Ackermann|first8=Rebecca R.|last9=Khrapko|first9=Konstantin|date=2017-10-19|title=Mitochondrial pseudogenes suggest repeated inter-species hybridization in hominid evolution.|url=https://www.biorxiv.org/content/early/2017/10/19/134502|journal=bioRxiv|language=en|article-number=134502|doi=10.1101/134502|hdl=11427/36660 |doi-access=free|hdl-access=free}}</ref>

===Evolution of bipedalism===
{{more citations needed|section|date=April 2022}}
{{see also|Human skeletal changes due to bipedalism}}
Recent studies of ''[[Ardipithecus ramidus]]'' (4.4 million years old) and ''[[Orrorin tugenensis]]'' (6 million years old) suggest some degree of bipedalism. ''[[Australopithecus]]'' and early ''[[Paranthropus]]'' may have been [[bipedal]]. Very early hominins such as ''[[Ardipithecus ramidus]]'' may have possessed an arboreal type of bipedalism.<ref>{{cite journal | vauthors = Kivell TL, Schmitt D | title = Independent evolution of knuckle-walking in African apes shows that humans did not evolve from a knuckle-walking ancestor | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 106 | issue = 34 | pages = 14241–6 | date = August 2009 | pmid = 19667206 | pmc = 2732797 | doi = 10.1073/pnas.0901280106 | bibcode = 2009PNAS..10614241K | doi-access = free }}</ref>

The evolution of [[bipedalism]] encouraged multiple changes among hominins especially when it came to [[bipedalism]] in humans as they were now able to do many other things as they began to walk with their feet. These changes included the ability to now use their hands to create tools or carry things with their hands, the ability to travel longer distances at a faster speed, and the ability to hunt for food. According to researchers, humans were able to be bipedalists due to Darwin's Principle of [[natural selection]]. Darwin himself believed that larger brains in humans made an upright gait necessary, but had no hypothesis for how the mechanism evolved.

The first major theory attempting to directly explanation the origins of [[bipedalism]] was the [[Savannah hypothesis]] (Dart 1925.) This theory hypothesized that hominins became bipedalists due to the environment of the Savanna such as the tall grass and dry climate. This was later proven to be incorrect due to fossil records that showed that hominins were still climbing trees during this era.

Anthropologist [[Owen Lovejoy (anthropologist)|Owen Lovejoy]] has suggested that [[bipedalism]] was a result of [[sexual dimorphism]] in efforts to help with the collecting of food. In his Male Provisioning Hypothesis introduced in 1981, lowered birth rates in early hominids increased pressure on males to provide for females and offspring. While females groomed and cared for their children with the family group, males ranged to seek food and returned bipadally with full arms. Males who could better provide for females in this model were more likely to mate and produce offspring.<ref>{{cite web|website=NOVA|title=Origins of Bipedalism|url=https://www.pbs.org/wgbh/nova/allfours/bipe-nf.html|access-date=2023-06-25}}</ref>

Anthropologist Yohannes Haile-Selassie, an expert on ''[[Australopithecus anamensis]]'', discusses the evidence that Australopithecus were one of the first hominins to evolve into obligate bipedalists. The remains of this subfamily are very important in the field of research as it presents possible information regarding how these primates adapted from tree life to terrestrial life. This was a huge adaptation as it encouraged many evolutionary changes within hominins including the ability to use their hand to make tools and gather food, as well as a larger brain development due to their change in diet.<ref>{{Cite journal |last=Haile-Selassie |first=Yohannes |date=2021-12-01 |title=From Trees to the Ground: The Significance of Australopithecus anamensis in Human Evolution |journal=Journal of Anthropological Research |volume=77 |issue=4 |pages=457–482 |doi=10.1086/716743 |s2cid=240262976 |issn=0091-7710}}</ref>

===Brain size evolution===
{{more citations needed|section|date=December 2020}}
There has been a gradual increase in brain volume ([[brain size]]) as the ancestors of modern humans progressed along the [[timeline of human evolution]], starting from about 600&nbsp;cm<sup>3</sup> in ''[[Homo habilis]]'' up to 1500&nbsp;cm<sup>3</sup> in ''[[Homo neanderthalensis]]''. However, modern ''Homo sapiens'' have a brain volume slightly smaller (1250&nbsp;cm<sup>3</sup>) than Neanderthals, women have a brain slightly smaller than men and the Flores hominids (''[[Homo floresiensis]]''), nicknamed hobbits, had a cranial capacity of about 380&nbsp;cm<sup>3</sup> (considered small for a chimpanzee), about a third of the ''[[Homo erectus]]'' average. It is proposed that they evolved from ''H. erectus'' as a case of insular dwarfism.{{Citation needed|date=March 2012}} In spite of their smaller brain, there is evidence that ''H. floresiensis'' used fire and made stone tools at least as sophisticated as those of their proposed ancestors ''H. erectus''.<ref>{{cite journal | vauthors = Brown P, Sutikna T, Morwood MJ, Soejono RP, Saptomo EW, Due RA | title = A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia | journal = Nature | volume = 431 | issue = 7012 | pages = 1055–61 | date = October 2004 | pmid = 15514638 | doi = 10.1038/nature02999| bibcode = 2004Natur.431.1055B | s2cid = 26441 | url = http://doc.rero.ch/record/15287/files/PAL_E2586.pdf }}</ref> In this case, it seems that for intelligence, the structure of the brain is more important than its size.<ref>{{cite book |last=Davidson |first=I. |chapter=As large as you need and as small as you can—implications of the brain size of ''Homo floresiensis'' |chapter-url=https://www.academia.edu/218472 |editor-first=A.C. |editor-last=Schalley |editor2-first=D. |editor2-last=Khlentzos |title=Mental States: Evolution, function, nature; 2. Language and cognitive structure |publisher=John Benjamins |year=2007 |isbn=978-90-272-3105-5 |pages=35–42 |volume=92–93 |series=Studies in language companion}}</ref>

The current size of the human brain is a big distinguishing factor that separates humans from other primates. Recent examination of the human brain shows that the brain of a human is about more than four times the size of [[great ape]]s and 20 times larger than the brain size of [[Old World monkey|old world monkeys]]. A study<ref name="Wang-2004">{{Cite journal |last1=Wang |first1=Yin-qiu |last2=Su |first2=Bing |date=2004-06-01 |title=Molecular evolution of microcephalin, a gene determining human brain size |journal=Human Molecular Genetics |language=en |volume=13 |issue=11 |pages=1131–1137 |doi=10.1093/hmg/ddh127 |pmid=15056608 |issn=1460-2083|doi-access=free }}</ref> was conducted to help determine the evolution of the brain size within the sub family Homininae that tested the genes ASPM ([[ASPM (gene)|abnormal spindle-like microcephaly]] associated) and MCHP1 [[Microcephalin|(microcephalin-1]]) and their association with the human brain. In this study researchers discovered that the increase in brain size is correlated to the increase of both ASP and MCPH1. MCPH1 is very polymorphic in humans compared to [[gibbon]]s, [[Old World monkey]]s. This gene helps encouragegrowth of the brain. Further research indicated that the MCPH1 gene in humans could have also been an encouraging factor of population expansion. Other researchers have included that the diet was an encouraging factor to brain size as protein intake increased this helped brain development.<ref name="Wang-2004"/>

===Evolution of family structure and sexuality===
{{Update|section|reason=Cited evidence is out of date.|date=June 2023}}
{{see also|Human sexuality}}
Sexuality is related to family structure and partly shapes it. The involvement of fathers in education is quite unique to humans, at least when compared to other Homininae. [[Concealed ovulation]] and [[menopause]] in females also occur in a few other primates, but are uncommon in other species. [[Testis]] and [[penis size]] seem to be related to family structure: [[monogamy]] or [[promiscuity]], or [[Harem (zoology)|harem]], in humans, chimpanzees or gorillas, respectively.<ref>{{cite book|last=Diamond|first=Jared | name-list-style = vanc |author-link=Jared M. Diamond|title=The Third Chimpanzee|year=1991|title-link=The Third Chimpanzee}}</ref><ref name="WiSF">{{cite book|last=Diamond|first=Jared| name-list-style = vanc |title=Why is Sex Fun?|year=1997|title-link=Why is Sex Fun?}}</ref> The levels of [[sexual dimorphism]] are generally seen as a marker of [[sexual selection]]. Studies have suggested that the earliest hominins were dimorphic and that this lessened over the course of the evolution of the genus ''Homo'', correlating with humans becoming more monogamous, whereas gorillas, who live in harems, show a large degree of sexual dimorphism. Concealed (or "hidden") ovulation means that the phase of fertility is not detectable in women, whereas chimpanzees advertise ovulation via an obvious swelling of the genitals. Females can be partly aware of their ovulation along with their menstrual phases, but men are essentially unable to detect ovulation in women. Most primates have semi-concealed ovulation.  Thus, one can think that the common ancestor had semi-concealed ovulation, which was inherited by gorillas, and that later evolved in concealed ovulation in humans and advertised ovulation in chimpanzees. Menopause also occurs in [[rhesus monkeys]], and possibly in chimpanzees, but does not in gorillas and is quite uncommon in other primates (and other mammal groups).<ref name="WiSF"/>

== See also ==
{{Portal|Primates}}
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* {{Annotated link |Chimpanzee–human last common ancestor}}
* {{Annotated link |Gorilla–human last common ancestor}}
* {{Annotated link |Orangutan–human last common ancestor}}
* {{Annotated link |Gibbon–human last common ancestor}}
* {{Annotated link |List of human evolution fossils}}
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==Notes==
{{Reflist|group="Note"}}

==References==
{{Reflist|30em}}

== Further reading ==
*{{cite journal |first1=Madelaine |last1=Böhme |first2=Nikolai |last2=Spassov |first3=Jochen |last3=Fuss |first4=Adrian |last4=Tröscher |first5=Andrew S. |last5=Deane |first6=Jérôme |last6=Prieto |first7=Uwe |last7=Kirscher |first8=Thomas |last8=Lechner |first9=David R. |last9=Begun |title=A new Miocene ape and locomotion in the ancestor of great apes and humans |journal=Nature |date=2019 |volume=575 |issue=7783 |pages=489–493 |url=https://www.nature.com/articles/s41586-019-1731-0 |doi=10.1038/s41586-019-1731-0 |pmid=31695194 |bibcode=2019Natur.575..489B |s2cid=207888156 |display-authors=2|url-access=subscription }}
*{{cite book |last1=Andrews |first1=P. |last2=Harrison |first2=T. |year=2005 |chapter=7 The Last Common Ancestor of Apes and Humans |title=Interpreting the Past |location=Leiden, The Netherlands |publisher=Brill |doi=10.1163/9789047416616_013|s2cid=203884394 }}
*{{cite journal |last1=Goodman |first1=Morris |first2=Danilo A. |last2=Tagle |first3=David H. A. |last3=Fitch |first4=Wendy |last4=Bailey |first5=John |last5=Czelusniak |first6=Ben F. |last6=Koop |first7=Philip |last7=Benson |first8=Jerry L. |last8=Slightom |title=Primate Evolution at the DNA Level and a Classification of Hominoids |journal=Journal of Molecular Evolution |url=https://link.springer.com/article/10.1007/BF02099995 |volume=30 |year=1990 |issue=3 |pages=260–266 |doi=10.1007/BF02099995 |pmid=2109087 |bibcode=1990JMolE..30..260G |s2cid=2112935 |display-authors=2|url-access=subscription }}
*{{cite journal |last1=Haile-Selassie |first1=Yohannes |year=2021 |title=From trees to the ground: the significance of Australopithecus anamensis in human evolution |journal=Journal of Anthropological Research |volume=77 |issue=4 |pages=457–482 |doi=10.1086/716743|s2cid=240262976 }}
*{{cite book |first1=Edward |last1=Hollox |first2=Matthew |last2=Hurles |first3=Toomas |last3=Kivisild |first4=Chris |last4=Tyler-Smith |title=Human Evolutionary Genetics |year=2013 |publisher=Garland Science |isbn=978-0-8153-4148-2 |edition=2nd |display-authors=2}}
*{{cite journal |last1=Ko |first1=Kwang Hyun |title=Origins of Bipedalism |journal=Brazilian Archives of Biology and Technology |year=2015 |volume=58 |issue=6 |pages=929–934 |doi=10.1590/S1516-89132015060399 |s2cid=761213 |issn=1678-4324|doi-access=free }}
*{{cite journal |first1=Sandra |last1=Leyva-Hernández |first2=Ricardo |last2=Fong-Zazueta |first3=Luis |last3=Medrano-González |first4=Ana Julia |last4=Aguirre-Samudio |year=2021 |title=The evolution of brain size among the Homininae and selection at ASPM and MCPH1 genes|journal=Biosis: Biological Systems |volume=2 |issue=2 |pages=293–310 |doi=10.37819/biosis.002.02.0104 |display-authors=2|doi-access=free }}
*{{cite web |title=''Homininae'' |work=NCBI Taxonomy Browser |url=https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=207598 |id=207598}}

== External links ==
{{Wikibooks|Dichotomous Key|Homininae}}
{{Wikispecies|Homininae}}
* [http://humanorigins.si.edu/evidence/human-evolution-timeline-interactive Human Timeline (Interactive)] – [[Smithsonian Institution|Smithsonian]], [[National Museum of Natural History]] (August 2016).

{{Hominidae nav}}
{{Apes}}
{{Haplorhini|Ho.}}
{{Taxonbar|from=Q242047}}

[[Category:Homininae| ]]
[[Category:Hominidae]]
[[Category:Extant Miocene first appearances]]
[[Category:Mammal subfamilies]]
[[Category:Taxa named by John Edward Gray]]
[[Category:Taxa described in 1825]]