Editing Homo habilis (section)

==Taxonomy==
===Research history===
[[File:KNM-ER 1813 skull.jpg|thumb|left|[[KNM-ER 1813]] reconstructed skull and jaw]]
The first recognised remains—[[OH 7]], partial juvenile skull, hand, and foot bones dating to 1.75 million years ago (mya)—were discovered in [[Olduvai Gorge]], [[Tanzania]], in 1960 by Jonathan Leakey, with other native Africans who dug into Olduvai Gorge, and who worked for Jonathan Leakey. However, the actual first remains—OH 4, a molar—were discovered by the senior assistant of [[Louis Leakey|Louis]] and [[Mary Leakey|Mary]] Leakey (Jonathan's parents), Heselon Mukiri, other native Africans, in 1959, but this was not realised at the time.<ref name=Tobias2006/> By this time, the Leakeys had spent 29 years excavating in Olduvai Gorge for early [[hominin]] remains, but had instead recovered mainly other animal remains as well as the [[Oldowan]] [[Stone tool|stone-tool]] [[industry (archaeology)|industry]]. The industry had been ascribed to ''[[Paranthropus boisei]]'' (at the time "''Zinjanthropus''") in 1959 as it was the first and only hominin recovered in the area, but this was revised upon OH 7's discovery.<ref name=Tobias2006/> In 1964, Louis, South African palaeoanthropologist [[Phillip V. Tobias]], and British primatologist [[John R. Napier]] officially assigned the remains into the [[genus]] ''[[Homo]]'', and, on recommendation by Australian anthropologist [[Raymond Dart]], the [[specific name (zoology)|specific name]] ''H. habilis'', meaning "able, handy, mentally skillful, vigorous" in [[Latin]].<ref name=Leakey1964/> The specimen's association with the Oldowan (then considered evidence of advanced cognitive ability) was also used as justification for classifying it into ''Homo''.<ref name=Torre2011>{{cite journal|first=I.|last=de la Torre|year=2011|title=The origins of stone tool technology in Africa: a historical perspective|journal=Philosophical Transactions of the Royal Society B|volume=366|issue=1567|pages=1028–1037|doi=10.1098/rstb.2010.0350|pmc=3049100|pmid=21357225}}</ref> OH 7 was designated the [[holotype specimen]].<ref name=Leakey1964>{{cite journal|first1=L.|last1=Leakey|author-link=Louis Leakey|first2=P. V.|last2=Tobias|author-link2=Phillip V. Tobias|first3=J. R.|last3=Napier|author-link3=John R. Napier|year=1964|title=A New Species of the Genus ''Homo'' from Olduvai Gorge|journal=Nature|volume=202|issue=4927|pages=7–9|url=http://users.clas.ufl.edu/krigbaum/proseminar/leakey_etal_nature_1964.pdf|doi=10.1038/202007a0|pmid=14166722|bibcode=1964Natur.202....7L|s2cid=12836722}}</ref>

After description, it was hotly debated if ''H. habilis'' should be reclassified into ''[[Australopithecus africanus]]'' (the only other early hominin known at the time), in part because the remains were so old and at the time ''Homo'' was presumed to have evolved in Asia (with the australopithecines having no living descendants). Also, the brain size was smaller than what [[Wilfrid Le Gros Clark]] proposed in 1955 when considering ''Homo''.<ref name=Tobias2006/><ref name=Wood2000>{{cite journal|first1=B.|last1=Wood|first2=B. G.|last2=Richmond|year=2000|title=Human evolution: taxonomy and paleobiology|journal=Journal of Anatomy|volume=197|issue=Pt 1 |pages=39–41|doi=10.1046/j.1469-7580.2000.19710019.x|pmid=10999270|pmc=1468107}}</ref> The classification ''H. habilis'' began to receive wider acceptance as more fossil elements and species were unearthed.<ref name=Tobias2006>{{cite book <!-- Citation bot bypass-->|first=P. V.|last=Tobias|chapter=''Homo habilis''—A Premature Discovery: Remembered by One of its Founding Fathers, 42 Years Later |author-link=Phillip V. Tobias|title=The First Humans – Origin and Early Evolution of the Genus ''Homo''|series=Vertebrate Paleobiology and Paleoanthropology|date=2009 |publisher=Springer, Dordrecht|pages=7–15|isbn=978-1-4020-9980-9|doi=10.1007/978-1-4020-9980-9_2 | editor1=Frederick E. Grine | editor2=John G. Fleagle|editor3= Richard E. Leakey}}</ref> In 1983, Tobias proposed that ''A. africanus'' was a direct ancestor of ''[[Paranthropus]]'' and ''Homo'' (the two were [[sister taxa]]), and that ''A. africanus'' evolved into ''H. habilis'' which evolved into ''[[H. erectus]]'' which evolved into modern humans (by a process of [[cladogenesis]]). He further said that there was a major evolutionary leap between ''A. africanus'' and ''H. habilis'', and thereupon human evolution progressed gradually because ''H. habilis'' brain size had nearly doubled compared to australopithecine predecessors.<ref name=Tobias1983>{{cite journal|first=P. V.|last=Tobias|author-link=Phillip V. Tobias|year=1983|title=Hominid evolution in Africa|journal=Canadian Journal of Anthropology|volume=3|issue=2|url=https://capa-acap.net/sites/default/files/newsletter/cja_vol_3_2_1983.pdf#page=35|pages=163–183}}</ref>
{{Multiple image
| footer = Human evolution according to Tobias, 1983<ref name=Tobias1983/>
| width1 = 100
| width2 = 100
| width3 = 93
| width4 = 82
| align = center
| image1 = Australopithecus Skull.png
| caption1 = ''[[Australopithecus]]''
| image2 = Habilis Skull.png
| caption2 = '''''H. habilis'''''
| image3 = Ergaster Skull.png
| caption3 = ''[[H. ergaster]]''<br />''[[H. erectus]]''
| image4 = Sapiens Skull.png
| caption4 = ''[[H. sapiens]]''
}}

[[File:OH 7 replica 04.JPG|thumb|upright|Cast of the [[type specimen]] [[OH 7]]]]

Many had accepted Tobias' model and assigned [[Late Pliocene]] to [[Early Pleistocene]] hominin remains outside the range of ''Paranthropus'' and ''H. erectus'' into ''H. habilis''. For non-skull elements, this was done on the basis of size as there was a lack of clear diagnostic characteristics.<ref name=Johanson1986/> Because of these practices, the range of variation for the species became quite wide, and the terms ''H. habilis'' [[sensu stricto]] (i.e. strictly) and ''H. habilis'' [[sensu lato]] (i.e. broadly) were in use to exclude and include, respectively, more discrepant morphs. To address this controversy, English palaeoanthropologist Bernard Wood proposed in 1985, that the comparatively massive skull KNM-ER 1470 from [[Lake Turkana]], Kenya, discovered in 1972 and assigned to ''H. habilis'', actually represented a different species,<ref>{{cite book|first=B.|last=Wood|year=1985|chapter=Early ''Homo'' in Kenya, systematic relationships|title=Ancestors: The hard evidence|editor-first=E.|editor-last=Delson|publisher=Alan R. Liss|isbn=978-0-8451-0249-7}}</ref> now referred to as ''[[Homo rudolfensis]]''. It is also argued that instead it represents a male specimen whereas other ''H. habilis'' specimens are female.<ref>{{Cite journal| volume = 36| issue = 1| pages = 115–118| last = Wood| first = B.| title = ''Homo rudolfensis'' Alexeev, 1986: Fact or phantom?| journal = Journal of Human Evolution| year = 1999| doi = 10.1006/jhev.1998.0246| pmid = 9924136}}</ref> Early ''Homo'' from South Africa have variously been assigned to ''H. habilis'' or ''H. ergaster''&nbsp;/&nbsp;''H. erectus'', but species designation has largely been unclear. In 2010, Australian archaeologist Darren Curoe proposed splitting off South African early ''Homo'' into a new species, "''[[Homo gautengensis]]''".<ref>{{Cite journal|last=Curnoe|first=D.|year=2010|title=A review of early ''Homo'' in southern Africa focusing on cranial, mandibular and dental remains, with the description of a new species (''Homo gautengensis'' sp. nov.)|url=https://www.sciencedirect.com/science/article/pii/S0018442X10000727|journal=HOMO: Journal of Comparative Human Biology|volume=61|issue=3|pages=151–177|doi=10.1016/j.jchb.2010.04.002|pmid=20466364}}</ref>

In 1986, OH 62, a fragmentary skeleton was discovered by American anthropologist [[Tim D. White]] in association with ''H. habilis'' skull fragments, definitively establishing aspects of ''H. habilis'' skeletal anatomy for the first time, and revealing more ''[[Australopithecus]]''-like than ''Homo''-like features.<ref name=Johanson1986>{{cite journal|first1=D. C.|last1=Johanson|author1-link=Donald Johanson|first2=F.|last2=Masao|first3=G. G.|last3=Eck|first4=T. D.|last4=White|author4-link=Tim D. White|display-authors=et al.|year=1987|title=New partial skeleton of ''Homo habilis'' from Olduvai Gorge, Tanzania|journal=Nature|volume=327|issue=6119|pages=205–209|doi=10.1038/327205a0|pmid=3106831|bibcode=1987Natur.327..205J|s2cid=4321698}}</ref> Because of this, as well as similarities in dental adaptations, Wood and biological anthropologist Mark Collard suggested moving the species to ''Australopithecus'' in 1999.<ref>{{cite journal|first1=B.|last1=Wood|first2=M.|last2=Collard|year=1999|title=The Human Genus|journal=Science|volume=284|issue=5411|pages=65–71|doi=10.1126/science.284.5411.65|pmid=10102822|bibcode=1999Sci...284...65.|s2cid=7018418|url=https://pdfs.semanticscholar.org/5cbf/24153dbb801176e3089052060a9d92b5082b.pdf|archive-url=https://web.archive.org/web/20201123192921/https://pdfs.semanticscholar.org/5cbf/24153dbb801176e3089052060a9d92b5082b.pdf|url-status=dead|archive-date=2020-11-23}}</ref><ref>{{cite journal | author = Miller J. M. A. | year = 2000 | title = Craniofacial variation in ''Homo habilis'': an analysis of the evidence for multiple species | journal = American Journal of Physical Anthropology | volume = 112 | issue = 1| pages = 103–128 | doi=10.1002/(SICI)1096-8644(200005)112:1<103::AID-AJPA10>3.0.CO;2-6 | pmid=10766947}}</ref><ref>{{cite journal|first=P. V.|last=Tobias|year=1991|title=The species ''Homo habilis'': example of a premature discovery|journal=Annales Zoologici Fennici|volume=28|issue=3–4|pages=371–380|jstor=23735461}}</ref><ref>{{Cite book | doi=10.1007/978-3-642-39979-4_51|chapter = Defining the Genus Homo|title = Handbook of Paleoanthropology| pages=2107–2144|year = 2015|last1 = Collard|first1 = Mark| last2=Wood| first2=Bernard| isbn=978-3-642-39978-7}}</ref> However, reevaluation of OH 62 to a more humanlike physiology, if correct, would cast doubt on this.<ref name=Haeusler2004/> The discovery of the 1.8 Ma Georgian [[Dmanisi skulls]] in the early 2000s, which exhibit several similarities with early ''Homo'', has led to suggestions that all contemporary groups of early ''Homo'' in Africa, including ''H. habilis'' and ''H. rudolfensis'', are the same species and should be assigned to ''H. erectus''.<ref name=Dmanisi>{{Cite journal |last1=Margvelashvili |first1=A. |last2=Zollikofer |first2=C. P. E. |last3=Lordkipanidze |first3=D. |last4=Peltomäki |first4=T. |last5=Ponce de León |first5=M. S. |year=2013 |title=Tooth wear and dentoalveolar remodeling are key factors of morphological variation in the Dmanisi mandibles |journal=Proceedings of the National Academy of Sciences |volume=110 |issue=43 |language=en |pages=17278–83 |doi=10.1073/pnas.1316052110 |issn=0027-8424 |pmid=24101504 |pmc=3808665 |bibcode=2013PNAS..11017278M|doi-access=free }}</ref><ref>{{Cite journal |last1=Lordkipanidze |first1=D. |last2=Ponce de León |first2=M. S. |last3=Margvelashvili |first3=A. |last4=Rak |first4=Y. |last5=Rightmire |first5=G. P. |last6=Vekua |first6=A. |last7=Zollikofer |first7=C. P. E. |year=2013 |title=A Complete Skull from Dmanisi, Georgia, and the Evolutionary Biology of Early Homo |journal=Science |language=en |volume=342 |issue=6156 |pages=326–331 |doi=10.1126/science.1238484 |issn=0036-8075 |pmid=24136960 |bibcode=2013Sci...342..326L |s2cid=20435482}}</ref>

===Classification===
{{cladogram|align=left|caption=''[[Homo]]'' family tree showing ''H. habilis'' and ''H. rudolfensis'' at the base as offshoots of the human line<ref>{{Cite book |last1=Strait |first1=D. |title=Handbook of Paleoanthropology |last2=Grine |first2=F. |last3=Fleagle |first3=J. G. |author3-link=John G. Fleagle |publisher=Springer |year=2015 |isbn=978-3-642-39979-4 |editor-last=Henke |editor-first=W. |edition=2nd |chapter=Analyzing Hominin Phylogeny: Cladistic Approach |page=2006 |doi=10.1007/978-3-642-39979-4_58 |editor-last2=Tattersall |editor-first2=I. |editor2-link=Ian Tattersall |chapter-url=http://www.academia.edu/download/55535112/Homo_ergaster_Handbook_2_2015.pdf |access-date=2020-06-12 |archive-date=2020-06-12 |archive-url=https://web.archive.org/web/20200612125818/http://www.academia.edu/download/55535112/Homo_ergaster_Handbook_2_2015.pdf |url-status=dead }}</ref>|cladogram={{clade|style=font-size:85%;line-height:75%;width:300px;
|1={{clade
 |1={{clade
  |1='''''H. habilis'''''
  |2=''[[H. rudolfensis]]''
  }}
 |2={{clade
  |1=''[[H. ergaster]]''
  |2={{clade
   |1=''[[H. erectus]]''
   |2={{clade
    |1=''[[H. antecessor]]''
    |2={{clade
     |1={{clade
      |1=''[[H. heidelbergensis]]''
      |2=''[[H. neanderthalensis]]''
      }}
     |2=''[[H. sapiens]]''
    }}
   }}
  }}
 }}
}}
}}}}

There is still no wide consensus as to whether or not ''H. habilis'' is ancestral to ''[[H. ergaster]]''&nbsp;/&nbsp;''H. erectus'' or is an offshoot of the human line,<ref>{{cite journal|first=I.|last=Tattersall|author-link=Ian Tattersall|year=2019|title=Classification and phylogeny in human evolution|journal=Ludus Vitalis|volume=9|issue=15|pages=139–140|url=http://www.ludus-vitalis.org/ojs/index.php/ludus/article/view/617|access-date=2020-06-10|archive-date=2021-04-15|archive-url=https://web.archive.org/web/20210415102615/http://www.ludus-vitalis.org/ojs/index.php/ludus/article/view/617|url-status=dead}}</ref> and whether or not all specimens assigned to ''H. habilis'' are correctly assigned or the species is an assemblage of different ''Australopithecus'' and ''Homo'' species.<ref>{{cite book|last1=Tattersall|first1=I.|author1-link=Ian Tattersall|last2=Schwartz|first2=J. H.|author2-link=Jeffrey H. Schwartz|title=Extinct Humans|publisher=Basic Books|year=2001|page=111|isbn=978-0-8133-3918-4}}</ref> Studies of the dental morphology of ''H. habilis'' have suggested that it shares greater similarity with ''Australopithecus'' than with later ''Homo'' species.<ref>{{Cite journal |last=Davies |first=Thomas W. |last2=Gunz |first2=Philipp |last3=Spoor |first3=Fred |last4=Alemseged |first4=Zeresenay |last5=Gidna |first5=Agness |last6=Hublin |first6=Jean-Jacques |last7=Kimbel |first7=William H. |last8=Kullmer |first8=Ottmar |last9=Plummer |first9=William P. |last10=Zanolli |first10=Clément |last11=Skinner |first11=Matthew M. |date=4 January 2024 |title=Dental morphology in Homo habilis and its implications for the evolution of early Homo |url=https://www.nature.com/articles/s41467-023-44375-9?fromPaywallRec=false |journal=[[Nature Communications]] |language=en |volume=15 |issue=1 |pages=286 |doi=10.1038/s41467-023-44375-9 |issn=2041-1723 |access-date=20 November 2024|pmc=10767101 }}</ref> Nonetheless, ''H. habilis'' and ''H. rudolfensis'' generally are recognised members of the genus at the base of the family tree, with arguments for synonymisation or removal from the genus not widely adopted.<ref>{{cite book|first1=D.|last1=Strait|first2=F. E.|last2=Grine|first3=J. G.|last3=Fleagle|year=2014|chapter=Analyzing Hominin Phylogeny: Cladistic Approach|title=Handbook of Paleoanthropology|edition=2nd|publisher=Springer|pages=2005–2006|isbn=978-3-642-39979-4}}</ref>

Though it is now largely agreed upon that ''Homo'' evolved from ''Australopithecus'', the timing and placement of this split has been much debated, with many ''Australopithecus'' species having been proposed as the ancestor. The discovery of [[LD 350-1]], the oldest ''Homo'' specimen, dating to 2.8 mya, in the [[Afar Region]] of Ethiopia may indicate that the genus evolved from ''[[A. afarensis]]'' around this time. This specimen was initially classified as ''Homo'' sp.,<ref>{{cite journal|first1=B.|last1=Villmoare|first2=W. H.|last2=Kimbel|first3=C.|last3=Seyoum|display-authors=et al.|year=2015|title=Early ''Homo'' at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia|journal=Science|volume=347|issue=6228|pages=1352–1355|doi=10.1126/science.aaa1343|pmid=25739410|bibcode=2015Sci...347.1352V|doi-access=free}}</ref> though subsequent studies have suggested that it also shares characteristics with ''Australopithecus'' and that it is clearly distinct from ''H. habilis''.<ref>{{cite journal|author1=Hawks, J.|author2=De Ruiter, D.J.|author3=Berger, L.R.|year=2015|title=Comment on “Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia”|journal=Science|volume=348|issue=6241|pages=1326|doi=10.1126/science.aab0591}}</ref><ref>{{cite journal|author1=Neves, W.|author2=Senger, M.H.|author3=Rocha, G.|author4=Suesdek, L.|author5=Hubbe, M.|year=2024|title=Ledi-Geraru strikes again: Morphological affinities of the LD 350-1 mandible with early ''Homo''|journal=Anais da Academia Brasileira de Ciências|volume=95|issue=1|doi=10.1590/0001-3765202320230032|doi-access=free}}</ref> The oldest ''H. habilis'' specimen, A.L. 666-1, dates to 2.3 mya, but is anatomically more [[Apomorphy and synapomorphy|derived]] (has less ancestral, or basal, traits) than the younger OH 7, suggesting derived and basal morphs lived concurrently, and that the ''H. habilis'' lineage began before 2.3 mya.<ref name=Spoor2015/> Based on 2.1-million-year-old stone tools from [[Shangchen]], China, ''H. habilis'' or an ancestral species may have dispersed across Asia.<ref>{{cite journal |last1=Zhu |first1=Z. |last2=Dennell |first2=R. |last3=Huang |first3=W. |last4=Wu |first4=Y. |last5=Qiu |first5=S. |last6=Yang |first6=S. |last7=Rao |first7=Z. |last8=Hou |first8=Y. |last9=Xie |first9=J. |last10=Han |first10=J. |last11=Ouyang |first11=T. |year=2018 |title=Hominin occupation of the Chinese Loess Plateau since about 2.1 million years ago |journal=Nature |volume=559 |issue=7715 |pages=608–612 |doi=10.1038/s41586-018-0299-4 |pmid=29995848 |bibcode=2018Natur.559..608Z |s2cid=49670311}}</ref> The youngest ''H. habilis'' specimen, OH 13, dates to about 1.65 mya.<ref name=Spoor2015/>

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{{African hominin timeline}}