View source for Homo habilis

{{Short description|Archaic human species from 2.4 to 1.65 mya}}
{{good article}}
{{Speciesbox
| fossil_range = {{fossil range|2.3|1.65}}
| image = KNM ER 1813 (H. habilis).png
| image_caption = Reconstruction of [[KNM-ER 1813]] at the [[Naturmuseum Senckenberg]], Germany
| extinct = yes
| genus = Homo
| species = habilis
| authority = [[Louis Leakey|Leakey]] et al., 1964
| synonyms =
* ''Australopithecus habilis''<br /><small>Wood and Collard, 1999</small>
* ''[[Homo microcranous]]''<br /><small>[[Walter Ferguson|Ferguson]], 1995</small>
* ''[[Homo gautengensis]]''?<br /><small>Curnoe, 2010</small>
* ''[[Homo rudolfensis]]''?<br /><small>Alexeev, 1986</small>
| synonyms_ref = <ref>{{cite journal|last=Antón|first=S. C.|year=2012|title=Early ''Homo'': Who, When, and Where|journal=Current Anthropology|volume=53|issue=6|page=279|doi=10.1086/667695|s2cid=84830570}}</ref>
}}

'''''Homo habilis''''' ({{lit}} 'handy man') is an extinct [[species]] of [[archaic human]] from the [[Early Pleistocene]] of East and South Africa about 2.4 million years ago to 1.65 million years ago ([[Million years ago|mya]]). It is among the oldest species of archaic humans. <ref>{{cite book|title= The Cambridge Encyclopedia of Human Evolution |last=Stringer |first=C.B. |author-link=Chris Stringer |chapter=Evolution of early humans |editor-last1=Jones |editor-first1=S. |editor-last2=Martin |editor-first2=R. |editor-last3=Pilbeam |editor-first3=D. |year=1994 |publisher=[[Cambridge University Press]] |location=Cambridge |page=242}}</ref><ref>{{cite book |last1=Schrenk |first1=F. |last2=Kullmer |first2=O. |last3=Bromage |first3=T. |chapter=Chapter 9: The Earliest Putative ''Homo'' Fossils |editor-last1=Henke |editor-first1=W. |editor-last2=Tattersall |editor-first2=I. |title=Handbook of Paleoanthropology |date=2007 |pages=1611–1631 |doi=10.1007/978-3-540-33761-4_52}}</ref> Suggestions for pushing back the age to 2.8 Mya were made in 2015 based on the discovery of [[LD 350-1|a jawbone]].<ref>{{cite journal |last1=Spoor |first1=F. |last2=Gunz |first2=P. |last3=Neubauer |first3=S. |last4=Stelzer |first4=S. |last5=Scott |first5=N. |last6=Kwekason |first6=A. |last7=Dean |first7=M.C. |title=Reconstructed Homo habilis type OH 7 suggests deep-rooted species diversity in early Homo |journal=[[Nature (journal)|Nature]] |volume=519 |issue=7541 |pages=83–86 |date=March 2015 |pmid=25739632 |doi=10.1038/nature14224 |s2cid=4470282 |bibcode=2015Natur.519...83S}}</ref> Upon species description in 1964, ''H. habilis'' was highly contested, with many researchers recommending it be [[synonym (taxonomy)|synonymised]] with ''[[Australopithecus africanus]]'', the only other early [[hominin]] known at the time, but ''H. habilis'' received more recognition as time went on and more relevant discoveries were made. By the 1980s, ''H. habilis'' was proposed to have been a human ancestor, directly evolving into ''[[Homo erectus]]'', which directly led to modern humans. This viewpoint is now debated. Several specimens with insecure species identification were assigned to ''H. habilis'', leading to arguments for splitting, namely into "''[[H. rudolfensis]]''" and "''[[H. gautengensis]]''" of which only the former has received wide support.

''H. habilis'' brain size generally varied from {{cvt|500|to(-)|900|cm3}}. The body proportions of ''H. habilis'' are only known from two highly fragmentary skeletons, and is based largely on assuming a similar anatomy to the earlier [[australopithecine]]s. Because of this, it has also been proposed ''H. habilis'' be moved to the [[genus]] ''[[Australopithecus]]'' as '''''Australopithecus habilis'''''. However, the interpretation of ''H. habilis'' as a small-statured human with inefficient long-distance travel capabilities has been challenged. The presumed female specimen OH 62 is traditionally interpreted as having been {{cvt|100–120|cm|ftin}} in height and {{cvt|20–37|kg}} in weight assuming australopithecine-like proportions, but assuming humanlike proportions she would have been about {{cvt|148|cm|ftin}} and {{cvt|35|kg}}. Nonetheless, ''Homo habilis'' may have been at least partially [[arboreal]] like what is postulated for australopithecines. Early hominins are typically reconstructed as having thick hair and marked [[sexual dimorphism]] with males much larger than females, though relative male and female size is not definitively known.

''H. habilis'' manufactured the [[Oldowan|Oldowan stone tool industry]] and mainly used tools in butchering. Early ''Homo'', compared to australopithecines, are generally thought to have consumed high quantities of meat and, in the case of ''H. habilis'', scavenged meat. Typically, early hominins are interpreted as having lived in [[polygynous]] societies, though this is highly speculative. Assuming ''H. habilis'' society was similar to that of modern savanna [[chimpanzee]]s and [[baboon]]s, groups may have numbered 70–85 members. This configuration would be advantageous with multiple males to defend against open savanna predators, such as big cats, hyenas and crocodiles. ''H. habilis'' coexisted with ''H. rudolfensis'', ''[[H. ergaster]]''&nbsp;/&nbsp;''H. erectus'' and ''[[Paranthropus boisei]]''.

==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=https://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| bibcode = 1999JHumE..36..115W}}</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|url-access=subscription}}</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|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 }}</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}}</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 |last1=Davies |first1=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 |journal=[[Nature Communications]] |language=en |volume=15 |issue=1 |page=286 |doi=10.1038/s41467-023-44375-9 |pmid=38177110 |issn=2041-1723 |pmc=10767101 |bibcode=2024NatCo..15..286D }}</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|page=1326|doi=10.1126/science.aab0591 |pmid=26089505 |bibcode=2015Sci...348.1326H }}</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|article-number=e20230032 |doi=10.1590/0001-3765202320230032|pmid=37493698 |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/>

{{clear}}
{{African hominin timeline}}

==Anatomy==
===Skull===
[[File:Homo habilis - forensic facial reconstruction.png|thumb|left|upright|''Homo habilis'' – forensic facial reconstruction]]
It has generally been thought that brain size increased along the human line especially rapidly at the transition between species, with ''H. habilis'' brain size smaller than that of ''H. ergaster''&nbsp;/&nbsp;''H. erectus'', jumping from about {{cvt|600–650|cc}} in ''H. habilis'' to about {{cvt|900–1000|cc}} in ''H. ergaster'' and ''H. erectus''.<ref name=Spoor2015/><ref name=Tobias1987/> However, a 2015 study showed that the brain sizes of ''H. habilis'', ''H. rudolfensis'', and ''H. ergaster'' generally ranged between {{cvt|500–900|cc}} after reappraising the brain volume of OH 7 from {{cvt|647–687|cc}} to {{cvt|729–824|cc}}.<ref name=Spoor2015/> This does, nonetheless, indicate a jump from australopithecine brain size which generally ranged from {{cvt|400–500|cc}}.<ref name=Tobias1987>{{cite journal|first=P. V.|last=Tobias|year=1987|title=The brain of ''Homo habilis'': A new level of organization in cerebral evolution|journal=Journal of Human Evolution|volume=16|issue=7–8|pages=741–761|doi=10.1016/0047-2484(87)90022-4 |bibcode=1987JHumE..16..741T }}</ref>
{{Human timeline}}
The brain anatomy of all ''Homo'' features an expanded [[cerebrum]] in comparison to australopithecines. The pattern of striations on the teeth of OH 65 slant right, which may have been accidentally self-inflicted when the individual was pulling a piece of meat with its teeth and the left hand while trying to cut it with a stone tool using the right hand. If correct, this could indicate right [[handedness]], and handedness is associated with major reorganisation of the brain and the [[lateralisation of brain function]] between the left and right hemispheres. This scenario has also been hypothesised for some Neanderthal specimens. Lateralisation could be implicated in tool use. In modern humans, lateralisation is weakly associated with language.<ref>{{cite journal|first1=D. W.|last1=Frayer|first2=R. J.|last2=Clarke|first3=I.|last3=Fiore|display-authors=et al.|year=2016|title=OH-65: The earliest evidence for right-handedness in the fossil record|journal=Journal of Human Evolution|volume=100|pages=65–72|doi=10.1016/j.jhevol.2016.07.002|pmid=27765150 |bibcode=2016JHumE.100...65F }}</ref>

The tooth rows of ''H. habilis'' were V-shaped as opposed to U-shaped in later ''Homo'', and the mouth jutted outwards (was [[prognathic]]), though the face was flat from the nose up.<ref name=Spoor2015>{{cite journal |author1=F. Spoor |author2=P. Gunz |author3=S. Neubauer |author4=S. Stelzer |author5=N. Scott |author6=A. Kwekason |author7=M. C. Dean | year = 2015 | title = Reconstructed ''Homo habilis'' type OH 7 suggests deep-rooted species diversity in early ''Homo'' | journal = Nature | volume = 519 |issue= 7541 | pages =83–86 | doi= 10.1038/nature14224 | pmid=25739632 | bibcode=2015Natur.519...83S|s2cid=4470282 }}</ref>

===Build===
Based on the fragmentary skeletons OH 62 (presumed female) and KNM-ER 3735 (presumed male), ''H. habilis'' body anatomy has generally been considered to have been more apelike than even that of the earlier ''A. afarensis''; this is consistent with an at least partially [[arboreal]] lifestyle in the trees as is assumed in australopithecines. Based on OH 62 and assuming comparable body dimensions to australopithecines, ''H. habilis'' has generally been interpreted as having been small-bodied like australopithecines, with OH 62 generally estimated at {{cvt|100–120|cm|ftin}} in height and {{cvt|20–37|kg}} in weight. However, assuming longer, modern humanlike legs, OH 62 would have been about {{cvt|148|cm|ftin}} and {{cvt|35|kg}}, and KNM-ER 3735 about the same size.<ref>{{cite journal|first1=M.|last1=Will|first2=J. T.|last2=Stock|year=2015|title=Spatial and temporal variation of body size among early ''Homo''|journal=Journal of Human Evolution|volume=82|pages=15–33|doi=10.1016/j.jhevol.2015.02.009|pmid=25818180|bibcode=2015JHumE..82...15W |doi-access=free}}</ref> For comparison, modern human men and women in the year 1900 averaged {{cvt|163|cm|ftin}} and {{cvt|152.7|cm|ft}}, respectively.<ref>{{cite journal|url=https://ourworldindata.org/human-height|first1=M.|last1=Roser|author1-link=Max Roser |first2=C.|last2=Appel|first3=H.|last3=Ritchie|author3-link=Hannah Ritchie |year=2013|title=Human Height|journal=Our World in Data|access-date=16 June 2020}}</ref> It is generally assumed that pre-''H. ergaster'' hominins, including ''H. habilis'', exhibited notable [[sexual dimorphism]] with males markedly bigger than females. However, relative female body mass is unknown in this species.<ref name=Ungar2006>{{cite journal|first1=P. S.|last1=Ungar|first2=F. E.|last2=Grine|year=2006|title=Diet in Early ''Homo'': A Review of the Evidence and a New Model of Adaptive Versatility|journal=Annual Review of Anthropology|volume=35|pages=208–228|doi=10.1146/annurev.anthro.35.081705.123153}}</ref>

Early hominins, including ''H. habilis'', are thought to have had thick body hair coverage like modern non-human apes because they appear to have inhabited colder regions and are thought to have had a less active lifestyle than (presumed hairless) post-''ergaster'' species. Consequently, they probably required thick body hair to stay warm.<ref>{{cite journal|first1=T.|last1=Dávid-Berrett|first2=R. I. M.|last2=Dunbar|year=2016|title=Bipedality and hair loss in human evolution revisited: The impact of altitude and activity scheduling|journal=Journal of Human Evolution|volume=94|pages=72–82|doi=10.1016/j.jhevol.2016.02.006|pmid=27178459|pmc=4874949 |bibcode=2016JHumE..94...72D }}</ref> Based on dental development rates, ''H. habilis'' is assumed to have had an accelerated growth rate compared to modern humans, more like that of modern non-human apes.<ref>{{cite journal|first=G. T.|last=Schwartz|year=2012|title=Growth, Development, and Life History throughout the Evolution of ''Homo''|journal=Current Anthropology|volume=53|issue=6|pages=400–401|doi=10.1086/667591|s2cid=84537505}}</ref>

===Limbs===
[[File:Olduvai Hominin 8.jpg|thumb|left|upright=1.3|OH 8, bearing crocodile tooth marks]]
The arms of ''H. habilis'' and australopithecines have generally been considered to have been proportionally long and so adapted for climbing and swinging.<ref>{{cite journal|first1=M.|last1=Haeusler|first2=H.|last2=McHenry|year=2007|title=Evolutionary reversals of limb proportions in early hominids? evidence from KNM-ER 3735 (''Homo habilis'')|journal=Journal of Human Evolution|volume=53|issue=4|pages=385–405|doi=10.1016/j.jhevol.2007.06.001|pmid=17688910 |bibcode=2007JHumE..53..383H }}</ref><ref>{{Cite journal|date=21 May 1987|author1=Donald C. Johanson |author2=Fidelis T. Masao |author3=Gerald G. Eck |author4=Tim D. White |author5=Robert C. Walter |author6=William H. Kimbel |author7=Berhane Asfaw |author8=Paul Manega |author9=Prosper Ndessokia |author10=Gen Suwa |title=New partial skeleton of ''Homo habilis'' from Olduvai Gorge, Tanzania |journal=Nature |volume=327 |pages=205–209 |doi=10.1038/327205a0 |pmid=3106831 |issue=6119 |bibcode=1987Natur.327..205J |s2cid=4321698 }}</ref><ref>{{Cite journal|year=1987|author=Wood, B. |title=Who is the 'real' ''Homo habilis''?|journal=Nature |volume=327 |pages=187–188 |doi= 10.1038/327187a0 |pmid=3106828 |issue=6119|bibcode=1987Natur.327..187W |s2cid=4329573 }}</ref> In 2004, anthropologists Martin Haeusler and [[Henry McHenry (anthropologist)|Henry McHenry]] argued that, because the [[humerus]] to [[femur]] ratio of OH 62 is within the range of variation for modern humans, and KNM-ER 3735 is close to the modern human average, it is unsafe to assume apelike proportions. Nonetheless, the humerus of OH 62 measured {{cvt|258–270|mm}} long and the [[ulna]] (forearm) {{cvt|245–255|mm}}, which is closer to the proportion seen in chimpanzees. The hand bones of OH 7 suggest precision gripping, important in dexterity, as well as adaptations for climbing. In regard to the femur, traditionally comparisons with the ''A. afarensis'' specimen AL 288-1 have been used to reconstruct stout legs for ''H. habilis'', but Haeusler and McHenry suggested the more gracile OH 24 femur (either belonging to ''H. ergaster''&nbsp;/&nbsp;''H. erectus'' or ''P. boisei'') may be a more apt comparison. In this instance, ''H. habilis'' would have had longer, humanlike legs and have been effective long-distance travellers as is assumed to have been the case in ''H. ergaster''.<ref name=Haeusler2004>{{cite journal|title=Body Proportions of ''Homo Habilis''|first1=M.|last1=Haeusler|first2=H. M.|last2=McHenry|journal=Journal of Human Evolution|volume=46|issue=4|pages=433–465|year=2004|doi=10.1016/j.jhevol.2004.01.004|pmid=15066379}}</ref> However, estimating the unpreserved length of a fossil is highly problematic. The thickness of the limb bones in OH 62 is more similar to chimpanzees than ''H. ergaster''&nbsp;/&nbsp;''H. erectus'' and modern humans, which may indicate different load bearing capabilities more suitable for arboreality in ''H. habilis''.<ref>{{cite journal|first=C.|last=Ruff|year=2009|title=Relative Limb Strength and Locomotion in ''Homo habilis''|journal=American Journal of Physical Anthropology|volume=138|issue=1|pages=90–100|doi=10.1002/ajpa.20907|pmid=18711733 |bibcode=2009AJPA..138...90R }}</ref> The strong [[fibula]] of OH 35 (though this may belong to ''P. boisei'') is more like that of non-human apes, and consistent with arboreality and vertical climbing.<ref>{{cite journal|first1=D.|last1=Marchi|first2=C. M.|last2=Harper|first3=H.|last3=Chirchir|first4=C. B.|last4=Ruff|year=2019|title=Relative fibular strength and locomotor behavior in KNM-WT 15000 and OH 35|journal=Journal of Human Evolution|volume=131|pages=48–60|doi=10.1016/j.jhevol.2019.02.005|pmid=31182206|bibcode=2019JHumE.131...48M |hdl=11568/994382 |s2cid=145846013|hdl-access=free}}</ref>

[[Olduvai Hominid 8|OH 8]], a foot, is better suited for terrestrial movement than the foot of ''A. afarensis'', though it still retains many apelike features consistent with climbing.<ref name=Haeusler2004/> However, the foot has projected toe bone and compacted mid-foot joint structures, which restrict rotation between the foot and ankle as well as at the front foot. Foot stability enhances the efficiency of force transfer between the leg and the foot and vice versa, and is implicated in the [[plantar arch]] elastic spring mechanism which generates energy while running (but not walking). This could possibly indicate ''H. habilis'' was capable of some degree of [[Endurance running hypothesis|endurance running]], which is typically thought to have evolved later in ''H. ergaster''&nbsp;/&nbsp;''H. erectus''.<ref>{{cite journal|last1=Bramble|first1=D.|last2=Lieberman|first2=D.|title=Endurance running and the evolution of Homo|journal=Nature|year=2004|volume=432|issue=7015|doi=10.1038/nature03052|pmid=15549097|pages=345–352|bibcode=2004Natur.432..345B|s2cid=2470602|url=https://doc.rero.ch/record/15289/files/PAL_E2588.pdf }}</ref>

==Culture==
===Society===
Typically, ''H. ergaster''&nbsp;/&nbsp;''H. erectus'' is considered to have been the first human to have lived in a [[monogamy in animals|monogamous]] society, and all preceding hominins were [[polygyny in animals|polygynous]]. However, it is highly difficult to speculate with any confidence the group dynamics of early hominins.<ref name=Werner2012/> The degree of [[sexual dimorphism]] and the size disparity between males and females is often used to correlate between polygyny with high disparity and monogamy with low disparity based on general trends (though not without exceptions) seen in modern primates. Rates of sexual dimorphism are difficult to determine as early hominin anatomy is poorly represented in the fossil record. In some cases, sex is arbitrarily determined in large part based on perceived size and apparent robustness in the absence of more reliable elements in sex identification (namely the pelvis). Mating systems are also based on dental anatomy, but early hominins possess a mosaic anatomy of different traits not seen together in modern primates; the enlarged cheek teeth would suggest marked size-related dimorphism and thus intense male–male conflict over mates and a polygynous society, but the small canines should indicate the opposite. Other selective pressures, including diet, can also dramatically impact dental anatomy.<ref name=Werner2012>{{cite journal|first=J. J.|last=Werner|year=2012|title=Mating Behavior in ''Australopithecus'' and Early ''Homo'': A Review of the Diagnostic Potential of Dental Dimorphism|journal=University of Western Ontario Journal of Anthropology|volume=22|issue=1|pages=11–19|url=https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=1307&context=totem}}</ref> The spatial distribution of tools and processed animal bones at the FLK Zinj and PTK sites in Olduvai Gorge indicate the inhabitants used this area as a communal butchering and eating grounds, as opposed to the [[nuclear family]] system of modern hunter gatherers where the group is subdivided into smaller units each with their own butchering and eating grounds.<ref>{{cite journal|first1=M.|last1=Domínguez-Rodrigo|first2=L.|last2=Cobo-Sánchez|year=2017|title=A spatial analysis of stone tools and fossil bones at FLK Zinj 22 and PTK I (Bed I, Olduvai Gorge, Tanzania) and its bearing on the social organization of early humans|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=488|pages=28–34|doi=10.1016/j.palaeo.2017.04.010|bibcode=2017PPP...488...21D}}</ref>

The behaviour of early ''Homo'', including ''H. habilis'', is sometimes modelled on that of savanna chimps and [[baboon]]s. These communities consist of several males (as opposed to a [[harem (zoology)|harem]] society) in order to defend the group on the dangerous and exposed habitat, sometimes engaging in a group display of throwing sticks and stones against enemies and predators.<ref>{{Cite journal|last1=Willems|first1=Erik P.|last2=van Schaik|first2=Carel P.|date=2017|title=The social organization of ''Homo ergaster'': Inferences from anti-predator responses in extant primates|url=https://www.researchgate.net/publication/317400374|journal=Journal of Human Evolution|volume=109|page=17|doi=10.1016/j.jhevol.2017.05.003|pmid=28688456 |bibcode=2017JHumE.109...11W }}</ref> The left foot OH 8 seems to have been bitten off by a crocodile,<ref name=Njau2012>{{cite journal|first1=J. K.|last1=Njau|first2=R. J.|last2=Blumenschine|year=2012|title=Crocodylian and mammalian carnivore feeding traces on hominid fossils from FLK 22 and FLK NN 3, Plio-Pleistocene, Olduvai Gorge, Tanzania|journal=Journal of Human Evolution|volume=63|issue=2|pages=408–417|doi=10.1016/j.jhevol.2011.05.008|pmid=21937084 |bibcode=2012JHumE..63..408N }}</ref> possibly ''[[Crocodylus anthropophagus]]'',<ref name=Brochu2010>{{cite journal |first1=C. A.|last1=Brochu|first2=J.|last2=Njau|first3=R. J.|last3=Blumenschine|first4=L. D.|last4=Densmore |year=2010 |title=A New Horned Crocodile from the Plio-Pleistocene Hominid Sites at Olduvai Gorge, Tanzania |journal=PLOS ONE |volume=5 |issue=2 |article-number=e9333 |doi=10.1371/journal.pone.0009333 |pmid=20195356 |pmc=2827537|bibcode=2010PLoSO...5.9333B|doi-access=free}}</ref> and the leg OH 35, which either belongs to ''P. boisei'' or ''H. habilis'', shows evidence of [[leopard]] predation.<ref name=Njau2012/> ''H. habilis'' and contemporary hominins were likely predated upon by other large carnivores of the time, such as (in Olduvai Gorge) the [[hunting hyena]] ''Chasmaporthetes nitidula'', and the saber-toothed cats ''[[Dinofelis]]'' and ''[[Megantereon]]''.<ref name=Lee2000>{{cite journal|first1=J.|last1=Lee-Thorp|first2=J. F.|last2=Thackeray|first3=N. V.|last3=der Merwe|year=2000|title=The hunters and the hunted revisited|journal=Journal of Human Evolution|volume=39|issue=6|pages=565–576|doi=10.1006/jhev.2000.0436|pmid=11102267 |bibcode=2000JHumE..39..565L }}</ref> In 1993, American palaeoanthropologist [[Leslie C. Aiello]] and British evolutionary psychologist [[Robin Dunbar]] estimated that ''H. habilis'' group size ranged from 70–85 members—on the upper end of chimp and baboon group size—based on trends seen in [[neocortex]] size and group size in modern non-human primates.<ref>{{Cite journal|last1=Aiello|first1=Leslie C.|last2=Dunbar|first2=R. I. M.|s2cid=144347664|date=1993|title=Neocortex Size, Group Size, and the Evolution of Language|journal=Current Anthropology|volume=34|issue=2|page=188|doi=10.1086/204160}}</ref>

''H. habilis'' coexisted with ''H. rudolfensis'', ''H. ergaster''&nbsp;/&nbsp;''H. erectus'', and ''P. boisei''. It is unclear how all of these species interacted.<ref name=Tobias2006/><ref>{{cite journal |first1=M. G. |last1=Leakey |author-link=Meave Leakey |first2=F. |last2=Spoor |first3=M. C. |last3=Dean |display-authors=et al. |year=2012 |title=New fossils from Koobi Fora in northern Kenya confirm taxonomic diversity in early ''Homo'' |journal=Nature |volume=488 |issue=7410 |pages=201–204 |doi=10.1038/nature11322 |pmid=22874966 |bibcode=2012Natur.488..201L |s2cid=4431262}}</ref><ref>{{cite journal |title=Implications of new early ''Homo'' fossils from Ileret, east of Lake Turkana, Kenya |first1=F. |last1=Spoor |first2=M. G. |last2=Leakey |author2-link=Mary Leakey |journal=Nature |issue=7154 |pages=688–691 |year=2007 |doi=10.1038/nature05986 |volume=448 |pmid=17687323 |bibcode=2007Natur.448..688S |s2cid=35845}}</ref> To explain why ''P. boisei'' was associated with Olduwan tools despite not being the [[knapping|knapper]] (the one who made the tools), Leakey and colleagues, when describing ''H. habilis'', suggested that one possibility was ''P. boisei'' was killed by ''H. habilis'',<ref name=Leakey1964/> perhaps as food.<ref name=Torre2011/> However, when describing ''P. boisei'' five years earlier, Louis Leakey said, "There is no reason whatever, in this case, to believe that [[OH 5|the skull]] represents the victim of a cannibalistic feast by some hypothetical more advanced type of man."<ref>{{cite journal|first=L. S. B.|last=Leakey|author-link=Louis Leakey|year=1959|title=A new fossil skull from Olduvai|journal=Nature|volume=185|issue=4685|page=491|doi=10.1038/184491a0|bibcode=1959Natur.184..491L|s2cid=4217460}}</ref>

===Diet===
[[File:Elife-24232-fig11-v1 Comparison of Homo naledi mandibles to other hominin species, from lateral view.jpg|left|thumb|upright|OH 13 mandible compared to other hominin species]]
It is thought ''H. habilis'' derived meat from scavenging rather than hunting (scavenger hypothesis), acting as a confrontational scavenger and stealing kills from smaller predators such as [[jackal]]s or [[cheetah]]s.<ref name=Cavallo1989>{{cite journal|first1=J. A.|last1=Cavallo|first2=R. J.|last2=Blumenschine|year=1989|title=Tree-stored leopard kills: expanding the hominid scavenging niche|journal=Journal of Human Evolution|volume=18|issue=4|pages=393–399|doi=10.1016/0047-2484(89)90038-9 |bibcode=1989JHumE..18..393C }}</ref> Fruit was likely also an important dietary component, indicated by dental erosion consistent with repetitive exposure to acidity.<ref>{{cite journal|first=P.-F.|last=Peuch|year=1984|title=Acidic-Food Choice in ''Homo habilis'' at Olduvai|journal=Current Anthropology|volume=25|issue=3|pages=349–350|doi=10.1086/203146|s2cid=143857086}}</ref> Based on [[dental microwear]]-texture analysis, ''H. habilis'' (like other early ''Homo'') likely did not regularly consume tough foods. Microwear-texture complexity is, on average, somewhere between that of tough-food eaters and leaf eaters ([[folivore]]s),<ref>{{Cite journal|last=Ungar|first=Peter|date=9 February 2012|title=Dental Evidence for the Reconstruction of Diet in African Early ''Homo''|journal=Current Anthropology|volume=53|pages=S318–S329|doi=10.1086/666700|s2cid=84437780}}</ref> and points to an increasingly [[generalist and specialist species|generalised]] and [[omnivorous]] diet.<ref>{{Cite journal|title = Dental Microwear and Diets of African Early ''Homo''|last1 = Ungar|first1 = Peter|date =1 January 2006|journal = Journal of Human Evolution|doi = 10.1016/j.jhevol.2005.08.007|pmid = 16226788|last2 = Grine|first2 = Frederick|last3 = Teaford|first3 = Mark|last4 = Zaatari|first4 = Sireen |volume=50 |issue = 1|pages=78–95 | bibcode=2006JHumE..50...78U }}</ref> Freshwater fish likely were also consumed, evidenced by the findings of fish remains at archaeological sites most likely associated with ''H. habilis''.<ref>{{Cite journal |last=Stewart |first=Kathlyn M. |date=1 July 1994 |title=Early hominid utilisation of fish resources and implications for seasonality and behaviour |url=https://www.sciencedirect.com/science/article/pii/S004724848471044X |journal=[[Journal of Human Evolution]] |volume=27 |issue=1 |pages=229–245 |doi=10.1006/jhev.1994.1044 |bibcode=1994JHumE..27..229S |issn=0047-2484 |access-date=4 February 2024 |via=Elsevier Science Direct|url-access=subscription }}</ref>

It is typically thought that the diets of ''H. habilis'' and other early ''Homo'' had a greater proportion of meat than ''Australopithecus'', and that this led to brain growth. The main hypotheses regarding this are: meat is energy- and nutrient-rich and put evolutionary pressure on developing enhanced cognitive skills to facilitate strategic scavenging and monopolise fresh carcasses, or meat allowed the large and calorie-expensive ape gut to decrease in size allowing this energy to be diverted to brain growth. Alternatively, it is also suggested that early ''Homo'', in a drying climate with scarcer food options, relied primarily on underground [[storage organ]]s (such as [[tuber]]s) and food sharing, which facilitated social bonding among both male and female group members. However, unlike what is presumed for ''H. ergaster'' and later ''Homo'', short-statured early ''Homo'' are generally considered to have been incapable of [[Endurance running hypothesis|endurance running]] and hunting, and the long and ''Australopithecus''-like forearm of ''H. habilis'' could indicate early ''Homo'' were still arboreal to a degree. Also, organised [[hunting and gathering]] is thought to have emerged in ''H. ergaster''. Nonetheless, the proposed food-gathering models to explain large brain growth necessitate increased daily travel distance.<ref>{{cite journal|first=H.|last=Pontzer|year=2012|title=Ecological Energetics in Early ''Homo''|journal=Current Anthropology|volume=56|issue=6|pages=346–358|doi=10.1086/667402|s2cid=31461168}}</ref> It has also been argued that ''H. habilis'' instead had long, modern humanlike legs and was fully capable of effective long distance travel, while still remaining at least partially arboreal.<ref name=Haeusler2004/>

Large [[incisor]] size in ''H. habilis'' compared to ''Australopithecus'' predecessors implies this species relied on incisors more. The [[Mandible#Body|bodies of the mandibles]] of ''H. habilis'' and other early ''Homo'' are thicker than those of modern humans and all living apes, more comparable to ''Australopithecus''. The mandibular body resists torsion from the [[bite force]] or chewing, meaning their jaws could produce unusually powerful stresses while eating. The greater molar [[cusp (anatomy)|cusp]] [[relief]] in ''H. habilis'' compared to ''Australopithecus'' suggests the former used tools to fracture tough foods (such as pliable plant parts or meat), otherwise the cusps would have been more worn down. Nonetheless, the jaw adaptations for processing mechanically challenging food indicates technological advancement did not greatly affect diet.<ref name=Ungar2006/>

===Technology===
[[File:Oldowan tradition chopper.jpg|thumb|upright=0.9|[[Oldowan]] chopper]]
''H. habilis'' is associated with the [[Lower Paleolithic|Early Stone Age]] Oldowan stone tool industry. Individuals likely used these tools primarily to butcher and skin animals and crush bones, but also sometimes to saw and scrape wood and cut soft plants. [[Knapping|Knappers]] – individuals shaping stones – appear to have carefully selected [[lithic core]]s and knew that certain rocks would break in a specific way when struck hard enough and on the right spot, and they produced several different types, including [[chopper (archaeology)|choppers]], [[polyhedron]]s, and discoids. Nonetheless, specific shapes were likely not thought of in advance, and probably stem from a lack of standardisation in producing such tools as well as the types of raw materials at the knappers' disposal.<ref name="Torre2011"/><ref name="Toth1985"/> For example, [[Spheroid (lithic)|spheroids]] are common at Olduvai, which features an abundance of large and soft [[quartz]] and [[quartzite]] pieces, whereas [[Koobi Fora]] lacks spheroids and provides predominantly hard [[basalt]] lava rocks. Unlike the later [[Acheulean]] culture invented by ''H. ergaster''&nbsp;/&nbsp;''H. erectus'', Oldowan technology does not require planning and foresight to manufacture, and thus does not indicate high cognition in Oldowan knappers, though it does require a degree of coordination and some knowledge of mechanics. Oldowan tools infrequently exhibit [[retouch (lithics)|retouching]] and were probably discarded immediately after use most of the time.<ref name="Toth1985">{{cite journal|first=N.|last=Toth|year=1985|title=The Oldowan<!--probably meant to be capitalised, as in the abstract--> reassessed: A close look at early stone artifacts|journal=Journal of Archaeological Science|volume=12|issue=2|pages=101–120|doi=10.1016/0305-4403(85)90056-1|bibcode=1985JArSc..12..101T }}</ref>

The Oldowan was first reported in 1934, but it was not until the 1960s that it become widely accepted as the earliest culture, dating to 1.8&nbsp;mya, and as having been manufactured by ''H. habilis''. Since then, more discoveries have placed the origins of material culture substantially backwards in time,<ref name="Torre2011"/> with the Oldowan being discovered in [[Ledi-Geraru]] and [[Gona, Ethiopia|Gona]] in Ethiopia dating to 2.6&nbsp;mya, perhaps associated with the evolution of the genus.<ref name="Torre2011"/><ref name="Braun2019">{{cite journal|first1=D. R.|last1=Braun|first2=V.|last2=Aldeias|first3=W.|last3=Archer|display-authors=et al.|year=2019|title=Earliest known Oldowan artifacts at >2.58 Ma from Ledi-Geraru, Ethiopia, highlight early technological diversity|journal=Proceedings of the National Academy of Sciences|volume=116|issue=24|pages=11712–11717|doi=10.1073/pnas.1820177116|pmid=31160451|pmc=6575601|bibcode=2019PNAS..11611712B |doi-access=free}}</ref> Australopithecines are also known to have manufactured tools, such as the 3.3&nbsp;Ma [[Lomekwi]] stone tool industry,<ref>{{cite journal|first1=S.|last1=Harmand|first2=J. E.|last2=Lewis|first3=C. S.|last3=Feibel|display-authors=et al.|year=2015|title=3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya|journal=Nature|volume=521|issue=7552|pages=310–315|doi=10.1038/nature14464|url=https://www.researchgate.net/publication/277004244|pmid=25993961|bibcode=2015Natur.521..310H|s2cid=1207285}}</ref> and some evidence of butchering from about 3.4&nbsp;mya.<ref>{{Cite journal | doi = 10.1038/nature09248 | volume = 466 | issue = 7308 | pages = 857–860 | last1 = McPherron | pmid = 20703305 | first1 = Shannon P. |first2=Zeresenay |last2=Alemseged |first3=Curtis W. |last3=Marean |first4=Jonathan G. |last4=Wynn |first5=Denne |last5=Reed |first6=Denis |last6=Geraads |first7=Rene |last7=Bobe |first8=Hamdallah A. |last8=Bearat | title = Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia | journal = Nature | year = 2010 |bibcode = 2010Natur.466..857M | s2cid = 4356816 }}</ref> Nonetheless, the comparatively sharp-edged Oldowan culture was a major innovation from australopithecine technology, and it would have allowed different feeding strategies and the ability to process a wider range of foods, which would have been advantageous in the changing climate of the time.<ref name="Braun2019"/> It is unclear if the Oldowan was independently invented or if it was the result of hominin experimentation with rocks over hundreds of thousands of years across multiple species.<ref name=Torre2011/>

In 1962, a {{cvt|12x14x1|ft|cm|order=flip}} circle made with volcanic rocks was discovered in Olduvai Gorge. At {{cvt|2–2.5|ft|cm|order=flip}} intervals, rocks were piled up to {{cvt|6–9|in|cm|order=flip}} high. Mary Leakey suggested the rock piles were used to support poles stuck into the ground, possibly to support a [[windbreak]] or a rough hut. Some modern-day nomadic tribes build similar low-lying rock walls to build temporary shelters upon, bending upright branches as poles and using grasses or animal hide as a screen.<ref>{{cite book|url={{google books|plainurl=yes|id=eepULHufmF8C|page=24}}|first=M. D.|last=Leakey|author-link=Mary Leakey|year=1971|title=Olduvai Gorge: Volume 3, Excavations in Beds I and II, 1960–1963|publisher=Cambridge University Press|page=24|isbn=978-0-521-07723-1}}</ref> Dating to 1.75&nbsp;mya, it is attributed to some early ''Homo'', and is the oldest-claimed evidence of architecture.<ref>{{cite book|first=T.|last=Ingold|year=2000|title=The Perception of the Environment: Essays on Livelihood, Dwelling and Skill|chapter=Building, dwelling, living: how animals and people make themselves at home in the world|publisher=Psychology Press|page=184|url={{google books|plainurl=yes|id=S3GakE5OT-kC|page=184}}|isbn=978-0-415-22832-9}}</ref>

==See also==
{{columns-list|colwidth=25em|
* [[African archaeology]]
* {{annotated link|Australopithecus africanus|''Australopithecus africanus''}}
* {{annotated link|Australopithecus sediba|''Australopithecus sediba''}}
* {{annotated link|Homo ergaster|''Homo ergaster''}}
* {{annotated link|Homo gautengensis|''Homo gautengensis''}}
* {{annotated link|Homo rudolfensis|''Homo rudolfensis''}}
* {{annotated link|LD 350-1}}
* {{annotated link|Paranthropus boisei|''Paranthropus boisei''}}
* {{annotated link|Paranthropus robustus|''Paranthropus robustus''}}
}}

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

==External links==
{{Commons category|Homo habilis}}
{{Wikispecies|Homo habilis}}
* [http://gurche.com/homo-floresiensis-1 Reconstructions of ''H. habilis''] by [[John Gurche]]
* [http://www.archaeologyinfo.com/homohabilis.htm Archaeology Info] {{Webarchive|url=https://web.archive.org/web/20110526073252/http://www.archaeologyinfo.com/homohabilis.htm |date=2011-05-26 }}
* [https://humanorigins.si.edu/evidence/human-fossils/species/homo-habilis ''Homo habilis''] – The Smithsonian Institution's Human Origins Program
* [http://humanorigins.si.edu/evidence/human-evolution-timeline-interactive Human Timeline (Interactive)] – [[Smithsonian Institution|Smithsonian]], [[National Museum of Natural History]] (August 2016).

{{Human Evolution}}
{{Taxonbar|from=Q101373}}
{{Authority control}}
{{portal bar|Evolutionary biology|Science}}

[[Category:1962 archaeological discoveries]]
[[Category:Lower Paleolithic]]
[[Category:Early species of Homo]]
[[Category:Hominini]]
[[Category:Transitional fossils]]
[[Category:Mammals described in 1964]]
[[Category:Fossil taxa described in 1964]]
[[Category:Prehistoric Tanzania]]
[[Category:Pleistocene mammals of Africa]]
[[Category:Prehistoric Kenya]]
[[Category:Pleistocene primates]]
[[Category:Taxa named by Richard Leakey]]