Editing Homo habilis (section)

===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}}</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}}</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 |pages=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}}</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|pages=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>