Homo habilis
Homo habilis Temporal range:
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Reconstruction of KNM-ER 1813 at the Naturmuseum Senckenberg, Germany | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Primates |
Suborder: | Haplorhini |
Infraorder: | Simiiformes |
Family: | Hominidae |
Subfamily: | Homininae |
Tribe: | Hominini |
Genus: | Homo |
Species: | †H. habilis
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Binomial name | |
†Homo habilis Leakey et al., 1964
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Synonyms[1] | |
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Homo habilis ("handy man") is an extinct
Like contemporary Homo, H. habilis brain size generally varied from 500–900 cm3 (31–55 cu in). 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
H. habilis manufactured the
Taxonomy
Research history
The first recognised remains—
After description, it was hotly debated if H. habilis should be reclassified into
Many had accepted Tobias' model and assigned
In 1986, OH 62, a fragmentary skeleton was discovered by American anthropologist
Classification
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Homo family tree showing H. habilis and H. rudolfensis at the base as offshoots of the human line[18] |
There is still no wide consensus as to whether or not H. habilis is ancestral to
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
Anatomy
Skull
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 / H. erectus, jumping from about 600–650 cc (37–40 cu in) in H. habilis to about 900–1,000 cc (55–61 cu in) in H. ergaster and H. erectus.[23][25] However, a 2015 study showed that the brain sizes of H. habilis, H. rudolfensis, and H. ergaster generally ranged between 500–900 cc (31–55 cu in) after reappraising the brain volume of OH 7 from 647–687 cc (39.5–41.9 cu in) to 729–824 cc (44.5–50.3 cu in).[23] This does, nonetheless, indicate a jump from australopithecine brain size which generally ranged from 400–500 cc (24–31 cu in).[25]
million years ago ) |
The brain anatomy of all Homo features an expanded
The tooth rows of H. habilis were V-shaped as opposed to U-shaped in later Homo, and the mouth jutted outwards (was
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 and consistent with an at least partially
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.[30] 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.[31]
Limbs
The arms of H. habilis and australopithecines have generally been considered to have been proportionally long and so adapted for climbing and swinging.[32][33][34] In 2004, anthropologists Martin Haeusler and 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 258–270 mm (10.2–10.6 in) long and the ulna (forearm) 245–255 mm (9.6–10.0 in), 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 / 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.[15] 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 / H. erectus and modern humans, which may indicate different load bearing capabilities more suitable for arboreality in H. habilis.[35] 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.[36]
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.[15] 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, which is typically thought to have evolved later in H. ergaster / H. erectus.[37]
Culture
Society
Typically, H. ergaster / H. erectus is considered to have been the first human to have lived in a
The behaviour of early Homo, including H. habilis, is sometimes modelled on that of savanna chimps and
H. habilis coexisted with H. rudolfensis, H. ergaster / H. erectus, and P. boisei. It is unclear how all of these species interacted.
Diet
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
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
Large
Technology
H. habilis is associated with the 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. Knappers - individuals shaping stones - appear to have carefully selected lithic cores 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 choppers, polyhedrons, 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.[4][54] For example, 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 / 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 retouching and were probably discarded immediately after use most of the time.[54]
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 mya, and as having been manufactured by H. habilis. Since then, more discoveries have placed the origins of material culture substantially backwards in time,[4] with the Oldowan being discovered in Ledi-Geraru and Gona in Ethiopia dating to 2.6 mya, perhaps associated with the evolution of the genus.[4][55] Australopithecines are also known to have manufactured tools, such as the 3.3 Ma Lomekwi stone tool industry,[56] and some evidence of butchering from about 3.4 mya.[57] 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.[55] 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.[4]
In 1962, a 366 cm × 427 cm × 30 cm (12 ft × 14 ft × 1 ft) circle made with volcanic rocks was discovered in Olduvai Gorge. At 61–76 cm (2–2.5 ft) intervals, rocks were piled up to 15–23 cm (6–9 in) 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.[58] Dating to 1.75 mya, it is attributed to some early Homo, and is the oldest-claimed evidence of architecture.[59]
See also
- African archaeology
- Australopithecus africanus – Extinct hominid from South Africa
- Australopithecus sediba – Two-million-year-old hominin from the Cradle of Humankind
- Homo ergaster – Extinct species or subspecies of archaic human
- Homo gautengensis – Name proposed for an extinct species of hominin from South Africa
- Homo rudolfensis – Extinct hominin from the Early Pleistocene of East Africa
- LD 350-1 – Earliest known specimen of the genus Homo
- Paranthropus boisei – Extinct species of hominin of East Africa
- Paranthropus robustus – Extinct species of hominin of South Africa
References
- S2CID 84830570.
- ^ ISBN 978-1-4020-9980-9.
- ^ S2CID 12836722.
- ^ PMID 21357225.
- PMID 10999270.
- ^ Tobias, P. V. (1983). "Hominid evolution in Africa"(PDF). Canadian Journal of Anthropology. 3 (2): 163–183.
- ^ S2CID 4321698.
- ISBN 978-0-8451-0249-7.
- PMID 9924136.
- PMID 20466364.
- S2CID 7018418. Archived from the original(PDF) on 2020-11-23.
- PMID 10766947.
- JSTOR 23735461.
- ISBN 978-3-642-39978-7.
- ^ PMID 15066379.
- PMID 24101504.
- S2CID 20435482.
- ISBN 978-3-642-39979-4. Archived from the original(PDF) on 2020-06-12. Retrieved 2020-06-12.
- ^ Tattersall, I. (2019). "Classification and phylogeny in human evolution". Ludus Vitalis. 9 (15): 139–140. Archived from the original on 2021-04-15. Retrieved 2020-06-10.
- ISBN 978-0-8133-3918-4.
- ISBN 978-3-642-39979-4.
- PMID 25739410.
- ^ S2CID 4470282.
- S2CID 49670311.
- ^ .
- PMID 27765150.
- PMID 25818180.
- ^ Roser, M.; Appel, C.; Ritchie, H. (2013). "Human Height". Our World in Data. Retrieved 16 June 2020.
- ^ .
- PMID 27178459.
- S2CID 84537505.
- PMID 17688910.
- S2CID 4321698.
- S2CID 4329573.
- PMID 18711733.
- S2CID 145846013.
- S2CID 2470602.
- ^ a b Werner, J. J. (2012). "Mating Behavior in Australopithecus and Early Homo: A Review of the Diagnostic Potential of Dental Dimorphism". University of Western Ontario Journal of Anthropology. 22 (1): 11–19.
- .
- PMID 28688456.
- ^ PMID 21937084.
- PMID 20195356.
- PMID 11102267.
- S2CID 144347664.
- S2CID 4431262.
- S2CID 35845.
- S2CID 4217460.
- .
- S2CID 143857086.
- S2CID 84437780.
- PMID 16226788.
- ISSN 0047-2484. Retrieved 4 February 2024 – via Elsevier Science Direct.
- S2CID 31461168.
- ^ .
- ^ PMID 31160451.
- S2CID 1207285.
- S2CID 4356816.
- ISBN 9780521077231.
- ISBN 9780415228329.
External links
- Reconstructions of H. habilis by John Gurche
- Archaeology Info Archived 2011-05-26 at the Wayback Machine
- Homo habilis – The Smithsonian Institution's Human Origins Program
- Human Timeline (Interactive) – Smithsonian, National Museum of Natural History (August 2016).