Origin of the Genus <Emphasis Type="Italic">Homo</Emphasis>

The origin of the genus Homo in Africa signals the beginning of the shift from increasingly bipedal apes to primitive, large-brained, stone tool-making, meat-eaters that traveled far and wide. This early part of the human genus is represented by three species: Homo habilis, Homo rudolfensis, and Homo erectus. H. habilis is known for retaining primitive features that link it to australopiths and for being the first stone tool makers. Little is known about H. rudolfensis except that it had a relatively large brain and large teeth compared to H. habilis and that it overlapped in time and space with other early Homo. Our understanding of the paleobiology and evolution of the larger-brained H. erectus is enhanced due to its rich fossil record. H. erectus was the first obligate, fully committed biped, and with a body adapted for modern striding locomotion, it was also the first in the human lineage to disperse outside of Africa. The early members of the genus Homo are the first to tip the scale from the more apish side of our evolutionary history toward the more human one.     

Homo floresiensis: a cladistic analysis

The announcement of a new species, Homo floresiensis, a primitive hominin that survived until relatively recent times is an enormous challenge to paradigms of human evolution. Until this announcement, the dominant paradigm stipulated that: 1) only more derived hominins had emerged from Africa, and 2) H. sapiens was the only hominin since the demise of Homo erectus and Homo neanderthalensis. Resistance to H. floresiensis has been intense, and debate centers on two sets of competing hypotheses: 1) that it is a primitive hominin, and 2) that it is a modern human, either a pygmoid form or a pathological individual. Despite a range of analytical techniques having been applied to the question, no resolution has been reached. Here, we use cladistic analysis, a tool that has not, until now, been applied to the problem, to establish the phylogenetic position of the species. Our results produce two equally parsimonious phylogenetic trees. The first suggests that H. floresiensis is an early hominin that emerged after Homo rudolfensis (1.86 Ma) but before H. habilis (1.66 Ma, or after 1.9 Ma if the earlier chronology for H. habilis is retained). The second tree indicates H. floresiensis branched after Homo habilis.     

Dental microwear texture analysis of hominins recovered by the Olduvai Landscape Paleoanthropology Project, 1995-2007

Dental microwear analysis has proven to be a valuable tool for the reconstruction of aspects of diet in early hominins. That said, sample sizes for some groups are small, decreasing our confidence that results are representative of a given taxon and making it difficult to assess within-species variation. Here we present microwear texture data for several new specimens of Homo habilis and Paranthropus boisei from Olduvai Gorge, bringing sample sizes for these species in line with those published for most other early hominins. These data are added to those published to date, and microwear textures of the enlarged sample of H. habilis (n = 10) and P. boisei (n = 9) are compared with one another and with those of other early hominins. New results confirm that P. boisei does not have microwear patterns expected of a hard-object specialist. Further, the separate texture complexity analyses of early Homo species suggest that Homo erectus ate a broader range of foods, at least in terms of hardness, than did H. habilis, P. boisei, or the “gracile” australopiths studied. Finally, differences in scale of maximum complexity and perhaps textural fill volume between H. habilis and H. erectus are noted, suggesting further possible differences between these species in diet.     

The history of the genusHomo

The genusHomo was established by Carolus Linnaeus in 1758. During the course of the past 150 years, the addition of fossil species to the genusHomo has resulted in a genus that, according to the taxonomic interpretation, could span as much time as 2.5 Myr, and include as many as ten species. This paper reviews the fossil evidence for each of the species involved, and sets out the case for their inclusion inHomo. It suggests that while the case for the inclusion of some species in the genus (e.g.Homo erectus) is well-supported, in the case of two of the species,Homo habilis andHomo rudolfensis, the case for their inclusion is much weaker. Neither the cladistic evidence, nor evidence about adaptation suggest a particularly close relationship with laterHomo.     

Human evolution

The common ancestor of modern humans and the great apes is estimated to have lived between 5 and 8 Myrs ago, but the earliest evidence in the human, or hominid, fossil record is Ardipithecus ramidus, from a 4.5 Myr Ethiopian site. This genus was succeeded by Australopithecus, within which four species are presently recognised. All combine a relatively primitive postcranial skeleton, a dentition with expanded chewing teeth and a small brain. The most primitive species in our own genus, Homo habilis and Homo rudolfensis, are little advanced over the australopithecines and with hindsight their inclusion in Homo may not be appropriate. The first species to share a substantial number of features with later Homo is Homo ergaster, or ‘early African Homo erectus’, which appears in the fossil record around 2.0 Myr. Outside Africa, fossil hominids appear as Homo erectus-like hominids, in mainland Asia and in Indonesia close to 2 Myr ago; the earliest good evidence of ‘archaic Homo’ in Europe is dated at between 600–700 Kyr before the present. Anatomically modern human, or Homo sapiens, fossils are seen first in the fossil record in Africa around 150 Kyr ago. Taken together with molecular evidence on the extent of DNA variation, this suggests that the transition from ‘archiac’ to ‘modern’ Homo may have taken place in Africa.     

Découverte d’un nouvel hominidé à Dmanissi (Transcaucasie,Géorgie)

Four human remains: one mandible, two skulls and one metatarsus were discovered between 1991 and 1999 at the open-air site of Dmanisi, Georgia, in a precise stratigraphic, palaeontological and archaeological context, in volcanic ashes dated to 1.81 ± 0.05 Ma. The first studies of these fossils enable the authors to compare them with the morphology of archaic African Homo erectus, ascribed to Homo ergaster, and to ascertain hominid presence at the gates of Europe 300 000 years earlier than the classical scenario forecasted. In September 2000, the discovery of a second more complete and robust mandible D 2600 presents a threefold interest: palaeontological, functional and pathological. A comparison with Homo habilis and Homo erectus leads to the recognition of a new Homo species: H. georgicus sp. nov. The morphofunctional characteristics and the antiquity of H. georgicus characterise the root of a long Eurasian line.     

The brain of Homo habilis: A new level of organization in cerebral evolution

New studies have been made on endocranial casts of Olduvai specimens of Homo habilis. The results have been compared with those on other East African H. habilis and other hominoids. The mean absolute endocranial capacity of H. habilis is appreciably larger than the mean for australopithecine species: on the new estimates, the H. habilis mean is 45·1% greater than the A. africanus mean and 24·8% greater than that of A. boisei. New data for relative brain size, expressed by Jerison's Nc and EQ and Hemmer's CC, strongly confirm that it was with H. habilis that there appeared the remarkable autapomorphy of Homo, disproportionate expansion of the brain. Encephalometric studies reveal marked transverse expansion of the cerebrum, especially the frontal and parieto-occipital parts, in H. habilis and increased bulk of the frontal and parietal lobes, a derived feature of Homo. There is moderate cerebral heightening, but little or no cerebral lengthening. The sulcal and gyral pattern of the lateral part of the frontal lobe of H. habilis differs from those of Australopithecus and resembles the derived pattern of Homo. The inferior parietal lobule is prominently developed—an autapomorphy of Homo. The two major cerebral areas governing spoken language in modern man are well represented in the endocasts of H. habilis, a functionally important autapomorphy of Homo. The pattern of middle meningeal vessels is more complex with more anastomoses than in australopithecines: H. habilis shares this derived feature with later forms of Homo. In all these features, the brain of H. habilis had made major advances, beyond the more ape-like australopithecine brain. With H. habilis, cerebral evolution had progressed beyond the stage of “animal hominids” (Australopithecus spp.) to that of “human hominids” (Homo spp.). In functional capacity, in particular, its possession of a structural marker of the neurological basis of spoken language, H. habilis had attained a new evolutionary level of organization.     

A SINGLE LINEAGE IN EARLY PLEISTOCENE HOMO: SIZE VARIATION CONTINUITY IN EARLY PLEISTOCENE HOMO CRANIA FROM EAST AFRICA AND GEORGIA

The relationship between Homo habilis and early African Homo erectus has been contentious because H. habilis was hypothesized to be an evolutionary stage between Australopithecus and H. erectus, more than a half‐century ago. Recent work re‐dating key African early Homo localities and the discovery of new fossils in East Africa and Georgia provide the opportunity for a productive re‐evaluation of this topic. Here, we test the hypothesis that the cranial sample from East Africa and Georgia represents a single evolutionary lineage of Homo spanning the approximately 1.9–1.5 Mya time period, consisting of specimens attributed to H. habilis and H. erectus. To address issues of small sample sizes in each time period, and uneven representation of cranial data, we developed a novel nonparametric randomization technique based on the variance in an index of pairwise difference from a broad set of fossil comparisons. We fail to reject the hypothesis of a single lineage this period by identifying a strong, time‐dependent pattern of variation throughout the sequence. These results suggest the need for a reappraisal of fossil evidence from other regions within this time period and highlight the critical nature of the Plio‐Pleistocene boundary for understanding the early evolution of the genus Homo.     

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.)

The southern African sample of early Homo is playing an increasingly important role in understanding the origins, diversity and adaptations of the human genus. Yet, the affinities and classification of these remains continue to be in a state of flux. The southern African sample derives from five karstic palaeocave localities and represents more than one-third of the total African sample for this group; sampling an even wider range of anatomical regions than the eastern African collection. Morphological and phenetic comparisons of southern African specimens covering dental, mandibular and cranial remains demonstrate this sample to contain a species distinct from known early Homo taxa. The new species Homo gautengensis sp. nov. is described herein: type specimen Stw 53; Paratypes SE 255, SE 1508, Stw 19b/33, Stw 75-79, Stw 80, Stw 84, Stw 151, SK 15, SK 27, SK 45, SK 847, SKX 257/258, SKX 267/268, SKX 339, SKX 610, SKW 3114 and DNH 70. H. gautengensis is identified from fossils recovered at three palaeocave localities with current best ages spanning ∼2.0 to 1.26-0.82 million years BP. Thus, H. gautengensis is probably the earliest recognised species in the human genus and its longevity is apparently well in excess of H. habilis.     

Les restes humains du Pliocène final et du début du Pléistocène inférieur de Dmanissi, Géorgie (1991-2000). I - Les crânes, D 2280, D 2282, D 2700

Since 1991, several human remains: 5 skulls, 4 mandibles and numerous postcranial fragments have been discovered on the Dmanissi prehistoric open site. It is an exceptional discovery due to the stratigraphical, paleontological and cultural context, which is well known and accurately well dated (Upper Pliocene-Early Pleistocene). Most of the hominids discovered in the level V and VI are dated between 1.81 My (level V) and 1.77 My (level VI) corresponding to a 40,000 years period. The assemblage of fossil human remains is peculiar due to (1) the quality of bone representation (distinct parts of the skeleton are preserved: skull, thorax, upper and lower limbs, belt), (2) the high degree of bone preservation (skulls and long bones are entire, rarely broken or crushed), (3) the diversity age at death estimated for each of the 5 individuals (3 adults, 1 young adult, 1 adolescent of both sexes). The study dealing with the first discovered mandibles and skulls has begun with Leo Gabounia since 1991 and represents several interests: 1) a paleoanthropological interest: the Dmanissi skulls are characterized by their small size; they are short, narrow and low. The skullcaps are less elevated than those of the Homo erectus group and even those of Homo ergaster. They are more elevated than those of Homo habilis and very close to Homo rudolfensis. The elevation and the transversal development of the middle part of the skull in the parietotemporal region are more significant: the Dmanissi specimens are intermediate between Homo habilis and Homo ergaster. In term of cranial capacity, a similar trend is observed. Generally speaking, the skull is slender. The vault is more flat than in Homo erectus, the frontal bone is less developed, divergent and the postorbital constriction is strong. The temporal bone is long, flat and the mastoid part is short. The upper part of the occipital bone is low and narrow. Crests are thin, less developed than in the Homo erectus group. The superior temporal crests are in a high position and a torus angularis is present on the adult-male specimen. The glenoid cavity is large with strong edges. The petrotympanic region is slender with a tympanic circle individualized and it shows a horizontal rotation in a posterior position, which is distinct from Homo erectus. The orthognathic trend of the face distinguishes the Dmanissi specimens from the early Pleistocene hominids (Homo habilis, Homo ergaster) and from the first Eurasian Homo erectus. Nevertheless, the subnasal region of the face is projected. The morphology of the mid-face, showing a developed pillar of the canine, an inframalar incurvation and an anterior position of the root of the zygomaticomaxillary crest, suggests strong masticatory stress. Considering the overall morphology, cranial and metrical features, the Dmanissi fossil skulls are intermediate to the Homo habilis-rudolfensis group and Homo ergaster while they are closer to the former and peculiarly to Homo rudolfensis (ER 1470). However, the Dmanissi fossil skulls are distinct from Homo rudolfensis by numerous features and among them: by their large maximum cranial width (Euryon-Euryon), the posterior rotation of their petrotympanic structure and the strong development of the pillar of their canine. Due to the gracility of their face, the narrowness of their occipital bone, and their cranial base pattern (mastoid region and petrotympanic structure), the Dmanissi fossil skulls are different from the Homo erectus group: 2) the abundance of the human fossils discovered in Dmanissi site provides information about the biodiversity of these hominids with the establishment of the morphological features related to either growth or sexual patterns: 3) compared to modern humans, the Dmanissi fossil skulls seem to follow a different growth pattern. The present study of the fossil skulls discovered is a pioneer step. Indeed, the Dmanissi site has yielded the oldest evidences of the first settlements in Eurasia, which were, until now, attributed to Homo erectus. The Dmanissi fossil skulls are close to the Homo habilis-rudolfensis African group. We attribute these hominids to Homo georgicus.     

Culture, Speciation and the Genus Homo in Early Humans

Human behaviour, in addition to morphology, is essential to identify man. The characteristics of cultural behaviour are expressed by planning in tool making and territorial organization and by their meaning in the context of life. Cultural behaviour enriched the adaptive strategies of the human species and took on significance in the definition of the genus Homo since H. habilis/H. rudolfensis. Culture probably played a double role in the process of human speciation: (1) in isolation and differentiation from other groups of hominids that did not had such behaviour; and (2) in adaptation to the environment and in communication between groups that had the same cultural behaviour, thus slowing down or preventing the conditions of isolation that lead to new species.     

Does KNM-ER 1481A establish Homo erectus at 2.0 myr BP?

Kennedy (1983) has proposed that the KNM-ER 1481A femur represents Homo erectus and establishes the presence of this species at ca. 2.0.myr BP. A reconsideration of her criteria for taxonomic attribution indicates that its morphology implies only that it is an archaic member of the genus Homo. Its geochronological position, in conjunction with its morphology, suggest that it is best referred to H. habilis.     

The endocast from Dana Aoule North (DAN5/P1): A 1.5 million year-old human braincase from Gona,Afar, Ethiopia

The nearly complete cranium DAN5/P1 was found at Gona (Afar, Ethiopia), dated to 1.5–1.6 Ma, and assigned to the species Homo erectus. Its size is, nonetheless, particularly small for the known range of variation of this taxon, and the cranial capacity has been estimated as 598 cc. In this study, we analyzed a reconstruction of its endocranial cast, to investigate its paleoneurological features. The main anatomical traits of the endocast were described, and its morphology was compared with other fossil and modern human samples. The endocast shows most of the traits associated with less encephalized human taxa, like narrow frontal lobes and a simple meningeal vascular network with posterior parietal branches. The parietal region is relatively tall and rounded, although not especially large. Based on our set of measures, the general endocranial proportions are within the range of fossils included in the species Homo habilis or in the genus Australopithecus. Similarities with the genus Homo include a more posterior position of the frontal lobe relative to the cranial bones, and the general endocranial length and width when size is taken into account. This new specimen extends the known brain size variability of Homo ergaster/erectus, while suggesting that differences in gross brain proportions among early human species, or even between early humans and australopiths, were absent or subtle.     

The changing face of genus Homo

Since its introduction in the 18th century, the genus Homo has undergone a number of reinterpretations, all of which have served to make it a more inclusive taxon. In this paper, we trace this trend towards greater inclusiveness, and explain how it has affected the way Homo is defined. We then demonstrate that the current criteria for identifying species of Homo are difficult, if not impossible, to operate using paleoanthropological evidence. We discuss alternative, verifiable, criteria, and show that when these new criteria are applied to Homo, two species, Homo habilis and Homo rudolfensis, fail to meet them. We contend that the lowest boundary of Homo should be redrawn so that the earliest species in the genus is Homo ergaster, or early African Homo erectus. The appearance of this species at around 1.9 Myr appears to mark a distinct shift in hominin adaptive strategy involving morphological and behavioral innovations.     

Variations and asymmetries in regional brain surface in the genus Homo

Paleoneurology is an important field of research within human evolution studies. Variations in size and shape of an endocast help to differentiate among fossil hominin species whereas endocranial asymmetries are related to behavior and cognitive function. Here we analyse variations of the surface of the frontal, parieto-temporal and occipital lobes among different species of Homo, including 39 fossil hominins, ten fossil anatomically modern Homo sapiens and 100 endocasts of extant modern humans. We also test for the possible asymmetries of these features in a large sample of modern humans and observe individual particularities in the fossil specimens.This study contributes important new information about the brain evolution in the genus Homo. Our results show that the general pattern of surface asymmetry for the different regional brain surfaces in fossil species of Homo does not seem to be different from the pattern described in a large sample of anatomically modern H. sapiens, i.e., the right hemisphere has a larger surface than the left, as do the right frontal, the right parieto-temporal and the left occipital lobes compared with the contra-lateral side. It also appears that Asian Homo erectus specimens are discriminated from all other samples of Homo, including African and Georgian specimens that are also sometimes included in that taxon. The Asian fossils show a significantly smaller relative size of the parietal and temporal lobes. Neandertals and anatomically modern H. sapiens, who share the largest endocranial volume of all hominins, show differences when considering the relative contribution of the frontal, parieto-temporal and occipital lobes. These results illustrate an original variation in the pattern of brain organization in hominins independent of variations in total size. The globularization of the brain and the enlargement of the parietal lobes could be considered derived features observed uniquely in anatomically modern H. sapiens.     

L’architecture de l’épaule au sein du genre Homo : nouvelles interprétations

The morphology of human clavicles can be estimated by projecting them on two perpendicular planes in order to assess the shapes of their cranial and dorsal primary curvatures. In cranial view no differences in curvature appear within the genus Homo, which means the different species had similar arms elevation capacity, especially in protraction. On the contrary, in dorsal view two clavicles morphologies could be defined. The first one is characterized by two curvatures in dorsal view and is possessed by all Homo species, from Homo habilis to Neanderthal, including Homo ergaster, but not modern human, Upper Paleolithic and anatomically modern human remains, who possess clavicles of the second type, characterized by either one curvature, or two slightly pronounced ones in dorsal view. Clavicles displaying two pronounced curvatures in dorsal view are associated with scapula sitting high on the thorax in regard to modern human. However, shoulder with high scapula on the thorax displays two different kinds of architectures: (i) shoulder with short clavicles associated to scapulas sitting more laterally than those of modern human. This group includes earlier Homo like Homo habilis and Homo ergaster and (ii) shoulder with long clavicles associated to scapulas sitting more dorsally on the thorax, like those of modern human. This group includes Homoantecessor and Neanderthals. In other words, within the genus Homo, three shoulders would have existed. Evolution of the shoulder complex is far more complex than previously thought and the arrival of modern bipedalism was not associated to modern shoulder.     

New evidence for a 67,000-year-old human presence at Callao Cave, Luzon, Philippines

Documentation of early human migrations through Island Southeast Asia and Wallacea en route to Australia has always been problematic due to a lack of well-dated human skeletal remains. The best known modern humans are from Niah Cave in Borneo (40-42 ka), and from Tabon Cave on the island of Palawan, southwest Philippines (47 ± 11 ka). The discovery of Homo floresiensis on the island of Flores in eastern Indonesia has also highlighted the possibilities of identifying new hominin species on islands in the region. Here, we report the discovery of a human third metatarsal from Callao Cave in northern Luzon. Direct dating of the specimen using U-series ablation has provided a minimum age estimate of 66.7 ± 1 ka, making it the oldest known human fossil in the Philippines. Its morphological features, as well as size and shape characteristics, indicate that the Callao metatarsal definitely belongs to the genus Homo. Morphometric analysis of the Callao metatarsal indicates that it has a gracile structure, close to that observed in other small-bodied Homo sapiens. Interestingly, the Callao metatarsal also falls within the morphological and size ranges of Homo habilis and H. floresiensis. Identifying whether the metatarsal represents the earliest record of H. sapiens so far recorded anywhere east of Wallace’s Line requires further archaeological research, but its presence on the isolated island of Luzon over 65,000 years ago further demonstrates the abilities of humans to make open ocean crossings in the Late Pleistocene.     

Stature,body mass,and brain size: A two-million-year odyssey

Physical size has been critical in the evolutionary success of the genus Homo over the past 2.4 million-years. An acceleration in the expansion of savannah grasslands in Africa from 1.6 Ma to 1.2 Ma witnessed concomitant increases in physical stature (150–170 cm), weight (50–70 kg), and brain size (750–900 cm³). With the onset of 100,000 year Middle Pleistocene glacial cycles (“ice ages”) some 780,000 years ago, large-bodied Homo groups had reached modern size and had successfully dispersed from equatorial Africa, Central, and Southeast Asia to high-latitude localities in Atlantic Europe and North East Asia. While there is support for incursions of multiple Homo lineages to West Asia and Continental Europe at this time, data does not favour a persistence of Homo erectus beyond ～400,000 years ago in Africa, west and Central Asia, and Europe. Novel Middle Pleistocene Homo forms (780,000–400,000 years) may not have been substantially taller (150–170 cm) than earlier Homo (1.6 Ma–800,000 years), yet brain size exceeded 1000 cm³ and body mass approached 80 kg in some males. Later Pleistocene Homo (400,000–138,000 years) were ‘massive’ in their height (160–190 cm) and mass (70–90 kg) and consistently exceed recent humans. Relative brain size exceeds earlier Homo, yet is substantially lower than in final glacial H. sapiens and Homo neanderthalensis. A final leap in absolute and relative brain size in Homo (300,000–138,000 years) occurred independent of any observed increase in body mass and implies a different selective mediator to that operating on brain size increases observed in earlier Homo.     

Variation among early Homo crania from Olduvai Gorge and the Koobi Fora region

Fossils recognized as early Homo were discovered first at Olduvai Gorge in 1959 and 1960. Teeth, skull parts and hand bones representing three individuals were found in Bed I, and more material followed from Bed I and lower Bed II. By 1964, L.S.B. Leakey, P.V. Tobias, and J.R. Napier were ready to name Homo habilis. But almost as soon as they had, there was confusion over the hypodigm of the new species. Tobias himself suggested that OH 13 resembles Homo erectus from Java, and he noted that OH 16 has teeth as large as those of Australopithecus. By the early 1970s, however, Tobias had put these thoughts behind him and returned to the opinion that all of the Olduvai remains are Homo habilis. At about this time, important discoveries began to flow from the Koobi Fora region in Kenya. To most observers, crania such as KNM-ER 1470 confirmed the presence of Homo in East Africa at an early date. Some of the other specimens were problematical. A.C. Walker and R.E. Leakey raised the possibility that larger skulls including KNM-ER 1470 differ significantly from smaller-brained, small-toothed individuals such as KNM-ER 1813. Other workers emphasized that there are differences of shape as well as size among the hominids from Koobi Fora. There is now substantial support for the view that in the Turkana and perhaps also in the Olduvai assemblages, there is more variation than would be expected among male and female conspecifics. One way to approach this question of sorting would be to compare all of the new fossils against the original material from Olduvai which was used to characterize Homo habilis in 1964. A problem is that the Olduvai remains are fragmentary, and none of them provides much information about vault form or facial structure. An alternative is to work first with the better crania, even if these are from other sites. I have elected to treat KNM-ER 1470 and KNM-ER 1813 as key individuals. Comparisons are based on discrete anatomy and measurements. Metric results are displayed with ratio diagrams, by which similarity in proportions for several skulls can be assessed in respect to a single specimen selected as a standard. Crania from Olduvai examined in this way are generally smaller than KNM-ER 1470, although OH 7 has a relatively long parietal. In the Koobi Fora assemblage, there is variation in brow thickness, frontal flattening and parietal shape relative to KNM-ER 1470. These comparisons are instructive, but vault proportions do not help much with the sorting process. Contrasts in the face are much more striking. Measurements treated in ratio diagrams show that both KNM-ER 1813 and OH 24 have relatively short faces with low cheek bones, small orbits and low nasal openings. Also, they display more projection of the midfacial region, just below the nose. This is not readily interpreted to be a female characteristic, since in most hominoid primates the females tend to have flatter lower faces than the males. The obvious size differences among these individuals have usually been interpreted as sex dimorphism, but, in fact, two taxa may be sampled at Olduvai and in the Turkana basin at the beginning of the Pleistocene. One large-brained group made up of KNM-ER 1470, several other Koobi Fora specimens, and probably OH 7, can be called Homo habilis. If these skulls go with femora such as KNM-ER 1481 and the KNM-ER3228 hip, then this species is close in postcranial anatomy to Homo erectus. The other taxon, including small-brained individuals such as KNM-ER 1813 and probably OH 13, seems also to be Homo rather than Australopithecus. If the OH 62 skeleton is part of this assemblage, then the small hominids have postcranial proportions unlike those of Homo erectus. However, it is too early to point unequivocally to one or the other of these groups as the ancestors of later humans. Both differ from Homo erectus in important ways, and both need to be better understood before we can map the earliest history of the Homo clade. © 1993 Wiley-Liss, Inc.     

Conclusions: implications of the Liang Bua excavations for hominin evolution and biogeography

Excavations at Liang Bua, on the Indonesian island of Flores, have yielded a stratified sequence of stone artifacts and faunal remains spanning the last 95 k.yr., which includes the skeletal remains of two human species, Homo sapiens in the Holocene and Homo floresiensis in the Pleistocene. This paper summarizes and focuses on some of the evidence for Homo floresiensis in context, as presented in this Special Issue edition of the Journal of Human Evolution and elsewhere. Attempts to dismiss the Pleistocene hominins (and the type specimen LB1 in particular) as pathological pygmy humans are not compatible with detailed analyses of the skull, teeth, brain endocast, and postcranium. We initially concluded that H. floresiensis may have evolved by insular dwarfing of a larger-bodied hominin species over 880 k.yr. or more. However, recovery of additional specimens and the numerous primitive morphological traits seen throughout the skeleton suggest instead that it is more likely to be a late representative of a small-bodied lineage that exited Africa before the emergence of Homo erectus sensu lato. Homo floresiensis is clearly not an australopithecine, but does retain many aspects of anatomy (and perhaps behavior) that are probably plesiomorphic for the genus Homo. We also discuss some of the other implications of this tiny, endemic species for early hominin dispersal and evolution (e.g., for the “Out of Africa 1” paradigm and more specifically for colonizing Southeast Asia), and we present options for future research in the region.