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105-594: Xintai has a long history dating back to the origins of the Chinese civilisation. In 1966, scientists concluded that a homo teeth fossil found in Xintai's Wuzhutai village belonged to a female teenager and that homo erectus were already living in the area five million years ago. Moreover, many primitive social sites belonging to ancient cultures were found on both sides of the Chaiwen River after archaeological excavations, such as

210-526: A be designated a subtribe of Hominini to include only the genus Homo — that is, not including the earlier upright walking hominins of the Pliocene such as Australopithecus , Orrorin tugenensis , Ardipithecus , or Sahelanthropus . Designations alternative to Hominina existed, or were offered: Australopithecinae (Gregory & Hellman 1939) and Preanthropinae (Cela-Conde & Altaba 2002); and later, Cela-Conde and Ayala (2003) proposed that

315-607: A common ancestor. With the publication of Dmanisi skull 5 in 2013, it has become less certain that Asian H. erectus is a descendant of African H. ergaster which was in turn derived from H. habilis . Instead, H. ergaster and H. erectus appear to be variants of the same species, which may have originated in either Africa or Asia and widely dispersed throughout Eurasia (including Europe , Indonesia , China ) by 0.5 Mya. Homo erectus has often been assumed to have developed anagenetically from H. habilis from about 2 million years ago. This scenario

420-440: A famous Australopithecus fossil, would only have been about 1 m (3 ft 3 in) tall at her death, Turkana Boy was about 1.62 m (5 ft 4 in) tall and would probably have reached 1.82 m (6 ft) or more if he had survived to adulthood. Adult H. ergaster are believed to have ranged in size from about 1.45 to 1.85 m (4 ft 9 in to 6 ft 1 in) tall. Because of being adapted to

525-618: A fragmentary skull from Olorgesailie in Kenya (dated to between 970,000 and 900,000 years ago). The Olduvai skull is similar to Asian H. erectus in its massive brow ridge, but the others only show minor differences to earlier H. ergaster skulls. The H. erectus in Asia, as well as later hominins in Europe (i. e. H. heidelbergensis and H. neanderthalensis ) and Africa ( H. sapiens ) are all probably lineages descended from H. ergaster. Because H. ergaster

630-440: A hot and arid climate, H. ergaster might also have been the earliest human species to have nearly hairless and naked skin. If instead H. ergaster had an ape-like covering of body hair, sweating (the primary means through which modern humans prevent their brains and bodies from overheating) would not have been as efficient. Though sweating is the generally accepted explanation for hairlessness, other proposed explanations include

735-588: A major change in diet) as well as body proportions and inferred lifestyles more similar to modern humans than to earlier and contemporary hominins. With these features in mind, some researchers view H. ergaster as being the earliest true representative of the genus Homo . H. ergaster lived on the savannah in Africa, a unique environment with challenges that would have resulted in the need for many new and distinct behaviours. Earlier Homo probably used counter-attack tactics, like modern primates, to keep predators away. By

840-599: A more barrel-shaped chest over narrow hips, another similarity to modern humans. The tibia (shin bone) of Turkana Boy is relatively longer than the same bone in modern humans, potentially meaning that there was more bend in the knee when walking. The slim and long build of Turkana Boy may be explained by H. ergaster living in hot and arid, seasonal environments. Through thinning of the body, body volume decreases faster than skin area and greater skin area means more effective heat dissipation. H. ergaster individuals were significantly taller than their ancestors. Whereas Lucy ,

945-414: A more easily digested diet composed of food of higher quality. It is likely that H. ergaster consumed meat in higher proportions than the earlier australopithecines. Meat was probably acquired through a combination of ambushes, active hunting and confrontational scavenging. H. ergaster must not only have possessed the ability of endurance running , but must also have been able to defend themselves and

1050-479: A nearly complete skeleton, as representing H. erectus . Turkana Boy was the first discovered comprehensively preserved specimen of H. ergaster / erectus found and constitutes an important fossil in establishing the differences and similarities between early Homo and modern humans. Turkana Boy was placed in H. ergaster by paleoanthropologist Bernard Wood in 1992, and is today, alongside other fossils in Africa previously designated as H. erectus , commonly seen as

1155-442: A number of features as well, notably in that the margins of KNM ER 3883's brow ridges are very thickened and protrude outwards but slightly downwards rather than upwards. Both skulls can be distinguished from the skull of Turkana Boy, which possesses only slightly substantial thickenings of the superior orbital margins, lacking the more vertical thickening of KNM ER 3883 and the aggressive protrusion of KNM ER 3733. In addition to this,

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1260-492: A possible 100,000 to 1000 individuals) occurred "around 930,000 and 813,000 years ago ... lasted for about 117,000 years and brought human ancestors close to extinction." Weiss (1984) estimated that there have been about 44 billion (short scale) members of the genus Homo from its origins to the evolution of H. erectus , about 56 billion individuals from H. erectus to the Neolithic , and another 51 billion individuals since

1365-532: A receding forehead. Many of the features of H. ergaster are clearly more primitive versions of features later expressed in H. erectus , which somewhat obscures the differences between the two. There are subtle, potentially significant, differences between the East African and East Asian fossils. Among these are the somewhat higher-domed and thinner-walled skulls of H. ergaster , and the even more massive brow ridges and faces of Asian H. erectus . The question

1470-602: A reduction of parasite load and sexual selection . It is doubtful if australopithecines and earlier Homo were sufficiently mobile to make hair loss an advantageous trait, whereas H. ergaster was clearly adapted for long-distance travel and noted for inhabiting lower altitudes (and open, hot savannah environments) than their ancestors. Australopithecines typically inhabited colder and higher altitudes 1,000–1,600 m (3,300–5,200 ft), where nighttime temperatures would have gotten significantly colder and insulating body hair may have been required. Alternatively and despite this,

1575-525: A reference to the more advanced tools used by the species in comparison to those of their ancestors. The fossil range of H. ergaster mainly covers the period of 1.7 to 1.4 million years ago, though a broader time range is possible. Though fossils are known from across East and Southern Africa, most H. ergaster fossils have been found along the shores of Lake Turkana in Kenya. There are later African fossils, some younger than 1 million years ago, that indicate long-term anatomical continuity, though it

1680-470: A representative of H. ergaster by those who support H. ergaster as a distinct species. H. ergaster is easily distinguished from earlier and more basal species of Homo , notably H. habilis and H. rudolfensis , by a number of features that align them, and their inferred lifestyle, more closely to modern humans than to earlier and contemporary hominins. As compared to their relatives, H. ergaster had body proportions more similar to later members of

1785-407: A single extant species, Homo sapiens (modern humans), along with a number of extinct species (collectively called archaic humans ) classified as either ancestral or closely related to modern humans; these include Homo erectus and Homo neanderthalensis . The oldest member of the genus is Homo habilis , with records of just over 2 million years ago. Homo , together with

1890-664: A steady rise in cranial capacity is observed already in Autralopithecina and does not terminate after the emergence of Homo , so that it does not serve as an objective criterion to define the emergence of the genus. Homo habilis emerged about 2.1 Mya. Already before 2010, there were suggestions that H. habilis should not be placed in the genus Homo but rather in Australopithecus . The main reason to include H. habilis in Homo , its undisputed tool use, has become obsolete with

1995-487: Is 13.2°C. As 2012, this city is divided to 2 subdistricts, 17 towns and 1 township. Xintai is an important area of production of foods, vegetables and petroleum. There are about 1,600 million tons of coal deposits, other mineral deposits include quartz, limestone and clay. The industrial structure of Xintai is centered on energy, building materials, machines and chemical engineering. There are more than 1,000 corporations of industry and mining. The Cilai railway runs through

2100-455: Is also possible that the loss of body hair occurred at a significantly later date. Genetic analysis suggests that high activity in the melanocortin 1 receptor , which produces dark skin, dates back to about 1.2 million years ago. This could indicate the evolution of hairlessness around this time, as a lack of body hair would have left the skin exposed to harmful UV radiation . Differences to modern humans would have been readily apparent in

2205-411: Is also the oldest known H. erectus s.l. specimen overall, showing clear similarities to KNM ER 3733, and demonstrates that early H. ergaster coexisted with other hominins such as Paranthropus robustus and Australopithecus sediba . There are also younger specimens of H. ergaster ; notably, Turkana Boy is dated to about 1.56 million years ago. A handful of even younger African skulls make

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2310-570: Is an extinct species or subspecies of archaic humans who lived in Africa in the Early Pleistocene . Whether H. ergaster constitutes a species of its own or should be subsumed into H. erectus is an ongoing and unresolved dispute within palaeoanthropology . Proponents of synonymisation typically designate H. ergaster as " African Homo erectus " or " Homo erectus ergaster ". The name Homo ergaster roughly translates to " working man",

2415-411: Is considered. With all H. ergaster skulls considered, the brain volume of the species mostly varied between 600 and 910 cc, with some small examples only having a volume of 508–580 cc. Since their brain was smaller than that of modern humans, the skull of H. ergaster immediately narrowed behind the eye sockets ( post-orbital constriction ). The brain case was long and low, and Turkana Boy's forehead

2520-697: Is instead whether these fossils represent a radiation of different species or the radiation of a single, highly variable and diverse, species over the course of almost two million years. This long-running debate remains unresolved, with researchers typically using the terms H. erectus s.s. ( sensu stricto ) to refer to H. erectus fossils in Asia and the term H. erectus s.l. ( sensu lato ) to refer to fossils of other species that may or may not be included in H. erectus , such as H. ergaster , H. antecessor and H. heidelbergensis . For obvious reasons, H. ergaster shares many features with H. erectus , such as large forward-projecting jaws, large brow ridges and

2625-501: Is known on when and which Homo first appeared in Europe and Asia, since Early Pleistocene fossil hominins are scarce on both continents, and that it would have been H. ergaster (or "early H. erectus ") that expanded, as well as the particular manner in which they did, remains conjecture. The presence of H. erectus fossils in East Asia means that a human species, most likely H. ergaster , had left Africa before 1 million years ago,

2730-455: Is likely that Homo sapiens (anatomically modern humans) has been the only extant species of Homo . John Edward Gray (1825) was an early advocate of classifying taxa by designating tribes and families. Wood and Richmond (2000) proposed that Hominini ("hominins") be designated as a tribe that comprised all species of early humans and pre-humans ancestral to humans back to after the chimpanzee–human last common ancestor , and that Hominin

2835-427: Is made more difficult since it regards how much intraspecific variation can be exhibited in a single species before it needs to be split into more, a question that in and of itself does not have a clear-cut answer. A 2008 analysis by anthropologist Karen L. Baab, examining fossils of various H. erectus subspecies, and including fossils attributed to H. ergaster , found that the intraspecific variation within H. erectus

2940-617: Is more similar to that of a modern 15-year-old and the brain is comparable to that of a modern 1-year-old. By modern standards, H. ergaster would thus have been cognitively limited, though the invention of new tools prove that they were more intelligent than their predecessors. H. ergaster possessed a significantly larger body mass in comparison to earlier hominins such as early Homo , Australopithecus and Paranthropus . Whereas australopithecines typically ranged in weight from 29–48 kg (64–106 lbs), H. ergaster typically ranged in weight from 52–63 kg (115–139 lbs). It

3045-520: Is no consensus as to which gave rise to Homo . Especially since the 2010s, the delineation of Homo in Australopithecus has become more contentious. Traditionally, the advent of Homo has been taken to coincide with the first use of stone tools (the Oldowan industry), and thus by definition with the beginning of the Lower Palaeolithic . But in 2010, evidence was presented that seems to attribute

3150-462: Is possible that the increased body size was the result of life in an open savannah environment, where increased size gives the ability to exploit broader diets in larger foraging areas, increases mobility and also gives the ability to hunt larger prey. The increased body mass also means that parents would have been able to carry their children to an older age and larger mass. Though reduced sexual dimorphism has often been cited historically as one of

3255-1364: Is still highly controversial. Approximate radiation dates of daughter clades are shown in millions of years ago (Mya). Sahelanthropus and Orrorin , possibly sisters to Australopithecus , are not shown here. The naming of groupings is sometimes muddled as often certain groupings are presumed before any cladistic analysis is performed. Hylobatidae (gibbons) Ponginae (orangutans) Gorillini (gorillas) Panina (chimpanzees) Australopithecines (incl. Australopithecus , Kenyanthropus , Paranthropus , Homo ) Cladogram based on Dembo et al. (2016): Ardipithecus ramidus (†) Australopithecus anamensis s.s. (†3.8) Australopithecus afarensis (†) Australopithecus garhi (†) Australopithecus deyiremeda (†3.4) Kenyanthropus platyops (†3.3) Australopithecus africanus (†2.1) Paranthropus (†1.2) Homo habilis (†1.5) [REDACTED] Homo rudolfensis (†1.9) [REDACTED] Homo ergaster (†1.4) [REDACTED] African Homo erectus s.s. (†) [REDACTED] Asian Homo erectus s.s. (†0.1) [REDACTED] Homo antecessor [REDACTED] (†0.8) H. neanderthalensis (†0.05) [REDACTED] Denisova people (†0.05) Homo sapiens [REDACTED] Australopithecus sediba (†2.0) Homo floresiensis (†0.05) Several of

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3360-428: Is thought to have been ancestral to these later Homo , it might have persisted in Africa until around 600,000 years ago, when brain size increased rapidly and H. heidelbergensis emerged. Traditionally, H. erectus was seen as the hominin that first left Africa to colonise Europe and Asia. If H. ergaster is distinct from H. erectus , this role would apply to H. ergaster instead. Very little concrete information

3465-407: Is unclear if H. ergaster was truly uniquely capable of expanding outside Africa; australopithecines had likely colonised savannah grasslands throughout Africa by 3 million years ago and there are no clear reasons as to why they would not have been able to expand into the grasslands of Asia before H. ergaster . The general assumption is that hominins migrated out of the continent either across

3570-465: Is unclear if they can be formally regarded as H. ergaster specimens. As a chronospecies , H. ergaster may have persisted to as late as 600,000 years ago, when new lineages of Homo arose in Africa. Those who believe H. ergaster should be subsumed into H. erectus consider there to be too little difference between the two to separate them into distinct species. Proponents of keeping the two species as distinct cite morphological differences between

3675-598: The Ancient Greek ἐργαστήρ, ergastḗr , 'workman') roughly translates to "working man" or "workman". Groves and Mazák also included many of the Koobi Fora fossils, such as KNM ER 803 (a partial skeleton and some isolated teeth) in their designation of the species, but did not provide any comparison with the Asian fossil record of H. erectus in their diagnosis, inadvertently causing some of the later taxonomic confusion in regards to

3780-865: The Dawenkou , Longshan and Yueshi cultures. This proves that the ancient Chinese had already created a prelude to the Oriental human civilisation in Xintai some four or five thousand years ago. In the Shang and Zhou dynasties, Xintai served as the capital of the Qi (杞) state . In 219 BC, Qin Shi Huang held a ceremony at Mount Liangfu. Emperor Wu and Emperor Guangwu of the Han dynasty also held similar ceremonies in Xintai. Besides, there were numerous famous Chinese people from Xintai, such as peace activist Liu Xiahui and musician Shi Kuang . In

3885-615: The Homo lineages appear to have surviving progeny through introgression into other lines. Genetic evidence indicates an archaic lineage separating from the other human lineages 1.5 million years ago, perhaps H. erectus , may have interbred into the Denisovans about 55,000 years ago. Fossil evidence shows H. erectus s.s. survived at least until 117,000 yrs ago, and the even more basal H. floresiensis survived until 50,000 years ago. A 1.5-million-year H. erectus -like lineage appears to have made its way into modern humans through

3990-578: The African fossils and H. erectus fossils from Asia, as well as early Homo evolution being more complex than what is implied by subsuming species such as H. ergaster into H. erectus . Additionally, morphological differences between the specimens commonly seen as constituting H. ergaster might suggest that H. ergaster itself does not represent a cohesive species. Regardless of their most correct classification, H. ergaster exhibit primitive versions of traits later expressed in H. erectus and are thus likely

4095-550: The Denisovans and specifically into the Papuans and aboriginal Australians. The genomes of non-sub-Saharan African humans show what appear to be numerous independent introgression events involving Neanderthal and in some cases also Denisovans around 45,000 years ago. The genetic structure of some sub-Saharan African groups seems to be indicative of introgression from a west Eurasian population some 3,000 years ago. Some evidence suggests that Australopithecus sediba could be moved to

4200-588: The Dmanisi fossils, stone tools manufactured by hominins have been discovered on the Loess Plateau in China and dated to 2.12 million years old, meaning that hominins must have left Africa before that time. An alternative hypothesis historically has been that Homo evolved in Asia from earlier ancestors that had migrated there from Africa, and then expanded back into Europe, where it gave rise to H. sapiens . This view

4305-591: The Neolithic. This provides the opportunity for an immense amount of new mutational variation to have arisen during human evolution. A separate South African species Homo gautengensis has been postulated as contemporary with H. erectus in 2010. A taxonomy of Homo within the great apes is assessed as follows, with Paranthropus and Homo emerging within Australopithecus (shown here cladistically granting Paranthropus , Kenyanthropus , and Homo ). The exact phylogeny within Australopithecus

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4410-639: The aforementioned Dmanisi skulls, which share many traits with H. ergaster in Africa, suggesting that H. ergaster might have expanded out of Africa as early as 1.7–1.9 million years ago. In addition to H. ergaster -like traits, the Dmanisi skulls possess a wide assortment of other traits, some of which are similar to traits in earlier hominins such as H. habilis , and the site notably lacks preserved hand axes (otherwise characteristic of H. ergaster ), which means that hominins might have spread out of Africa even earlier than H. ergaster . The skull D2700 (Dmanisi skull 3) in particular resembles H. habilis in

4515-459: The ambiguity of classifying groups as incertae sedis (uncertain placement)—for example, H. neanderthalensis vs. H. sapiens neanderthalensis , or H. georgicus vs. H. erectus georgicus . Some recently extinct species in the genus have been discovered only lately and do not as yet have consensus binomial names (see Denisova hominin ). Since the beginning of the Holocene , it

4620-764: The assumption historically having been that they first migrated out of Africa around 1.9 to 1.7 million years ago. Discoveries in Georgia and China push the latest possible date further back, before 2 million years ago, also casting doubt on the idea that H. ergaster was the first hominin to leave Africa. The main reason for leaving Africa is likely to have been an increasing population periodically outgrowing their resource base, with splintering groups moving to establishing themselves in neighboring, empty territories over time. The physiology and improved technology of H. ergaster might have allowed them to travel to and colonise territories that no one had ever occupied before. It

4725-535: The carcasses of their prey from the variety of contemporary African predators. It is possible that a drop in African carnivoran species variety around 1.5 million years ago can be ascribed to competition with opportunistic and carnivorous hominins. On its own, meat might not have been able to fully sustain H. ergaster . Modern humans can not sufficiently metabolize protein to meet more than 50% of their energy needs and modern humans who heavily rely on animal-based products in their diet mostly rely on fat to sustain

4830-541: The case for long-term anatomical continuity, though it is unclear if they can appropriately be formally regarded as H. ergaster specimens; the " Olduvai Hominid 9 " skull from Olduvai Gorge is dated to about 1.2 to 1.1 million years ago and there are also skulls from Buia (near the coast of Eritrea, dated to ~1 million years old), the Bouri Formation in Ethiopia (dated to between 1 million and 780,000 years old) and

4935-458: The city. The Jinghu and the Boxu expressways converge there. This Shandong location article is a stub . You can help Misplaced Pages by expanding it . Homo For other species or subspecies suggested, see below . Homo (from Latin homō  'human') is a genus of great ape (family Hominidae) that emerged from the genus Australopithecus and encompasses only

5040-488: The decades of the 20th century, fossil finds of pre-human and early human species from late Miocene and early Pliocene times produced a rich mix for debating classifications. There is continuing debate on delineating Homo from Australopithecus —or, indeed, delineating Homo from Pan . Even so, classifying the fossils of Homo coincides with evidence of: (1) competent human bipedalism in Homo habilis inherited from

5145-460: The development of Homo close to or even past 3 Mya. This finds support in a recent phylogenetic study in hominins that by using morphological, molecular and radiometric information, dates the emergence of Homo at 3.3 Ma (4.30 – 2.56 Ma). Others have voiced doubt as to whether Homo habilis should be included in Homo , proposing an origin of Homo with Homo erectus at roughly 1.9 Mya instead. The most salient physiological development between

5250-459: The differences. The differences between Turkana Boy's skull and KNM ER 3733 and KNM ER 3883, as well as the differences in dentition between Turkana Boy and KNM ER 992 have been interpreted by some, such as paleoanthropologist Jeffrey H. Schwartz, as suggesting that Turkana Boy and the rest of the H. ergaster material does not represent the same taxon. Schwartz also noted none of the fossils seemed to represent H. erectus either, which he believed

5355-483: The direct ancestors of later H. erectus populations in Asia. Additionally, H. ergaster is likely ancestral to later hominins in Europe and Africa, such as modern humans and Neanderthals . Several features distinguish H. ergaster from australopithecines as well as earlier and more basal species of Homo , such as H. habilis . Among these features are their larger body mass, relatively long legs, obligate bipedalism , relatively small jaws and teeth (indicating

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5460-409: The discovery of Australopithecus tool use at least a million years before H. habilis . Furthermore, H. habilis was long thought to be the ancestor of the more gracile Homo ergaster ( Homo erectus ). In 2007, it was discovered that H. habilis and H. erectus coexisted for a considerable time, suggesting that H. erectus is not immediately derived from H. habilis but instead from

5565-490: The earlier Australopithecus of more than four million years ago, as demonstrated by the Laetoli footprints ; and (2)  human tool culture having begun by 2.5 million years ago to 3 million years ago. From the late-19th to mid-20th centuries, a number of new taxonomic names, including new generic names, were proposed for early human fossils; most have since been merged with Homo in recognition that Homo erectus

5670-415: The earlier australopithecine species and Homo is the increase in endocranial volume (ECV), from about 460 cm (28 cu in) in A. garhi to 660 cm (40 cu in) in H. habilis and further to 760 cm (46 cu in) in H. erectus , 1,250 cm (76 cu in) in H. heidelbergensis and up to 1,760 cm (107 cu in) in H. neanderthalensis . However,

5775-453: The earliest known hand axes . Though undisputed evidence is missing, H. ergaster might also have been the earliest hominin to master control of fire . The systematics and taxonomy of Homo in the Early to Middle Pleistocene is one of the most disputed areas of palaeoanthropology . In early palaeoanthropology and well into the twentieth century, it was generally assumed that Homo sapiens

5880-550: The early Qing dynasty , in order to improve transport between north and south China, the Yongzheng Emperor ordered the construction of a new connecting road. After Yangliu station was set up, Xintai became an important centre of transport between the north and south. In August 2007, the Shandong coal mine flood killed 181 miners. Xintai lies in the north temperate zone with a monsoon climate . The average annual temperatures

5985-476: The earth, the boundaries and definitions of the genus have been poorly defined and constantly in flux. Because there was no reason to think it would ever have any additional members, Carl Linnaeus did not even bother to define Homo when he first created it for humans in the 18th century. The discovery of Neanderthal brought the first addition. The genus Homo was given its taxonomic name to suggest that its member species can be classified as human. And, over

6090-412: The emergence of H. erectus , so that the evolution of H. erectus would not have been anagenetically, and H. erectus would have existed alongside H. habilis for about half a million years ( 1.9 to 1.4 million years ago ), during the early Calabrian . On 31 August 2023, researchers reported, based on genetic studies, that a human ancestor population bottleneck (from

6195-411: The energy requirements of earlier species. If they had increased energy requirements, H. ergaster would have needed to eat either vastly more food than australopithecines, or would have needed to eat food of superior quality. If they ate the same type of foods as the australopithecines, feeding time would then have had to be dramatically increased in proportion to the extra calories required, reducing

6300-551: The expected lifespan of H. ergaster and H. erectus was lower than that of later and modern humans. It is frequently assumed that the larger body and brain size of H. ergaster , compared to its ancestors, would have brought with it increased dietary and energy needs. In 2002, palaeoanthropologists Leslie C. Aiello and Jonathan C. K. Wells stated that the average resting metabolic requirements of H. ergaster would have been 39% higher than those of Australopithecus afarensis , 30% higher in males and 54% higher in females. However,

6405-405: The face and skull of H. ergaster . Turkana Boy's brain was almost fully grown at the time of his death, but its volume (at 880 cc) was only about 130 cc greater than the maximum found in H. habilis , about 500 cc below the average of modern humans. The 130 cc increase from H. habilis becomes much less significant than what could be presumed when the larger body size of Turkana Boy and H. ergaster

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6510-474: The facial structure of Turkana Boy is narrower and longer than that of the other skulls, with a higher nasal aperture and likely a flatter profile of the upper face. It is possible that these differences can be accounted for through Turkana Boy being a subadult, 7 to 12 years old. Furthermore, KNM ER 3733 is presumed to have been the skull of a female (whereas Turkana Boy is traditionally interpreted as male), which means that sexual dimorphism may account for some of

6615-500: The far younger type specimen of H. erectus (950 cc). Another significant fossil was a fossil mandible recovered at Ileret and described by Leakey with the designation KNM ER 992 in 1972 as " Homo of indeterminate species". In 1975, palaeoanthropologists Colin Groves and Vratislav Mazák designated KNM ER 992 as the holotype specimen of a distinct species, which they dubbed Homo ergaster . The name ( ergaster being derived from

6720-587: The fossils of Java Man ( H. erectus erectus , more than five thousand miles away). The dating of key Asian H. erectus specimens (including Java Man) is not entirely certain, but they are all likely to be 1.5 million years old or younger. Ubeidiya is also the oldest firmly confirmed site of Acheulean tools (one of the tool industries associated with H. ergaster ) outside Africa, the tools recovered there closely resembling older tools discovered in East Africa. The earliest fossil evidence of Homo in Asia are

6825-500: The four genera Australopithecus , Ardipithecus , Praeanthropus , and Sahelanthropus be grouped with Homo within Hominini (sans Pan ). Several species, including Australopithecus garhi , Australopithecus sediba , Australopithecus africanus , and Australopithecus afarensis , have been proposed as the ancestor or sister of the Homo lineage. These species have morphological features that align them with Homo , but there

6930-407: The generic sense of "human being, mankind". The binomial name Homo sapiens was coined by Carl Linnaeus (1758). Names for other species of the genus were introduced from the second half of the 19th century ( H. neanderthalensis 1864, H. erectus 1892). The genus Homo has not been strictly defined, even today. Since the early human fossil record began to slowly emerge from

7035-609: The genus Paranthropus , is probably most closely related to the species Australopithecus africanus within Australopithecus . The closest living relatives of Homo are of the genus Pan ( chimpanzees and bonobos ), with the ancestors of Pan and Homo estimated to have diverged around 5.7-11 million years ago during the Late Miocene . H. erectus appeared about 2 million years ago and spread throughout Africa (debatably as another species called Homo ergaster ) and Eurasia in several migrations . The species

7140-558: The genus Homo , notably relatively long legs which would have made them obligately bipedal. The teeth and jaws of H. ergaster are also relatively smaller than those of H. habilis and H. rudolfensis , indicating a major change in diet. In 1999, palaeoanthropologists Bernard Wood and Mark Collard argued that the conventional criteria for assigning species to the genus Homo were flawed and that early and basal species, such as H. habilis and H. rudolfensis , might appropriately be reclassified as ancestral australopithecines . In their view,

7245-495: The genus Homo , or placed in its own genus, due to its position with respect to e.g. H. habilis and H. floresiensis . By about 1.8 million years ago, H. erectus is present in both East Africa ( H. ergaster ) and in Western Asia ( H. georgicus ). The ancestors of Indonesian H. floresiensis may have left Africa even earlier. Homo erectus and related or derived archaic human species over

7350-625: The geographical distribution of their descendants and tools matching those in East Africa, fossils of the species are mainly from East Africa in the time range of 1.8 to 1.7 million years ago. Most fossils have been recovered from around the shores of Lake Turkana in Kenya. The oldest known specimen of H. erectus s.l. in Africa (i.e. H. ergaster ) is DNH 134 , a skull recovered in the Drimolen Palaeocave System in South Africa, dated to 2.04 to 1.95 million years ago. The skull

7455-577: The growth and development in early Homo can be drawn from the Mojokerto child , a ~1.4–1.5 million year old ~1-year old Asian H. erectus , which had a brain at about 72–84% the size of an adult H. erectus brain, which suggests a brain growth trajectory more similar to that of other great apes than of modern humans. Both the Gona pelvis and the Mojokerto child suggest that the prenatal growth of H. ergaster

7560-598: The jaw), nor with the mandible preserved in Turkana Boy, which has markedly different dentition. The most "iconic" fossil of H. ergaster is the KNM ER 3733 skull, which is sharply distinguished from Asian H. erectus by a number of characteristics, including that the brow ridges project forward as well as upward and arc separately over each orbit and the braincase being quite tall compared to its width, with its side walls curving. KNM ER 3733 can be distinguished from KNM ER 3883 by

7665-626: The jaws projecting farther outwards ( prognathism ). Though the jaws and teeth were smaller than those of the average australopithecine and H. habilis , they were still significantly larger than those of modern humans. Since the jaw slanted sharply backwards, it is probable that they were chinless. The overall structure of Turkana Boy's skull and face is also reflected in other H. ergaster skulls, which combine large and outwardly projecting faces with brow ridges, receding foreheads, large teeth and projecting nasal bones. Though Turkana Boy would have been no more than 12 years old when he died, their stature

7770-491: The loss of body hair could have occurred significantly earlier than H. ergaster . Though skin impressions are unknown in any extinct hominin, it is possible that human ancestors were already losing their body hair around 3 million years ago. Human ancestors acquired pubic lice from gorillas about 3 million years ago, and speciation of human from gorilla pubic lice was potentially only possible because human ancestors had lost most of their body hair by this early date. It

7875-458: The mean difference between male and female individuals. The dimensions of a 1.8 million years old adult female H. ergaster pelvis from Gona , Ethiopia suggests that H. ergaster would have been capable of birthing children with a maximum prenatal (pre-birth) brain size of 315 cc, about 30–50 % of adult brain size. This value falls intermediately between that of chimpanzees (~40 %) and modern humans (28%). Further conclusions about

7980-526: The name for an adaptive grade of human fossils from throughout Africa and Eurasia. Though Tattersall concluded that the H. ergaster material represents the fossils of a single clade of Homo , he also found there to be considerable diversity within this clade; the KNM ER 992 mandible accorded well with other fossil mandibles from the region, such as OH 22 from Olduvai and KNM ER 3724 from Koobi Fora, but did not necessarily match with cranial material, such as KNM ER 3733 and KNM ER 3883 (since neither preserves

8085-668: The next 1.5 million years spread throughout Africa and Eurasia (see: Recent African origin of modern humans ). Europe is reached by about 0.5 Mya by Homo heidelbergensis . Homo neanderthalensis and H. sapiens develop after about 300 kya. Homo naledi is present in Southern Africa by 300 kya. Homo ergaster † Telanthropus capensis Broom and Robinson , 1949 † Homo erectus ergaster (Groves and Mazák, 1975) † Homo louisleakeyi Kretzoi, 1984 † Homo kenyaensis Zeitoun, 2000 † Homo okotensis Zeitoun, 2000 Homo ergaster

8190-565: The origins of H. ergaster are obscured by the fact that the species marks a radical departure from earlier species of Homo and Australopithecus in its long limbs, height and modern body proportions. Though a large number of Pleistocene tools have been found in East Africa, it can not be fully ascertained that H. ergaster originated there without further fossil discoveries. It is assumed that H. ergaster evolved from earlier species of Homo , probably H. habilis . Though populations of H. ergaster outside of Africa have been inferred based on

8295-458: The radical differences between H. ergaster and earlier Homo and australopithecines, it is unclear whether australopithecines were significantly more sexually diamorphic than H. ergaster or modern humans. Skeletal evidence suggests that sexes in H. ergaster differed no more in size than sexes in modern humans do, but a 2003 study by palaeoanthropologists Philip L. Reno, Richard S. Meindl, Melanie A. McCollum and C. Owen Lovejoy suggested that

8400-408: The rest of their energy requirements. Multiple reasons make a fully meat-based diet in H. ergaster unlikely, the most prominent being that African ungulates (the primary prey available) are relatively low in fat and that high meat diets demand increased intake of water, which would have been difficult in an open and hot environment. Modern African hunter-gatherers who rely heavily on meat, such as

8505-413: The same was also true for the significantly earlier Australopithecus afarensis . Sexual dimorphism is difficult to measure in extinct species since the sex of fossils is usually not determinable. Historically, scientists have typically measured differences between the extreme ends (in terms of size and morphology) of the fossil material attributed to a species and assumed that the resulting ratio applies to

8610-402: The small volume of its braincase (600 cc), the form of the middle and upper face and the lack of an external nose. The mixture of skulls at Dmanisi suggests that the definition of H. ergaster (or H. erectus ) might most appropriately be expanded to contain fossils that would otherwise be assigned to H. habilis or that two separate species of archaic humans left Africa early on. In addition to

8715-511: The so-called Southern Dispersal , beginning about 70–50,000 years ago, leading to the lasting colonisation of Eurasia and Oceania by 50,000 years ago. H. sapiens met and interbred with archaic humans in Africa and in Eurasia. Separate archaic (non- sapiens ) human species including Neanderthals are thought to have survived until around 40,000 years ago. The Latin noun homō (genitive hominis ) means "human being" or " man " in

8820-691: The southern end of the Red Sea or along the Nile Valley , but there are no fossil hominins known from either region in the Early Pleistocene. The earliest Homo fossils outside Africa are the Dmanisi skulls from Georgia (dated to 1.77–1.85 million years old, representing either early H. ergaster or a new taxon, H. georgicus ), three incisors from Ubeidiya in Israel (about 1.4 to 1 million years old) and

8925-661: The species and what it should encompass. Some researchers, such as palaeoanthropologist Ian Tattersall in 2013, have questioned H. erectus since it contains an "unwieldly" number of fossils with "substantially differing morphologies". In the 1970s, palaeoanthropologists Richard Leakey and Alan Walker described a series of hominin fossils from Kenyan fossil localities on the eastern shore of Lake Turkana . The most notable finds were two partial skulls; KNM ER 3733 and KNM ER 3883 , found at Koobi Fora . Leakey and Walker assigned these skulls to H. erectus , noting that their brain volumes (848 and 803 cc respectively) compared well to

9030-418: The species. A nearly complete fossil, interpreted as a young male (though the sex is actually undetermined), was discovered at the western shore of Lake Turkana in 1984 by Kenyan archaeologist Kamoya Kimeu . The fossils were described by Leakey and Walker, alongside paleoanthropologists Frank Brown and John Harris, in 1985 as KNM-WT 15000 (nicknamed "Turkana Boy"). They interpreted the fossil, consisting of

9135-403: The time H. ergaster could use for resting, socialising and travelling. Though this would have been possible, it is considered unlikely, especially since the jaws and teeth of H. ergaster are reduced in size compared to those of the australopithecines, suggesting a shift in diet away from fibrous and difficult-to-chew foods. Regardless of energy needs, the small gut of H. ergaster also suggests

9240-476: The time of H. ergaster , this behaviour had probably resulted in the development of true hunter-gatherer behaviour, a first among primates. H. ergaster was an apex predator . Further behaviours that might first have arisen in H. ergaster include male-female divisions of foraging and true monogamous pair bonds. H. ergaster also marks the appearance of more advanced tools of the Acheulean industry, including

9345-537: The torso proportions of H. ergaster implies a relatively small gut, which means that energy needs might not necessarily have been higher in H. ergaster than in earlier hominins. This is because the earlier ape (and australopithecine) gut was large and energy-expensive since it needed to synthesize fat through fermenting plant matter, whereas H. ergaster likely ate significantly more animal fat than their predecessors. This would have allowed more energy to be diverted to brain growth, increasing brain size while maintaining

9450-408: The true earliest representative of Homo was H. ergaster . Au. africanus Au. garhi H. habilis H. rudolfensis H. ergaster H. erectus H. antecessor H. heidelbergensis H. neanderthalensis H. sapiens Since its description as a separate species in 1975, the classification of the fossils referred to H. ergaster has been in dispute. H. ergaster

9555-437: The type specimen of H. erectus , in 2013, Ian Tattersall concluded that referring to the African material as H. ergaster rather than "African H. erectus " was a "considerable improvement" as there were many autapomorphies distinguishing the material of the two continents from one another. Tattersall believes it to be appropriate to use the designation H. erectus only for eastern Asian fossils, disregarding its previous use as

9660-447: The use of stone tools to Australopithecus afarensis around 3.3 million years ago, close to a million years before the first appearance of Homo . LD 350-1 , a fossil mandible fragment dated to 2.8 Mya, discovered in 2013 in Afar, Ethiopia , was described as combining "primitive traits seen in early Australopithecus with derived morphology observed in later Homo . Some authors would push

9765-623: The years, including a massive set of jaws from Indonesia which were perceived to be similar to those of australopithecines and dubbed Meganthropus (now believed to be an unrelated hominid ape ). The discovery of H. floresiensis in 2003, which preserved primitive foot and wrist anatomy reminiscent of that of H. habilis and Australopithecus again led to suggestions of pre- erectus hominins in Asia, though there are no known comparable foot or wrist bones from H. erectus which makes comparisons impossible. The idea that H. ergaster / H. erectus first evolved in Asia before expanding back into Africa

9870-538: Was a single species with a large geographic spread of early migrations. Many such names are now regarded as " synonyms " with Homo , including Pithecanthropus , Protanthropus , Sinanthropus , Cyphanthropus , Africanthropus , Telanthropus , Atlanthropus , and Tchadanthropus . Classifying the genus Homo into species and subspecies is subject to incomplete information and remains poorly done. This has led to using common names ("Neanderthal" and "Denisovan"), even in scientific papers, to avoid trinomial names or

9975-541: Was adaptive and successful, and persisted for more than a million years before gradually diverging into new species around 500,000 years ago. Anatomically modern humans ( H. sapiens ) emerged close to 300,000 to 200,000 years ago in Africa, and H. neanderthalensis emerged around the same time in Europe and Western Asia . H. sapiens dispersed from Africa in several waves , from possibly as early as 250,000 years ago, and certainly by 130,000 years ago, with

10080-668: Was either a single but variable species, several subspecies divided by time and geography or several geographically dispersed but closely related species. In 2015, paleoanthropologists David Strait, Frederick Grine and John Fleagle listed H. ergaster as one of the seven "widely recognized" species of Homo , alongside H. habilis , H. rudolfensis , H. erectus , H. heidelbergensis , H. neanderthalensis and H. sapiens , noting that other species, such as H. floresiensis and H. antecessor , were less widely recognised or more poorly known. Comparing various African fossils attributed to H. erectus or H. ergaster to Asian fossils, notably

10185-677: Was flat and receding, merging at an angle with the brow ridge above their eyes. A noticeable difference between Turkana Boy and the australopithecines and H. habilis would have been their nose, which would have been similar to that of modern humans in projecting forwards and having nostrils oriented downwards. This external nose may have also been an adaptation towards a warmer climate, since the noses of modern humans are usually cooler than their central bodies, condensing moisture that would otherwise have been exhaled and lost during periods of increased activity. The face of Turkana Boy would have been longer from top to bottom than that of modern humans, with

10290-417: Was greater than expected for a single species when compared to modern humans and chimpanzees , but fell well within the variation expected for a species when compared to gorillas , and even well within the range expected for a single subspecies when compared to orangutans (though this is partly due to the great sexual dimorphism exhibited in gorillas and orangutans). Baab concluded that H. erectus s.l.

10395-454: Was immediately dismissed by Leakey and Walker and many influential researchers, such as palaeoanthropologist G. Philip Rightmire, who wrote an extensive treatise on H. erectus in 1990, continued to prefer a more inclusive and comprehensive H. erectus . Overall, there is no doubt that the group of fossils composing H. erectus and H. ergaster represent the fossils of a more or less cohesive subset of closely related archaic humans. The question

10500-459: Was in need of significant revision. In 2000, French palaeoanthropologist Valéry Zeitoun suggested that KNM ER 3733 and KNM ER 3883 should be referred to two separate species, which she dubbed H. kenyaensis (type specimen KNM ER 3733) and H. okotensis (type specimen KNM ER 3883), but these designations have found little acceptance. Although frequently assumed to have originated in East Africa ,

10605-543: Was notably held by Eugène Dubois , who first described H. erectus fossils in the 19th century and considered the fossils of Java Man, at the time undeniably the earliest known hominin fossils, as proof of the hypothesis. Though the discovery of australopithecines and earlier Homo in Africa meant that Homo itself did not originate in Asia, the idea that H. erectus (or H. ergaster ) in particular did, and then expanded back into Africa, has occasionally resurfaced. Various fossil discoveries have been used to support it through

10710-460: Was similar to that of modern humans but that the postnatal (post-birth) growth and development was intermediate between that of chimpanzees and modern humans. The faster development rate suggests that altriciality (an extended childhood and a long period of dependency on your parents) evolved at a later stage in human evolution, possibly in the last common ancestor of Neanderthals and modern humans. The faster development rate might also indicate that

10815-631: Was strengthened with the discovery of Homo erectus georgicus , early specimens of H. erectus found in the Caucasus , which seemed to exhibit transitional traits with H. habilis . As the earliest evidence for H. erectus was found outside of Africa, it was considered plausible that H. erectus developed in Eurasia and then migrated back to Africa. Based on fossils from the Koobi Fora Formation, east of Lake Turkana in Kenya, Spoor et al. (2007) argued that H. habilis may have survived beyond

10920-493: Was substantially weakened by the dating of the DNH 134 skull as approximately 2 million years old, predating all other known H. ergaster / H. erectus fossils. The only well-preserved post-cranial remains of H. ergaster come from the Turkana Boy fossil. Unlike the australopithecines, Turkana Boy's arms were not longer relative to their legs than the arms of living people and the cone-shaped torso of their ancestors had evolved into

11025-476: Was the end result of gradual modifications within a single lineage of hominin evolution. As the perceived transitional form between early hominins and modern humans, H. erectus , originally assigned to contain archaic human fossils in Asia, came to encompass a wide range of fossils covering a large span of time (almost the entire temporal range of Homo ). Since the late twentieth century, the diversity within H. erectus has led some to question what exactly defines

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