Homo erectus appeared about two million years ago and, in several early migrations, it spread throughout Africa (where it is dubbed Homo ergaster) and Eurasia.
It was likely the first human species to live in a hunter-gatherer society and to control fire.
An adaptive and successful species, Homo erectus persisted for more than a million years, and gradually diverged into new species by around 500,000 years ago.
Evolutionary tree chart emphasizing the subfamily Homininae and the tribe Hominini. After diverging from the line to Ponginae the early Homininae split into the tribes Hominini and Gorillini. The early Hominini split further, separating the line to Homo from the lineage of Pan. Currently, tribe Hominini designates the subtribesHominina, containing genus Homo; Panina, genus Pan; and Australopithecina, with several extinct genera--the subtribes are not labelled on this chart.
A model of the evolution of the genus Homo over the last 2 million years (vertical axis). The rapid "Out of Africa" expansion of H. sapiens is indicated at the top of the diagram, with admixture indicated with Neanderthals, Denisovans, and unspecified archaic African hominins. Late survival of robust australopithecines (Paranthropus) alongside Homo until 1.2 Mya is indicated in purple.
The Latin noun hom? (genitive hominis) means "human being" or "man" in the generic sense of "human being, mankind". The binomial nameHomo sapiens was coined by Carl Linnaeus (1758).
Names for other species of the genus were introduced beginning in the second half of the 19th century (H. neanderthalensis 1864, H. erectus 1892).
Even today, the genus Homo has not been properly defined. Since the early human fossil record began to slowly emerge from the earth, the boundaries and definitions of the genus Homo 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 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, as one body of scientists argues that the two species of chimpanzee should be classed with genus Homo rather than Pan. Even so, classifying the fossils of Homo coincides with evidence of: 1) competent human bipedalism in Homo habilis inherited from 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.
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 was a single and singular species with a large geographic spread of early migrations. Many such names are now dubbed as "synonyms" with Homo, including Pithecanthropus,Protanthropus,Sinanthropus,Cyphanthropus,Africanthropus,Telanthropus,Atlanthropus,
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") in even scientific papers to avoid trinomial names or 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 Homo are only recently discovered and do not as yet have consensus binomial names (see Denisova hominin and Red Deer Cave people).
Since the beginning of the Holocene, it 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 Hominina 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 the four genera Australopithecus, Ardipithecus, Praeanthropus, and Sahelanthropus be grouped with Homo within Hominina.[failed verification]
Especially since the 2010s, the delineation of Homo from 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 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 2015 in Afar, Ethiopia, was described as combining "primitive traits seen in early Australopithecus with derived morphology observed in later Homo.
Some authors would push the development of Homo close to or even past 3 Mya.
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 the earlier australopithecine species and Homo is the increase in endocranial volume (ECV), from about 460 cm3 (28 cu in) in A. garhi to 660 cm3 (40 cu in) in H. habilis and further to 760 cm3 (46 cu in) in H. erectus, 1,250 cm3 (76 cu in) in H. heidelbergensis and up to 1,760 cm3 (107 cu in) in H. neanderthalensis.
However, 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.
Forensic reconstruction of Homo habilis, exhibit in LWL-Museum für Archäologie, Herne, Germany (2007 photograph).
Homo habilis emerged about 2.1 Mya. Already before 2010, there were suggestions that H. habilis should not be placed in genus Homo but rather in Australopithecus.
The main reason to include H. habilis in Homo, its undisputed tool use, has become obsolete with 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 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 Homo habilis from about 2 million years ago.
This scenario 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 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 1.4million years ago), during the early Calabrian.
A separate South African species Homo gautengensis has been postulated as contemporary with Homo erectus in 2010.
A taxonomy of the 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 is still highly controversial. Approximate radiation dates of daughter clades are shown in millions of years ago (Mya). Sahelanthropus, Orrorin, and Ardipithecus, possibly sisters to Australopithecus, are not shown here. Note that the naming of groupings is sometimes muddled as often certain groupings are presumed before a cladistic analyses is performed.
Several of the Homo lineages appear to have surviving progeny through introgression into other lines. 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, although H. erectus is generally regarded as being extinct by then. However, the thigh bone, dated at 14,000 years, found in a Maludong cave (Red Deer Cave people) strongly resembles very ancient species like early Homo erectus or the even more archaic lineage, Homo habilis, which lived around 1.5 million year ago. There is evidence for introgression of H. Heidelbergensis into H. sapiens. 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. Likewise the genetic structure of sub-Saharan Africans seems to be indicative of introgression from a distinct, as yet unidentified archaic human lineage such as H. heidelbergensis.
H. sapiens soon after its first emergence spread throughout Africa, and to Western Asia in several waves, possibly as early as 250 kya, and certainly by 130 kya. In July 2019, anthropologists reported the discovery of 210,000 year old remains of a H. sapiens and 170,000 year old remains of a H. neanderthalensis in Apidima Cave, Peloponnese, Greece, more than 150,000 years older than previous H. sapiens finds in Europe.
Among extant populations of Homo sapiens, the deepest temporal division is found in the San people of Southern Africa, estimated at close to 130,000 years,
or possibly more than 300,000 years ago.
Temporal division among non-Africans is of the order of 60,000 years in the case of Australo-Melanesians.
Division of Europeans and East Asians is of the order of 50,000 years, with repeated and significant admixture events throughout Eurasia during the Holocene.
There has historically been a trend to postulate "new human species" based on as little as an individual fossil. A "minimalist" approach to human taxonomy recognizes at most three species, Homo habilis (2.1-1.5 Mya, membership in Homo questionable), Homo erectus (1.8-0.1 Mya, including the majority of the age of the genus, and the majority of archaic varieties as subspecies, including H. heidelbergensis as a late or transitional variety) and Homo sapiens (300 kya to present, including H. neanderthalensis and other varieties as subspecies).
^The conventional estimate on the age of H. habilis is at roughly 2.1 to 2.3 million years. Stringer, C.B. (1994). "Evolution of early humans". In Steve Jones; Robert Martin; David Pilbeam (eds.). The Cambridge Encyclopedia of Human Evolution. Cambridge: Cambridge University Press. p. 242.
Friedemann Schrenk, Ottmar Kullmer, Timothy Bromage, "The Earliest Putative Homo Fossils", chapter 9 in: Winfried Henke, Ian Tattersall (eds.), Handbook of Paleoanthropology, 2007, pp. 1611-1631, doi:10.1007/978-3-540-33761-4_52.
Suggestions for pushing back the age to 2.8 Mya were made in 2015 based on the discovery of a jawbone:
Spoor, Fred; Gunz, Philipp; Neubauer, Simon; Stelzer, Stefanie; Scott, Nadia; Kwekason, Amandus; Dean, M. Christopher (March 5, 2015). "Reconstructed Homo habilis type OH 7 suggests deep-rooted species diversity in early Homo". Nature. 519 (7541): 83-86. Bibcode:2015Natur.519...83S. doi:10.1038/nature14224. ISSN0028-0836. PMID25739632..
^H. erectus in the narrow sense (the Asian species) was extinct by 140,000 years ago, Homo erectus soloensis, found in Java, is considered the latest known survival of H. erectus. Formerly dated to as late as 50,000 to 40,000 years ago, a 2011 study pushed back the date of its extinction of H. e. soloensis to 143,000 years ago at the latest, more likely before 550,000 years ago. Indriati E, Swisher CC III, Lepre C, Quinn RL, Suriyanto RA, et al. 2011 The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia.PLoS ONE 6(6): e21562. doi:10.1371/journal.pone.0021562.
^Lowery, R.K.; Uribe, G.; Jimenez, E.B.; Weiss, M.A.; Herrera, K.J.; Regueiro, M.; Herrera, R.J. (2013). "Neanderthal and Denisova genetic affinities with contemporary humans: Introgression versus common ancestral polymorphisms". Gene. 530 (1): 83-94. doi:10.1016/j.gene.2013.06.005. PMID23872234.
This study raises the possibility of observed genetic affinities between archaic and modern human populations being mostly due to common ancestral polymorphisms.
^The word "human" itself is from Latin humanus, an adjective formed on the root of homo, thought to derive from a Proto-Indo-European word for "earth" reconstructed as *dh?hem-. dhghem The American Heritage Dictionary of the English Language: Fourth Edition. 2000.
^Linné, Carl von (1758). Systema naturæ. Regnum animale (10 ed.). Sumptibus Guilielmi Engelmann. pp. 18, 20. Retrieved 2012..
Note: In 1959, Linnaeus was designated as the lectotype for Homo sapiens (Stearn, W T. 1959. "The background of Linnaeus's contributions to the nomenclature and methods of systematic biology", Systematic Zoology 8 (1): 4-22, p. 4) which means that following the nomenclatural rules, Homo sapiens was validly defined as the animal species to which Linnaeus belonged.
^"ape-man", from Pithecanthropus erectus (Java Man), Eugène Dubois, Pithecanthropus erectus : eine menschenähnliche Übergangsform aus Java (1894), identified with the Pithecanthropus alalus (i.e. "non-speaking ape-man") hypothesized earlier by Ernst Haeckel
^"African man", used by T.F. Dreyer (1935) for the Florisbad Skull he found in 1932 (also Homo florisbadensis or Homo helmei). Also the genus suggested for a number of archaic human skulls found at Lake Eyasi by Weinert (1938). Leaky, Journal of the East Africa Natural History Society' (1942), p. 43.
^"remote man"; from Telanthropus capensis (Broom and Robinson 1949), see (1961), p. 487.
^from Atlanthropus mauritanicus,
name given to the species of fossils (three lower jaw bones and a parietal bone of a skull) discovered in 1954 to 1955 by Camille Arambourg in Tighennif, Algeria. Arambourg, C. (1955). "A recent discovery in human paleontology: Atlanthropus of ternifine (Algeria)". American Journal of Physical Anthropology. 13 (2): 191-201. doi:10.1002/ajpa.1330130203.
^Y. Coppens, "L'Hominien du Tchad", Actes V Congr. PPEC I (1965), 329f.; "Le Tchadanthropus", Anthropologia 70 (1966), 5-16.
^J.E. Gray, "An outline of an attempt at the disposition of Mammalia into Tribes and Families, with a list of genera apparently appertaining to each Tribe", Annals of Philosophy', new series (1825), pp. 337-344.
^ abMcPherron, S.P.; Alemseged, Z.; Marean, C.W.; Wynn, J.G.; Reed, D.; Geraads, D.; Bobe, R.; Bearat, H.A. (2010). "Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia". Nature. 466 (7308): 857-860. Bibcode:2010Natur.466..857M. doi:10.1038/nature09248. PMID20703305.
"The oldest direct evidence of stone tool manufacture comes from Gona (Ethiopia) and dates to between 2.6 and 2.5 million years (Myr) ago. [...] Here we report stone-tool-inflicted marks on bones found during recent survey work in Dikika, Ethiopia [... showing] unambiguous stone-tool cut marks for flesh removal [..., dated] to between 3.42 and 3.24 Myr ago [...] Our discovery extends by approximately 800,000 years the antiquity of stone tools and of stone-tool-assisted consumption of ungulates by hominins; furthermore, this behaviour can now be attributed to Australopithecus afarensis."
^"the adaptive coherence of Homo would be compromised if H. habilis is included in Homo. Thus, if these arguments are accepted the origins of the genus Homo are coincident in time and place with the emergence of H. erectus, not H. habilis"
Bernard Wood, "Did early Homo migrate 'out of' or 'in to' Africa?", PNAS vol. 108, no.26 (28 June 2011), 10375-10376.
^" A fresh look at brain size, hand morphology and earliest technology suggests that a number of key Homo attributes may already be present in generalized species of Australopithecus, and that adaptive distinctions in Homo are simply amplifications or extensions of ancient hominin trends. [...] the adaptive shift represented by the ECV of Australopithecus is at least as significant as the one represented by the ECV of early Homo, and that a major 'grade-level' leap in brain size with the advent of H. erectus is probably illusory" William H. Kimbel, Brian Villmoare, "From Australopithecus to Homo: the transition that wasn't", Philosophical Transactions of the Royal Society B, 13 June 2016, doi:10.1098/rstb.2015.0248.
^by W. Schnaubelt & N. Kieser (Atelier WILD LIFE ART); see Westfalen_in_der-Alt-und_Mittelsteinzeit, Landschaftsverband Westfalen-Lippe, Münster (2013), fig. 42.
^F. Spoor; M.G. Leakey; P.N. Gathogo; F.H. Brown; S.C. Antón; I. McDougall; C. Kiarie; F.K. Manthi; L.N. Leakey (2007-08-09). "Implications of new early Homo fossils from Ileret, east of Lake Turkana, Kenya". Nature. 448 (7154): 688-691. Bibcode:2007Natur.448..688S. doi:10.1038/nature05986. PMID17687323.F. Spoor; M.G. Leakey; P.N. Gathogo; F.H. Brown; S.C. Antón; I. McDougall; C. Kiarie; F.K. Manthi; L.N. Leakey (2007-08-09). "Implications of new early Homo fossils from Ileret, east of Lake Turkana, Kenya". Nature. 448 (7154): 688-691. Bibcode:2007Natur.448..688S. doi:10.1038/nature05986. PMID17687323. "A partial maxilla assigned to H. habilis reliably demonstrates that this species survived until later than previously recognized, making an anagenetic relationship with H. erectus unlikely"
"A partial maxilla assigned to H. habilis reliably demonstrates that this species survived until later than previously recognized, making an anagenetic relationship with H. erectus unlikely. The discovery of a particularly small calvaria of H. erectus indicates that this taxon overlapped in size with H. habilis, and may have shown marked sexual dimorphism. The new fossils confirm the distinctiveness of H. habilis and H. erectus, independently of overall cranial size, and suggest that these two early taxa were living broadly sympatrically in the same lake basin for almost half a million years."
Spoor, F; Leakey, M.G; Gathogo, P.N; Brown, F.H; Antón, S.C; McDougall, I; Kiarie, C; Manthi, F.K.; Leakey, L.N. (2007). "Implications of new early Homo fossils from Ileret, east of Lake Turkana, Kenya". Nature. 448 (7154): 688-691. Bibcode:2007Natur.448..688S. doi:10.1038/nature05986. PMID17687323.
^Curnoe, D (2010). "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.)". HOMO: Journal of Comparative Human Biology. 61 (3): 151-177. doi:10.1016/j.jchb.2010.04.002. PMID20466364.
^The conventional estimate on the age of H. habilis is at roughly 2.1 to 2.3 million years. Stringer, C.B. (1994). "Evolution of early humans". In Steve Jones; Robert Martin; David Pilbeam (eds.). The Cambridge Encyclopedia of Human Evolution. Cambridge: Cambridge University Press. p. 242. Friedemann Schrenk, Ottmar Kullmer, Timothy Bromage, "The Earliest Putative Homo Fossils", chapter 9 in: Winfried Henke, Ian Tattersall (eds.), Handbook of Paleoanthropology, 2007, pp. 1611-1631, doi:10.1007/978-3-540-33761-4_52. Suggestions for pushing back the age to 2.8 Mya were made in 2015 based on the discovery of a jawbone: Spoor, Fred; Gunz, Philipp; Neubauer, Simon; Stelzer, Stefanie; Scott, Nadia; Kwekason, Amandus; Dean, M. Christopher (March 5, 2015). "Reconstructed Homo habilis type OH 7 suggests deep-rooted species diversity in early Homo". Nature. 519 (7541): 83-86. Bibcode:2015Natur.519...83S. doi:10.1038/nature14224. ISSN0028-0836. PMID25739632..
^H. erectus in the narrow sense (the Asian species) was extinct by 140,000 years ago, Homo erectus soloensis, found in Java, is considered the latest known survival of H. erectus. Formerly dated to as late as 50,000 to 40,000 years ago, a 2011 study pushed back the date of its extinction of H. e. soloensis to 143,000 years ago at the latest, more likely before 550,000 years ago. Indriati E, Swisher CC III, Lepre C, Quinn RL, Suriyanto RA, et al. 2011 The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia.PLoS ONE 6(6): e21562.doi:10.1371/journal.pone.0021562.
^ abZeitoun, Valery (2003). "High occurrence of a basicranial feature in Homo erectus: Anatomical description of the preglenoid tubercle". The Anatomical Record Part B: The New Anatomist. 274B (1): 148-156. doi:10.1002/ar.b.10028. ISSN1552-4914. PMID12964205.
^Mounier, A.; Caparros, M. (2015). "The phylogenetic status of Homo heidelbergensis - a cladistic study of Middle Pleistocene hominins". BMSAP (in French). 27 (3-4): 110-134. doi:10.1007/s13219-015-0127-4. ISSN0037-8984.
^Confirmed H. habilis fossils are dated to between 2.1 and 1.5 million years ago. This date range overlaps with the emergence of Homo erectus. Schrenk, Friedemann; Kullmer, Ottmar; Bromage, Timothy (2007). "The Earliest Putative Homo Fossils". In Henke, Winfried; Tattersall, Ian (eds.). Handbook of Paleoanthropology. 1. In collaboration with Thorolf Hardt. Berlin, Heidelberg: Springer. pp. 1611-1631. doi:10.1007/978-3-540-33761-4_52. ISBN978-3-540-32474-4.DiMaggio, Erin N.; Campisano, Christopher J.; Rowan, John; et al. (March 20, 2015). "Late Pliocene fossiliferous sedimentary record and the environmental context of early Homo from Afar, Ethiopia". Science. 347 (6228): 1355-1359. Bibcode:2015Sci...347.1355D. doi:10.1126/science.aaa1415. ISSN0036-8075. PMID25739409. Hominins with "proto-Homo" traits may have lived as early as 2.8 million years ago, as suggested by a fossil jawbone classified as transitional between Australopithecus and Homo discovered in 2015.
^Curnoe, Darren (June 2010). "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.)". HOMO - Journal of Comparative Human Biology. 61 (3): 151-177. doi:10.1016/j.jchb.2010.04.002. ISSN0018-442X. PMID20466364. A species proposed in 2010 based on the fossil remains of three individuals dated between 1.9 and 0.6 million years ago. The same fossils were also classified as H. habilis, H. ergaster or Australopithecus by other anthropologists.
^Haviland, William A.; Walrath, Dana; Prins, Harald E.L.; McBride, Bunny (2007). Evolution and Prehistory: The Human Challenge (8th ed.). Belmont, CA: Thomson Wadsworth. p. 162. ISBN978-0-495-38190-7.H. erectus may have appeared some 2 million years ago. Fossils dated to as much as 1.8 million years ago have been found both in Africa and in Southeast Asia, and the oldest fossils by a narrow margin (1.85 to 1.77 million years ago) were found in the Caucasus, so that it is unclear whether H. erectus emerged in Africa and migrated to Eurasia, or if, conversely, it evolved in Eurasia and migrated back to Africa.
^Formerly dated to as late as 50,000 to 40,000 years ago, a 2011 study pushed back the date of its extinction of H. e. soloensis to 143,000 years ago at the latest, more likely before 550,000 years ago.
Indriati E, Swisher CC III, Lepre C, Quinn RL, Suriyanto RA, et al. 2011 The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia.PLoS ONE 6(6): e21562. doi:10.1371/journal.pone.0021562.
^The type fossil is Mauer 1, dated to ca. 0.6 million years ago.
The transition from H. heidelbergensis to H. neanderthalensis between 300 and 243 thousand years ago is conventional, and makes use of the fact that there is no known fossil in this period. Examples of H. heidelbergensis are fossils found at Bilzingsleben (also classified as Homo erectus bilzingslebensis).
^Muttoni, Giovanni; Scardia, Giancarlo; Kent, Dennis V.; Swisher, Carl C.; Manzi, Giorgio (2009). "Pleistocene magnetochronology of early hominin sites at Ceprano and Fontana Ranuccio, Italy". Earth and Planetary Science Letters. 286 (1-2): 255-268. Bibcode:2009E&PSL.286..255M. doi:10.1016/j.epsl.2009.06.032.
^Dirks, P.; et al. (9 May 2017). "The age of Homo naledi and associated sediments in the Rising Star Cave, South Africa". eLife. 6: e24231. doi:10.7554/eLife.24231. PMID28483040.
^Bischoff, James L.; Shamp, Donald D.; Aramburu, Arantza; et al. (March 2003). "The Sima de los Huesos Hominids Date to Beyond U/Th Equilibrium (>350 kyr) and Perhaps to 400-500 kyr: New Radiometric Dates". Journal of Archaeological Science. 30 (3): 275-280. doi:10.1006/jasc.2002.0834. ISSN0305-4403.
The first humans with "proto-Neanderthal traits" lived in Eurasia as early as 0.6 to 0.35 million years ago (classified as H. heidelbergensis, also called a chronospecies because it represents a chronological grouping rather than being based on clear morphological distinctions from either H. erectus or H. neanderthalensis). There is a fossil gap in Europe between
300 and 243 kya, and by convention, fossils younger than 243 kya are called "Neanderthal".
D. Dean; J.-J. Hublin; R. Holloway; R. Ziegler (1998). "On the phylogenetic position of the pre-Neandertal specimen from Reilingen, Germany". Journal of Human Evolution. 34 (5). pp. 485-508. doi:10.1006/jhev.1998.0214.
^Détroit, F.; Mijares, A. S.; Corny, J.; Daver, G.; Zanolli, C.; Dizon, E.; Robles, E.; Grün, R.; Piper, P. J. (2019). "A new species of Homo from the Late Pleistocene of the Philippines". Nature. 568 (7751): 181-186. doi:10.1038/s41586-019-1067-9.