Extinct species of the genus Homo

Homo heidelbergensis is an extinct species or subspecies of archaic humans in the genus homo, which radiated in the Middle Pleistocene from about 700,000 to 300,000 years ago,[2] known from fossils found in Southern Africa, East Africa and Europe. African H. heidelbergensis has several subspecies. The subspecies are Homo heidelbergensis heidelbergensis, Homo heidelbergensis daliensis, Homo rhodesiensis, and Homo heidelbergensis steinheimensi.[3] The derivation of Homo sapiens from Homo rhodesiensis has often been proposed, but is obscured by a fossil gap from 400–260 kya.[4] The species was originally named Homo heidelbergensis due to the skeleton's first discovery in Heidelberg, Germany.[5]

The first discovery—a mandible—was made in 1907 by Otto Schoetensack.[5][6] The skulls of this species share features with both Homo erectus and the anatomically modern Homo sapiens; its brain was nearly as large as that of Homo sapiens.[7] The Sima de los Huesos cave at Atapuerca in northern Spain holds particularly rich layers of deposits where excavations were still in progress as of 2018.[8][9][10][11]

H. heidelbergensis was dispersed throughout Eastern and Southern Africa (Ethiopia, Namibia, Southern Africa) as well as Europe (England, France, Germany, Greece, Hungary, Italy, Portugal, Spain).[12] Its exact relation both to the earlier Homo antecessor and Homo ergaster, and to the later lineages of Neanderthals, Denisovans, and modern humans is unclear.[13][14][15]

Homo sapiens has been proposed as derived from H. heidelbergensis via Homo rhodesiensis, present in East and North Africa from around 400,000 years ago.[16][17] The correct assignment of many fossils to a particular chronospecies is difficult and often differences in opinion ensue among paleoanthropologists due to the absence of universally accepted dividing lines (autapomorphies) between Homo erectus, Homo heidelbergensis, Homo rhodesiensis and Neanderthals.

It is uncertain whether H. heidelbergensis is ancestral to Homo sapiens, as a fossil gap in Africa between 400,000 and 260,000 years ago obscures the presumed derivation of H. sapiens from H. rhodesiensis.[18] Genetic analysis of the Sima de los Huesos fossils (Meyer et al. 2016) seems to suggest that H. heidelbergensis in its entirety should be included in the Neanderthal lineage, as "pre-Neanderthal" or "archaic Neanderthal" or "early Neanderthal", while the divergence time between the Neanderthal and modern lineages has been pushed back to before the emergence of H. heidelbergensis, to about 600,000 to 800,000 years ago, the approximate time of disappearance of Homo antecessor.[19]

The delineation between early H. heidelbergensis and H. erectus is also unclear.[11][20][21] Given the evidence, it means there is no direct evidence that suggest the Homo heidelbergensis is related to modern-day humans.

Derivation and taxonomy [ edit ]

H. heidelbergensis is thought to be derived from Homo antecessor, around 800,000 to 700,000 years ago. The oldest-known fossil classified as H. heidelbergensis dates to around 600,000 years ago, but the flint tools found in 2005 at Pakefield near Lowestoft in Suffolk with teeth from the water vole Mimomys savini, a key dating species, suggest human presence in England at 700,000 years ago, assumed to correspond to a transitional form between H. antecessor and H. heidelbergensis.[22][23][24][25][26]

In Europe, H. heidelbergensis is taken to have given rise to H. neanderthalensis at 240,000 years ago (a conventional date dictated by a fossil gap; late H. heidelbergensis in Europe prior to 240 kya is also called "pre-Neanderthal" or "ante-Neanderthal").[27] Homo sapiens most likely derived from H. rhodesiensis (African H. heidelbergensis) after around 300,000 years ago.

A morphological separation of a European and an African branch of H. heidelbergensis during the Wolstonian Stage and Ipswichian Stage, the last of the prolonged Quaternary glacial periods, has been argued[by whom?] based on the evidence of the Atapuerca skull in Spain and the Kabwe skull in modern-day Zambia.[28]

Neither the derivation of H. heidelbergensis from H. erectus, nor the derivation of anatomically modern humans and Neanderthals from H. heidelbergensis, are clear-cut and are the object of debate. Both H. erectus and H. heidelbergensis are described as polytypic species, which went through a number of population bottlenecks and associated [29] In the summary of Hublin (2013), Middle Pleistocene humans in Eurasia underwent a succession of population bottlenecks due to glaciations. The "Western Eurasian clade" derived form H. rhodesiensis or H. heidelbergensis sensu lato (i.e. the Neanderthals) diverge at MIS 12 (480 kya) but coalesce as late as MIS 5 (130 kya), suggesting a division between Eurasian H. heidelbergensis and H. neanderthalensis before MIS 11 (424 kya). A fossil gap in Africa between 400 and 260 kya obscures the presumed derivation of H. sapiens from H. rhodesiensis.[18]

Chris Stringer (2012) argues for Homo heidelbergensis as an independent chronospecies.[30] A 2013 genetic study on the Sima de los Huesos fossils classified them as H. heidelbergensis or "early Neanderthal". [31]

For more than half a century, many experts were reluctant to accept Homo heidelbergensis as a separate taxon due to the rarity of specimens, which prevented sufficient informative morphological comparisons and the distinction of H. heidelbergensis from other known human species.[32] The species name "heidelbergensis" only experienced a renaissance with the many discoveries of Middle Pleistocene fossils since the 1990s.[33][34]

The paleontology institute at Heidelberg University, where the type specimen is kept since 1908, as late as 2010 still classified it as Homo erectus heidelbergensis, i.e. categorizing it as a Homo erectus subspecies. This was reportedly changed to Homo heidelbergensis, accepting the categorization as separate species, in 2015.[35]

"Rhodesian Man" (Kabwe 1) is now mostly classified as Homo heidelbergensis, though other designations such as Homo sapiens arcaicus[36] and Homo sapiens rhodesiensis[37] have also been proposed. White et al. (2003) suggested Rhodesian Man as ancestral to Homo sapiens idaltu (Herto Man).[38]

Morphology [ edit ]

H. heidelbergensis adult male, reconstruction by adult male, reconstruction by Élisabeth Daynès (2010) based on fragments from Sima de los Huesos

Homo heidelbergensis is intermediate between Homo erectus and Homo neanderthalensis, with a typical cranial volume of approximately 1,250 cm3 (76 cu in).[39] "The anatomy [of H. heidelbergensis] is clearly more primitive than that of Neanderthal, but the harmoniously rounded dental arch and the complete row of teeth...already typically human."[40]

In general, the findings show a continuation of evolutionary trends that are emerging from around the Lower into Middle Pleistocene. Along with changes in the robustness of cranial and dental features, a remarkable increase in brain size from H. erectus towards H. heidelbergensis is noticeable.[41]

Male H. heidelbergensis averaged about 1.75 m (5 ft 9 in) tall and 62 kg (136 lb). Females averaged 1.57 m (5 ft 2 in) and 51 kg (112 lb).[42] A reconstruction of 27 complete human limb bones found in Atapuerca (Burgos, Spain) has helped to determine the height of H. heidelbergensis compared with H. neanderthalensis; the conclusion was that these H. heidelbergensis averaged about 170 cm (5 ft 7in) in height and were only slightly taller than Neanderthals.[43][44]

According to Lee R. Berger of the University of the Witwatersrand, tibia and femora remains indicate that populations of H. heidelbergensis between 350,000 and 400,000 years ago were routinely over 2.13 m (7 ft) tall.[45][46][47] According to him, this was a short-lived experiment that lasted during a grassland expansion, which lead to very large ungulates and antelopes.

Otto Schoetensack described the mandible Mauer 1 in his original species description in 1907:[48]

The "nature of our object" reveals itself "at first sight" since "a certain disproportion between the jaw and the teeth" is obvious: "The teeth are too small for the bone. The available space would allow for a far greater flexibility of development" and "It shows a combination of features, which has been previously found neither on a recent nor a fossil human mandible. Even the scholar should not be blamed if he would only reluctantly accept it as human: Entirely missing is the one feature, which is regarded as particularly human, namely an outer projection of the chin portion, yet this deficiency is found to be combined with extremely strange dimensions of the mandibular body. The actual proof that we are dealing with human parts here only lies within the nature of the dentition. The completely preserved teeth bear the stamp 'human' as evidence: The canines show no trace of a stronger expression in relation to the other groups of teeth. They suggest a moderate and harmonious co-evolution, as it is the case in recent humans."

Behavior [ edit ]

One of hundreds of handaxes found at Boxgrove

Discoveries in a pit in Atapuerca (Spain) of 28 human skeletons suggest that H. heidelbergensis might have been the first species of the genus Homo to bury its dead.[49]

The morphology of the outer and middle ear suggests they had an auditory sensitivity similar to modern humans. They were probably able to differentiate between many different sounds.[50] Dental wear analysis suggests they were as likely to be right-handed as modern people.[51] Steven Mithen[52] believes that H. heidelbergensis, like its descendant H. neanderthalensis, acquired a pre-linguistic system of communication. No forms of art have been uncovered, although red ochre, a mineral that can be used to mix a red pigment which is useful as a paint, has been found at Terra Amata excavations in the south of France.

An archeological site in Schöningen, Germany contained eight exceptionally well-preserved roughly-400,000-year-old spears for hunting, and various other wooden tools. Five-hundred-thousand-year-old hafted stone points used for hunting are reported from Kathu Pan 1 in South Africa, tested by way of use-wear replication.[53] This find could mean that modern humans and Neanderthals inherited the stone-tipped spear, rather than developing the technology independently.[53][54]

The Schöningen spears are eight wooden throwing spears, dated to before 300,000 years ago, discovered between 1994 and 1998 in the open-cast lignite mine, in Schöningen, county Helmstedt, Germany, together with thousands of animal bones. They are regarded as the direct evidence for active hunting by H. heidelbergensis (pre-Neanderthals).[55]

Fossils [ edit ]

Europe [ edit ]

Mauer 1, the first fossil discovery of this species, was found on 21 October 1907, at Mauer, near Heidelberg, Germany. However, it was not until 1908 that the discovery gained traction among public interest.[56] It is a jaw in good condition except for the missing premolar teeth, which were eventually found near the jaw. Otto Schoetensack, from the University of Heidelberg, identified and named the fossil.[57]

The next H. heidelbergensis remains were found in Steinheim an der Murr, Germany (the Steinheim skull, 350kya), Arago, France (Arago 21), Petralona, Greece, and Ciampate del Diavolo, Italy.

Boxgrove Man is the name associated with a lower tibia discovered in 1994 at the Boxgrove Quarry site, close to the English Channel. The fossil was found along with hundreds of hand axes, and has been dated between 478,000 and 524,000 years old.[58] Several H. heidelbergensis teeth were found at the same site in subsequent seasons.

Beginning in 1992, a Spanish team has located more than 5,500 human bones dated to an age of at least 350,000 years in the Sima de los Huesos site in the Sierra de Atapuerca in northern Spain. The pit contains fossils of perhaps 32 individuals together with remains of Ursus deningeri and other carnivores and a biface nicknamed Excalibur.[59] It is hypothesized that this Acheulean axe made of red quartzite was some kind of ritual offering for a funeral. If it is so, it would be the oldest evidence of known of funerary practices.[59] Ninety percent of the known H. heidelbergensis remains have been obtained from this site. The fossil pit bones include:

A complete cranium (skull 5), nicknamed Miguelón , and fragments of other crania, such as skull 4, nicknamed Agamemnón and skull 6, nicknamed Rui (from El Cid, a local hero).

, and fragments of other crania, such as skull 4, nicknamed and skull 6, nicknamed (from El Cid, a local hero). A complete pelvis (pelvis 1), nicknamed Elvis, in remembrance of Elvis Presley.

Mandibles, teeth, and many postcranial bones (femurs, hand and foot bones, vertebrae, ribs, etc.)

Nearby sites contain the only known and controversial Homo antecessor fossils.

There is current debate among scholars whether the remains at Sima de los Huesos are those of H. heidelbergensis or early H. neanderthalensis.[60] In 2015, the study of mitochondrial DNA samples from three caves Sima de los Huesos revealed that they are "distantly related to the mitochondrial DNA of Denisovans rather than to that of Neanderthals."[61]

In 2016 nuclear DNA analysis determined the Sima hominins are Neanderthals and not Denisova hominins, and the divergence between Neanderthals, Denisovans and anatomically modern humans predates 430,000 years ago.[62][63]

Recent studies have hypothesized that homo sapiens and Neanderthals separated from the Homo heidelbergensis branch. They also proposed that "[a]s there are potential H. heidelbergensis fossils from Asia, it is possible they could represent the ancestors of the Denisovans."[5]

Africa [ edit ]

Replica of the Kabwe skull

Facial reconstruction based on the Kabwe skull by John Gurche (2010), Smithsonian Museum of Natural History

A number of morphologically-comparable fossil remains came to light in East Africa (Bodo, Ndutu, Eyasi, Ileret) and North Africa (Salé, Rabat, Dar-es-Soltane, Djbel Irhoud, Sidi Aberrahaman, Tighenif) during the 20th century.[64] The Saldanha cranium, found in 1953 in South Africa was subject to at least three taxonomic revisions from 1955 to 1996.[65]

Kabwe 1, also called the Broken Hill skull, was assigned by Arthur Smith Woodward in 1921 as the type specimen for Homo rhodesiensis; it is today mostly assigned to Homo heidelbergensis.[66][67] It was found in a lead and zinc mine in Broken Hill, Northern Rhodesia (now Kabwe, Zambia) in 1921 by Tom Zwiglaar, a Swiss miner. In addition to the cranium, an upper jaw from another individual, a sacrum, a tibia, and two femur fragments were also found. The skull was dubbed "Rhodesian Man" at the time of the find, but is now commonly referred to as the Broken Hill skull or the Kabwe cranium. Cranial capacity of the Broken Hill skull has been estimated at 1,230 cm3 (75 cu in).[68] Bada, & al., (1974) published the direct date of 110 ka for this specimen measured by aspartic acid racemization.[69][70] The destruction of the paleoanthropological site has made layered dating impossible. The skull suggests an extremely robust individual with the comparatively largest brow-ridges of any known hominin. It was described as having a broad face similar to that of Homo neanderthalensis (i.e. large nasal bones and thick protruding brow ridges). Consequently, researchers came up with interpretations such as "African Neanderthal".[citation needed] However, with regard to the skull's extreme robustness, recent research[citation needed] has highlighted several intermediate features between modern Homo sapiens and Neanderthal. The skull has cavities in ten of the upper teeth and is considered one of the oldest known occurrences of cavities. Pitting indicates significant infection before death and implies that the cause of death may have been due to dental disease infection or possibly chronic ear infection.[citation needed] The skull is kept in the Natural History Museum, London.[71] There is a replica in the Museum in Livingstone, Zambia.

The 600,000-year-old[72] Bodo cranium was found in 1976 by members of an expedition led by Jon Kalb at Bodo D'ar in the Awash River valley of Ethiopia.[73] The initial discovery—a lower face—was made by Alemayhew Asfaw and Charles Smart. Two weeks later, Paul Whitehead and Craig Wood found the upper portion of the face. The skull is 600,000 years old.[74] Although the skull is most similar to those of Kabwe, Woodward's nomenclature was discontinued and its discoverers attributed it to H. heidelbergensis.[75] It has features that represent a transition between Homo ergaster/erectus and Homo sapiens.[76]

Another specimen,[77] "the hominid from Lake Ndutu" in northern Tanzania, around 400,000 years old. In 1976 R. J. Clarke classified it as Homo erectus and it has generally been viewed as such since, although points of similarity to H. sapiens have also been recognized. After comparative studies with similar finds in Africa allocation to an African subspecies of H. sapiens seems most appropriate.[78] An indirect cranial capacity estimate suggests 1,100 ml (39 imp fl oz; 37 US fl oz). Its supratoral sulcus morphology and the presence of protuberance as suggested by Philip Rightmire "give the Nudutu occiput an appearance which is also unlike that of Homo erectus", but Stinger (1986) pointed out that a thickened iliac pillar is typical for Homo erectus.[79] In a 1989 publication Clarke concludes: "It is assigned to archaic Homo sapiens on the basis of its expanded parietal and occipital regions of the brain".[80]

The Saldanha cranium, or Elandsfontein cranium, are fossilized remains later identified as Homo heidelbergensis, found in 1954 in Elandsfontein, located in the Hopefield of South Africa.[81]





New evidence [ edit ]

Language

The Homo heidelbergensis has been indicated as an ancestor of modern humans that did not have air sacs. It is said that the loss of air sacs contributed to humans' ability to develop further in vocal language. Ancestors, such as the Australopithecus, did not have air sacs.[82] Furthermore, evidence has shown that Homo heidelbergensis were right-handed. Right-handedness is associated with the development of language among hominins.[83] Considering this evidence, scientist have hypothesized about the speaking capabilities of the species. A recent study, that compared the speech frequency of humans and chimpanzees, reported that the Homo heidelbergensis speech abilities most resemble that of modern-day humans. More specifically, "the Atapuerca SH hominins show[ed] a bandwidth that [wa]s slightly displaced and considerably extended to encompass the frequencies that contain relevant acoustic information in human speech."[84]

Homo heidelbergenis firsts

The Homo heidelbergensis is home to many firsts for the human species. It has been noted by the Smithsonian National Museum of Natural History to be the first species of the homo genus branch to build permanent shelters.[86] Furthermore, the physical build of the Homo heidlebergensis allowed it to be the first of the homo genus to withstand colder temperatures, paving the way for its successors to evolve to withstand even colder landscapes. The ratio of height to width, with a wide body in comparison to height, is what enabled the species to conserve more body heat to endure harsher climates.[86][87] It has also been proposed by scientist that the Homo heidelbergensis was the first to contract odontogenic orbital cellulitis, or a severe eye infection, that developed from an abscess in the mouth.[88][89]

Fossils [ edit ]

The "Galilee skull", found in 1925/6 at Mugharet el-Zuttiyeh, now in Israel, has been described as "the most likely Heidelberg candidate from Western Asia". [90]

Petralona 1, discovered in Petralona cave, Greece, in 1960, dated to between roughly 350,000 and 150,000 years old. It has been classified as either H. heidelbergensis or H. neanterthalensis . [91]

or . Tautavel Man (Arago 21) is a human skull discovered on 22 July 1971 near the village of Tautavel in Pyrénées-Orientales, dated at 450,000 years old. The fossil was classified as Homo erectus tautavelensis, and as such would not belong to H. heidelbergensis but to a different lineage of H. erectus which occupied Europe at the same time as H. heidelbergensis.[92]

See also [ edit ]

Further reading [ edit ]

References [ edit ]

Media related to Homo heidelbergensis at Wikimedia Commons