Neanderthals became extinct around 40,000 years ago. Hypotheses on the causes of the extinction include violence, transmission of diseases from modern humans which Neanderthals had no immunity to, competitive replacement, extinction by interbreeding with early modern human populations, natural catastrophes, climate change and inbreeding depression. It is likely that multiple factors caused the demise of an already low population.
In research published in Nature in 2014, an analysis of radiocarbon dates from forty Neanderthal sites from Spain to Russia found that the Neanderthals disappeared in Europe between 41,000 and 39,000 years ago with 95% probability. The study also found with the same probability that modern humans and Neanderthals overlapped in Europe for between 2,600 and 5,400 years. [1] Modern humans reached Europe between 45,000 and 43,000 years ago. [2] Improved radiocarbon dating published in 2015 indicates that Neanderthals disappeared around 40,000 years ago, which overturns older carbon dating which indicated that Neanderthals may have lived as recently as 24,000 years ago, [3] including in refugia on the south coast of the Iberian peninsula such as Gorham's Cave. [4] Zilhão et al. (2017) argue for pushing this date forward by some 3,000 years, to 37,000 years ago. [5] Inter-stratification of Neanderthal and modern human remains has been suggested, [6] but is disputed. [7] Stone tools that have been proposed to be linked to Neanderthals have been found at Byzovya (ru:Бызовая) in the polar Urals, and dated to 31,000 to 34,000 years ago, [8] but is also disputed. [9] At Mandrin Cave the French palaeolontologist Ludovic Slimak and colleagues developed a new method of analysing soot from fires. They were able to distinguish between fires made by Neanderthals and modern humans based on the differing food residues in the soot as a result of their different diets. The researchers found that the last layer of soot from Neanderthal fires was a year or less before the first made by modern humans, and in Slimak's view this shows that the two species met and supports the hypothesis that the Neanderthals disappeared due to competitive replacement. [10]
Kwang Hyun Ko discusses the possibility that Neanderthal extinction was either precipitated or hastened by violent conflict with Homo sapiens. Violence in early hunter-gatherer societies usually occurred as a result of resource competition following natural disasters. It is therefore plausible to suggest that violence, including primitive warfare, would have transpired between the two human species. [11] The hypothesis that early humans violently replaced Neanderthals was first proposed by French paleontologist Marcellin Boule (the first person to publish an analysis of a Neanderthal) in 1912. [12]
Infectious diseases carried by Homo sapiens may have passed to Neanderthals, who would have had poor protection to infections they had not previously been exposed to, leading to devastating consequences for Neanderthal populations. Homo sapiens were less vulnerable to Neanderthal diseases, partly because they had evolved to cope with the far higher disease load of the tropics and so were more able to cope with novel pathogens, and partly because the higher numbers of Homo sapiens meant that even devastating outbreaks would still have left enough survivors for a viable population. [13] If viruses could easily jump between these two similar species, possibly because they lived near together, Homo sapiens might have infected Neanderthals and prevented the epidemic from burning out as Neanderthal numbers declined. The same process may also explain Homo sapiens' resilience to Neanderthal diseases and parasites. Novel human diseases likely moved from Africa into Eurasia. This purported "African advantage" remained until the agricultural revolution 10,000 years ago in Eurasia, after which domesticated animals surpassed other primates as the most prevalent source of new human infections, replacing the "African advantage" with a "Eurasian advantage". The catastrophic impact of Eurasian viruses on Native American populations in the historical past offers a sense of how modern humans may have affected hominin predecessor groups in Eurasia 40,000 years ago. Human and Neanderthal genomes and disease or parasite adaptations may give insight on this. [14] [15]
Infectious illness interactions may express the prolonged period of stagnation before the modification, as per disease ecology. Mathematical models have been used to make forecasts for future investigations, giving information about inter-species interactions during the shift between the Middle and Upper Paleolithic eras. This can be useful given the sparse material record from this time and the potential of DNA sequencing and dating technology. Such modeling, together with modern technology and prehistoric archaeological methodologies, may provide a fresh understanding of this time in human origins. [15]
Slight competitive advantage on the part of modern humans may have accounted for Neanderthals' decline on a timescale of thousands of years. [16] [17]
Generally small and widely dispersed fossil sites suggest that Neanderthals lived in less numerous and socially more isolated groups than contemporary Homo sapiens. Tools such as Mousterian flint stone flakes and Levallois points are remarkably sophisticated from the outset, yet they have a slow rate of variability and general technological inertia is noticeable during the entire fossil period. Artifacts are of utilitarian nature, and symbolic behavioral traits are undocumented before the arrival of modern humans in Europe around 40,000 to 35,000 years ago. [16] [18] [19]
The noticeable morphological differences in skull shape between the two human species also have cognitive implications. These include the Neanderthals' smaller parietal lobes [20] [21] [22] and cerebellum, [23] [24] areas implicated in tool use, [25] visuospatial integration, [26] numeracy, [27] creativity, [28] and higher-order conceptualization. [29] The differences, while slight, would have possibly been enough to affect natural selection and may underlie and explain the differences in social behaviors, technological innovation, and artistic output. [16]
Jared Diamond, a supporter of competitive replacement, points out in his book The Third Chimpanzee that the replacement of Neanderthals by modern humans is comparable to patterns of behavior that occur whenever people with advanced technology clash with people with less developed technology. [30]
In 2006, it was posited that Neanderthal Division of labour between the sexes was less developed than Middle paleolithic Homo sapiens. Both male and female Neanderthals participated in the single occupation of hunting big game, such as bison, deer, gazelles, and wild horses. This hypothesis proposes that the Neanderthal's relative lack of labour division resulted in less efficient extraction of resources from the environment as compared to Homo sapiens. [31]
Researchers such as Karen L. Steudel of the University of Wisconsin have highlighted the relationship of Neanderthal anatomy (shorter and stockier than that of modern humans) and the ability to run and the requirement of energy (30% more). [32]
Nevertheless, in the recent study, researchers Martin Hora and Vladimir Sladek of Charles University in Prague show that Neanderthal lower limb configuration, particularly the combination of robust knees, long heels, and short lower limbs, increased the effective mechanical advantage of the Neanderthal knee and ankle extensors, thus reducing the force needed and the energy spent for locomotion significantly. The walking cost of the Neanderthal male is now estimated to be 8–12% higher than that of anatomically modern males, whereas the walking cost of the Neanderthal female is considered to be virtually equal to that of anatomically modern females. [33]
Other researchers, like Yoel Rak, from Tel-Aviv University in Israel, have noted that the fossil records show that Neanderthal pelvises in comparison to modern human pelvises would have made it much harder for Neanderthals to absorb shocks and to bounce off from one step to the next, giving modern humans another advantage over Neanderthals in running and walking ability. However, Rak also notes that all archaic humans had wide pelvises, indicating that this is the ancestral morphology and that modern humans underwent a shift towards narrower pelvises in the late Pleistocene. [34]
Pat Shipman argues that the domestication of the dog gave modern humans an advantage when hunting. [35] Evidence shows the oldest remains of domesticated dogs were found in Belgium (31,700 BP) and in Siberia (33,000 BP). [36] [37] A survey of early sites of modern humans and Neanderthals with faunal remains across Spain, Portugal and France provided an overview of what modern humans and Neanderthals ate. [38] Rabbit became more frequent, while large mammals – mainly eaten by the Neanderthals – became increasingly rare. In 2013, DNA testing on the "Altai dog", a paleolithic dog's remains from the Razboinichya Cave (Altai Mountains), has linked this 33,000-year-old dog with the present lineage of Canis familiaris . [39]
At the time of the last Neanderthals, approximately 45 to 40 thousand years ago, genetic analysis suggests that there was a gene flow from Neanderthals to modern humans of around 10%, but almost no flow from modern humans to Neanderthals. This may be an artifact due to the small number of late Neanderthal genomes, or because hybrids were not viable in Neanderthal groups, or because fertile Neanderthals were being absorbed into modern human groups but not vice versa. If the effect was real over an extended period, it would have increased the size of the modern human gene pool and reduced that of the already sparse Neanderthals, contributing to reduce their numbers below a viable population and thus to their extinction. [40] [41]
According to a study by Rios et al, kinship patterns among recovered Neanderthal remains suggests that there was inbreeding, [42] such as pairings between half-siblings and/or uncle/aunt and niece/nephew. [43] Researchers hypothesize that Neanderthals may have become isolated into small groups during harsh climatic conditions, which contributed to inbreeding behaviours. [44] Due to the lack of genetic diversity, Neanderthal populations would have become more vulnerable to climatic changes, diseases, and other stressors, which may have contributed to their extinction. [45] [46] A similar model to the inbreeding hypothesis can be seen among endangered lowland gorillas. Their populations are so small that it has caused inbreeding, making them even more vulnerable to extinction. [47] [48]
Neanderthals went through a demographic crisis in Western Europe that seems to coincide with climate change that resulted in a period of extreme cold in Western Europe. "The fact that Neanderthals in Western Europe were nearly extinct, but then recovered long before they came into contact with modern humans came as a complete surprise to us," said Love Dalén, associate professor at the Swedish Museum of Natural History in Stockholm. If so, this would indicate that Neanderthals may have been very sensitive to climate change. [49]
The data reveal that sudden climatic change, although crucial locally, had a limited effect on the worldwide Neanderthal population. Interbreeding and assimilation, which were hypothesized as causes in the death of European Neanderthal populations, are successful only for low levels of food competition. Future research will examine models of interbreeding, and hybridization may be evaluated using genomic records from the last ice age (Fu et al., 2016). [50]
A number of researchers have argued that the Campanian Ignimbrite Eruption, a volcanic eruption near Naples, Italy, about 39,280 ± 110 years ago (older estimate ~37,000 years), erupting about 200 km3 (48 cu mi) of magma (500 km3 (120 cu mi) bulk volume) contributed to the extinction of Neanderthals. [51] The argument has been developed by Golovanova et al. [52] [53] The hypothesis posits that although Neanderthals had encountered several Interglacials during 250,000 years in Europe, [54] inability to adapt their hunting methods caused their extinction facing H. sapiens competition when Europe changed into a sparsely vegetated steppe and semi-desert during the last Ice Age. [55] Studies of sediment layers at Mezmaiskaya Cave suggest a severe reduction of plant pollen. [53] The damage to plant life would have led to a corresponding decline in plant-eating mammals hunted by the Neanderthals. [53] [56] [57]
Human evolution is the evolutionary process within the history of primates that led to the emergence of Homo sapiens as a distinct species of the hominid family that includes all the great apes. This process involved the gradual development of traits such as human bipedalism, dexterity, and complex language, as well as interbreeding with other hominins, indicating that human evolution was not linear but weblike. The study of the origins of humans involves several scientific disciplines, including physical and evolutionary anthropology, paleontology, and genetics; the field is also known by the terms anthropogeny, anthropogenesis, and anthropogony.
Early modern human (EMH), or anatomically modern human (AMH), are terms used to distinguish Homo sapiens that are anatomically consistent with the range of phenotypes seen in contemporary humans, from extinct archaic human species. This distinction is useful especially for times and regions where anatomically modern and archaic humans co-existed, for example, in Paleolithic Europe. Among the oldest known remains of Homo sapiens are those found at the Omo-Kibish I archaeological site in south-western Ethiopia, dating to about 233,000 to 196,000 years ago, the Florisbad site in South Africa, dating to about 259,000 years ago, and the Jebel Irhoud site in Morocco, dated about 315,000 years ago.
Homo heidelbergensis is an extinct species or subspecies of archaic human which existed during the Middle Pleistocene. It was subsumed as a subspecies of H. erectus in 1950 as H. e. heidelbergensis, but towards the end of the century, it was more widely classified as its own species. It is debated whether or not to constrain H. heidelbergensis to only Europe or to also include African and Asian specimens, and this is further confounded by the type specimen being a jawbone, because jawbones feature few diagnostic traits and are generally missing among Middle Pleistocene specimens. Thus, it is debated if some of these specimens could be split off into their own species or a subspecies of H. erectus. Because the classification is so disputed, the Middle Pleistocene is often called the "muddle in the middle".
Homo is a genus of great ape that emerged from the genus Australopithecus and encompasses only a single extant species, Homo sapiens, along with a number of extinct species 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 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, with the ancestors of Pan and Homo estimated to have diverged around 5.7-11 million years ago during the Late Miocene.
The Max Planck Institute for Evolutionary Anthropology is a research institute based in Leipzig, Germany, that was founded in 1997. It is part of the Max Planck Society network.
Human taxonomy is the classification of the human species within zoological taxonomy. The systematic genus, Homo, is designed to include both anatomically modern humans and extinct varieties of archaic humans. Current humans have been designated as subspecies Homo sapiens sapiens, differentiated, according to some, from the direct ancestor, Homo sapiens idaltu.
Archaic humans is a broad category denoting all species of the genus Homo that are not Homo sapiens, which are sometimes also called Homo sapiens sapiens, in which case the singular use of sapiens has been applied to some archaic humans as well. Among the earliest modern human remains are those from Jebel Irhoud in Morocco, Florisbad in South Africa (259 ka), Omo-Kibish I in southern Ethiopia, and Apidima Cave in Southern Greece. Some examples of archaic humans include H. antecessor (1200–770 ka), H. bodoensis (1200–300 ka), H. heidelbergensis (600–200 ka), Neanderthals, H. rhodesiensis (300–125 ka) and Denisovans.
The Neanderthal genome project is an effort of a group of scientists to sequence the Neanderthal genome, founded in July 2006.
Early human migrations are the earliest migrations and expansions of archaic and modern humans across continents. They are believed to have begun approximately 2 million years ago with the early expansions out of Africa by Homo erectus. This initial migration was followed by other archaic humans including H. heidelbergensis, which lived around 500,000 years ago and was the likely ancestor of Denisovans and Neanderthals as well as modern humans. Early hominids had likely crossed land bridges that have now sunk.
The chimpanzee–human last common ancestor (CHLCA) is the last common ancestor shared by the extant Homo (human) and Pan genera of Hominini. Estimates of the divergence date vary widely from thirteen to five million years ago.
Jean-Jacques Hublin is a French paleoanthropologist. He is a professor at the Max Planck Society, Leiden University and the University of Leipzig and the founder and director of the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. He is best known for his work on the Pleistocene hominins, and on the Neandertals and early Homo sapiens, in particular.
In paleoanthropology, the recent African origin of modern humans or the "Out of Africa" theory (OOA) is the mainstream academic model of the geographic origin and early migration of anatomically modern humans. It follows the early expansions of hominins out of Africa, accomplished by Homo erectus and then Homo neanderthalensis.
The multiregional hypothesis, multiregional evolution (MRE), or polycentric hypothesis, is a scientific model that provides an alternative explanation to the more widely accepted "Out of Africa" model of monogenesis for the pattern of human evolution.
The Denisovans or Denisova hominins are an extinct species or subspecies of archaic human that ranged across Asia during the Lower and Middle Paleolithic, and lived, based on current evidence, from 285 to 25 thousand years ago. Denisovans are known from few physical remains; consequently, most of what is known about them comes from DNA evidence. No formal species name has been established pending more complete fossil material.
Neanderthals are an extinct group of archaic humans who lived in Eurasia until about 40,000 years ago. The type specimen, Neanderthal 1, was found in 1856 in the Neander Valley in present-day Germany.
The Skhul and Qafzeh hominins or Qafzeh–Skhul early modern humans are hominin fossils discovered in Es-Skhul and Qafzeh caves in Israel. They are today classified as Homo sapiens, among the earliest of their species in Eurasia. Skhul Cave is on the slopes of Mount Carmel; Qafzeh Cave is a rockshelter near Nazareth in Lower Galilee.
Neanderthal anatomy differed from modern humans in that they had a more robust build and distinctive morphological features, especially on the cranium, which gradually accumulated more derived aspects, particularly in certain isolated geographic regions. This robust build was an effective adaptation for Neanderthals, as they lived in the cold environments of Europe. In which they also had to operate in Europe's dense forest landscape that was extremely different from the environments of the African grassland plains that Homo sapiens adapted to with a different anatomical build.
Interbreeding between archaic and modern humans occurred during the Middle Paleolithic and early Upper Paleolithic. The interbreeding happened in several independent events that included Neanderthals and Denisovans, as well as several unidentified hominins.
Southwest Asian Neanderthals were Neanderthals who lived in Turkey, Lebanon, Syria, Israel, Palestine, Iraq, and Iran - the southernmost expanse of the known Neanderthal range. Although their arrival in Asia is not well-dated, early Neanderthals occupied the region apparently until about 100,000 years ago. At this time, Homo sapiens migration seem to have replaced them in one of the first anatomically-modern expansions out of Africa. In their turn, starting around 80,000 years ago, Neanderthals seem to have returned and replaced Homo sapiens in Southwest Asia. They inhabited the region until about 55,000 years ago.
This article records new taxa of fossil primates of every kind are scheduled to be described during the year 2019, as well as other significant discoveries and events related to paleontology of primates that are scheduled to occur in the year 2019.
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