From Wikipedia, the free encyclopedia
Neanderthals,
Homo neanderthalensis or
Homo sapiens neanderthalensis) are an extinct species or subspecies of
archaic humans in the
genus Homo, who lived within Eurasia from circa 400,000 until 40,000 years ago.
Currently the earliest fossils of Neanderthals in Europe are
dated between 450,000 and 430,000 years ago, and thereafter Neanderthals
expanded
into Southwest and Central Asia. They are known from numerous fossils, as well as
stone tool assemblages. Almost all assemblages younger than 160,000 years are of the so-called
Mousterian techno-complex, which is characterised by
tools made out of stone flakes.
The type specimen is
Neanderthal 1, found in
Neander Valley in the German
Rhineland, in 1856.
Compared to
modern humans, Neanderthals were stockier, with shorter legs and bigger bodies. In conformance with
Bergmann's rule, as well as
Allen's rule, this was likely was an
adaptation to preserve heat in cold climates. Male and female Neanderthals had
cranial capacities averaging 1,600 cm
3 (98 cu in) and 1,300 cm
3 (79 cu in), respectively,
within the range of the values for anatomically modern humans.
Average males stood around 164 to 168 cm (65 to 66 in) and females 152 to 156 cm (60 to 61 in) tall.
There has been growing evidence for
admixture
between Neanderthals and anatomically modern humans, reflected in the
genomes of all modern non-African populations but not in the genomes of
most sub-Saharan Africans. This suggests that interbreeding between Neanderthals and
anatomically modern humans took place after the
recent "out of Africa" migration, around 70,000 years ago.
Recent admixture analyses have added to the complexity, finding that
Eastern Neanderthals derived up to 2% of their ancestry from
anatomically modern humans who left Africa some 100,000 years ago.
Name and classification
Neanderthals are named after one of the first sites where their fossils were discovered in the mid-19th century in the
Neander Valley, just east of
Düsseldorf, at the time in the
Rhine Province of the
Kingdom of Prussia (now in
Northrhine-Westphalia,
Germany). The valley itself was named for
Joachim Neander,
Neander being the graecicized form of the surname
Neumann ("new man").
The German spelling of
Thal "Valley" was current in the 19th century (contemporary German
Tal).
Neanderthal 1
was known as the "Neanderthal cranium" or "Neanderthal skull" in
anthropological literature, and the individual reconstructed on the
basis of the skull was occasionally called "the Neanderthal man".
The binomial name
Homo neanderthalensis—extending the name "Neanderthal man" from the individual
type specimen to the entire group—was first proposed by the Anglo-Irish geologist
William King in a paper read to the
British Association in 1863, although in the following year he stated that the specimen was not human and rejected the name.
King's name had priority over the proposal put forward in 1866 by
Ernst Haeckel,
Homo stupidus.
Popular English usage of "Neanderthal" as shorthand for "Neanderthal
man", as in "the Neanderthals" or "a Neanderthal", emerged in the
popular literature of the 1920s.
Since the historical spelling
-th- in German represents
the phoneme /t/ or /tʰ/, not the fricative /θ/, standard British
pronunciation of "Neanderthal" is with /t/ (
IPA:
/niːˈændərtɑːl/).
Because of the
usual sound
represented by digraph ⟨th⟩ in English, "Neanderthal" is also
pronounced with the voiceless fricative /θ/, at least in "layman's
American English" (as
/niːˈændərθɔːl/).
The spelling
Neandertal is occasionally seen in English, even in scientific publications.
Since "Neanderthal", or "Neandertal", is a
common name, there is no authoritative prescription on its spelling, unlike the spelling of the binominal name
H. neanderthalensis, which is
predicated by King 1864.
The common name in German is always invariably
Neandertaler (lit. "of the valley of Neander"), not
Neandertal,
but the spelling of the name of the Neander Valley itself (
Neandertal vs.
Neanderthal) has been affected by the
species name, the names of the
Neanderthal Museum and of
Neanderthal station persisting with pre-1900 orthography.
Ever since the discovery of the Neanderthal fossils, expert
opinion has been divided as to whether Neanderthals should be considered
a separate species (
Homo neanderthalensis) or a subspecies (
Homo sapiens neanderthalensis) relative to modern humans.
Pääbo (2014) described such "
taxonomic wars" as unresolveable in principle, "since there is no definition of species perfectly describing the case."
The question depends on the definition of
Homo sapiens as a
chronospecies,
which has also been in flux throughout the 20th century. Authorities
preferring classification of Neanderthals as subspecies have introduced
the subspecies name
Homo sapiens sapiens for the anatomically modern
Cro-Magnon
population which lived in Europe at the same time as Neanderthals,
while authorities preferring classification as separate species use
Homo sapiens as equivalent to "anatomically modern humans".
During the early 20th century, a prevailing view of Neanderthals as "simian", influenced by
Arthur Keith and
Marcellin Boule,
tended to exaggerate the anatomical differences between Neanderthals
and Cro Magnon.
Beginning in the 1930s, revised reconstructions of Neanderthals
increasingly emphasized the similarity rather than differences from
modern humans. From the 1940s throughout the 1970s, it was increasingly
common to use the subspecies classification of
Homo sapiens neanderthalensis vs.
Homo sapiens sapiens.
The
hypothesis of "multiregional origin" of modern man
was formulated in the 1980s on such grounds, arguing for the presence
of an unbroken succession of fossil sites in both Europe and Asia.
Hybridization between Neanderthals and Cro Magnon had been suggested on
skeletal and craniological grounds since the early 20th century, and
found increasing support in the later 20th century, until
Neanderthal admixture was found to be present in modern populations genetics in the 2010s.
Evolution
Stage 2: Archaic Neanderthal (Miguelón, 430 ka)
Both Neanderthals and
anatomically modern humans were initially thought to have evolved from
Homo erectus between 300,000 and 200,000 years ago.
H. erectus had emerged around 1.8 million years ago, and had
long been present, in various
subspecies throughout Eurasia.
The divergence time between the Neanderthal and archaic
Homo sapiens lineages is estimated to be between 800,000 and 400,000 years ago.
The more recent time depth has been suggested by Endicott et al. (2010)
and Rieux et al. (2014).
The time of divergence between archaic
Homo sapiens and ancestors of Neanderthals and
Denisovans caused by a
population bottleneck
of the latter was dated at 744,000 years ago, combined with repeated
early admixture events and Denisovans diverging from Neanderthals 300
generations after their split from
Homo sapiens, was calculated by Rogers et al. (2017).
Homo heidelbergensis,
dated 600,000 to 300,000 years ago, has long been thought to be a
likely candidate for the last common ancestor of the Neanderthal and
modern human lineages.
However, genetic evidence from the
Sima de los Huesos fossils published in 2016 seems to suggest that
H. heidelbergensis
in its entirety should be included in the Neanderthal lineage, as
"pre-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 age of
Homo antecessor.
The taxonomic distinctions between
H. heidelbergensis and Neanderthals is mostly due to a fossil gap in Europe between
300,000 and 243,000 years ago (
MIS 8). "Neanderthals", by conventions, are fossils which date to after this gap.
The quality of the fossil record greatly increases from 130,000 years ago onwards.
Specimens younger than this date make up the bulk of known Neanderthal
skeletons and were the first whose anatomy was comprehensively studied.
In morphological studies, the term "classic Neanderthal" may be used in
a narrower sense for Neanderthals younger than 71,000 years old (
MIS 4 and 3).
Microbiome
Neanderthals lived along-side humans until their extinction between 40,000-30,000 years ago, and share a common ancestor which could tell us more about how our microbiome evolved. Using
dental calculus,
calcified bone that traps microorganism, researchers have been able to
look into how ancient human microbiomes may have existed. Based on a 16s
shotgun sequence
of dental calculus found in neanderthal specimens, researchers have
found a large portion of neanderthal oral microbiome contains
Actinobacteria,
Firmicutes,
Bacteroidetes,
Proteobacteria, much like modern humans; however, neanderthals also had,
Euryarchaeota, fungi and some oral pathogens that modern humans lack.
Diet of neanderthals depend on the environment they live in. Neanderthal remains recovered from Spy Cave,
Belgium and examined them using
dental calculus which indicated neanderthals in this area had meat based diet, including
woolly rhinoceros and wild sheep. This is compared to neanderthal remains found in Spain. In El Sidrón Cave,
Spain, they examined remains indicating a large amount of plant material such as nuts and moss, as well as mushrooms.
Researchers determined that the difference in diets contributed to the
neanderthal microbiota, and meat based diet caused the most variation. According to fecal
biomarkers, neanderthals were able to convert
cholesterol to
coprostanol at a high rate, much like modern humans, because of the bacteria present in their gut.
Habitat and range
Approximate Neanderthal range; pre-Neanderthal and early Neanderthal range shown in magenta, late Neanderthal range in blue.
Sites where "classic Neanderthal" fossils (70–40 ka) have been found. Ice sheets of the last glacial maximum are indicated (partly ice-free during the Eemian interglacial)
Early Neanderthals, living before the
Eemian interglacial
(130 ka), are poorly known and come mostly from European sites. From
130 ka onwards, the quality of the fossil record increases dramatically.
From then on, Neanderthal remains are found in Western, Central,
Eastern, and Mediterranean Europe, as well
as Southwest, Central, and Northern Asia up to the
Altai Mountains in Siberia. No Neanderthal has ever been found outside Central to Western Eurasia, namely neither to the south of 30°N (
Shuqba, Levant), nor east of 85°E (
Denisova, Siberia).
The limit of their northern range appears to have been south of
53°N (
Bontnewydd, Wales),
although it is difficult to assess because glacial advances destroy most
human remains, the Bontnewydd tooth being exceptional. Middle
Palaeolithic artefacts have been found up to 60°N on the Russian plains.
Total Neanderthal
effective population
size has been estimated at close to 15,000 individuals (corresponding
to a total population of roughly 150,000 individuals), living in small,
isolated, inbred groups.
Anatomy
Comparison of faces of early European Homo sapiens (left) and Homo neanderthalensis (right) based on forensic facial reconstructions exhibited at the Neanderthal Museum.
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 as it was described by
Marcellin Boule,
particularly in certain isolated geographic regions. These include
shorter limb proportions, a wider, barrel-shaped rib cage, a reduced
chin, sloping forehead, and a large nose, being at the modern human
higher end in both width and length,
and started somewhat higher on the face than in modern humans. The
Neanderthal skull is typically more elongated and less globular than
that of
anatomically modern humans, and features a notable
occipital bun. Inherited Neanderthal DNA variants may subtly influence the skull shape of living people.
Neanderthals were much
stronger than modern humans, with particularly strong arms and hands, while they were comparable in
height;
based on 45 long bones from 14 males and 7 females, three different
methods of estimating height produced averages for Neanderthal males
from 164 to 168 cm (65 to 66 in) and 152 to 156 cm (60 to 61 in) for
females. Samples of 26 specimens found an average weight of 77.6 kg (171 lb) for males and 66.4 kg (146 lb) for females.
Neanderthals are known for their large
cranial capacity, which at 1,600 cm
3 (98 cu in) is larger on average than that of modern humans. One study has found that drainage of the
dural venous sinuses
(low pressure blood vessels that run between the meninges and skull
leading down through the skull) in the occipital lobe region of
Neanderthal brains appears more asymmetric than other hominid brains.
Three-dimensional computer-assisted reconstructions of Neanderthal
infants based on fossils from Russia and Syria indicated that
Neanderthal and modern human brains were the same size at birth, but
that by adulthood, the Neanderthal brain was larger than the modern
human brain. They had almost the same degree of
encephalisation (i.e. brain-to-body-size ratio) as modern humans.
Three-dimensional reconstructions of nasal cavities and
computational fluid dynamics
techniques have found that Neanderthals and modern humans both adapted
their noses (independently and in a convergent way) to help breathe in
cold and dry conditions. The large nose seen in Neanderthals, as well as
Homo heidelbergensis, affected the shape of the skull and the muscle attachments, and gave them a weaker bite force than in modern humans. Larger eye sockets and larger areas of the brain devoted to vision suggest that their
eyesight may have been better than that of modern humans.
Dental remains from two Italian sites indicate that Neanderthal dental
features had evolved by around 450,000 years ago during the
Middle Pleistocene epoch.
Two Neanderthal specimens from Italy and Spain were found to have an allele of the
melanocortin 1 receptor
(MC1R) with reduced activity. This receptor plays a role in mammalian
pigmentation, and the activity of the novel allele in Neanderthals was
found to be reduced sufficiently to allow for visibly lighter pigment
expression.
Although not found in the small European sample studied by Lalueza et
al., a larger study found that the derived variant was present at 70%
frequency in Taiwanese Aborigines, 50% frequency in Cheyenne Native
Americans, 30% frequency in Han Chinese, and 5% frequency in Europeans.
It is therefore unclear whether this loss-of-function variant is
responsible for any other traits other than lightening the skin (such as
red or blonde hair). This allele was not found in the Croatian or Altai
Neanderthal specimens subjected to whole-genome sequencing, nor have
the MC1R variants known to cause red hair in modern humans, though the
Altai specimen was polymorphic for another variant MC1R allele of
unknown effect.
Genomic analysis of three Croatian specimens for the alleles of
numerous genes that affect pigment in modern humans showed the
Neanderthals to have more dark-pigment-producing alleles than those
producing reduced pigmentation. Based on this they concluded these
Neanderthals had darker hair, skin and eye coloration than modern
Europeans. Skin pigmentation prediction for archaic humans is a
controversial field, as there are no living samples to confirm or
identify novel SNPs.
The overall shorter limbs and in general more stout body
proportions of Neanderthals may have been an adaptation to colder
climates. In comparison to modern humans, Neanderthals were more suited
for sprinting and pouncing activities rather than endurance running,
which would have been adaptive in the forests and woodlands that seem to
have been their preferred environment. Genomic evidence possibly points
to a higher proportion of fast-twitch muscle fiber in the Neanderthal. Evidence suggests that Neanderthals walked upright much like modern humans.
Behaviour
Neanderthals made stone tools, used fire,
and were hunters. This is the extent of the consensus on their
behaviour. It had long been debated whether Neanderthals were hunters or
scavengers, but the discovery of the pre-Neanderthal
Schöningen wooden spears in Germany helped settle the debate in favour of hunting. A
Levallois point embedded in the vertebrae of a
wild ass indicated that a javelin had been thrown with a parabolic trajectory to disable the animal. Most available evidence suggests they were
apex predators, and fed on
red deer,
reindeer,
ibex,
wild boar,
aurochs and on occasion
mammoth,
straight-tusked elephant and
rhinoceros. They appear to have occasionally used vegetables as fall-back food, revealed by
isotope analysis of their teeth and study of their
coprolites (fossilised faeces). Dental analysis of specimens from
Spy, Belgium and
El Sidrón, Spain
suggested that these Neanderthals had a wide-ranging diet, with no
evidence at all that the El Sidrón Neanderthals were carnivorous,
instead living on "a mixture of forest moss, pine nuts and a mushroom
known as
split gill". Nonetheless,
isotope
studies of Neanderthals from two French sites showed similar profiles
to other carnivores, suggesting that these populations may have eaten
meat.
The Neanderthal skeleton suggests they consumed 100 to 350 kcal (420
to 1,460 kJ) more per day than modern male humans of 68.5 kg (151 lb)
and females of 59.2 kg (131 lb).
The size and distribution of Neanderthal sites, along with
genetic evidence, suggests Neanderthals lived in much smaller and more
sparsely distributed groups than anatomically-modern
Homo sapiens. The bones of twelve Neanderthals were discovered at
El Sidrón cave in northwestern
Spain. They are thought to have been a group killed and butchered about 50,000 years ago. Analysis of the
mtDNA
showed that the three adult males belonged to the same maternal
lineage, while the three adult females belonged to different ones. This
suggests a social structure where males remained in the same social
group and females "married out".
The bones of the El Sidrón group show signs of defleshing, suggesting that they were victims of
cannibalism.
The St. Césaire 1 skeleton from La Roche à Pierrot, France, showed a
healed fracture on top of the skull apparently caused by a deep blade
wound, suggesting interpersonal violence.
Shanidar 3, an adult male dated to the late middle Paleolithic, was
found to have a rib lesion characteristic of projectile weapon injuries,
which some anthropologists consider evidence for interspecies conflict.
Neanderthals suffered a high rate of traumatic injury, with by
some estimates 79% of specimens showing evidence of healed major trauma.
It was thus theorized that Neanderthals employed a riskier and possibly
less sophisticated hunting strategy. However, rates of cranial trauma
are not significantly different between Neanderthal and middle
paleolithic Anatomically Modern Human samples. Both populations evidently cared for the injured and had some degree of medical knowledge.
Claims that Neanderthals deliberately buried their dead, and if they did, whether such burials had any symbolic meaning, are heavily contested. The debate on deliberate Neanderthal burials has been active since the 1908 discovery of the well-preserved
Chapelle-aux-Saints 1
skeleton in a small hole in a cave in southwestern France. In this
controversy's most recent installment, a team of French researchers
reinvestigated the
Chapelle-aux-Saints cave and in January 2014 reasserted the century-old claim that the 1908 Neanderthal specimen had been deliberately buried, and this has in turn been heavily criticised.
According to archaeologist John F. Hoffecker:
Neanderthal sites show no evidence
of tools for making tailored clothing. There are only hide scrapers,
which might have been used to make blankets or ponchos. This is in
contrast to Upper Paleolithic (modern human) sites, which have an
abundance of eyed bone needles and bone awls. Moreover, microwear
analysis of Neanderthal hide scrapers shows that they were used only for
the initial phases of hide preparation, and not for the more advanced
phases of clothing production.
— John F. Hoffecker, The Spread of Modern Humans in Europe
Culture
Whether Neanderthals created art and used adornments, which would
indicate a capability for complex symbolic thought, remains unresolved. A
2010 paper on radiocarbon dates cast doubt on the association of
Châtelperronian beads with Neanderthals, and
Paul Mellars considered the evidence for symbolic behaviour to have been refuted. This conclusion, however, is controversial, and others such as
Jean-Jacques Hublin and colleagues have re-dated material associated with the Châtelperronian artifacts and used proteomic evidence to restate the challenged association with Neanderthals.
Artist's reconstruction of a Neanderthal man with child
A large number of other claims of Neanderthal art, adornment, and
structures have been made. These are often taken by the media as showing
Neanderthals were capable of symbolic thought, or were "mental equals" to anatomically modern humans. As evidence of symbolism, none of them are widely accepted, although the same is true for
Middle Palaeolithic anatomically modern humans. Among many others:
- Flower pollen on the body of pre-Neanderthal Shanidar 4, Iraq, had in 1975 been argued to be a flower burial. Once popular, this theory is no longer accepted.
- Bird bones were argued to show evidence for feather plucking in a
2012 study examining 1,699 ancient sites across Eurasia, which the
authors controversially took to mean Neanderthals wore bird feathers as personal adornments.
- Deep scratches were found in 2012 on a cave floor underlying Neanderthal layer in Gorham's Cave, Gibraltar, which some have controversially interpreted as art.
- Two 176,000-year-old stalagmite ring structures, several metres wide, were reported in 2016 more than 300 metres from the entrance within Bruniquel Cave,
France. The authors claim artificial lighting would have been required
as this part of the cave is beyond the reach of daylight and that the
structures had been made by early Neanderthals, the only humans in
Europe at this time.
- In 2015, a study argued that a number of 130,000-year-old eagle
talons found in a cache near Krapina, Croatia along with Neanderthal
bones, had been modified to be used as jewellery.
All of these appeared only in single locations. Yet in 2018, using
uranium-thorium dating methods,
red painted symbols comprising a scalariform (ladder shape), a negative
hand stencil, and red lines and dots on the cave walls of three Spanish
caves 700 km (430 mi) apart were dated to at least 64,000 years old.
If the dating is correct, they were painted before the time
anatomically modern humans are thought to have arrived in Europe.
Paleoanthropologist
John D. Hawks
argues these findings demonstrate Neanderthals were capable of symbolic
behaviour previously thought to be unique to modern humans.
Interbreeding with archaic and modern humans
Pre-2010 interbreeding hypotheses
Until the early 1950s, most scholars thought Neanderthals were not in the ancestry of living humans.
Nevertheless, Thomas H. Huxley in 1904 saw among Frisians the presence
of what he suspected to be Neanderthaloid skeletal and cranial
characteristics as an evolutionary development from Neanderthal rather
than as a result of interbreeding, saying that "the blond long-heads may
exhibit one of the lines of evolution of the men of the Neanderthaloid
type," yet he raised the possibility that the Frisians alternatively
"may be the result of the admixture of the blond long-heads with
Neanderthal men," thus separating "blond" from "Neanderthaloid."
Hans Peder Steensby proposed interbreeding in 1907 in the article
Race studies in Denmark. He strongly emphasised that all living humans are of mixed origins.
He held that this would best fit observations, and challenged the
widespread idea that Neanderthals were ape-like or inferior. Basing his
argument primarily on cranial data, he noted that the Danes, like the
Frisians and the Dutch, exhibit some Neanderthaloid characteristics, and
felt it was reasonable to "assume something was inherited" and that
Neanderthals "are among our ancestors."
Carleton Stevens Coon in 1962 found it likely, based upon
evidence from cranial data and material culture, that Neanderthal and
Upper Paleolithic peoples either interbred or that the newcomers
reworked Neanderthal implements "into their own kind of tools."
Christopher Thomas Cairney in 1989 went further, laying out a rationale
for hybridisation and adding a broader discussion of physical
characteristics as well as commentary on interbreeding and its
importance to adaptive European phenotypes. Cairney specifically
discussed the "intermixture of racial elements" and "hybridisation."
By the early 2000s, the majority of scholars supported the
Out of Africa hypothesis,
according to which anatomically modern humans left Africa about 50,000
years ago and replaced Neanderthals with little or no interbreeding.
Yet some scholars still argued for hybridisation with Neanderthals. The
most vocal proponent of the hybridisation hypothesis was
Erik Trinkaus of
Washington University. Trinkaus claimed various fossils as products of hybridised populations, including the
skeleton of a child found at
Lagar Velho in
Portugal and the
Peștera Muierii skeletons from Romania.
Genetic evidence
In 2010, geneticists announced that interbreeding had likely taken place, a result confirmed in 2012. The genomes of all non-Africans include portions that are of Neanderthal origin, a share estimated in 2014 to 1.5–2.1%. This DNA is absent in Sub-Saharan Africans (
Yoruba people and
San subjects).
Ötzi the iceman, Europe's oldest preserved mummy, was found to possess an even higher percentage of Neanderthal ancestry.
The two percent of Neanderthal DNA in Europeans and Asians is not the
same in all Europeans and Asians: in all, approximately 20% of the
Neanderthal genome appears to survive in the modern human gene pool.
Genomic studies suggest that modern humans mated with at least two groups of
archaic humans: Neanderthals and Denisovans.
Some researchers suggest admixture of 3.4–7.9% in modern humans of
non-African ancestry, rejecting the hypothesis of ancestral population
structure.
Detractors have argued and continue to argue that the signal of
Neanderthal interbreeding may be due to ancient African substructure,
meaning that the similarity is only a remnant of a common ancestor of
both Neanderthals and modern humans and not the result of interbreeding.
John D. Hawks
has argued that the genetic similarity to Neanderthals may indeed be
the result of both structure and interbreeding, as opposed to just one
or the other.
An approximately 40,000 year old anatomically-modern human skeleton from
Peștera cu Oase,
Romania, was found in 2015 to have a much larger proportion of DNA
matching the Neanderthal genome than seen in humans of today, and this
was estimated to have resulted from an interbreeding event as few as
four generations earlier. However, this hybrid Romania population does
not appear to have made a substantial contribution to the genomes of
later Europeans.
While some modern human
nuclear DNA has been linked to the extinct Neanderthals, no
mitochondrial DNA of Neanderthal origin has been detected, which in primates is
almost always maternally transmitted.
This observation has prompted the hypothesis that whereas female humans
interbreeding with male Neanderthals were able to generate fertile
offspring, the progeny of female Neanderthals who mated with male humans
were either rare, absent or sterile.
However, Eastern Neanderthals derive significant portions of
their ancestry from an earlier dispersal of modern humans unrelated to
the one that gave rise to Eurasians today.
It is estimated that they split off shortly after the Khoisan
divergence some 200 kya. Such unidirectional flow is significant given
the current scenario of no Eurasian admixture in Western European
Neanderthals. This is not contradictory to the Out-of-Africa model,
which claims a single-dispersal to give rise to all Eurasians today. A
signal of an early dispersal is present in the genome of New Guineans,
who derive up to 2% of their ancestry from this group that apparently
diverged from other Africans 120 kya.
However, it is noted that the Denisovans do not carry this early human
dispersal signal. Pagani et al. therefore argue that the admixture
between this early modern human group, modern Eurasians, and
Neanderthals took place in Southern Arabia or the Levant and that the
latter group consisted of migrants from the Middle East into Siberia.
Interbreeding with Denisovans
Sequencing of the genome of a Denisovan, a distinct but related
archaic hominin, from the Denisova cave in the Siberian Altai region has
shown that 17% of its genome represents Neanderthal DNA.
Unsurprisingly, the genome from a 120,000 year old Neanderthal bone
found in the same cave more closely resembled the Neanderthal DNA
present in the Denisovan genome than that of Neanderthals from the
Vindija cave in Croatia or the
Mezmaiskaya cave in the Caucasus, suggesting that the gene flow came from a local interbreeding. However, the
complete genome sequencing of DNA from a 90,000 year old bone fragment,
Denisova 11,
showed it to have belonged to a Denisovan-Neanderthal hybrid, whose
father was a typical Denisovan with the Altai Neanderthal component
dating to an interbreeding more than 300 generations earlier, but the
specimen's mother was a Neanderthal belonging to a population more
closely related to the Vindija Neanderthal than to the sequenced Altai
Neanderthal genome. This suggests mobility or turnover among the
distinct Neanderthal populations.
Extinction
According to a 2014 study by
Thomas Higham and colleagues of organic samples from European sites, Neanderthals died out in Europe between 41,000 and 39,000 years ago.
New dating in Iberia, where Neanderthal dates as late as 24,000 years
had been reported before, now suggests evidence of Neanderthal survival
in the peninsula after 42,000 years ago is almost non-existent.
Anatomically modern humans arrived in Mediterranean Europe
between 45,000 and 43,000 years ago, so the two different human
populations shared Europe for several thousand years. The exact nature of biological and cultural interaction between Neanderthals and other human groups is contested.
Possible scenarios for the extinction of the Neanderthals are:
- Neanderthals were a separate species from modern humans, and
became extinct (because of climate change or interaction with modern
humans) and were replaced by modern humans moving into their habitat
between 45,000 and 40,000 years ago. Jared Diamond has suggested a scenario of violent conflict and displacement.
- Neanderthals were a contemporary subspecies that bred with modern humans and disappeared through absorption (interbreeding theory).
- Volcanic catastrophe: see Campanian Ignimbrite Eruption
mtDNA-based simulation of modern human expansion in Europe starting 1,600 generations ago. Neanderthal range in light grey
Climate change
About 55,000 years ago, the climate began to fluctuate wildly from
extreme cold conditions to mild cold and back in a matter of decades.
Neanderthal bodies were well-suited for survival in a cold climate—their
stocky chests and limbs stored body heat better than the Cro-Magnons.
Neanderthals died out in Europe between 41,000 and 39,000 years ago,
coinciding with the start of a very cold period.
Raw material sourcing and the examination of faunal remains found in the southern
Caucasus
suggest that modern humans may have had a survival advantage, being
able to use social networks to acquire resources from a greater area. In
both the Late Middle Palaeolithic and Early Upper Palaeolithic more
than 95% of stone artifacts were drawn from local material, suggesting
Neanderthals restricted themselves to more local sources.
Coexistence with modern humans
In November 2011 tests conducted at the Oxford Radiocarbon
Accelerator Unit in England on what were previously thought to be
Neanderthal baby teeth, which had been unearthed in 1964 from the Grotta
del Cavallo in Italy, were identified as the oldest modern human
remains discovered anywhere in Europe, dating from between 43,000 and
45,000 years ago.
Given that the 2014 study by Thomas Higham of Neanderthal bones and
tools indicates that Neanderthals died out in Europe between 41,000 and
39,000 years ago, the two different human populations shared Europe for
as long as 5,000 years.
Nonetheless, the exact nature of biological and cultural interaction
between Neanderthals and other human groups has been contested.
Modern humans co-existed with them in Europe starting around
45,000 years ago and perhaps even earlier. Neanderthals inhabited that
continent long before the arrival of modern humans. These modern humans
may have introduced a disease that contributed to the extinction of
Neanderthals, and that may be added to other recent explanations for
their extinction. When Neanderthal ancestors left Africa potentially as
early as over 800,000 years ago they adapted to the pathogens in their
European environment, unlike modern humans, who adapted to African
pathogens. This transcontinental movement is known as the
Out of Africa model.
If contact between humans and Neanderthals occurred in Europe and Asia
the first contact may have been devastating to the Neanderthal
population, because they would have had little, if any, immunity to the
African pathogens. More recent historical events in Eurasia and the
Americas show a similar pattern, where the unintentional introduction of
viral or bacterial pathogens to unprepared populations has led to mass
mortality and local population extinction. The most well-known example of this is the arrival of
Christopher Columbus
to the New World, which brought and introduced foreign diseases when he
and his crew arrived to a native population who had no immunity.
Anthropologist Pat Shipman, of Pennsylvania State University, suggested that
domestication of the dog could have played a role in Neanderthals' extinction.
History of research
Spy 2 skull, sex unclear (1886)
The first discovery which was recognized as representing an archaic form of humans was made in August 1856, three years before
Charles Darwin's
On the Origin of Species was published.
This was the discovery of the type specimen,
Neanderthal 1, in a
limestone quarry (
Feldhofer Cave), located in
Neandertal Valley in the German
Rhineland, about 12 km (7 mi) east of
Düsseldorf).
The find consisted of a skull cap, two
femora, three bones of the right arm, two of the left arm, parts of the left
ilium, fragments of a
scapula,
and ribs. The workers who recovered the objects originally thought them
to be the remains of a cave bear. However, they eventually gave the
material to amateur naturalist
Johann Carl Fuhlrott, who turned the fossils over to anatomist
Hermann Schaaffhausen.
To date, the bones of over 400 Neanderthals have been found.
- 1829: A damaged skull of a Neanderthal child, Engis 2, is discovered in Engis, Netherlands (now Belgium).
- 1848: A female Neanderthal skull, Gibraltar 1, is found in Forbes' Quarry, Gibraltar, but its importance is not recognised.
- 1856: Limestone miners discover the Neanderthal-type specimen, Neanderthal 1, in Neandertal, western Prussia (now Germany).
- 1864: William King is the first to recognise Neanderthal 1 as belonging to a separate species, for which he gives the scientific name Homo neanderthalensis. He then changed his mind on placing it in the genus Homo,
arguing that the upper skull was different enough to warrant a separate
genus since, to him, it had likely been "incapable of moral and
theistic conceptions."
- 1880: The mandible of a Neanderthal child is discovered in a secure context in Šipka cave, in the Austro-Hungarian Empire (now the Czech Republic), associated with cultural debris, including hearths, Mousterian tools, and bones of extinct animals.
- 1886: Two well-preserved Neanderthal skeletons are found at Spy, Belgium, making the hypothesis that Neanderthal 1 was only a diseased modern human difficult to sustain.
- 1899: Sand excavation workers find hundreds of fragmentary
Neanderthal remains representing at least 12 and likely as much as 70
individuals on a hill in Krapina, in the Austro-Hungarian Empire (now Croatia).
- 1908: A very well preserved Neanderthal, La Chapelle-aux-Saints 1, is found in its eponymous site in France, said by the excavators to be a burial, a claim still heatedly contested. For historical reasons it remains the most famous Neanderthal skeleton.
- 1912: Marcellin Boule publishes his now discredited influential study of Neanderthal skeletal morphology based on La Chapelle-aux-Saints 1.
- 1953–1957: Ten Neanderthal skeletons are excavated in Shanidar Cave, Iraqi Kurdistan, by Ralph Solecki and colleagues.
- 1975: Erik Trinkaus's study of Neanderthal feet strongly argues that Neanderthals walked like modern humans.
- 1981: The site of Bontnewydd, Wales yielded an early Neanderthal tooth, the most north-western Neanderthal remain ever.
- 1987: Israeli Neanderthal Kebara 2 is dated (by TL and ESR) to 60,000 BP, thus later than the Israeli anatomically modern humans dated to 90,000 and 80,000 BP at Qafzeh and Skhul.
- 1997: Matthias Krings et al. are the first to amplify Neanderthal mitochondrial DNA (mtDNA) using a specimen from Feldhofer grotto in the Neander valley.
- 2005: The Max Planck Institute for Evolutionary Anthropology and associated institutions launch the Neanderthal genome project to sequence the Neanderthal nuclear genome.
- 2010: Discovery of Neanderthal admixture in the genome of modern populations.
- 2014: A comprehensive dating of Neanderthal bones and tools from
hundreds of sites in Europe dates the disappearance of Neanderthals to
41,000 and 39,000 years ago.
- 2018: Report on the complete genomic sequence of Denisova 11, a first generation of Neanderthal-Denisovan hybrid.
Specimens
Notable European Neanderthals
Remains of more than 300 European Neanderthals have been found.
- Neanderthal 1:
The first human bones recognised as showing a non-modern anatomy.
Discovered in 1856 in a limestone quarry at the Feldhofer grotto in
Neanderthal, Germany, they consist of a skull cap, the two femora, the
three right arm bones, two left arm bones, the ilium, and fragments of a
scapula and ribs.
- La Chapelle-aux-Saints 1: Called the Old Man, a fossilised skull discovered in La Chapelle-aux-Saints,
France, by A. and J. Bouyssonie, and L. Bardon in 1908. Characteristics
include a low vaulted cranium and large browridge typical of
Neanderthals. Estimated to be about 60,000 years old, the specimen was
severely arthritic and had lost all his teeth long before death, leading
some to suggest he was cared for by others.
- La Ferrassie 1:
A fossilised skull discovered in La Ferrassie, France, by R. Capitan in
1909. It is estimated to be 70,000 years old. Its characteristics
include a large occipital bun, low-vaulted cranium and heavily worn
teeth.
- Le Moustier
1: One of the rare nearly complete Neanderthal skeletons to be
discovered, it was excavated by a German team in 1908, at
Peyzac-le-Moustier, France. Sold to a Berlin museum, the post cranial
skeleton was bombed and mostly destroyed in 1945, and parts of the mid
face were lost sometime after then. The skull, estimated to be less than
45,000 years old, includes a large nasal cavity and a less developed
brow ridge and occipital bun than seen in other Neanderthals. The Mousterian tool techno-complex is named after its discovery site.
Notable Southwest Asian Neanderthals
Remains of more than 70 Southwest Asian Neanderthals have been found.
- Shanidar 1 to 10: Eight Neanderthals and two pre-Neanderthals (Shanidar 2 and 4) were discovered in the Zagros Mountains in Iraqi Kurdistan. One of the skeletons, Shanidar 4, was once thought to have been buried with flowers, a theory no longer accepted. To Paul B. Pettitt
the "deliberate placement of flowers has now been convincingly
eliminated", since "[a] recent examination of the microfauna from the
strata into which the grave was cut suggests that the pollen was
deposited by the burrowing rodent Meriones tersicus, which is common in the Shanidar microfauna and whose burrowing activity can be observed today".
- Amud 1: A male adult Neanderthal, dated to roughly 55,000 BP, and one of several found in a cave at Nahal Amud, Israel.
At 178 cm (70 in), it is the tallest known Neanderthal. It also has the
largest cranial capacity of all extinct hominins: 1,736 cm3.
- Kebara 2: A male adult post-cranial skeleton, dated to roughly 60,000 BP, that was discovered in 1983 in Kebara Cave,
Israel. It has been studied extensively, for its hyoid, ribcage, and
pelvis are much better preserved than in all other Neanderthal
specimens.
Notable Central Asian Neanderthal
- Teshik-Tash 1: An 8–11-year-old skeleton discovered in Uzbekistan by Okladnikov
in 1938. This is the only fairly complete skeleton discovered to the
east of Iraq. Okladnikov claimed it was a deliberate burial, but this is
debated.
Chronology
Mixed with H. heidelbergensis traits
- older than 350 ka: Sima de los Huesos c. 500:350 ka ago
- 350–200 ka: Pontnewydd 225 ka ago.
- 200–135 ka: Atapuerca, Vértesszőlős, Ehringsdorf, Casal de'Pazzi, Biache, La Chaise, Montmaurin, Prince, Lazaret, Fontéchevade
H. neanderthalensis fossils
- 130–50 ka: Krapina, Saccopastore skulls, Malarnaud, Altamura, Gánovce, Denisova, Okladnikov, Pech de l'Azé, Tabun 120–100±5 ka, Shanidar 1 to 9 80–60 ka, La Ferrassie 1 70 ka, Kebara 60 ka, Régourdou, Mt. Circeo, Combe Grenal, Erd 50 ka, La Chapelle-aux Saints 1 60 ka, Amud I 53±8 ka, Teshik-Tash.
- In radiocarbon range, > 50 ka: Le Moustier, Feldhofer, La Quina, l'Hortus, Kulna, Šipka, Saint Césaire, Bacho Kiro, El Castillo, Bañolas, El Sidrón (48±3 cal ka), Arcy-sur-Cure, Châtelperron, Figueira Brava, Mezmaiskaya (41±1 cal ka), Zafarraya, Vindija, Velika Pećina.
H. s. sapiens with traits reminiscent of Neanderthals
In popular culture
Neanderthals have been portrayed in popular culture including
appearances in literature, visual media and comedy. Early 20th century
artistic interpretations often presented Neanderthals as beastly
creatures, emphasising hairiness and a rough, dark complexion.
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