©1
Background: Early finds and distribution
Analysis of 11 different human gene trees suggests that our species
arose in Africa, and that there were at least two major population
expansions out of Africa; one over 600,000 and another 95,000 years
ago (Cann, 2002). Recent fossil finds in norther Spain extend
this earliest migration to 1.2 million years ago. An earlier
expansion of Homo erectus
from Africa occurred 1.7 million years ago (Templeton, 2002).
The first corresponds with the movement of Homo
neanderthalensis out of Africa and an increase in
hominid (see hominid books)
fossil cranial capacity. Archaeologists have found much
physical evidence to confirm this date, such as the 0.73 Mya old
fossils with stone tools and bison and other animal bones of a
generalised Homo species from Isernia in west central
Italy. The other date matches the movement of modern humans,
Homo sapiens sapiens out of Africa and the appearance
of modern traits in fossil skulls. Fossil skull traits such as high,
rounded skulls, small brow ridges, a vertical forehead and a
pronounced chin first appear in Africa about 130,000 years ago. They
then appear outside of Africa over 90,000 years ago (Templeton,
2002). Phylogenetic analysis
of Neanderthal mitochondrial DNA leads to a date for the common
ancestor of the neanderthal and modern humans at around 465,000 to
600,000 years ago (four times the estimate for the common ancestor of
all modern humans) (Disotell, 1999). The common ancestor of the mtDNAs
of all living humans lived about 170,000 years ago (Hofreiter et al,
2001). All hominid remains of the last 100,000 years belong
to one of these two species (Roe in Waechter, 1990). Ancient
remains from a Spanish cave site (La Sima de los Huesos), are a
transitional form between Homo erectus and Neanderthals.
The first Neanderthal remains,
discovered in Germany in 1856, were presented to the world of science
at a meeting of the Lower Rhine Medical and Natural History Society
held in Bonn in February 1857 (Reader, 1988) and named a species,
Homo neanderthalensis, by William King in 1864. Some Neanderthal
fossils and other remains are in excellent condition, giving a good
idea of Neanderthal culture. In 1887, two complete skeletons were found
in a cave near Spy in Belgium, and more from sites in France in 1887,
1908 and 1911. These and other finds showed that the Neanderthals had
populated Europe widely from about 130,000 to 28,000 years ago after
which they became extinct. Most of these fossils were found in caves.
Usually they are associated with cold adapted species such as reindeer,
arctic fox, lemming and mammoth. The current conclusion drawn from
fossil evidence is that Neanderthals emerged at least 230,000 to
300,000 years ago (Andrews & Stringer, 1993), (Gore et
al, 1996) years and
maybe even 350,000 years ago (Bischoff
et al, 2003). In the Far East, we first find H. erectus ,
then a
generalised H. sapiens and later H. sapiens sapiens
with Mongoloid features, but no Neanderthal presence (Roe in Waechter,
1990). 800,000 year old fossils from northern Spain, has been proposed
as the common ancestor to humans and Neanderthals and named Homo
antecessor (Lemonick & Dorfman, 1999). ( H. antecessor
may in fact be a variant of H. heidelbergensis ). Others say
that Homo heidelbergensis is the more likely common ancestor
between humans and Neanderthals, The discovery of such ancient fossils
with a mix of modern (tooth development, projecting face, sunken
cheekbones) and primitive features (jaw and brow ridges) hints at some
surprises as more fossils from this period are unearthed. One line of
thought places Homo ergaster as ancestral to Homo
antecessor in Africa. A population of Homo antecessor
migrated ( see map of migration from migration article ) via the
Middle East to Europe about one million years ago and evolved into
Homo heidelbergensis and then into Neanderthals.
This idea is strengthened by
the find of a fossilised H. antecessor jaw bone and teeth found in a
cave in northern Spain and dated at between between 1.1 million and 1.2
million years old. Along with the hominin remains were 32 rock
fragments of stone tools or flakes produced by making the tools, and
numerous animal bones from a variety of species including rats,
ferrets, bison, foxes, bears and big cats.
The population of Homo antecessor that remained in Africa likely evolved into Homo sapiens . In this scheme, H. antecessor is ancestral to both H. sapiens and H. neanderthalensis (via H. heidelbergensis ).
Remains of Neanderthals found associated with tools in France and
dated at between 31,000 and 34,000 years old, overlap with the earliest
remains of modern humans from the same area! The fact that we are the
only extant species of our genus has contributed to our distorted
opinion of superiority, yet the fossil skeletons of modern man and
Neanderthals found in the same vicinity and time at Saint Cezaire
suggest a period when two intelligent beings coexisted (Parker, 1992)!
Further, primitive, but modern human fossils found at Jebel Qafzeh,
near Nazareth, Israel, are 100,000 years old, while Neanderthal remains
from the Kebara cave, on Mount Carmel, are 60,000 years old (Parker,
1992), giving the impression of these two creatures living side by side
for 40,000 years with no apparent interbreeding (Wilson & Cann,
1992). Another implication derived from this finding is that modern
humans did not evolve from Neanderthals (Reader, 1988). Other fossil
finds of Neanderthals and modern humans found on Mount Carmel are
120,000 and 100,000 years old respectively. These early humans thus
lived in the same area as Neanderthals during the same time. From this
perspective, humans are NOT the only species that have developed
culture, intelligence, language and self-awareness. Neanderthals were
skilled
hunters and craftsmen who made tools, used fire, cared for their sick
and injured and even had a few symbolic notions, probably with some
facility for language.
Genetics, DNA
The Neanderthal was probably not human ( Krings , 1999).
Mitochondrial DNA (mtDNA)
|
Genetic evidence from a comparison
of human and Neanderthal mitochondrial DNA (mtDNA) shows that while
chimpanzee and human lineages diverged over five million years ago, the
Neanderthals diverged over 550,000 to 690,000 years ago. Other data
places this estimate at between 365,000 and 853,000 years ago
(Ovchinnikov, et al, 2000) and 465,000 before present with confidence
limits of 317,000 and 741,000 (Krings, 1999) . Human trunk and
limb bones of Homo antecessor , recovered from the Gran
Dolina site, in the Sierra de Atapuerca (Burgos, Spain) have been dated
at about 780,000 old and are said to represent the last common
ancestor for H. sapiens (modern humans) and H.
neanderthalensis (Neanderthals) (Carretero et al ,
1999).
Living humans have on average eight differences in the 378-unit DNA
strand investigated, while the Neanderthal differed in 27 places and
the chimpanzees differ in 55 places. Further, the mtDNA sequence
of Neanderthals was equally distant from all modern groups of humans.
Two other studies gave similar differences between humans, neanderthals
and chimpanzees, putting the Neanderthals outside the range of modern
human mtDNA and therefore a different species. The two
Neanderthal
individuals studied differed from each
other in 12 base pairs. By comparison, 37% of modern Africans differ by
12 or more base pairs, while for Europeans and Asians, the diversity is
much less (<1%). Research by Knight (2003) strongly
confirmed the deeply divergent histories for modern human
mtDNA lineages and the known Neanderthal mtDNA.
Serre et al (2004) reinvestigated the "evidence of Neandertal mtDNA contribution to early modern humans" and concluded that:
"mitochondrial DNA (mtDNA) sequences from four Neandertal fossils from Germany, Russia, and Croatia has demonstrated that these individuals carried closely related mtDNAs that are not found among current humans. However, these results do not definitively resolve the question of a possible Neandertal contribution to the gene pool of modern humans since such a contribution might have been erased by genetic drift or by the continuous influx of modern human DNA into the Neandertal gene pool". Additionally, "all Neandertal remains analyzed yielded mtDNA sequences that are not found in the human mtDNA gene pool today but are similar to those found in four previously published Neandertals (Krings et al. 1997, Krings et al. 2000; Ovchinnikov et al. 2000; Schmitz et al. 2002)".
Perhaps, where they coexisted, some difference prevented interbreeding or the production of (fertile) hybrids between these neanderthal populations and early human ancestors. Usually such differences between related species originate as adaptations to the environment, not as devices for reproductive isolation (Wilson, 1992). Studies of chromosome 1 and 22 sequences indicates that non-Africans humans shared a common ancestor long before modern humans appeared. Chromosome 22 research suggests a date of 634,000 years ago (Zhao, et al, 2000), while chromosome 1 results show an ancestral link at 757,000 to 805,000 years ago (Yu, et al, 2001). These very ancient dates for non-African DNA sequences oppose the idea that a single African population of modern humans exited Africa about 100,000 years ago, totally replacing all the archaic humans of Eurasia. Could this be an echo of Neanderthal genes in the European genome? A study of Australian mtDNA from 40-45,000 years ago has shown that Neanderthals were more genetically divergent from us than were these older Australians. This indicates that Neanderthals and early modern humans followed separate evolutionary paths (Brown, 2001). There was little genetic diversity among Neanderthals, so DNA studies show their fossils to be closely related, but not related to modern humans.
Habitat of Neanderthals:
Neanderthals were hunter-gatherers who moved across Europe with the advance and retreat of the Ice Age glaciers. Their total population probably never exceeded 100,000. From 180,000 to 130,000 years ago large glaciers covered much of Europe and Neanderthal remains are scarce. After 130,000 years ago, tool technology developed rapidly to become the classic Neanderthal technology called the Mousterian tradition. They created sets of tools with great variety and finely trimmed cutting edges. Flint stone properly chipped, forms a cutting edge sharper than a steel scalpel. Faunal remains, and lithic (stone) and bone tools at Neanderthal archaeological sites shows that hunting of medium to large mammals was an important part of Neanderthal subsistence. Plant foods are rare in the archaeological record, making it difficult to accurately determine their dietary importance. A scientific tool, stable isotope (13C and 15N) analysis of mammal bone collagen, can show if the diet was carnivorous, omnivorous or herbivorous. By measuring of the ratios of the stable isotopes of carbon and nitrogen in mammal bone collagen, scientists can get an indication of aspects of diet over the last few years of life. When applied to two Croatian Neanderthals, the isotopes present showed that the Neanderthals were largely top-level carnivores, obtaining most of their dietary protein from animal sources. Earlier Neanderthals samples from France and Belgium yielded similar results (Richards, et al , 2000). In summary, the Neanderthals were effective predators.
A study of fossils found with the Neanderthal remains can reveal interesting facts about where and how the Neanderthals lived. Mammal bone collagen 13C and 15N isotope values reflect the 13C and 15N values of dietary protein. The technique, termed isotopic analysis, measures the ratios of the different types (isotopes) of carbon and nitrogen found in Neanderthal and associated animal bones.
These isotopes provide a record of aspects of the animal's diet by
giving an average of the 13C and 15N values of all of the protein
consumed over the last years before it died. 13C values can even be
used to distinguish between terrestrial and marine dietary proteins
and forest or open environments in humans and other mammals. 15N
isotopic values can be used to determine the trophic level of the
protein consumed. Through the measurement of these two isotopes in the
fossils of a paleo-ecosystem, it is possible to reconstruct some
of the trophic level relationships within that ecosystem. A comparison
of the 13C and 15N isotopic values of omnivores such as hominids (see hominid books) with
the values of herbivores and carnivores from the same ecosystem,
enables scientists to establish whether those omnivores were obtaining
dietary protein from plant or animal sources. The application of
isotopic analysis to some Neanderthal fossils, showed that they were
carnivores that hunted open-ranging herbivores. Had the Neanderthals
been scavengers, plant material would have formed a larger portion of
their diet, giving rise to different isotopic values than measured.
These Neanderthals had diets similar to nonhuman carnivores (Richards,
et al , 2000). This was achieved by different researchers for
different sites, dated 40,000–45,000 years B.P., 80,000-130,000 years
B.P. and the above study at 28,500 years B.P., showing that
geographically and chronologically dispersed Neanderthals hunted as
top-level carnivores.
Neanderthals were adapted to the cold northern climate (Groves,
1994), with short limbs and stocky bodies and flourished during a
warmer interglacial period. There was great anatomical variation within
this population. Neanderthals had a short period of dental growth (an
excellent indicator of somatic development), indicating that they
developed faster even than their immediate ancestor, H. heidelbergensis (Ramirez Rozzi
& De Castro, 2004). Tooth enamel patterns suggest that Neanderthals
grew to adult size by age 15. This specific distinction between H. sapiens and H. neanderthalensis was probably a
climatic adaptation.
There is evidence that they took care of injured associates and sometimes carried out burials. Fossil remains provide evidence that they moved in small groups possibly occupying areas seasonally and subsisting by hunting big-game such as reindeer. As they did not use bows and arrows, or other projectiles, hunting such big game would have required a group strategy. Animal bones found with Neanderthal remains are mostly cold adapted species such as reindeer, bison, elk, arctic fox, lemming and mammoth (Andrews and Stringer, 1993). A wooden spear found in the ribs of an Elephas skeleton at Lehringen (Germany), and a Levallois point embedded an Equus (horse) cervical vertebra from Umm el Tlel (Syria), are both attributed to Neanderthal hunting activity.
In a cave at Krapina in Croatia are many juvenile rhinoceros bones, showing that here the hunters concentrated on very dangerous large game. By hunting such big animals, they did not have to compete with other predators and focused on high energy rewards in return for their efforts. This came at a cost, and many Neanderthal remains have old injuries. A study of 17 Neanderthals showed that they suffered 27 traumatic injuries. A comparison of these injuries with current lifestyles shows them to be most similar to the injuries of American rodeo riders. Their hunting, using eight foot long wooden lances, must have brought them in very close contact with their prey. Neck and head traumas suggested that they were often thrown off large prey. Few lived beyond 30 years of age (Gore et al, 1996)! What a magnificent era that must have been!
Anthropologists classify Neanderthal tools as Mousterian , a
kit of stone-flake tools. Earlier Homo erectus
Acheulean tools are made of hand axes. Some early humans also
used Mousterian tools, as hand-axes, scrapers, borers, knives and
points of stone, are found beyond the Neanderthal range and associated
with non-Neanderthal fossils. Their tools, evolved little during their
100,000 year history, and they did not use bone, antler or ivory. They
used wood, such a spears, and regularly used fire. Why they did not
make tools from their prey is unexplained. At the end of their
existence their tools became more complex, possibly through copying
modern humans, trade, or as a direct response to this new competitor,
but the change was too late. Some Neanderthals even started using bone
tools, as in a beveled bone spear tip, found in Vindija,
Croatia.
Three areas of Neanderthal habitation have distinct fossil remains.
Western Europe (SW France) has many fossils dated at between 70,000 and
40,000 years old. The most recently existing remains are 36,300 years
old, while modern human fossil remains from the same area are 30,000 to
34,000 years old. Russia and central and eastern Europe has sparser
Neanderthal remains. One interesting find is a child buried and
surrounded with goat skulls. These finds are between 40,000 and 25,000
years old and show some transition between Neanderthal and modern
morphologies. In the middle East, Neanderthal fossils as old as 100,000
years have been found. Other finds come from Wales in the northwest,
Gibraltar in the southwest, near Moscow in the north and Uzbekistan in
the east (Andrews & Stringer, 1993). Generally, the fossils fall
between 40,000 and 80,000 years old (Bilsborough, 1992).
Anthropologists date modern human fossils from the same area at between
92,000 and 101,000 years.
Morphology
These heavily built and muscled people had a brain volume of 1200
to 1800 cubic centimetres, equal to and even larger than modern human
brains. Neanderthals were much more muscular than are modern humans -
bulking about 30 percent more in weight. Both their skull (Harvati,
2003) and body morphology are different to archaic and modern H.
sapiens morphology (see image of human and Neanderthal skull from Hunterian
Museum ). Their faces showed a particular adaptation, with the
midface projecting and ending in large front teeth. The mid-facial
projection and large nasal sinuses can be seen in Neanderthal
skulls from children e.g. La Quina 18 (from a eight year old) and
Teshik Tash 1 (from a nine year old) and Le Moustier, a 15 year old. (Neanderthal skull - front view) (Neanderthal skull - oblique view) (Neanderthal skull - side view) (Neanderthal jaws) ©1
. Neanderthal skull reconstructions provide further evidence that the
creatures were a separate species to modern humans. Distinctive
Neanderthal skull features were established in early infancy. Physical
features in skull development, such as the Neanderthal's receding
chin and low, sloping forehead, were fixed by the age of two years.
Their hyoid bones, involved in speech, were basically identical to
humans. Neanderthal inner ear morphology
is now being studied and differences are being found to the human inner
ear They had heavy brow ridges, a low sloping forehead and a very large
nose. Their teeth usually showed distinct wear from some type of
repeated use ( see image from Ramanank ). They lacked the
projecting chin of modern humans. Their build suggested the possibility
of cold adaptations, being very robust or stockily built with the lower
legs and forearms short. A similar feature is found in modern-human
cold-adapted races, such as Eskimos, and serves to reduce heat loss
through the extremities. They must have been very strong and powerfully
muscled. Markings on the leg bones show that they squatted habitually.
Strong evidence for the
difference between humans and Neanderthals can be found in the
morphology of the Neanderthal
pelvis, which is different to a human pelvis.
There
is a different
relationship of the pelvis to the hip joints and other features such as
the iliac blades (Aiello & Dean, 1990).
A list of distinctive Neanderthal features is as follows:
- Large round " apical tufts " to the finer tips;
- Robust finger bones;
- Enlarged rib cage, with barrel-chested build;
- Stout, bowed femoral shaft;
- Dorsal sulcus on scapula for more muscle attachments;
- Relatively short, bowed scapula;
- Long pelvic pubis (superior pubic ramus);
- Relatively short tibia and fibula (lower leg);
- Low forehead with occipital bun (chignon, occipital torus) & projecting mid-face ;
- Lack of chin (mental eminence);
- Long clavicle and large shoulder joint;
- Large and thick patella;
- occipital depression ( suprainiac fossa );
- supraorbital torus;
- A mastoid crest located behind the external auditory meatus ;
- Absence of a canine fossa;
- Presence of a retromolar space;
Extinction:
With the arrival in Europe of modern humans, with an advanced and sophisticated technology 40,000 years ago, Neanderthals started to vanish. Around 35,000 years ago temperatures started to decline and the most recent Neanderthal remains are found south in isolated seaside caves in Spain. Some tools are 29,000 years old. Neanderthals were still living in Croatia as recently as 28,000 years ago and in southern Spain only 30,000 years ago (Hall, 1999). The Croatian population had some modern human anatomical characteristics. Neanderthals from France, Spain (Zafarraya), and possibly Italy (Cavallo), fall within the period 32-36,000 B.P. There was not enough time for these late Neanderthals to have evolved into the 31,000-year-old modern humans from England and Germany (Brown, 2001). A fossil of a 24,500-year-old early modern human child unearthed in Portugal shows distinctive Neanderthal characteristics, possibly the result of interbreeding. After that, all record vanish.
Although DNA tests show that modern humans and neanderthals diverged from a common ancestor more than 500,000 years ago and that modern humans do not carry neanderthal genes and so did not interbreed when they encountered each other 50,000 years ago, the discovery of possible hybrids suggests that we still have not fully completed the Neanderthal story.
Nature' Holism is a self funded research project. Please help with this progress by advertising, sponsoring or donating now. See more details on sponsorship or advertising. PayPal allows free, easy, secure and safe transactions. They will not charge you any fee.
Donate any amount to keep this site and research progressing.