The prevailing logic in the popular science media regarding the physical appearance of Neanderthals seems to be: if humans don’t resemble other primates—then neither did Neanderthals. Even though the other 192 primate species don’t look like us, we somehow assume that Neanderthals did. This premise is sometimes supported by the fact that human and Neanderthal skeletons are so superficially similar (they have the same bones in roughly the same places) their facial features must be similar too. But then again, human and chimp skeletons are also similar and yet their facial features are quite different.
It’s not only the media that has perpetrated the anthropomorphic view that Neanderthals and humans were like two peas in a pod— scientists have too. In the pictorial ‘evolution of man’, ancient hominids like Australopithecus, and Homo robustus and habilis stand at one end of a monkey-human continuum, while Neanderthals stand proudly with early humans at the other end—a little hairier—but demonstrably human.
It has even been claimed that if you gave a Neanderthal a bath, a shave, a haircut and a new Armani suit, he could pass off unnoticed on the New York subway as yet another surly stockbroker.295
As recently as 2007, Professor of Biological Anthropology at Harvard University Daniel Lieberman was quoted as saying, “If a Neanderthal were to come along, we’d think he was kind of weird. But we might also wonder whether to admit him to Harvard.”296
The Field Museum of Natural History in Chicago commissioned this reconstruction of a classic European Neanderthal (from La Chapelle-aux-Saints, in France) to illustrate just how modern-looking these guys were. Graphic adapted from J H McGregor.
There is no scientific evidence to support this contention. Anthropologist Judith Berman, who has carried out a detailed study of the perception of prehistoric hominids in both the media and science, makes the point that the familiar iconography of the ‘cave man’ has its origins not in science or hard evidence, but in medieval European art,297 and has simply continued, driven by anthropomorphism, into modern popular culture.
As soon as an objective evolutionary perspective is applied to the Neanderthals’ external appearance, it becomes obvious that what they looked like was determined by natural selection. Ecology, which includes the physical environment and the behaviours required to survive in that particular environment, is what determines an animal’s appearance. Only by disregarding our anthropomorphic bias and concentrating on examining the relationship between Neanderthals and the environment in which they evolved, can we create an accurate identikit picture of a Neanderthal.
Neanderthals evolved in ice-age Europe, and survived in that ice-box environment for hundreds of thousands of years only because they man- aged to adapt biologically to the cold. Having argued that climate played a pivotal role in Neanderthal behaviour (by forcing them to adopt the carnivorous diet that segued into a predatory lifestyle), we must expect that the climate would also have affected their physiology.
Cold-climate Neanderthal adaptations are thought to include novel features like short limbs,298 the shape of the femur and pelvis,299,300 large noses, and compact torsos—all of which are thought to minimise heat loss.301,302 The same stocky build is evident in people (like the Inuit) living in arctic regions today. Of course, the exceptionally cold temperatures of ice-age Europe would have created an extreme version in European Neanderthals—what anthropologist, Trenton Holliday from the University of Central Florida calls the ‘hyperpolar’ body shape.303
What Neanderthals looked like is de- fined by numerous features, but let’s consider the ‘big ticket’ items—the major physical features that create the all- important first impression. The most noticeable, from a distance at least, would be the amount of body hair and its colour, raising the question—how hairy were they? Were they smooth- skinned and hairless like us, or covered with thick fur like other primates? And if so, what colour was their fur?
Today, every single warm blooded mammalian species living in a similar icy climate has acquired a thick coat of body fur to maintain their core body temperature. Most primates live in warm or tropical climates, but a few have taken up residence in very cold regions of the earth and this provides an opportunity to see how they have adapted to the cold. Not surprisingly, cold-adapted modern primates, such as Japanese macaques and gelada baboons, have not only acquired extra long, extra thick fur coats, but have also evolved an annual thicker ‘winter coat’ for when temperatures really plummet.
This indicates that the iconic view of Neanderthals—as almost as devoid of body hair as modern humans—is an anthropomorphic relic and needs to be re-examined. As part of my investigation, I re-examined the fossil and cave art evidence from Europe during the period of Neanderthal occupation. This revealed that every Late Pleistocene terrestrial mammal species inhabiting Europe and the Middle East had long thick hairy coats to protect them from the cold.304,305,306,307
If all these animals acquired thick fur to insulate them against the freezing cold, it seems likely that Neanderthals did too.
The only thing standing between a hairless Neanderthal and a snap- frozen Neanderthal would be some form of cultural buffeting, such as clothing, fire or shelter. But Neanderthals made only simple fires and, apart from the odd wind break, did not build complex structures.308 So far, significant improvements in clothing, pyrotechnology and shelter have been associated only with Upper Palaeolithic people,309,310 but it is important to consider whether clothing—skinned from animals and fashioned into something resembling a loosely fitting garment—helped Neanderthals survive the worst of the European winters. If so, did this lead to them discarding their ancestral primate fur?
But first, we must discard preconceptions derived from the countless pictorial representations of Neanderthals dressed in over-the-shoulder furs and loin cloths. These illustrations are mostly rooted in antiquated concepts of sexual modesty and fanciful imagination. There is no direct evidence that Neanderthals ever wore clothes. In fact, it is difficult to see why their unique cold-adaptive ‘hyperpolar’ body shape would be needed if they did. Australian anthropologist Ian Gilligan argues that clothing could not have been a major factor “as regular use of complex garments would result in a consistently warmer microenvironment for the body and hence a less cold-adapted physique”.311
And what exactly is meant by clothing—or more precisely, the type of clothing required to keep someone alive in ice-age Europe? University of Durham archaeologist Mark White makes the point that to provide anything like the level of insulation necessary for survival:
Neanderthal clothing would have needed to be more than the ragged loincloth, off-the-shoulder wrap or cape of popular depiction (the last of which would pin the arms inside, preventing effective action). Some form of tailoring would probably have been required,[312] but the Middle Palaeolithic has thus far yielded no evidence of needlecraft technology, which first appears in the Upper Palaeolithic.313
Having discarded the familiar picture of the burly Neanderthal in a loin cloth, our focus shifts to whether they could tailor the kind of closely fit- ting ‘body suits’ needed to survive. Ian Gilligan explains that :
[Such] complex garments demand that the skins be carefully shaped by cutting, especially for the separate rectangular pieces that form cylinders to cover the limbs, and these need to be joined together in some way, usually by sewing. Where multiple layers are used, the inner garments must be carefully prepared, with finer cutting and sewing to achieve the necessary close fit.314
Complex garment manufacture requires needles to sew pieces together and, to date, no eyed needles have been recovered from Neanderthal sites, although some creationist web sites would have you believe otherwise.
Literally thousands of Neanderthal stone tools and pieces of bone and ivory have been found but, despite the fact that they fossilise well and are common in Upper Palaeolithic human sites, eyed needles have never been found at Neanderthal sites. While Donald Johanson and Blake Edgar note in From Lucy to Language, “there is no scrap of archaeological evidence for Neanderthal clothing”,316 this would not preclude Neanderthals throwing the odd fur over their shoulders or tossing a skin down on the cave floor to make a more comfortable nest. But the absence of sewing needles is telling and indicates that Neanderthals relied primarily on biological means rather than sewn garments to keep themselves warm.
But, even if Neanderthals could make thermal garments able to withstand the cold and wind chill of ice-age Europe, they also had to know how to maintain their effectiveness. For example, wet clothes can be extremely dangerous, and can increase heat loss by a factor of five.317, 318
Another factor that may have a bearing on this question is that archaeological evidence reveals that when culturally insulated modern humans finally entered Europe, they were able to colonise the continent and Siberia as high as latitude 60o North. But significantly, European Neanderthals rarely strayed above 50o North. After an extensive survey of hominid and human colonisation of high latitudes, John Hoffecker, a research scientist from the University of Colorado at Boulder, concluded that the Neanderthal’s northern expansion was halted by climate:
Despite their special cold-adapted traits, the Neanderthal range of climate tolerance was limited compared to that of modern humans. They probably were unable to cope with average winter temperatures much below –10 o C and were generally restricted to wooded terrain.319
Similarly, another survey of Pleistocene acclimatisation found that European Neanderthals avoided areas where the winter temperatures fell below -8 o C, and preferred summer temperatures between 12 o and 25 o C.320
While there may be several reasons for this, it seems likely that while modern humans could live in sub -10oC temperatures because they had properly fitting tailored thermal garments, Neanderthals could not because they did not have clothes that could provide enough warmth. It also implies that -8 o to -10 oC was the absolute insulating limit of their body hair. Any colder than -10 o C and their fur simply could not maintain their core body temperature. Without clothes, cold stress (hyperthermia) was like a brick wall that stopped them in their tracks.
The cold factor may also explain why Neanderthals essentially lived in forests which sheltered them from the icy winds that swept across the open savannahs.
All this leads to the hypothesis that Neanderthals not only retained the ancestral primate body hair they acquired in Africa, but that in periglacial Europe their hair increased in length, thickness and density in order to aid thermoregulation and heat retention. And, if the thick body fur of these primate ancestors was bolstered by a seasonal ‘winter coat’ to provide extra warmth in icy conditions, in summer the Neanderthals almost certainly moulted.
These conclusions redefine the Neanderthal appearance, suggesting it more closely resembled that of a tall, hairy ape than a modern human.
As to the colour of the Neanderthal fur, while it is impossible to say for certain, in 2007 Carles Lalueza-Fox and a group of geneticists amplified and sequenced part of a gene called MC1R (one of the genes thought to regulate skin colour) from two European Neanderthals. This revealed the MC1R was slightly different from the normal human form.321 Although there is a possibility that the samples were contaminated (easy to do with samples of ancient DNA) the researchers believe the Neanderthal version of the gene may have been less effective than ours, so may have resulted in reduced pigmentation levels, “possibly even similar to the pale skin colour and/or red hair observed in modern humans”.
Although these conclusions made for good press they are, of course, highly speculative, as genes are so complex it is virtually impossible to say what effect even one nucleotide substitution will have on protein synthesis. Besides, while fur and hair may be one colour, the underlying skin may be a different colour.
While it may seem appropriate to speculate that, because the fur of Neanderthals’ three closest primate relatives (chimpanzees, bonobos and gorillas) is black, theirs would be black too, this doesn’t necessarily follow. Other factors need to be considered as well.
The colour of the fur of many modern animals, including most primates, appears to be influenced to varying degrees by the need to hide from predators and prey.322,323 Generally, mammals tend to assume the colours of their overall environment, a phenomena called background matching. It means that primates that live in desert environments or open grasslands tend to be a mottled brown colour, while those that reside in forest habitats tend to have darker fur.324 Of course, this would not apply to Neanderthals if they were an apex predator.
Another consideration is climate. A few modern cold-climate, snow- dwelling mammals, such as the polar bear, have acquired an all-white coat as an aid to camouflage. However, Pleistocene Europe was not the Arctic and its climate, although cold, wasn’t polar, so an all-white fur would probably prove maladaptive in the long term. All other bear species, including the ones that live in cold climates similar to that of the Neanderthals (like the Asiatic black bear, kodiak bear, Himalayan black bear, Formosan black bear, brown bear and the grizzly bear), have opted for dark-coloured fur, almost certainly because dark pigmentation absorbs solar radiation and converts it to heat325—an adaptive feature in ice-age Europe.
Ultimately, primates come in a striking range of fur and skin colours from white to jet black, and include brightly coloured features like the noses of male mandrills, the lurid chest patches of gelada baboons and the discombobulating red faces of the red uakari. Even closely related species sometimes display markedly different colours.326 Given this, it is impossible to come to any definitive conclusion regarding Neanderthal colouration. Unless global warming dramatically reveals a deep-frozen Neanderthal (a la Ötzi the Neolithic ‘iceman’) we may never know for sure what colour their fur really was.
Another visually striking aspect of Neanderthals was their faces. Although they retained some ancestral primate elements, their features were also shaped by the glacial environment of ice-age Europe—so we need to examine them individually.
Chimps and bonobos have relatively large protruding ears and we might reasonably expect Neanderthals to have had the same. But ears tend to be strongly influenced by the particular environment an animal inhabits, so we need to consider whether climate may have impacted on the shape and size of Neanderthals’ ears.
In hot tropical climates, some animals (like elephants) adopt large ears which act like a car radiator, cooling the blood pumping through them. Conversely, in environments where low winter temperatures and high wind chill are major factors, small ears get selected because they lose less body heat and are less susceptible to frost bite. Primates that live in Japan and other northern latitudes have small ears covered with fur—large ears would prove maladaptive in a glacial climate, creating selection pressure for small ears close to the head, covered by thick fur.
What are the behavioural implications of this? Well, polar bears have very small ears and therefore don’t hear very well. This isn’t a problem because polar bears rely on their exceptional sense of smell to locate prey up to 24 kilometres (15 miles) away. The same was probably true for Neanderthals. They most likely did not have particularly acute hearing but, if their sense of smell was as keen as the evidence suggests, they would not have needed it.
When speculating on the appearance of the Neanderthal nose, anthropologists tend to take the all too familiar anthropomorphic view—their noses looked like ours, albeit larger and broader. The fact that the Neanderthal nose was bigger than ours is usually explained as an adaptation to cold climate—that a large nose would somehow warm the cold air-but there is not the slightest evidence to support this contention. Some palaeoanthropologists, like Alfred Czarnetzki, argue the opposite is true— that large noses are adaptations to hot, humid regions.327
Marc Meyer and his colleagues from the University of Pennsylvania provide another opinion—that Neanderthal “nasal morphology may have a stronger association with masticatory or paramasticatory functions than with climate”.328 Robert Franciscus and Erik Trinkaus argue in the American Journal of Physical Anthropology that Neanderthals evolved their extra large noses as an adaptation to their active and strenuous lifestyle,
329 to get more air in and out of their lungs, more quickly. That seems somewhat counterintuitive as animals (including humans) breath through their mouths during peak physical exercise.
The absence of a consensus suggests the need for a fresh look at Neanderthal noses and, in particular, why they were so large.
The noses of the closest primate relatives of Neanderthals (gorillas, chimps, and bonobos) are broad and flat—nothing at all like ours. If you remove humans from the equation (because, as we will see later, we’re a special case), the law of homology, or common descent, would say Neanderthals retained the ancestral primate nose—unless special ecological circumstances created selection pressure for something different.
Neanderthals evolved in glacial Europe and, if this icy environment appears to have influenced every other aspect of their physiology and behaviour, the question is: could the freezing climate also have influenced the shape of their noses? And the answer is, most certainly. A large protruding nose would be more prone to freezing— recent field observations of Finnish solders demonstrated that their noses and ears suffered the most from frostbite.330 In glacial conditions like those experienced by Neanderthals, any appendages that stuck out—like lips or noses—were more susceptible to becoming frostbitten, so natural selection would most likely retain the flat ancestral nose (just as it opted for small ears) rather than adopting a protruding human-like nose.
The cold climate explains the flat nose. But it doesn’t explain why their noses were so large. For that we need to consider another ecological constraint that may have affected the shape and size of the Neanderthal nose. My ecological review of Neanderthal physiology suggests they were nocturnal—they hunted at night.