Despite a great deal of recent evidence showing Neanderthals ate only meat, the behavioural implications of an exclusively carnivorous diet have been largely ignored by anthropologists.
This may well be anthropomorphic reticence—we don’t like to think of our sister species as callous killers. Or perhaps it simply conjures up an unpalatable association with predators like lions and wolves—predators we instinctively fear. Whatever the reason for this, it seems strange, as the findings are an important and exciting new line of evidence with the potential to reveal new insights into Neanderthals. Why? Because what an animal eats—and how it obtains its food—says a great deal about the kind of species it is.
Analysis of animal bones and teeth that litter Neanderthal caves not only shows they were carnivores, but that they were trying to extract maximum nutritional sustenance from every carcass. “They weren’t just eating steaks off these animals,” Erik Trinkaus reports, “they were eating everything that was edible. They were smashing up the skulls and eating brains. They were eating tongues.”179
Moreover, evidence from a number of European Neanderthal sites reveals cut marks on Neanderthal bones. These marks, and the way the bones have been cracked open to extract the marrow, has been interpreted as evidence of cannibalism. Neanderthal sites where cannibalism has been reported include Krapina180 and Vindija181 in Croatia; Marillac,182 Combe Grenal,183 Macassargues184 and Les Pradelles185 in France; and Zafarraya186 in Spain. While some of these findings have been questioned, recent unambiguous forensic evidence of cannibalism from several new European excavations has come to light.
In northern Spain the El Sidrón Neanderthal cave has surrendered the bones of eight Neanderthals that bear the unmistakable slashing and butchering marks caused by cannibals wielding hand axes, saw-toothed knives and scrapers to cut up and deflesh the bodies.187 The research team, led by palaeoanthropologist Antonio Rosas, reported that leg and arm joints had been dismembered, long bones smashed to extract marrow and, in a few cases, the skulls deftly skinned with flint blades. The victims were of all ages—four adults, two teenagers, a child and a baby. Once the bones were processed, they were treated the same as the other animal bones—scattered indiscriminately around the cave.
At the Moula-Guercy rock shelter, in Ardèche, France, three Neanderthal victims of cannibalism have been unearthed.188 Defleshing and disarticulation involved cutting their arms off at the shoulders and elbows, hacking off the thigh muscles, severing the Achilles' tendon on one individual, slicing the temporalis muscle on the side of the skull on another two, and cutting out the tongue of the youngest. The bones—except the hand and foot bones—were then cracked open on a hammerstone to extract the nutrient rich marrow.
The evidence of cannibalism: at Moula-Guercy, in France, Neanderthals used a flint knife to fillet the temporalis (chewing) muscle from the side of the skull. Photo: A Defleur Science 286:130
Interestingly, although the Moula-Guercy Neanderthals were fire-makers, and simple hearths were found in the cave, the cannibalised bones reveal few signs of cooking. Either they preferred to eat the flesh raw or else they hacked it from the bone before roasting it. In either case, once the bones had given up all their nutritional value they were, like the El Sidrón bones, tossed onto a scrap heap along with those of other animals.
“The Neanderthal bones”, writes Karoline Lukaschek in her doctoral thesis The History of Cannibalism, “were mingled with those of the deer and scattered throughout the cave. Both types of bones appear to have been littered across the cave floor rather than buried. If the deer were butchered for food, then the Neanderthals were, too.”189
The Krapina rock shelter in Croatia is arguably the largest Neanderthal site ever discovered. As many as 800 fossilised Neanderthal bones have been discovered there, representing about 80 individuals. Although the way some of these bones have been hacked and scratched has long been suspected to be the result of cannibalism, until recently not everyone agreed. That was until 2005, when the bones were re-examined by a team from the British Museum using the latest high-tech digital-imaging microscopes.
Jill Cook and her team confirm that many of the bones had cut marks, percussion pits from hammerstone strikes, striations, crushed spongy bone and abrasion patterns consistent with dismemberment and defleshing. Cuts were made to the pelvic and leg bones which had been stripped of their flesh and rubbed with an abrasive to remove the fat and gristle. Some of the skulls had their ears lopped off, their tongues cut out, their lower jaws removed, and the skin on their heads peeled off.190 Again, the bones were dumped with those of other butchered animals.
Collectively, the findings from El Sidrón in Spain, Moula-Guercy in France, and Krapina in Croatia prove beyond doubt what Croatian palaeontologist Dragutin Gorjanović-Kramberger asserted over a 100 years ago,191—Neanderthals, at least periodically, practised cannibalism.
The evidence of Neanderthal cannibalism in Europe is consistent with the discovery that their European ancestors were also cannibals. Excavations at the Gran Dolina cave, near Atapuerca, in northern Spain have revealed unambiguous evidence of cannibalism going back 780,000 years, by Homo antecessor, hominids who are thought to be direct ancestors of Neanderthals.192
Whether Neanderthal cannibalism was dietary (for food) or ritualistic (for religious or quasi-religious reasons) is impossible to say for sure. But it is not difficult to see that dietary cannibalism would be a highly adaptive survival strategy during times of food shortage, providing a much needed extra source of protein. On the other hand, ritual cannibalism involves an appreciation of religious and spiritual concepts, symbolism and ritualised ceremonies that would require complex symbolic intelligence. So far, this has been associated only with fully Upper Palaeolithic cultures rather than Middle Palaeolithic hominids.
The logical question that follows on from this is, did European Neanderthals also eat archaic humans in Europe? The answer of course is no, simply because Middle Palaeolithic humans did not live in Europe. Indeed, there is no evidence that archaic humans ever entered Europe during the entire 500,000 years of Neanderthal occupation. I will argue later that this was because the Neanderthals vigorously defended their territory against all intruders. It was only much later (towards the end of the Neanderthal occupation) that Upper Palaeolithic humans (Cro- Magnons) armed with high-tech weapons finally managed to enter Europe.
This brings us to the question of cannibalism in the Levant by Eurasian Neanderthals. From the solid evidence of Neanderthal cannibalism in Europe it is highly likely that Eurasian Neanderthals also ate each other in the Levant, even though evidence from cannibalised bones has not yet been uncovered in that region. This lack of evidence is hardly surprising— in Europe, 500 Neanderthal sites have been discovered which had been occupied for half a million years. In the Levant only a handful have been uncovered and these had been occupied sporadically for less than 60,000 years. Also, cannibalised bones were less likely to be preserved in the Levant because of the warmer climate. The icy climate of Europe was much more conducive to the preservation of fossilised bones.
The recent corroboration of Neanderthal cannibalism lends itself to an intriguing new theory—the possibility that Eurasian Neanderthals also cannibalised Skhul-Qafzeh humans. From an adaptationist perspective, it makes sense that for a carnivore predator like a Neanderthal, no edible, economically procurable species would be off the menu.
If recovered animal bones reveal that Neanderthals were trying to extract every last morsel, and if they hunted every large animal in their territory - even formidable ones like mammoths, bears and lions— then, in the absence of cultural, moral and religious constraints against cannibalism (which to date have only been attributed to fully modern humans), we need to seriously consider whether they also hunted and ate Skhul-Qafzeh humans.
This does not necessarily mean Neanderthals hunted the Levantine humans as a priority. After all, their ancestors in Europe had acquired a preference for deer, horse, mammoth and other herbivores, so the Eurasian Neanderthals probably maintained that preference—under normal conditions. What can be inferred though, is that the Levant human population (which has been estimated to number between 5000–10,000 individuals)193 would have provided Eurasian Neanderthals with an additional food source that could be exploited as required, particularly when their preferred prey was scarce or seasonally unavailable.
Even though cannibalism has been observed in over 1300 animal species,194 including chimpanzees,195,196 for a few scholars the idea that Neanderthals would want to hunt humans for food is anathema. Over the last decade, Neanderthals have increasingly been perceived as gentle, humane cousins, displaying almost the same intellectual and emotional proclivities and sensitivities as modern humans.
This is due in part to the suggestion that Neanderthals may have demonstrated symbolic thinking, including playing musical instruments and burying their dead with flowers. For example, several researchers have claimed that a fragment of a cave bear’s femur with two holes, from Divje Babe in Slovenia, is a ‘Neanderthal flute’.197,198
In 2006, Iain Morley, from Cambridge University, conducted a detailed microscopic analysis of the Divje Babe bone. He discovered that, although the bone looks like a flute, it shows evidence of gnawing by a carnivore along its entire length. Also, the size and shape of the holes are the same as the canine teeth of brown bears and cave bears. He concludes that the bone is “the product of a number of stages of carnivore activity, and there is no need to invoke any hominin agency in the creation of the object”.199
What is so convincing about Morley’s argument is that under a microscope, on the underside of the bone, the indentations of the carnivore’s bottom teeth are clearly visible, directly opposite the so-called ‘flute holes’.
A second case is the alleged burial with flowers of the Shanidar IV Neanderthal, which one researcher has interpreted as a ritual burial by symbolic people.200 This made quite an impact in the media at the time and created an image of Neanderthals as the gentle hippies of the Pleistocene. But this too has been disputed. Anthropologist Jeffrey Sommer concludes in the Cambridge Archaeological Journal that the flower pollen found in the grave was more likely to have been brought there by rats that had burrowed into the grave.201
Because cannibalism raises such emotive issues, it is worth emphasising that, from a purely Darwinian perspective, eating archaic humans wouldn’t involve the negative connotations normally associated with murder or cannibalism. Judging by other predators, killing for food isn’t personal. Nor is it motivated by homicidal rage, insanity or even anger. A lion has no personal animosity towards the antelope it brings down. There may be the excitement of the hunt, the suspense of stalking a prey for hours or even days, the exhilaration of the chase and the satisfaction of a clean kill—but ultimately, it’s not personal.
Primatologist and anthropologist Richard Wrangham, from Harvard University, who has studied social predators in Africa, says that they don’t show obvious signs of excitement when killing a prey,202 and Johan van der Dennen, from the University of Groningen in the Netherlands, notes that social carnivores don’t play with or taunt their prey, preferring instead to dispatch them quickly with a fatal bite.203 Ultimately, within the context of food procurement in the endless winter of the European Stone Age, cannibalism would often be a question of survival of the fittest. It was all just meat.
The reluctance to attribute the ferocity and viciousness of modern feline and canine predators to Neanderthals has delayed the resolution of the Neanderthal problem. Ferocity and brutality are key prerequisites of predation which, in turn, is widely acknowledged to be an important driver of physical evolution.204,205,206 Predacious behaviour is among the most important single determinants of a species’ evolution, creating specific demands on an animal’s physiology and behaviour. If a species’ raison d’être is killing, then killing guides its evolution.
While dietary cannibalism would be one reason why Neanderthals hunted early humans, it would not be the only reason. Another factor that may have played a role in the Levant is intraguild predation—the killing and consumption of an intermediate predator by a top predator from the same guild,207 for example, the killing of cheetahs by lions.208
Intraguild predation is a widespread phenomenon among mammalian carnivores,209 but it is unusual in that the top predator does not always eat the middle predator it kills. Of 21 reported cases of intraguild predation in one study,210 the top predator ate the middle predator in only ten cases. For example, spotted hyenas always ate the cheetahs they killed, but lions weren’t observed eating any cheetahs. This has prompted several researchers in the field to maintain that the evolutionary function of intraguild predation might be to reduce competition for a shared prey resource.211,212
With intraguild predation being a common occurrence among mammalian land-based predators that have been around for at least three hundred million years, its evolutionary origins clearly go back far enough to apply to Neanderthal-human interactions in the Levant. If all the modern social carnivore species practise intraguild predation, then it is appropriate to suggest that Neanderthals also practised it on early humans.
Apart from killing animals for food, lethal violence is rare among mammals. When it occurs, though, it is usually between individuals.213 But a rar- er form of lethal violence has also been observed among wild animals— coalitionary killing—which is characterised by lethal violence between groups, or violence directed by a group towards an individual. Coalitionary killing has been observed among spotted hyenas, 214 wolves,215 lions 216 and cheetahs 217—all social predators—but is most common among chimpanzees and humans.218
Among populations of chimps which have been studied in their natural habitat, there have been countless cases of violence observed. A primatologist at Sydney’s Taronga Park Zoo told me, “the chimps are the most dangerous animals we have at the zoo. We never ever go into their enclosure.” I have witnessed a number of outbursts of aggression in the Taronga troop, characterised by quick vicious attacks, lots of blood- curdling shrieking, high-speed chases and the use of branches as weapons. Then it’s over and the females go in to comfort the victims.
Despite this, no lethal case of violence by a single individual has ever been reported, either in a zoo or in the wild. All the fatal attacks have been by groups (or coalitions). Victims sometimes include members of the same group, but more likely they’re members of neighbouring communities. Usually, a group assault lasts a minimum of 10 minutes, during which the attackers hold down the victim and continue to bite, strike, tear and drag until the victim is killed or immobilised.219
A graphic example of coalitionary killing by captive chimpanzees was observed at the Arnhem Zoo in the Netherlands in 1980. Primatologist Frans de Waal, who spent several years observing what at the time was the world’s largest captive colony of chimpanzees, reported that on 12 September the males’ sleeping quarters “turned red with blood”.220 On that night, two chimps (Nikkie and Yeröen) ganged up on the alpha male (Luit) and inflicted such injuries (including tearing off his testicles and several of his fingers and toes) that he died the following day.
While it may be an unpalatable concept, Eurasian Neanderthals were social carnivores, so coalitionary killing would be part of their genetic make-up, simply another string to their adaptationist bow.
Lethal raiding is yet another form of deadly group behaviour. It describes the intrusion by a group of predators into a neighbouring territory, specifically to conduct a surprise attack, cause casualties, and retreat to the home territory.221 Like coalitionary killing, lethal raiding is the exclusive preserve of social predators. Wolves, lions and spotted hyenas have been observed making lethal raids into neighbouring territories222, 223 but, again, chimpanzee and human males are by far the most frequent exponents of lethal raiding.
Lethal raiding is perplexing because field studies consistently show the raids are not escalations of current conflicts, acts of self defence, or aimed at poaching food from a neighbour’s territory.224 In all observed cases of chimpanzee raiding, the males encroach in unusual silence, in single file, into a neighbouring territory until they locate and capture a vulnerable individual who is then mercilessly attacked and, in most cases, killed.
Richard Wrangham says, “lethal raids indicate an appetite for hunting and killing rivals that is akin to predation.”225 Based on her own observations of chimps at Tanzania’s Gombe Stream National Park, Jane Goodall argues that killing is the sole objective of lethal raiding.226
Although many theories try to explain coalitionary killing, lethal raiding and intergroup aggression among chimpanzees (see Johan van der Dennen, for an excellent review),227 to date no consensus has emerged. One suggestion is that lethal raiding and coalitionary killing in contemporary chimpanzees is derived from an innate hostility towards outsiders—a primate form of xenophobia.
Another theory is that it represents an extreme form of sexual competition, aimed at killing rival males and gaining access to sexually mature females from neighbouring communities.228,229,230 This fits with the fact that lethal raiding is almost exclusively carried out by males,231,232 and that ten out of eleven victims of lethal raiding by chimpanzees at Gombe National Park were males.233 It also seems significant that male raiding parties of wild chimpanzees at Gombe were observed violently ‘kidnapping’ females, resulting in prolonged fighting and skirmishes lasting several days.234,235 These females eventually joined the raiders’ community.
When it comes to the body count, however, chimps pale into insignificance compared to humans. Throughout recorded history, humans living in small tribes have shown themselves to be masters of both lethal raiding and coalitionary killing. And judging by well-observed accounts of modern hunter-gatherer groups, the pattern of violence is surprisingly similar to that of chimpanzees. For example, the Yanomamö people of Central Brazil undertake commando-style incursions deep into their neighbours’ territory, attacking unsuspecting villages, killing whoever they can as quickly as they can, then beating a hasty retreat before the villagers can organise a proper defence.236,237,238
The similarity to human patterns of intergroup aggression and warfare are so striking that most researchers in the field believe they represent a direct continuity between modern human violence and primate aggression, going back five to six million years to common ancestors.239, 240, 241,242,243
In The Origins of War Keith Otterbein draws on the evidence of warfare among primates, prehistoric hominids, early agriculturists, and contemporary hunter-gatherer societies to show that coalitionary killings and intergroup warfare by males have been a ubiquitous feature of our species for over five million years.244
If we draw an evolutionary link between the violent tendencies of our closest (surviving) relative and our own, then it is necessary to include Neanderthals in that link. They are as closely related to chimps as humans are, and even more closely related to humans than chimps. If coalitionary violence and lethal raiding are a significant feature of chimpanzee and human societies, then they were almost certainly present in Neanderthal society.
In Europe, where the original and largest population of Neanderthals lived in isolation, European Neanderthals could only have directed lethal raiding, coalitionary killing and cannibalism against other European Neanderthals, who were obviously a formidable and well-armed adversary. Raiders faced the risk of being injured or even killed during incursions.
But in the Levant, I suggest, Skhul-Qafzeh humans represented a less aggressive, more docile, but nevertheless sexually compatible option— not to mention an alternative supply of fresh meat during times of food stress. They represented a ‘soft’ target for aggressive Eurasian Neanderthals. This—and the margin of safety it provided—would have encouraged lethal raiding against Levantine early humans.
It is not difficult to see that a group of aggressive Neanderthal males, faced with the decision of which troop to attack—a neighbouring group of heavily armed Eurasian Neanderthals, or a group of timid Skhul- Qafzehs—would opt to attack the human camp. How terrifying this must have been for our primitive ancestors—when the Neanderthals came with spears and stone knives, to terrorise and kill the men and kidnap the young girls and women. Such traumatic experiences would become indelibly encoded into their communal psyche, to leave them scarred for life.
If the portrayal of Neanderthals as a proficient spear-wielding apex predator-carnivore is accurate, then lethal raiding and coalitionary killing by Eurasian Neanderthals would result in significantly more casualties than an equivalent raid by modern chimps (who do not use sophisticated weapons), or even by Middle Palaeolithic humans.
Were Neanderthals territorial? And, if so, what are the behavioural implications? Modern humans certainly are.245 A cursory glance at an atlas reveals humans pegging out national boundaries, signposting them with flags and a common language, and defending the borders of their villages, cities, states and countries against all invaders, often with their lives.
While territoriality—the use of physical force, threat, or advertisement to defend an area—is a feature of human society, it is also prevalent among chimpanzees.246,247 Male chimps regularly patrol the borders of their territory and intruders are usually attacked and, in some cases, killed. For primatologists, one of the most intriguing aspects of chimpanzee territoriality is just how violent they are towards intruders from neighbouring communities.248, 249 Jane Goodall makes the point:
In the chimpanzee, territoriality functions not only to repel intruders from the home range, but sometimes to injure or eliminate them; not only to defend the existing home range and its resources, but to enlarge it opportunistically at the expense of weaker neighbours; not only to protect the female resources of a community, but to actively and aggressively recruit new sexual partners from neighbouring social groups.250
Chimpanzee territory size is thought to be directly correlated to their survival—the larger the territory, the more food and other resources it contains.251 So we might reasonably conclude that if both humans and chimpanzees are aggressively territorial, then so too were Neanderthals.
We can also look at Neanderthal territoriality from another perspective. Several scholars have pointed out that because modern social carnivores like chimps, lions and hyenas have similar group dynamics, dominance hierarchies, land tenure systems and cooperative hunting techniques, they can be used to infer behaviour in early hominids.252, 253 The reasoning goes that, as social carnivores, Neanderthals probably evolved similar territorial imperatives as those of modern social carnivore species because the evolutionary constraints are similar.
Ecological studies show that territoriality is common in all modern social carnivores, particularly in lions, hyenas, wolves and chimpanzees and, not surprisingly, involves extreme violence.254 What is perhaps surprising is that of all the social carnivores, chimpanzees are the most violent.255, 256
This raises the likelihood that, as social carnivores, populations of Eurasian Neanderthals defended their territory aggressively, and probably expanded it by replacing other groups of Neanderthals and Skhul-Qafzeh humans.
Yet another, more direct insight into possible Neanderthal territoriality comes from Oxford University archaeologist Sarah Milliken’s comprehensive 2007 study of Neanderthals in Italy. She writes:
At Falce del Viaggio in the northern part of the Murge, high quality chert [a flint-like stone] was procured from the Gargano promontory, 70 km to the north, while at sites located 90 km to the south, chert was procured from the Basilicata Apennines, 70 km to the west. The absence of Gargano chert at the southern sites, and of Basilicata Apennines chert at Falce del Viaggio, suggests that the sites in these areas were part of two completely separate Neanderthal territories.257
Several other lines of evidence reveal that Neanderthals occupied forest areas, both in the Levant and in Europe. While in Europe forests provided some protection against icy winds and near-lethal wind chill, they were also home to some of their favourite prey, such as deer. Forests may have also suited their hunting style, where they could use the cover of trees to get close enough to ambush their prey. Again, in the Levant, archaeological assemblages reveal Neanderthals mostly hunted woodland species,258 suggesting they occupied the inland mountains and forests, while humans resided in the flat coastal lowlands.259 This evidence supports the premise that each species occupied its own well-defined separate territory.
It seems telling that, although Middle Palaeolithic humans colonised all areas of the Levant (before the Neanderthals arrived), there is no evidence they ever colonised Europe.260 Was that because Europe was Neanderthal territory? Did humans try to push into Europe? And were they repelled by a determined species hell-bent on protecting their territory? Richard Klein believes this may have been the case—that Middle Palaeolithic humans did not colonise Europe because they couldn’t compete against the Neanderthals.261 This adds credence to the model that Neanderthals were a formidable and hostile adversary who poached territory from the Levantine early humans and tenaciously defended it.
The prospect of Neanderthal territoriality broadens the concept of ‘them and us’ to include ‘theirs and ours’. Territory, with all its direct connotations to resource procurement and survival, provided yet another arena of conflict between the two competing species. In practical terms it meant that, when on hunting and gathering expeditions, Skhul-Qafzehs had to be careful not to stray inadvertently into Neanderthal territory or they risked being attacked and seriously injured, if not killed. No matter how lost they were, the last thing a group of Levantine hunters could afford to do was ask a stranger for directions.
In summary, it is reasonable to conclude that coalitionary killing, lethal raiding, dietary predation and aggressive territoriality would have resulted in the reduction of the Skhul-Qafzeh population in the Levant. And this in turn, could have serious long-term evolutionary implications. But there was one more reason that Eurasian Neanderthals were attracted to the Levantine humans, and this was arguably the most important reason of all—sex.