AS IS usual in such cases, Armin Meiwes’s neighbours in the small German town of Rotenburg an der Fulda described him as “quiet”. The truth, as the world now knows, was very different. Meiwes was a cannibal killer who in 2000 butchered and partially ate a man known as Jurgen B, a 42-year-old from Berlin who he met in an internet chat room. What makes the case even more shocking was that Jurgen B was apparently a willing victim.
The Meiwes case, and the global media frenzy it whipped up, served as a reminder of cannibalism’s power to shock and fascinate. From Anthony Hopkins’s portrayal of the fictional Hannibal Lecter to the real-life testimonies of the Donner Party – a band of US pioneers who in December 1846 became stranded in the Sierra Nevada mountains and had to resort to eating their companions – stories of cannibalism are utterly compelling. Who hasn’t gasped at the tale of the Uruguayan rugby union team who crashed in a remote part of the Andes in 1972 and were forced to eat their dead team mates?
Modern-day cannibalism is fascinating because it is widely seen as an extreme anomaly of human behaviour – either a last-ditch bid to survive or a sick crime perpetrated by a madman. What is perhaps surprising, though, is that ancient cannibalism is often viewed through the same lens. Despite extensive archaeological and anthropological evidence for its occurrence, most scientists believe that cannibalism was only an irregular feature of prehistoric human societies.
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But in the past year or so studies have been published suggesting that human cannibalism was once much more widespread than we might care to think. Genetic and biochemical evidence has now convinced many scientists that the consumption of human flesh was once commonplace, perhaps even socially acceptable. And chillingly, if they are right, many of us carry genetic protection against diseases passed on by eating our fellow humans.
These controversial claims have reignited a lively and highly polarised debate that stretches back several decades. Until recently, the arguments have centred on two types of evidence – accounts of cannibalism documented by explorers and anthropologists, and telltale “butchery” marks on human bones found at archaeological sites.
Among the believers in widespread cannibalism is archaeologist Timothy Taylor of the University of Bradford, UK. He cites anthropological evidence for cannibalism going back hundreds of years, from accounts by the ancient Greeks, to explorers including Christopher Columbus and Captain Cook, to 20th-century anthropologist Edward Gifford of the University of California at Berkeley. In 1951, after a study of prehistoric Fijian culture, Gifford concluded that “outside of fish, man was the most popular of the vertebrates used for food”. Taylor also points to the archaeological evidence. “We can infer from cut-marked animal bones that animals were part of the human diet,” he says. “The same logic should be applied to cut-marked human bones.”
Bones like these have turned up all over the world and throughout human history. Recently, for example, palaeoanthropologist Tim White of the University of California at Berkeley unearthed three 160,000-year-old fossil skulls in Ethiopia. They were the oldest known fossils of modern humans, but that wasn’t all: each skull had cut marks indicating they had been “de-fleshed” (Nature, vol 423, p 742). Previous studies by White have found similar cut marks on hominid bones dating back 600,000 years, and what he describes as “compelling evidence” for cannibalism from Neanderthal remains found in France (Science, vol 286, p 128).
Similar evidence has also been found at an Anasazi site known as Houck K in Arizona. Back in the early 1990s, the site, which dates from the mid 12th century, yielded a large cache of human bones. The bones show signs of having been butchered and cooked: they bear cut marks and also have a worn appearance indicating they have been subjected to prolonged boiling. What is more, the vertebrae are selectively missing, which some researchers suggest is because some had been crushed to extract bone marrow. “Wherever you look in the prehistoric record you come across this phenomenon,” says White. “There is widespread evidence for cannibalism in France, England, Mexico and North America.”
However, the anthropological and archaeological evidence is circumstantial. Sceptics point out that no outsider, whether explorer or anthropologist, has ever witnessed an act of cannibalism: all the reports are second-hand and therefore unreliable. Even the supposedly well-established cannibalistic “mortuary feasts” of Papua New Guinea have never been confirmed. “Out of the 10,000 anthropologists in the world, not one has ever witnessed a human being butchered and eaten,” says Bill Arens, professor of anthropology at Stony Brook University in New York and author of The Man-Eating Myth (Oxford University Press, 1980). What is more, cut marks on bones could have arisen in all sorts of ways that need to be excluded before concluding that they were made by cannibals. They could have come about through conflict with enemies, executions or burial rituals, for example. And even if some butchery was going on, that does not necessarily mean the flesh was subsequently eaten.
But in the past year or so, new evidence has emerged that looks like swinging the argument in the favour of believers such as Taylor.
The first piece of evidence concerns some peculiar goings-on 850 years ago in what is now south-western Colorado. There, in a tiny pueblo, at least seven people were butchered, cooked and eaten. The evidence for cannibalism at the site is comprehensive, providing the first solid proof that humans were being killed an eaten in pre-Columbian America (Nature, vol 407, p 74).
The site, a typical settlement on a broad flood plain called Cowboy Wash, comprised three cylindrical houses 3 to 5 metres in diameter and built from sun-dried adobe brick. Previous studies at the site indicated that, after being occupied for around 30 years, the houses were suddenly abandoned in around 1150. The occupants left behind everything from cooking pots and utensils to polished stone tools and ornaments. It appeared that nothing had been scavenged from the site and no structures had been destroyed – they were just left to crumble.
But it was the more grisly discoveries that the team, led by pathologist Richard Marlar of the University of Colorado School of Medicine in Denver, chose to investigate further. In the remains of one of the pit houses were more than a thousand human bones and bone fragments. Some were scattered across the floor, others were piled up in a side chamber. Closer examination revealed cut marks on the bones and traces of human blood on two stone cutting tools. Nearby were the remains of a cooking pot and, in the ash of the hearth, a deposit of human faeces known as a coprolite.
Marlar and his team suspected cannibalism, so they carried out biochemical tests on the cooking pot and coprolite. They were looking for traces of human myoglobin, a protein found only in skeletal and cardiac muscle cells, where it is used to store and transport oxygen.
Cooked and eaten
They subjected shards of the cooking pot to an immunological test that uses antibodies that bind only to a target protein – in this case human myoglobin. Analysis revealed that human myoglobin was indeed present in the pot, whereas it was not found in 29 samples taken from other cooking pots from nearby archaeological sites dating from 150 to 1175. In other words, human flesh had almost certainly been cooked at the site.
But had it been eaten? To find out, they subjected the coprolite to the same type of analysis. Under the microscope, the absence of starch granules from the faeces suggested that the depositor hadn’t eaten any plant material for up to 36 hours previously, and had probably consumed only meat. No one would have been surprised to find human proteins in the faeces, as we are constantly shedding epithelial cells from the lining of our intestines. But finding myoglobin would be almost unthinkable.
A control group of 39 modern humans, including some with blood in their faeces, as well as samples from 20 other prehistoric coprolites, showed no human myoglobin. Because the protein is found only in skeletal and cardiac muscle, the test would only prove positive if human flesh had been consumed. It did, giving Marlar “the first direct evidence of cannibalism in the American south-west”.
But some anthropologists think we should be cautious about how this finding is interpreted. “What the study proves is that cannibalism may have occurred at this particular site,” says Arens. “It doesn’t prove it was widespread.” He has devoted much of the past 30 years to debunking the claims of those who believe cannibalism was endemic in human societies. “I sometimes feel I’m banging my head against a brick wall,” he says. “We look at one or two archaeological finds and say, people were cannibals. There is no evidence that there was cultural cannibalism.”
Arens clearly has a point. There might be specific instances of cannibalism, but where is the evidence that cannibalism was widespread in early human societies? John Collinge of University College London thinks he has it, and his evidence comes from an unlikely source.
In a paper published last year (Science, vol 300, p 640), Collinge’s team, led by Simon Mead, reported on their study of the effect of the brain disease called kuru found amongst the Fore people from the remote highlands of Papua New Guinea.
Eat the ancestors
Kuru is a prion disease, rather like BSE and CJD, that is widely believed to have been contracted during mortuary feasts. Though such feasts were never witnessed by outsiders, reports that the Fore had a custom of eating their dead have been central to studies of kuru since it was first investigated by Carleton Gajdusek of the National Institutes of 91ɫƬ in Bethesda, Maryland in the 1950s. There is some evidence to support the reports, not least that kuru started to decline once the Australian colonial authorities banned mortuary feasts in the 1950s. Kuru also affected mostly women and children, who were said to be the main participants at the feasts.
Collinge’s team set out to study the genetic effect of the disease on the Fore population. From studies of people in the UK infected with variant CJD, they knew that some people are more likely to contract the disease than others. Was this the case with kuru too?
The basis for differences in susceptibility to vCJD is that there are two forms of the gene that codes for the prion protein. They differ by a single amino acid – one form codes for the amino acid valine, the other codes for methionine. For reasons that are not well understood, people with one of each type, known as heterozygotes, seem to be more resistant than homozygotes – people who have two of the same form, whether they code for valine or methionine (Nature, vol 352, p 340).
Collinge’s team analysed the genotypes of a large group of Fore people and compared the data with 1000 other genotypes, representing different ethnic groups from around the world. Their first discovery was that more than three-quarters of Fore women over the age of 50 were heterozygotes. Statistically this is much, much higher than would be expected. Mead and Collinge proposed that because the Fore were exposed to kuru through cannibalism, the population was subjected to evolutionary pressure to preserve both variant genes.
If true, this would be a rare instance of what is known as balancing selection. For most genes one version is slightly better than another and so variants tend to disappear over evolutionary time. Only occasionally do two or more variants persist in a population: the best example is the haemoglobin gene, which has several variants that, singly, offer a degree of protection against malaria. The downside is that having two copies of one of the variants causes sickle-cell anaemia or thalassaemia.
But the bigger discovery was still to come. When Collinge analysed DNA samples from ethnic groups around the world, he discovered that the Fore weren’t alone. Heterozygotes are found in every population, suggesting that the rest of us have also been exposed to balancing selection to preserve both variants of the prion gene in the population. In other words, all human populations have inbuilt resistance to prion diseases.
What has given us this resistance? It is of course possible that the selection pressure came from eating infected animals. But Collinge believes that the most plausible explanation is that our ancestors were cannibals. The implication is that, rather than being an aberration, cannibalism was widespread in traditional human societies.
It’s a conclusion that Arens maintains is fundamentally flawed. “There is no evidence that the Fore were cannibals,” he says, “This whole study is based on a practice that never existed. It was never witnessed.” Arens reckons the more likely explanation for kuru is that it was contracted when pigs were fed on other pigs before being eaten by humans, in much the same way that feeding cows to cows led to the BSE epidemic and, ultimately, vCJD. However, there is scant evidence for his claim.
For White, meanwhile, the biochemical and genetic studies vindicate what he has been saying for years. “The question now is not did cannibalism happen,” he says, “but why did it happen?” If cannibalism was widespread, it would suggest the consumption of human flesh went beyond merely nutritional necessity, also known as survival cannibalism. In his book The Buried Soul (Fourth Estate, 2002) Taylor suggests any number of reasons, some more unsavoury than others. For example, it could be aggression, spirituality or even for pleasure.
Despite the new evidence, however, the unsettling conclusion that our ancestors regularly consumed human flesh is something that many people will still find hard to accept. Taylor reckons there’s a taboo to overcome: people simply don’t want to believe. Perhaps that’s no great surprise. After all, it’s not too big a leap from accepting our cannibal legacy to believing the chilling statement that Meiwes made to the police after his arrest: “There are about 800 cannibals in Germany.”