For two hours we watched them. They were enormous and they walked on their hind legs. Their faces I could not see in detail, but the heads were squarish and their ears must lie close to the skull because there was no projection from the silhouette against the snow. The shoulders sloped sharply down to a powerful chest and long arms, the wrists of which reached the knees. The nearest I can get to deciding their colour is a rusty camel. They were covered with a long loose straight hair. They were doing nothing but moving around slowly together and occasionally just standing and looking about them, like people admiring the view.
This graphic description of a close encounter with a pair of yetis in western Nepal comes from the journal of Slavomir Rawicz, a Polish army officer who escaped from a Siberian prisoner-of-war camp in 1941. He and six companions trekked over four thousand miles across tundra and desert before crossing the Himalayas, where they encountered the yetis, before finally reaching safety in India.1
Like many of us, I am thrilled by tales like this from faraway lands. Tales of creatures, half-man, half-beast, that roam the high peaks or survive in the densest jungles. I wasn't sure I believed them, but neither was I ready completely to dismiss them. There could be something ‘out there’.
I have spent my professional life as a scientist, most of it in Oxford, where I specialised in using DNA to explore various aspects of the human past. In particular I have used DNA to work out how our ancestors spread across the planet, when and where they came from and what routes they took. As well as publishing my research in conventional scientific journals, I have written four books which cover the main areas for general readers. The Seven Daughters of Eve, published in 2001, concentrates on tracing our ancestry using the maternally inherited mitochondrial DNA, which also features heavily in The Yeti Enigma. Other books focus on the paternally inherited Y-chromosome and the evolution of sex (Adam's Curse, 2003), on genealogy and the genetic history of Britain and Ireland (Blood of the Isles, 2006) and America (DNA USA, 2012). I mention these titles in case readers want fuller details of some of the technical aspects that we are going to cover here, though let me reassure you that it is certainly not necessary to have read any of them to follow The Yeti Enigma.
I have always been curious about other human species, like the Neanderthals, that we know lived alongside our Homo sapiens ancestors. I wondered what happened to them. Did they become extinct, as most authorities believe, or do they live on as creatures such as Rawicz describes? Until very recently this was an absurd notion, but scientific developments over the last few years, which I shall describe, have come some way to making this less of a whimsical fantasy and more of a realistic possibility.
As I began to think seriously about making a scientific investigation in this area, I was frustrated by how little of any value had been published. I read the regular reports in the newspapers about mysterious remains being sent away to un-named laboratories for DNA testing but these were hardly ever followed up, and certainly never published in scientific journals in such a way that I could scrutinise the results.
As I read more, I also discovered a worrying undertone. In almost every book written by cryptozoologists, as those who study creatures ‘unknown to science’ are called, I encountered the complaint that they had been ‘rejected by science’. As a scientist, I knew very well that science does not reject anything out of hand. Science is a way of trying to make sense of the world that relies on evidence. As such science is, at heart, a branch of philosophy, which is the reason practitioners qualify as PhDs – Doctors of Philosophy. Science is a philosophy based not on opinion or subjective judgement or orders from a higher authority or from God, but on evidence. I felt as though my profession was being unfairly accused by the community of cryptozoologists.
For a mixture of these reasons, I set out to explore what I call the yeti enigma using the standard approach of my profession. I would gather genetic evidence for the existence of ‘anomalous primates’, as yetis, Bigfoot and others are collectively known, have a close look at it and, importantly, try to publish what I found in a mainstream scientific journal. I was strongly of the opinion that, bizarre though such a project might appear to be, it did not lie outside the scope of scientific enquiry.
There are many good reasons for doubting the claims of the yeti-hunters. No body has ever been found and fully examined. There are no completely convincing films or photographs of these creatures, even nowadays when superb footage of extremely rare animals is on our television screens at regular intervals and everyone has a mobile with a built-in camera. And yet eyewitness reports of these creatures still come streaming in. Are these all the invention of vivid imaginations, phantasms of the mind of the harmlessly deluded or just plain fraud? In August 2012, forty-four-year-old Randy Lee Tanley, dressed in a monkey suit, was run over and killed on Highway 93 near Kalispell, Montana when he jumped out in front of a car. How many times had his dangerous antics triggered a new report of a sasquatch sighting from a bewildered and frightened motorist?
What would it take to convince us all of the almost miraculous existence of these creatures? In Scotland, Edinburgh's Royal Mile runs up a gentle slope in the Old Town between the Palace of Holyroodhouse and Edinburgh Castle. About halfway up is the seated bronze statue of the eighteenth-century philosopher David Hume. His big toe protrudes beyond the stone plinth and is polished by the touch of tourists flowing constantly up and down the hill. I doubt many of them know much about David Hume, apart from his irresistibly tangible hallux. Hume agonised over the existence of God and wrote an influential essay ‘On Miracles’ which sets out what it would take for him to believe in one. After insisting on multiple eyewitness accounts and other criteria, he summarises the level of proof required to convince him and, by implication, all those with a rational mind:
No testimony is sufficient to establish a miracle, unless the testimony itself be of such kind that its falsehood would be more miraculous than the fact which it endeavours to establish.
In other words, the proof would need to be so convincing that for it not to prove the miracle would itself be miraculous. That seemed like a good standard to aim for in my examination of the yeti and Bigfoot evidence. If I had doubts, then I only had to imagine myself presenting each piece of evidence to David Hume for his opinion on its value.
Hume also clearly recognised in his essay that rationality and human nature do not always agree when he wrote:
With what greediness are the miraculous accounts of travellers received, their descriptions of sea and land monsters, their relations of wonderful adventures, strange men and uncouth manners? . . . The avidum genus auricularum, the gazing populace, receives greedily without examination whatever soothes superstition and promotes wonder.
He could have been writing about yetis. I see close similarities between the level of proof he insists upon for miracles, given the fanciful inclinations of human nature ranged against reason, and what most of us would need before we believed in yetis or sasquatch or any other anomalous primate. A live capture, a thoroughly investigated body, possibly even a good-quality, unadulterated film or photograph might be enough. But in their absence is there anything else capable of providing such high levels of proof? It is my belief that DNA, if used properly, does have that capability. It cannot be forged, so far as I know, and with the results independently verified, would, I am fairly certain, satisfy even the great philosopher.
This adventure was not my first excursion into the world of anomalous primates. In 2000, I had received three hair samples in my laboratory from the remote Himalayan kingdom of Bhutan. They were from the migoi, the Bhutanese equivalent of the yeti. I had been asked to identify the migoi hairs using modern DNA analysis, in much the same way that I had used these techniques for many years to explore the human past.
The migoi hairs did not surrender their secrets easily, but eventually two of them were identified as known species of bear. The third remained a mystery. There was DNA, but I could not identify the creature it had come from. The migoi project was a sideline, an amusing distraction from the main work of the laboratory. The unused migoi samples joined the thousands of others in the freezer and we carried on with our mainstream research into human origins. But I never completely forgot about the migoi.
Ten years later, two scientific developments caused the migoi to bubble up into my thoughts once again. The first was purely technical. Our main difficulty in getting DNA from the migoi hairs had been that there was very little of it in the first place. Only the hair follicle, the root, contained enough DNA for analysis using the lab protocols of the time. Between then and now the protocols have improved a lot, so that these days an intact follicle is no longer necessary, and I found that I could get a very good DNA signal from a single hair with no root attached. This proved to be the technical breakthrough that made this current project feasible.
The second development was more intellectual than technical and arose from the surprising conclusion of a paper published in the journal Science in 2010. This article contained details of the DNA sequence from the fossilised remains of another human species, a Neanderthal, widely thought to be extinct. By comparing the Neanderthal DNA sequence with that of modern humans the researchers had concluded that the genomes of Europeans and Asians, but not Africans, contain a small amount of Neanderthal DNA. The explanation offered was that the ancestors of Europeans and Asians had interbred with Neanderthals. This conclusion supplied an intellectual focus for examining the notion, popular among cryptozoologists, that small groups of Neanderthals had somehow managed to survive in remote forests and mountains until recent times, or maybe even to the present day.
While scarcely guaranteeing success, these two developments – the technical ability to identify the species origin of any hair sample from a single shaft, coupled with the strong intellectual case for interbreeding – persuaded me that I now had the tools to do some proper science in what most scientists, for reasons we will explore later, regard as a taboo field. I certainly would not have contemplated getting involved in this work any earlier in my career. Now I am less concerned about what other people think, and have the freedom to explore avenues of research that would have been foolish when I was younger.
Let me be completely clear. I deliberately did not set out to find the yeti. Instead I set a goal to locate and analyse as many hair samples as I was able that had been attributed to anomalous primates, in particular to the Himalayan yeti, the Bigfoot/sasquatch of North America (I use the term interchangeably throughout), the Russian almasty and the diminutive orang-pendek of Sumatra.
In doing so, I found myself entering a strange world of mystery and sensationalism, fraud and obsession and even, at times, the supernatural. I felt safe in doing so only because I was protected by the ruthless rigour of genetic analysis. I was ready to listen to the stories of enthusiasts and eccentrics, liars and lunatics, without having to form an opinion. The only opinion that mattered belonged to the DNA. I certainly met some extraordinary characters along the way, many of whom you will meet later on – people who have spent their lives looking for these creatures and are utterly convinced of their existence. Any doubt is tantamount to heresy and at least one website devoted to Bigfoot has adopted this quotation from the American economist and social theorist Stuart Chase as their mantra.2
For those who believe, no proof is necessary.
For those who don't believe, no proof is possible.
The distinction between this and Hume's rationalism could not be more stark.
Cryptozoologists are the unrepentant advocates for one face of the yeti enigma, with plenty of ‘evidence’ to back their claims. On the other are the all too obvious holes in their argument and the glaring absence of a single piece of evidence that is universally convincing and accepted. This is the enigma I set out to explore.