Snakes – Natural histories of extraordinary species that changed our world
Venom and Antidote
The snake makes his first appearance in the Bible in the third chapter of the Book of Genesis; and it would be fair to say that he doesn’t make a very good impression: ‘Now the serpent was more crafty than any of the wild animals the Lord God had made. He said to the woman, “Did God really say, ‘You must not eat from any tree in the garden’?”’
Using all his arts of persuasion, in Adam’s absence, the crafty snake coaxes Eve to take a bite of the forbidden fruit. She does so, and as a result Adam and Eve – and the whole of the future human race – are cast out of the Garden of Eden. It all goes downhill from there. Eve blames the serpent for deceiving her, and from that moment on, the sly and sinister snake takes the blame for our Fall from Grace, and will for ever be considered untrustworthy and – for many – evil. The wrathful Old Testament God leaves us in no doubt as to how we should regard these duplicitous creatures:
Cursed are you above all livestock
and all wild animals!
You will crawl on your belly
and you will eat dust
all the days of your life.
And I will put enmity
between you and the woman,
and between your offspring and hers;
he will crush your head,
and you will strike his heel.
But perhaps this version of the story isn’t quite as cut and dried as it might at first appear. Richard Kerridge is a nature writer and lecturer at Bath Spa University, who has a lifelong fascination with reptiles, especially snakes:
In that story there is a deep ambivalence, because the Fall was a catastrophe that produced a world dominated by Original Sin. Because of the Fall, human beings became mortal, capable of evil and treachery, and subject to the randomness of fate; but because of it they also became creatures that could be responsible for their own redemption, their own salvation from damnation. And without the Fall there would have been no intercession by Christ. So paradoxically the snake is at once an object of terror and loathing and one of gratitude. And thus our ambivalence about our whole condition then focuses on the snake, and becomes our ambivalence about snakes.
Nevertheless, this story has had serious consequences: in many cultures it’s considered sensible to kill any snake on sight. Snakes are among the most persecuted creatures on earth: during the pioneering conquest of the Wild West in nineteenth-century North America, rattlesnakes were virtually wiped out.
Even when we don’t subscribe to snake genocide, the word is always used in a loaded way: from expressions such as ‘snake in the grass’ (a metaphor first used, incidentally, by the Roman poet Virgil) to ‘snake-oil’, meaning a fraudulent health product or unproven medicine. Comparing someone to a snake is almost always an insult, unless, of course, you are referring to their hips or sinuous dancing. But as with the serpent in the Garden of Eden, it’s not always as black and white as that.
One case in point is one of the most popular and enduring children’s board games, snakes and ladders. The premise of the game is simple: it’s a race to get to the end. The board is a grid of squares with snakes and ladders on them. Each player throws the dice in turn, and if they land on a square with the bottom of a ladder on it, they go up it; but if they land on a snake’s head, they slide all the way down its body to the tail. The moral couldn’t be clearer: good children succeed and are rewarded; naughty ones fail and are not. The early versions of the game, which first appeared in Britain towards the end of Queen Victoria’s reign in 1892, made this message much more explicit. The vices of Cruelty, Covetousness, Unpunctuality and Avarice were written on the snake squares, and the virtues ranging across Patience, Kindness, Forgiveness and all the way to Self-denial were on the ladder squares, often accompanied by self-explanatory illustrations. Catherine Howell, the Collections Manager at the Victoria and Albert Museum of Childhood, explains the rationale behind the design of the board:
Victorian morality at the time is shown really well: Pride coming before a Fall is portrayed as a man in a top hat walking along with a peacock behind him (as a symbol of Pride); and going all the way down the snake, he has literally fallen over, as the peacock flies away. [At the top of another snake] you have a little child being selfish by eating an extra slice of cake; and you go down that snake and the child has ended up at the bottom with toothache.
However, it turns out that as usual the Victorians were borrowing the idea from elsewhere and that the game is very old indeed. The original Indian game – hence all those snakes – was played by adults, not children; and before the nineteenth century it did not feature ladders, instead showing two kinds of snake: good and evil. Under the name Moksha Patam, it has been played in India for hundreds of years. It too was a moral exercise that was designed to make the players aware of the role of karma or fate. Both the Hindu and Jain religions had their own separate versions.
Deepak Shimkhada is Professor at the Claremont School of Theology in California:
The idea of such a game existed perhaps at the time of the Buddha [between the sixth and fourth centuries BC], but since then, over the centuries it has had many modifications. The black snake – a cobra – stands for evil, and if you land on its head the snake swallows you and you end up at its tail, whereas the red snake, or naga (a mythical serpent), brings goodness, prosperity and good luck, and is worthy of worship. So it serves as a ladder.
The Indian version also had a higher purpose: Moksha Patam was used as a tool for teaching the effects of good deeds versus bad. The board was covered with symbolic images, the top featuring gods, angels and majestic beings, while the rest of the board displayed pictures of animals, flowers and people. The morality lesson of the game was that a person can attain salvation (moksha) through doing good, whereas by doing evil one will be reborn into a lower form of life. The number of red snakes was less than the number of black as a reminder that a good path is much more difficult to tread than a path of sins. ‘The game was to measure one’s level of karma, like a measuring rod. Someone who has good karma would be able to reach his destination, and those with bad karma would not be able to progress and obviously would be the losers. It’s a karma barometer,’ says Deepak Shimkhada.
By the nineteenth century the good snakes had been replaced by ladders – perhaps because to our Victorian forebears, the idea of a ‘good snake’ was something they couldn’t understand – and the game appealed to the sturdy Christianity of the British colonials stationed in India. They saw it as a Game of Life: if you behaved badly you slid down the snakes to hell; but if you behaved well you went straight up to heaven.
Snakes and ladders is not just an enjoyable way to pass a rainy afternoon, or to improve your moral tone; it also fascinates mathematicians because previous moves have no influence on current and future ones – unlike chess or draughts – the odds of moving to the next square being fixed and finite. On average, on a board with 100 squares and nineteen snakes or ladders, a player will take about forty moves to reach the last square. And the first player also has a marginal advantage – they are likely to win 50.9 per cent of the time.
One feature of snakes and ladders – the ability to be close to victory and then go right back to the beginning by landing on the head of a snake – is thought to have introduced the phrase ‘back to square one’ into the English language.
The original version of snakes and ladders highlights the complex relationship we have with snakes. They can be both good and bad, evil and helpful, in our journey through life; and this duality slides through our culture and winds its way – rather like a snake itself – through art, literature and religion. Time, perhaps, to take a closer look at the reality – rather than the myth – of snakes.
Snakes are long, legless, carnivorous vertebrate animals that, together with lizards, belong to the order Squamata, or ‘scaled reptiles’. There are almost 3,000 different species, found on every continent bar Antarctica, and from the Arctic Circle to the southern part of South America. They can live at below sea level, in the case of the world’s sixty or so species of sea snakes, which live in the Pacific and Indian Oceans, and as high as 4,900 metres above sea level, in the Andes and Himalayas. They are, however, absent from many islands, including New Zealand, Iceland and famously Ireland, due to the inability of terrestrial snakes to swim across even narrow stretches of sea, rather than because kindly saints like St Patrick banished them.
They are known to have evolved from lizards; but there is some controversy as to which route they took: were their ancestors burrowing lizards, found on land, or did they evolve in the sea, from marine lizards? At present the jury is out, but we do know that they first appeared on earth roughly 150 million years ago, during the Jurassic period, and began to diversify into the different groups we see today around 60 million years ago.
Snakes can still be confused with legless lizards such as the slow-worm, but have several key differences, including their inability to blink – a snake’s eyes are always open. Their exterior is made up of a series of tightly overlapping scales, creating what appears to be a smooth surface. Their bodies have several crucial adaptations as a result of their unusually elongated shape: notably organs such as their kidneys are not placed side by side but one in front of the other; they completely lack front limbs and have only rudimentary ‘spurs’ instead of hind limbs; and their skeletons are basically a long, extended ribcage, with up to 400 vertebrae. They lack external ears and, instead, detect vibrations from the ground via their jaws. Most famously of all, snakes have an incredibly flexible jaw structure, enabling them to open their mouths wide enough to swallow prey much larger than you would imagine – usually live and whole.
Snakes vary considerably in size. There is the tiny Barbados threadsnake, a blind, wormlike creature endemic to that Caribbean island, whose adults measure just 10 centimetres long. At the other end of the scale two species vie for supremacy: the reticulated python of South East Asia, which can reach a length of almost 7 metres; and the South American anaconda, which although ‘only’ 5.2 metres long, tips the scales at almost 100 kilos. But these are dwarfed by the largest snake that ever lived: Titanoboa cerrejonensis, which roamed South America about 60 million years ago, and was 13 metres long.
Today’s snakes are excellent hunters, using their acute sense of smell to track down their prey; and then their forked tongue to both taste and smell, and to work out the direction of their victim. Although their eyesight differs a great deal between species, some snakes (such as rattlesnakes) have a very special sense: the ability to perceive infrared rays through special receptors on their upper lips, enabling them to detect the heat given off by any potential prey – a useful asset given that many snakes hunt after dark.
Being constantly in contact with the ground means their skin needs to be both tough and flexible; hence the need for snakes to shed their skin from time to time – up to four times a year for some individuals, and even more frequently for baby snakes.
The most obvious characteristic of snakes – one that every child knows – is their venomous bite. Except that the majority of snakes are not venomous; and even those that are, do not habitually attack or bite humans – the venom is normally used to paralyse their prey. Non-venomous snakes either use constriction techniques to kill, or, if their victim is small enough, swallow it alive.
Yet sufficient numbers of snakes are venomous to explain the long-running enmity between people and snakes. This distrust isn’t purely a cultural artefact: modern psychological research has shown it is hard-wired into our neurones too. Gordon Orians is a Professor of Biology at Washington State University:
It’s not surprising that we have an inborn fear of snakes, because until fairly recently our ancestors lived in small hunter-gatherer groups, and were in constant contact with nature, 24 hours a day and 365 days a year. They had to deal with the many challenges that nature posed; and among the challenges were dangers – things that could hurt us. Throughout the history of primates snakes have been a very important cause of mortality, and in areas of the tropics they still are today. So learning how to detect and avoid snakes would have been very important for our ancestors.
We are not the only species hard-wired to fear snakes: monkeys raised in captivity, that have never seen a snake, show extremely strong responses when they are confronted with one. Human eyesight even shows a special sensitivity to that distinctive tessellated pattern along the backs of many snakes – a pattern very rare in the rest of nature.
It is of course sensible to avoid snakes, especially those that may be venomous: about 720 species worldwide, of which roughly one-third can kill a human with a single bite. Although the number of human deaths from snakebites is mercifully rare in the developed world, the same is not true elsewhere. In India alone it is thought that as many as 50,000 people die each year from snakebite.
The vaults of the Natural History Museum contain millions of preserved animals, including the head and gaping jaws of an African Gaboon viper. According to Ronald Jenner, researcher in the Department of Life Sciences, among herpetologists this particular snake is renowned for having the largest fangs and injecting the most amount of venom into its victim:
If you look at the animal you can already infer something about its biology: it looks like a dried leaf, pale with darker brown spots; and this is perfect camouflage for when the snake lies in wait for its prey on the forest floor. It’s actually quite docile, and can spend a lot of time without moving; but then when the prey comes near, it strikes in the typical manner of snakes, with its mouth wide open, with its two very large fangs – about 5 centimetres long – through which the snake injects its venom.
Rather than paralysing, the venom of the Gaboon viper works differently: once the prey is bitten it starts to bleed internally, the blood vessels relax, and its blood pressure drops very rapidly. This causes shock, and that’s how the snake prevents its victim from escaping. The other difference with this species is that unlike most snakes, which bite their prey and then let go to avoid being injured as the victim struggles, the Gaboon viper keeps a tight hold with those fearsome fangs, until its quarry finally becomes immobile and is ready to eat.
It’s a gruesome – though fairly quick – death, but as well as providing a suitable horror story to terrify newcomers to the African bush, the effect of the snake’s venom is also of great interest to scientists. Venom is a highly complex cocktail of different chemicals, all of which do specific damage to the body. And in a neat reversal of expectations, this can be harnessed to save life as well as cause death, as Ronald Jenner explains:
Venom components have been shaped by evolution to do one specific thing very carefully – for instance they will knock out one pathway, with which two nerve cells communicate, with almost no side effects. Those abilities can be exploited to develop drugs; and there are already several different drugs derived from snake venom available, and being used for treatment for blood clots, and also for the opposite use, to stem bleeding during operations. So snake venoms have been developed into very useful tools.
Venom from all kinds of animals, not just snakes, is now used in medicine to control pain, to slow the heart rate, to treat cancer and lower blood pressure. Snake venom is even used in anti-wrinkle cream, because it can stop the skin from contracting.
The connection between snakes and health is not a modern phenomenon. The Rod of Asclepius – showing a snake wrapped around a long staff – has been the symbol of healing for over 2,000 years. Asclepius was the Greek god of healing, and he had two symbols: the snake and the staff. The staff represents support, helping someone to walk; the snake, knowledge – and if you think about the serpent in the Garden of Eden you can understand that in classical times the snake was very much associated with the acquisition of knowledge. It’s also an animal that sheds its skin and so can rejuvenate itself. So when you put those two together – the rod and the serpent – they have come to symbolise medicine.
In classical Greece, temples established in the name of Asclepius became centres of healing – you might even call them the first medical schools – and Hippocrates was a graduate of one of them. But aside from being places where people went to be healed or learn about healing, the temples would also have been places where, because of their symbolism, snakes would be allowed to live and roam free. There is even a species of snake in the eastern Mediterranean called the Asclepian snake, named as a result of this tradition.
Oddly, the Asclepian (or as it is sometimes known, the Aesculapian) snake can be found living wild in the middle of London: along the banks of the Regent’s Canal near London Zoo, where a small, self-sustaining population was released and became established during the 1980s. Fortunately for passing Londoners, this particular species of snake is not venomous, but is a constrictor, squeezing the breath from its victims; so apart from striking terror into the local rodent population, it does no harm.
Since the time of ancient Greece the symbolism of the Rod of Asclepius has spread globally; a process that began when Alexander the Great conquered much of Asia, carried on through the Roman Empire, and continues to this day. The symbol crops up in many places, with hundreds of different organisations – including the British Medical Association, ambulances and some commercial pharmacy chains – using it as an instantly recognisable shorthand for medical care.
Despite these benevolent associations, snakes continue to terrify most people, as the success of the 2006 action thriller movie Snakes on a Plane, starring Samuel L. Jackson, bears witness. The plot, as anyone suffering from ophidiophobia (a fear of snakes) would appreciate, is pretty terrifying: hundreds of these venomous creatures are released on a passenger plane in an attempt to kill a witness to a crime. Although highly exaggerated, the film is loosely based on a real event, when Indonesian brown tree snakes (one of those species that is venomous but not enough to threaten humans) climbed aboard a cargo plane during the Second World War.
J.K. Rowling used snakes as a dark theme throughout her Harry Potter novels. Voldemort, the villain so terrifying that most characters refer to him as ‘You-Know-Who’ rather than dare say his name, has a special affinity with snakes and is one of the few characters who can speak their hissing sibilant language, Parseltongue. D.H. Lawrence, a poet and novelist never afraid of celebrating a phallic symbol, wrote a fascinating poem that explores our contradictory relationship with snakes. Lawrence is mesmerised by the majesty of a snake – which he comes across by chance on a hot summer’s day in Sicily:
He lifted his head from his drinking, as cattle do,
And looked at me vaguely, as drinking cattle do,
And flickered his two-forked tongue from his lips, and mused a moment,
And stooped and drank a little more,
Being earth-brown, earth-golden from the burning bowels of the earth …
While Lawrence is intellectually fascinated by the snake, he cannot override his teaching that it is his ancient enemy:
The voice of my education said to me
He must be killed,
For in Sicily the black, black snakes are innocent, the gold are venomous.
Lawrence is unable to go through with actually killing the reptile, and ends up throwing a log in the water-trough where the snake is drinking to scare it away:
And immediately I regretted it.
I thought how paltry, how vulgar, what a mean act!
I despised myself and the voices of my accursed human education.
So what is it that the snake represented that made Lawrence’s educated self want to kill it? Sometimes this is interpreted as being about sexuality, about a kind of innocent joy in sexuality that is suddenly interrupted by fear and a kind of panic-stricken recoil. But it doesn’t only have to mean that. Perhaps what Lawrence is also looking for is some sort of world in which we really do not need to be dominated by our very traditional attitudes towards these creatures; by the old morality play that we traditionally impose upon the non-human world. Richard Kerridge argues that we should understand it differently: we can see a snake as part of its environment, as another manifestation of life, an essential part of the whole ecosystem; we can even find it beautiful. Lawrence says, ‘I missed my chance with one of the lords of life’, and that phrase returns the snake to being regarded as an amazing natural phenomenon rather than representing it as a villainous, treacherous outsider as it has so often been portrayed.
Although we have an inbuilt fear of snakes hard-wired into our brains, we do have a choice as to how we respond to that fear, as Gordon Orians explains:
There certainly is a tremendous variability in how strong the snake fear is: some people have it very powerfully, while others have it very weakly. But this is not surprising: we are a sexually reproducing, highly variable species, and so any particular trait can also be highly variable – anyone who has raised kids knows this – and that’s the way it is with every response that we have.
So while many people – probably the majority – are fearful of snakes, at the other end of the scale are a few who simply love them. For these rare ophidiophiles, snakes are simply beautiful, compelling creatures they have to get close to. Nigel Marven, naturalist, animal-wrangler and TV presenter, is one such person, who has kept snakes since he was a child. His enthusiasm for his favourite snake, a four-year-old bull snake named Bully, is infectious:
This is a magnificent snake: I’ve had him since he was a tiny hatchling, and he’s now longer than I am tall – nearly 2 metres. He’s been specially bred for his colour: he has lovely pink blotches, and orange scales – he really is one of my favourite pets. They are so beautiful: when I was a boy and kept my first snakes as pets I used to admire their patterns, as every snake seems to be different; they really are things of beauty.
So whether you are terrified or passionate about snakes, one thing cannot be denied: that since Eve was first tempted by the serpent in the Garden of Eden, these fascinating creatures have wound their way intricately through our lives.
yes, in spite of all,
Some shape of beauty moves away the pall
From our dark spirits. Such the sun, the moon,
Trees old and young, sprouting a shady boon
For simple sheep; and such are daffodils
With the green world they live in;