But that’s the mare’s tale. What about the stallion’s? It turns out they have a completely different story to tell. The anthropologist David Anthony describes horses as ‘genetically schizophrenic’. Maternally inherited mitochondrial DNA suggests that modern, domestic horses come from a great variety of wild female ancestors. The mitochondrial genetic diversity of horses is prodigious – and very unusual compared with other domesticates. But the paternally-inherited Y chromosome records only a very few wild, male antecessors.
The discrepancy between mitochondrial and Y chromosome data may – to some extent – reflect natural breeding patterns. Both Przewalski’s horses and feral horses operate in harems. This seems to be the natural state of things in horse society: polygyny is the norm, with one, dominant stallion presiding over a herd of mares and foals. Young males leave the herd and hang around in bachelor groups for a few years before they attempt to form their own harems – either by stealing mares from other stallions, or fighting to take over an existing harem. And so the genetics of modern horses may reflect social and reproductive patterns which are natural in horse populations.
But actually this isn’t enough to explain the stark contrast between the variation seen in mitochondrial lineages, compared with the Y chromosome. This pattern strongly suggests that many more mares were domesticated than stallions. To me, this makes so much sense. Stallions are, by their nature, feisty, independent, even dangerous. It would always have been difficult to find a young, male wild horse that wouldn’t go crazy, throw you off, kick you in the head. Mares are naturally more docile. If you’re a herder looking to catch and tame a wild horse, you’ve got a much better chance with a mare. So it’s not surprising that, historically, more wild mares than wild stallions were caught and tamed. But whilst mares were easier to tame, at least one stallion would have been needed for successful breeding. That’s basic biology.
Looking at the DNA of modern horses, however, there are missing parts to the puzzle. You don’t know where and when particular lineages were added to herds of domesticated horses, and you don’t know how much past diversity has been lost over time. Ancient DNA – extracted from age-old bones – provides much more depth to the story. Towards the end of the Ice Age, there was a large, genetically connected, population of wild horses ranging from Alaska to the Pyrenees. By 10,000 years ago, the North American horses had disappeared, and the population on the Eurasian Steppe had become separated from the one in Iberia. The latest genetic studies also reveal that Y chromosome diversity has been lost over time – giving us the mistaken impression that only a few stallions were ever domesticated.
While ancient and modern DNA is consistent with horse domestication starting in the western Eurasian Steppe, in the Copper Age, it also shows maternally inherited, mitochondrial DNA – from wild mares – entering domestic herds again and again, as domestic horses spread across Europe and Asia. More wild mares were caught and domesticated in the Iron Age, and again in the Middle Ages, adding their wild genes to the already domesticated herds.
A few maternal lineages found in ancient, pre-domestic Iberian horses – walled off from the rest of Europe by the Pyrenees – found their way into the domestic stock, and are still there in some Iberian breeds today, such as Marismeño, Lusitano and Caballo de Carro. As it was the Spanish who reintroduced the horse to South America, it’s not surprising that this ancient Iberian signature also turns up in South American breeds, such as the Argentinean Creole and Puerto Rican Paso Fino. But it’s also found in some French and Arabian horses, probably reflecting ancient trade between Iberia and France, and the close connections between Spain and North Africa. In China, most of the mitochondrial DNA lineages point to domestic horses spreading to East Asia from further west – but then with a few lineages being added from local, wild populations.
Rather than multiple, independent centres of domestication, the picture that’s now emerging is one of domesticated horses spreading from their original homeland in the steppes – but with plenty of wild mares being added to the existing domestic herds along the way, and through history. So it wasn’t just a spread of an idea and a new technology after all – it was a spread of horses, too.
Like other domestic species, the story doesn’t stop there. Selective breeding has promoted certain traits while suppressing others. Just as with dogs, cattle and chickens, strong artificial selection, brought about by strict breeding regimes, has operated over the last two centuries to create the range of modern breeds we know today. But selection was happening way back in the past, too. Small horses, built for speed and agility, were favoured for pulling light chariots – a Bronze Age invention – while the Iron Age Scythians bred larger horses, selecting for endurance in some, and speed in others. Medium-weight horses were pressed into battle service pulling wagons and, later, artillery. By the Middle Ages, draught horses had become massive, weighing up to 2,000 pounds.
Some traits which appear in our modern breeds were already there in pre-domestic horses. The horses running across the walls at Lascaux are brown and black – these could easily have been naturalistic coat colours. The spottiness of the horses at Pech Merle has been suggested to be rather imaginative, perhaps symbolic, even psychedelic – fitting in with the abstract spot patterns that appear around the horses. But on the other hand, the dappling of the Pech Merle horses looks very much like the ‘leopard’ pattern of coat seen in some modern breeds, such as Knabstrupper, Appaloosa and Noriker. The genetic basis of this ‘leopard’ pattern is well known – it’s down to a particular variant or allele of the LP gene on horse chromosome 1. Geneticists screened DNA from a range of thirty-one pre-domestic, ancient horses from Europe and Asia to see if they could pick up this variant. None of the Asian horses had the LP allele, but it was there in four out of the ten western European horses they looked at. There’s definitely some artistic licence at work in Pech Merle – the horses have particularly tiny heads and spindly legs – but the dappled pattern could easily represent the real-life appearance of Ice Age horses, copied straight from nature. It also seems to have been a characteristic which was particularly favoured by some early horse breeders – the LP gene turned up in six out of ten horses from a Bronze Age site in western Turkey, for instance.
Up in northern Siberia, it’s been suggested that Yakutian horses might have interbred with local, wild horses – imbuing them with key physiological and anatomical characteristics which allow them to survive in subarctic conditions. These horses are compact, with short legs, and they’re also incredibly hairy. But in this case, genetic studies of ancient and modern Yakutian horses have revealed no particular connection between them. The modern horses of Yakutia seem to have been introduced in the thirteenth century CE – and they’ve adapted extraordinarily quickly to a cold environment. Such rapid changes in genes related to hair growth, metabolism and blood-vessel constriction (to lessen heat loss at the surface of the body) must have been crucial to survival. Amongst domestic horses more generally, other genes that show evidence of having been positively selected for in the past appear to relate to changes in the skeleton, circulatory system, brain – and behaviour.
There are some fascinating elements of behaviour that horse owners may have known about, or at least suspected, for a very long time – and which scientific studies are just beginning to elucidate. Evidence suggests that cats and dogs are able to understand human emotions, expressed both physically and vocally. Dogs really do seem to understand what a happy human face looks like. It’s known that horses themselves make facial expressions, and that they can recognise emotions in another horse’s face. In a recent study, horses were shown pictures of men making angry, frowning faces and happy faces. The heart rate of the horses tended to increase more when they were looking at an angry face, compared with a smiling one. If this means that horses really do read human emotions, there are a few explanations for this ability. It could be that horses, having been able to interpret expressions on other horses’ faces for a very long t
ime, started to be able to do the same with humans after they were domesticated. Or it could be something that horses learn to do during their lifetimes, associating other cues indicating angriness with an angry human face, for instance. This could still stem from an inbuilt predisposition to inferring emotion from physical appearances, inherited from their wild ancestors.
Another recent, carefully constructed study showed that not only are horses able to interpret our behaviour, they attempt to influence it as well: some gestures made by horses really do seem to be an intentional form of communication. Horses were seen to stretch their necks, pointing their heads towards a bucket full of food they liked, but could not reach. They’d look at the human experimenter, then ‘point’ at the bucket, then look at the experimenter again. If the experimenter walked away, they’d stop. When the experimenter walked towards them, they’d alternate their gaze more frequently. The horses also used nods and shakes of the head to get attention. It suggests that horses not only wish to communicate, they recognise humans as capable of receiving communication. It’s unlikely that horses have evolved to be able to do this over just a few thousand years of being domesticated, but it’s also unlikely that it’s innate. Instead, horses are probably predisposed to learn this sort of behaviour, through interacting with other horses – and now humans as well – in their social environment. So whilst the behaviour isn’t innate, the tendency to develop it is. Being naturally sociable animals, much like dogs, meant that horses were well suited to teaming up with another, sociable animal. They’ve made good allies, ever since the Copper Age, when the horse-hunters of the Pontic-Caspian Steppe became horse-riders. They became fellow-travellers – but it wasn’t only humans that they were carrying. The beginning of the diaspora of our next domesticated species started with the saddlebags of travellers along what would become the western end of the Silk Road. Stuffed into those saddlebags were fruits for the journey – apples.
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APPLES
Malus domestica
Wassail! wassail! all over the town,
Our toast it is white and our ale it is brown;
Our bowl it is made of the white maple tree;
With the wassailing bowl, we’ll drink to thee.
Gloucestershire wassail
Wassailing
It’s late January, and a cold evening in north Somerset. A small crowd of people gathers in an orchard. Bare twigs stretch up into the night sky. Ice crystals are already crunching underfoot. Everyone, young and old, is well-coated, and muffled up with scarves and woolly hats. Breath comes out steaming in the frosty air. The kids have got instruments. It’s hard to call them ‘musical’ – they’re anything that will make a noise: maracas; tambourines; tin cans with bottle-caps inside; more bottle-caps strung on to a bit of wire attached to a forked stick, as an improvised rattle. One of the adults has got a trumpet. The crowd starts to move, becoming a snaking procession, making its way under the trees, with much jangling and banging and shaking. It’s an almighty racket.
We’re waking up the cider trees and scaring away evil spirits, to ensure a good harvest when autumn arrives. The procession comes to a halt and a man clears his throat to begin the wassailing song. People bursting into song in public has always made me feel deeply uncomfortable. It’s showing off. It’s like having to watch other people’s children perform a play they’ve just made up that afternoon. You can’t escape, and it’s impolite to laugh. You have to sit there, smile encouragingly rather than grimace, and then congratulate them afterwards, with not a note of irony. But here – in this orchard – my icy cynicism melts a little. The man has a beautiful, mellifluous, age-old voice, and he throws himself into this performance wholeheartedly. I feel as though we’re slipping through time, re-enacting, re-voicing the echo of something that has been happening for centuries.
Then we all troop back into the house. We shed the woollens and the coats and the past. We start chatting to friends, and we’re free from the spell, back in the now. But we’ll still grab a cup of mulled cider and drink each other’s health, and that’s another ancient echo. This tradition of wassailing goes back to at least Medieval times – but its roots probably go back deeper into antiquity. It’s an unashamedly pagan ritual, designed to propitiate the tree spirits and secure a good harvest. The first recorded mention of a wassail is from 1585, from Kent, where young men were rewarded for wassailing in the orchards. In the seventeenth century, the writer and antiquary John Aubrey recorded a West Country custom where men went into the orchard with a wassail bowl and went ‘about the trees to bless them’. In the eighteenth century, wassailing rhymes and songs proliferated. The nineteenth century saw a steep decline. In the twentieth century, revivals of the old rite were variably successful. It seemed to cling on most tenaciously in the Welsh and English counties around the Severn. My friends’ wassail in their orchard was a contemporary echo of a long tradition, albeit a revived one.
‘Wassail’ comes from Old Norse – ‘ves heil’, meaning ‘be you healthy’. As we retreat inside and drink each other’s health in warm, spiced cider, we’re marking the beginning of a new year, and hoping that it will turn out well for our friends, and for the apple harvest.
Apples are so quintessentially English. The wassail celebrates and underlines our primeval connection with these trees and their fruit. But apples – like all the other domesticated species in this book – don’t come from this little island in north-west Europe. The original homeland of apples was over three and a half thousand miles away.
On the flanks of the Heavenly Mountains
We’ve been here before, or at least very close. The region of Dzungaria is named after an ancient Mongolian kingdom, and most of it is now encapsulated by the Chinese province of Xinjiang – sandwiched between Kazakhstan to the west and Mongolia to the east. But the eastern tail of old Dzungaria still lies in Mongolia, and this is where the last Przewalski’s horse was spotted in 1969, before the species disappeared. To the south, Dzungaria is bounded by the Tian Shan Mountains. The mountain range continues to the west, expanding into an altitudinous wedge of land which forms modern-day Kyrgyzstan, separating Kazakhstan in the north from the south-western projection of Xinjiang Province in China.
A fertile oasis amongst steppe and desert. ‘Tian Shan’ means ‘heavenly mountains’, and they seem to live up to their name. Botanist Barrie Juniper described their beauty: ‘With its jagged, glistening, snow-covered peaks, forest-clad slopes, and high, sheltered pastures bejewelled in spring with flowering bulbs and fruit blossoms, and in the autumn with a cornucopia of fruit, the Tian Shan is the apotheosis of a favoured, ancient mountain kingdom.’
In 1790, a German pharmacist-botanist called Johann Sievers joined a Russian expedition to southern Siberia and China, in search of a particular species of medicinal rhubarb. But he wasn’t so obsessed by his quest for rhubarb that he ignored the other plants he found along the way. On the flanks of the Tian Shan, in what is now south-eastern Kazakhstan, Sievers found forests of huge apple trees, laden with unusually large and colourful fruit – some green or yellow, others red and purple. These weren’t mixed deciduous forests with an occasional apple tree: apples were the predominant species. And they weren’t the dwarfed and pruned apples of our modern orchards – these apple trees grew up to 60 feet high. Sievers himself died very soon after returning from the expedition, at the age of just thirty-three, before he’d had a chance to describe his discovery – but he was later immortalised in the botanical name of the apple that he’d found in the heavenly mountains of central Asia: Malus sieversii.
In the early nineteenth century, botanists and apple growers were trying to make sense of the twisted branches of the genus Malus. The large-fruited trees of the forests around the Tian Shan seemed to have been largely forgotten about. Instead, the prevailing idea was that cultivated apples had been domesticated from European wild apples – including Malus sylvestris, the ‘woodland apple’; Malus dasyphylla, the south-east European ‘Paradise
apple’; and Malus praecox, the ‘primitive apple’.
In 1929, thirteen years after his Persian expedition to track down the origins of wheat, Nikolai Vavilov, widely regarded as the world’s greatest plant-hunter, set off in the footsteps of Sievers. He trekked to south-east Kazakhstan – which by then had been swallowed up by the expanding Russian Empire. There, around the city of Almaty, in the foothills of the Tian Shan, he explored the wild apple forests. Today, Almaty is the largest city in Kazakhstan, home to nearly 2 million people, but its name enshrines its ancient connection with apples. The Russian version of the name, Alma-ata, means ‘Father of Apples’. The first reference to the city in literature, from the thirteenth century, calls it Almatau, which is thought to mean ‘Apple Mountain’.
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