The Horse, the Wheel, and Language: How Bronze-Age Riders From the Eurasian Steppes Shaped the Modern World

by David W. Anthony

  The Domestication of the Horse and the Origins of Riding The Tale of the Teeth

  The importance of the horse in human history is matched only by the difficulties

  inherent in its study; there is hardly an incident in the story which is not the

  subject of controversy, often of a violent nature.

  1—Grahame Clark, 1941

  In the summer of 1985 I went with my wife Dorcas Brown, a fellow archaeologist, to the Veterinary School at the University of Pennsylvania to ask a veterinary surgeon a few questions. Do bits create pathologies on horse teeth? If they do, then shouldn’t we be able to see the signs of bitting—scratches or small patches of wear—on ancient horse teeth? Wouldn’t that be a good way to identify early bitted horses? Could he point us toward the medical literature on the dental pathologies associated with horse bits? He replied that there really was no literature on the subject. A properly bitted horse wearing a well-adjusted bridle, he said, really can’t take the bit in its teeth very easily, so contact between the bit and the teeth would have been too infrequent to show up with any regularity. Nice idea, but it wouldn’t work. We decided to get a second opinion.

  At the Veterinary School’s New Bolton Center for large mammals, outside Philadelphia, the trainers, who worked every day with horses, responded very differently. Horses chewed their bits all the time, they said. Some rolled the bit around in their mouths like candy. You could hear it clacking against their teeth. Of course, it was a vice—properly trained and harnessed horses were not supposed to do it, but they did. And we should talk to Hilary Clayton, formerly at New Bolton, who had gone to a university job somewhere in Canada. She had been studying the mechanics of bits in horses’ mouths.

  We located Hilary Clayton at the University of Saskatchewan and found that she had made X-ray fluoroscopic videos of horses chewing bits (figure 10.1). She bitted horses and manipulated the reins from a standing position behind. An X-ray fluoroscope mounted beside the horses’ heads took pictures of what was happening inside their mouths. No one had done this before. She sent us two articles co-authored with colleagues in Canada.1 Their images showed just how horses manipulated a bit inside their mouths and precisely where it sat between their teeth. A well-positioned bit is supposed to sit on the tongue and gums in the space between the front and back teeth, called bars “the” of the mouth. When the rider pulls the reins, the bit presses the tongue and the gums into the lower jaw, squeezing the sensitive gum tissue between the bit and the underlying bone. That hurts. The horse will dip its head toward a one-sided pull (a turn) or lower its chin into a two-sided pull (a brake) to avoid the bit’s pressure on its tongue and gums.

  Figure 10.1 A modern metal bit in a horse’s mouth. Mandible bone tinted gray. (a) jointed snaffle bit; (b) X-ray of jointed snaffle sitting on the tongue in proper position; (c) X-ray of snaffle being grasped in the teeth; (d) bar bit showing chewing wear; (e) X-ray of bar bit sitting on the tongue in proper position; (f) X-ray of bar bit being grasped in the teeth. After Clayton and Lee 1984; and Clayton 1985.

  Clayton’s X-rays showed how horses use their tongues to elevate the bit and then retract it, pushing it back into the grip of their premolars, where it can no longer cause pressure on soft tissue no matter how hard the rider pulls on the reins. The soft corners of the mouth are positioned in front of the molars, so in order to get a bit into its teeth the horse has to force it back against the corners of its mouth. These stretched tissues act like a spring. If the bit is not held very firmly between the tips of the teeth it will pop forward again onto the bars of the mouth. It seemed likely to us that this repeated back-and-forth movement over the tips of the front premolars should affect the lower teeth more than the uppers just because of gravity—the bit sat on the lower jaw. The wear from bit chewing should be concentrated on one small part of two teeth (the lower second premolars, or P2s), unlike the wear from chewing anything else. Clayton’s X-rays made it possible, for the first time, to say positively that a specific part of a single tooth was the place to look for bit wear. We found several published photographs of archaeological horse P2s with wear facets or bevels on precisely that spot. Two well-known archaeological zoologists, Juliet Clutton-Brock in London and Antonio Azzaroli in Rome, had described this kind of wear as “possibly” made by a bit. Other zoologists thought it was impossible for horses to get a bit that far back into their mouth with any frequency, like our first veterinary surgeon. No one knew for sure. But they had not seen Clayton’s X-rays.2

  Encouraged and excited, we visited the anthropology department at the Smithsonian Museum of Natural History in Washington, and asked Melinda Zeder, then a staff archaeozoologist, if we could study some never-bitted ancient wild horse teeth—a control sample—and if she could offer us some technical advice about how to proceed. We were not trained as zoologists, and we did not know much about horse teeth. Zeder and a colleague who knew a lot about dental microwear, Kate Gordon, sat us down in the staff cafeteria. How would we distinguish bit wear from tooth irregularities caused by malocclusion? Or from dietary wear, created by normal chewing on food? Would the wear caused by a bit survive very long, or would it be worn away by dietary wear? How long would that take? How fast do horse teeth grow? Aren’t they the kind of teeth that grow out of the jaw and are worn away at the crown until they become little stubs? Would that change bit wear facets with increasing age? What about rope or leather bits—probably the oldest kind? Do they cause wear? What kind? Is the action of the bit different when a horse is ridden from when it pulls a chariot? And what, exactly, causes wear—if it exists? Is it the rider pulling the bit into the front of the tooth, or is it the horse chewing on the bit, which would cause wear on the occlusal (chewing) surface of the tooth? Or is it both? And if we did find wear under the microscope, how would we describe it so that the difference between a tooth with and without wear could be quantified?

  Mindy Zeder took us through her collections. We made our first molds of ancient equid P2s, from the Bronze Age city of Malyan in Iran, dated about 2000 BCE. They had wear facets on their mesial corners; later we would be able to say that the facets were created by a hard bit of bone or metal. But we didn’t know that yet, and, as turned out, there really was not a large collection of never-bitted wild horse teeth at the Smithsonian. We had to find our own, and we left thinking that we could do it if we took one problem at a time. Twenty years later we still feel that way.3

  WHERE WERE HORSES FIRST DOMESTICATED?

  Bit wear is important, because other kinds of evidence have proven uncertain guides to early horse domestication. Genetic evidence, which we might hope would solve the problem, does not help much. Modern horses are genetically schizophrenic, like cattle (chapter 8) but with the genders reversed. The female bloodline of modern domesticated horses shows extreme diversity. Traits inherited through the mitochondrial DNA, which passes unchanged from mother to daughter, show that this part of the bloodline is so diverse that at least seventy-seven ancestral mares, grouped into seventeen phylogenetic branches, are required to account for the genetic variety in modern populations around the globe. Wild mares must have been taken into domesticated horse herds in many different places at different times. Meanwhile, the male aspect of modern horse DNA, which is passed unchanged on the Y chromosome from sire to colt, shows remarkable homogeneity. It is possible that just a single wild stallion was domesticated. So horse keepers apparently have felt free to capture and breed a variety of wild mares, but, according to these data, they universally rejected wild males and even the male progeny of any wild stallions that mated with domesticated mares. Modern horses are descended from very few original wild males, and many, varied wild females.4

  Why the Difference?

  Wildlife biologists have observed the behavior of feral horse bands in several places around the world, notably at Askania Nova, Ukraine, on the barrier islands of Maryland and Virginia (the horses described in the childrens’ classic Misty of Chincoteague), and in northwestern
Nevada. The standard feral horse band consists of a stallion with a harem of two to seven mares and their immature offspring. Adolescents leave the band at about two years of age. Stallion-and-harem bands occupy a home range, and stallions fight one another, fiercely, for control of mares and territory. After the young males are expelled they form loose associations called “bachelor bands,” which lurk at the edges of the home range of an established stallion. Most bachelors are unable to challenge mature stallions or keep mares successfully until they are more than five years old. Within established bands, the mares are arranged in a social hierarchy led by the lead mare, who chooses where the band will go during most of the day and leads it in flight if there is a threat, while the stallion guards the flanks or the rear. Mares are therefore instinctively disposed to accept the dominance of others, whether dominant mares, stallions—or humans. Stallions are headstrong and violent, and are instinctively disposed to challenge authority by biting and kicking. A relatively docile and controllable mare could be found at the bottom of the pecking order in many wild horse bands, but a relatively docile and controllable stallion was an unusual individual—and one that had little hope of reproducing in the wild. Horse domestication might have depended on a lucky coincidence: the appearance of a relatively manageable and docile male in a place where humans could use him as the breeder of a domesticated bloodline. From the horse’s perspective, humans were the only way he could get a girl. From the human perspective, he was the only sire they wanted.

  Where Did He Live? And When?

  Animal domestication, like marriage, is the culmination of a long prior relationship. People would not invest the time and energy to attempt to care for an animal they were unfamiliar with. The first people to think seriously about the benefits of keeping, feeding, and raising tame horses must have been familiar with wild horses. They must have lived in a place where humans spent a lot of time hunting wild horses and learning their behavior. The part of the world where this was possible contracted significantly about ten thousand to fourteen thousand years ago, when the Ice Age steppe—a favorable environment for horses—was replaced by dense forest over much of the Northern Hemisphere. The horses of North America became extinct as the climate shifted, for reasons still poorly understood. In Europe and Asia large herds of wild horses survived only in the steppes in the center of the Eurasian continent, leaving smaller populations isolated in pockets of naturally open pasture (marsh-grass meadows, alpine meadows, arid mesetas) in Europe, central Anatolia (modern Turkey), and the Caucasus Mountains. Horses disappeared from Iran, lowland Mesopotamia, and the Fertile Crescent, leaving these warm regions to other equids (onagers and asses) (figure 10.2).

  Figure 10.2 Map of the distribution of wild horses (Equus caballus) in the mid-Holocene, about 5000 BCE. The numbers show the approximate frequencies of horse bones in human kitchen garbage in each region, derived from charts in Benecke 1994 and from various Russian sources.

  In western and central Europe, central Anatolia, and the Caucasus the isolated pockets of horses that survived into the Holocene never became important in the human food quest—there just weren’t enough of them. In Anatolia, for example, a few wild horses probably were hunted occasionally by the Neolithic occupants of Catal Hüyök, Pinarbaşi, and other farming villages in the central plateau region between about 7400 and 6200 BCE. But most of the equids hunted at these sites were Equus hydruntinus (now extinct) or Equus hemionus (onagers), both ass-like equids smaller than horses. Only a few bones are large enough to qualify as possible horses. Horses were not present in Neolithic sites in western Anatolia, or in Greece or Bulgaria, or in the Mesolithic and Early Neolithic of Austria, Hungary, or southern Poland. In western and northern Europe, Mesolithic foragers hunted horses occasionally. But horse bones accounted for more than 5% of the animals in only a few post-Glacial sites in the coastal plain of Germany/Poland and in the uplands of southern France. In the Eurasian steppes, on the other hand, wild horses and related wild equids (onagers, E. hydruntinus) were the most common wild grazing animals. In early Holocene steppe archaeological sites (Mesolithic and early Neolithic) wild horses regularly account for more than 40% of the animal bones, and probably more than 40% of the meat diet because horses are so big and meaty. For this reason alone we should look first to the Eurasian steppes for the earliest episode of domestication, the one that probably gave us our modern male bloodline.5

  Early and middle Holocene archaeological sites in the Pontic-Caspian steppes contain the bones of three species of equids. In the Caspian Depression, at Mesolithic sites such as Burovaya 53, Je-Kalgan, and Istai IV, garbage dumps dated before 5500 BCE contain almost exclusively the bones of horses and onagers (see site map, figure 8.3). The onager, Equus hemionus, also called a “hemione” or “half-ass,” was a fleet-footed, long-eared animal smaller than a horse and larger than an ass. The natural range of the onager extended from the Caspian steppes across Central Asia and Iran and into the Near East. A second equid, Equus hydruntinus, was hunted in the slightly moister North Pontic steppes in Ukraine, where its bones occur in small percentages in Mesolithic and Early Neolithic components at Girzhevo and Matveev Kurgan, dated to the late seventh millennium BCE. This small, gracile animal, which then lived from the Black Sea steppes westward into Bulgaria and Romania and south into Anatolia, became extinct before 3000 BCE. The true horse, Equus caballus, ranged across both the Caspian Depression and the Black Sea steppes, and it survived in both environments long after both E. hemionus and E. hydruntinus were hunted out. Horse bones contributed more than 50% of the identified animal bones at Late Mesolithic Girzhevo in the Dniester steppes and Meso/Neolithic Matveev Kurgan and Kammenaya Mogila in the Azov steppes; also at Neo/Eneolithic Varfolomievka and Dzhangar in the Caspian Depression, Ivanovskaya on the Samara River, and Mullino in the southern foothills of the Ural Mountains. The long history of human dependence on wild equids in the steppes created a familiarity with their habits that would later make the domestication of the horse possible.6

  WHY WERE HORSES DOMESTICATED?

  The earliest evidence for possible horse domestication in the Pontic-Caspian steppes appeared after 4800 BCE, long after sheep, goats, pigs, and cattle were domesticated in other parts of the world. What was the incentive to tame wild horses if people already had cattle and sheep? Was it for transportation? Almost certainly not. Horses were large, powerful, aggressive animals, more inclined to flee or fight than to carry a human. Riding probably developed only after horses were already familiar as domesticated animals that could be controlled. The initial incentive probably was the desire for a cheap source of winter meat.

  Horses are easier to feed through the winter than cattle or sheep, as cattle and sheep push snow aside with their noses and horses use their hard hooves. Sheep can graze on winter grass through soft snow, but if the snow becomes crusted with ice than their noses will get raw and bloody, and they will stand and starve in a field where there is ample winter forage just beneath their feet. Cattle do not forage through even soft snow if they cannot see the grass, so a snow deep enough to hide the winter grass will kill range cattle if they are not given fodder. Neither cattle nor sheep will break the ice on frozen water to drink. Horses have the instinct to break through ice and crusted snow with their hooves, not their noses, even in deep snows where the grass cannot be seen. They paw frozen snow away and feed themselves and so do not need water or fodder. In 1245 the Franciscan John of Plano Carpini journeyed to Mongolia to meet Güyük Khan (the successor to Genghis) and observed the steppe horses of the Tartars, as he called them, digging for grass from under the snow, “since the Tartars have neither straw nor hay nor fodder.” During the historic blizzard of 1886 in the North American Plains hundreds of thousands of cattle were lost on the open range. Those that survived followed herds of mustangs and grazed in the areas they opened up.7 Horses are supremely well adapted to the cold grasslands where they evolved. People who lived in cold grasslands with domesticated cattle and sheep would soon h
ave seen the advantage in keeping horses for meat, just because the horses did not need fodder or water. A shift to colder climatic conditions or even a particularly cold series of winters could have made cattle herders think seriously about domesticating horses. Just such a shift to colder winters occurred between about 4200 and 3800 BCE (see chapter 11).

  Cattle herders would have been particularly well suited to manage horses because cattle and horse bands both follow the lead of a dominant female. Cowherds already knew they needed only to control the lead cow to control the whole herd, and would easily have transferred that knowledge to controlling lead mares. Males presented a similar management problem in both species, and they had the same iconic status as symbols of virility and strength. When people who depended on equid-hunting began to keep domesticated cattle, someone would soon have noticed these similarities and applied cattle-management techniques to wild horses. And that would quickly have produced the earliest domesticated horses.

  This earliest phase of horse keeping, when horses were primarily a recalcitrant but convenient source of winter meat, may have begun as early as 4800 BCE in the Pontic-Caspian steppes. This was when, at Khvalynsk and S’yezzhe in the middle Volga region, and Nikol’skoe on the Dnieper Rapids, horse heads and/or lower legs were first joined with the heads and/or lower legs of cattle and sheep in human funeral rituals; and when bone carvings of horses appeared with carvings of cattle in a few sites like S’yezzhe and Varfolomievka. Certainly horses were linked symbolically with humans and the cultured world of domesticated animals by 4800 BCE. Horse keeping would have added yet another element to the burst of economic, ritual, decorative, and political innovations that swept across the western steppes with the initial spread of stockbreeding about 5200–4800 BCE.