Horses: They may not look alike but they arise from one source 제주마육성팀 / CC-BY-SA-4.

Backing the Wrong Wild Horse: New Studies Demolish Equine Domestication Theory

Widespread beliefs about how Indo-European languages spread have also ridden into the sunset

Over 5,500 years ago, with the dog leashed, the goat cowed and the sheep rendered woolly in mind and body, nomads roaming the windswept steppes of Asia became the first to master the mighty horse.

The question is, which nomads? Another question is, which horse?

Surprising answers to both questions have birthed new theories not only about the domestication of the steed, but also about the spread of Indo-European languages.

Not those nomads

Until recently, descendants of goat and sheep herders who formed  the Yamnaya culture in the steppes of today’s Ukraine and western Russia about 5,000 years ago were thought to have domesticated the horse. They were believed to have ridden the subdued animal as they spread southeast, bringing the Indo-European group of languages to Anatolia (a vast region mostly in today’s Turkey).

Or not. Two papers published in May have new theories about horse domestication and the spread of Indo-European tongues.

The Yamnaya definitely rode horses into the European sunset. But one paper, published in Science by Peter de Barros Damgaard and colleagues, argues that the Yamnaya hadn’t been the first to tame the horse. Completely different nomads – a smaller group named the Botai, who arose about 500 years earlier east of there, in Kazakhstan – domesticated the horse before the Yamnaya.

But genetic analyses led to startling conclusions about the origin of today’s steeds.

Not that horse

The Eurasian steppe is a vast grassland stretching 8,000 kilometers (about 5,000 miles), from Hungary and Ukraine in the west through Kazakhstan to Mongolia and China in the east. The Botai lived in what is now Kazakhstan, from about 5,700 years to 5,100 years ago.

It is among the Botai that archaeologists located the oldest evidence of horse domestication (found so far, at least): Pottery with traces of mares’ milk, and horse teeth that seem worn down by bits.

Genetic analysis of Botai horse remains and what was thought to be the only surviving wild horse – the so-called wild Przewalski – by the French National Center for Scientific Research and Université Toulouse III–Paul Sabatier, resulted in some unexpected findings.

The first unexpected finding is that the “only wild horse still existing,” the wild Przewalski, is not actually wild. It descended from the Botai horses.

The second unexpected finding is that the Botai did not domesticate the Przewalski, but some other unknown wild horse. This unknown animal is the forefather of the Przewalksi.

The third unexpected finding is that none of today’s horses are descended from either the Przewalksi or its Botai-tamed descendent. We don’t know where today’s horses came from.

The fourth unexpected conclusion is that there are no more wild horses, anywhere. Wild horses are long extinct.

GerardM / CC-BY-SA-3.0

The fifth and final unexpected conclusion is that the horse was domesticated not once but twice. That’s according to Damgaard, the molecular biologist from the Natural History Museum of Denmark who led the project. One domestication event created the race the Botai rode, which is extinct; another created today’s horses, he says.

It is tempting to think the western pastoralists related to Yamnaya also domesticated a different breed of horses, Damgaard adds.

Not friends

Maybe the Botai did give the Yamnaya the idea of how to train horses. But to be clear, the Botai were not ancestral to, or even related to, the more western Yamnaya, report the researchers.

It is speculative, but likely that when the two groups did encounter each other, they fought.

Hostility with the Botai could explains why, when the Yamnaya-related groups meandered eastward, they didn’t strike roots mid-route, but continued all the way to the Altai Mountains of Southern Siberia – thousands of kilometers in distance, says Damgaard. There, these pastoralists who came from eastern Europe became the forefathers of the culture called the Afanasievo.

This far-flung wandering by the Yamnaya fits with Russian literature, which indicates that Botai descendants were warring with them, Damgaard observes. Why would they clash? “Probably because the descendants of the Botai people didn’t like their hunting territory being overrun,” he speculates.

As for the Botai themselves, following their Bronze Age heyday their homeland central steppe was totally overrun by groups coming in with wheeled vehicles, Damgaard explains. The descendents of the Botai hunter-gatherers retreated into the forest-steppe.

These relocated Botai may even have been the forefathers of the highly nomadic forest groups of Siberia, who left a pattern of burials from Finland to Mongolia from about 2100 B.C.E. to 1900 B.C.E. (known as the Seima-Turbino phenomenon), Damgaard says.

So, the Botai tamed the horse before the Yamnaya. But it seems that, wherever they rode their steeds, neither went south to Anatolia just when Indo-European languages began to arise there. Mass migration isn’t how Indo-European languages were spread southward from their point of origin.

The authors agree that Indo-European Anatolian was brought in from the outside, but the genetic data indicates that the population which adopted it was not genetically impacted by the groups from the steppes. Instead, apparently the local populations in the big cities of the time were multi-lingual and adopted the Indo-European tongue on top of their own.

Not speaking

Long lost in time, the Indo-European languages' point of origin is hypothetical. In theory, related tongues should have a predecessor. Wouldn’t the Indo-European languages – from Greek to Latin to Hittite to Hindi – have had an Ur-tongue?

“We suspect proto-Indo-European emerged at the interface between the Caucasus and the eastern European steppe, perhaps through a ‘Caucasification’ of a Uralic language,” Damgaard says. He adds that, in any case, this hypothetical mother tongue probably took the form of local dialects.

Wherever it originated, the question is how this group of languages spread. As said, genetic analysis of 74 skeletons shows that the Yamnaya and Botai weren’t even related: The Botai arose from a hunter-gatherer population “deeply diverged” from the Yamnaya, the researchers say.

And they found no evidence of either Botai or Yamnaya in skeletal remains of Bronze Age Anatolians who lived when Indo-European languages are thought to have arrived there – over 5,000 years ago, based on ancient texts found in Ebla, Syria.

“Our genetic data basically tells us that whoever brought in the Indo-European languages (which we agree came from the outside) did not come in a massive population movement that affected the local gene pool,” Damgaard sums up.

Hittite is the oldest-known written Indo-European language, and may be the earliest to have split off from the proto-Indo-European tongue. Along the line, more tongues would branch off: the Iranian and Greek languages, for example, split off later than Hittite, in the late Bronze Age, Damgaard says.

Previously, the Anatolians would have spoken very distinct non-Indo-European languages: Assyrian, Hattian and Hurrian. If they didn’t get and maintain the use of Indo-European languages through mass migrations from the steppes, that leaves some sort of cultural seepage.

“We are pretty sure Indo-European languages were introduced to Anatolia – either through the Balkans or the Caucasus, by a minority,” Damgaard says. The languages would then have been sustained in Anatolia through cultural processes, he adds.

The Yamnaya survived. Their descendents moved into Europe, becoming the Afanasievo in the Altai Montains and possibly China. That last postulation is based on archaeology, including the 3,800-year-old mummies from western China (the Tarim mummies), and on linguistics – the sheer existence of the Indo-European language called Tocharian, which must have split off from the Indo-European language group before the Late Bronze Age chariot groups, says Damgaard.

The Botai survived for long centuries, but their descendents seem to have disappeared from the central steppe in the Late Bronze Age, Damgaard notes.

Wild horses did not survive; we do not know when they went extinct.

The Botai-domesticated horses did survive and became wild Przewalskis – which did not produce today’s racing steeds, just more wild Przewalksis. We still don’t know where or how today’s domestic horses originated, or if they understood Indo-European commands. But the hunt for clues in the genetic record continues.

skip all comments

Comments

Sign in to join the conversation.

Required field
Required field

By adding a comment, I agree to this site’s Terms of use

  1. 1