Mykhailivka, a village on the right bank of the Dnieper River in Ukraine, lies dangerously close to the front line of Russia’s war on its western neighbor. Seventy years ago it was the site of an excavation by Ukrainian archaeologists. There, they discovered one of the earliest known settlements of the Yamnaya culture. The Yamnaya, who lived 5,000 years ago, are considered the world’s first nomadic pastoralists. Having invented a way to subsist on the hostile Eurasian steppe, moving with their herds and the seasons, they expanded east and west with wagons, possibly riding horses, leaving barely a physical trace of themselves besides long lines of burial mounds, or kurgans. Yet they and their descendants would go on to transform Europe and much of Asia genetically, culturally and linguistically. Among the many innovations these steppe migrants ushered in, scientists believe, are the Indo-European languages that are dominant in Europe today, and which are spoken by nearly half of humanity. But where this ancient culture was born has long been unknown.
Among the objects found by archaeologists at Mykhailivka in 1952 was a single human tooth. There was not much they could do with it at that time. But, in the past 20 years, new tools to extract and analyse ancient dna have finally let scientists read the secrets hidden within the tooth, along with hundreds of other remains of Yamnaya herders. At a conference in Budapest in late April, a team of researchers shared some of those secrets, shedding light on the origins of these mysterious people and who their ancestors were.
The researchers described how the Yamnaya were born out of an ancestral population that formed on the steppe in the fourth millennium B.C. when multiple waves of migration and interbreeding brought genes originating in Caucasian, Siberian and European populations together. The team placed the herders’ origins, quite precisely, between the lower reaches of the Dnieper and Don rivers, in the heart of a modern war zone.
For Alexey Nikitin, a Ukrainian-born palaeogeneticist at Grand Valley State University in Michigan and one of the leaders of the latest research, trying to identify the Yamnaya’s origins had until now been like straining to make out a fantastical fresco in a dimly lit room. “All of a sudden, we’ve turned on the lights.” This imagined fresco depicts the Bronze Age migrations initiated by the Yamnaya. These marked the second major transformation of Europe’s population since the last Ice Age ended 10,000 years ago. (The first was caused by the arrival of farmers from the Near East 4,000 years earlier.)
Dr Nikitin’s research was presented in Budapest as one of two preprints co-ordinated by David Reich, a palaeogeneticist at Harvard University, and his colleagues. The preprints, which have not yet been peer-reviewed, draw on the same data sets, share many authors and offer similar accounts, but differ in one striking respect: the Russian contributors are named on one paper, the Ukrainians on the other. Politically, it could not have been otherwise.
Geneticists had already shown, in two papers published in Nature in 2015, that the Yamnaya quickly expanded westward into Europe and eastward into Asia. Subsequent work has led to a completely new understanding of how they and their descendants succeeded in imposing their genes and languages on a territory that extended, eventually, from Ireland to the Altai Mountains of Central Asia. (The image above, the first facial reconstruction of a western Yamnaya, is based on remains found in Hungarian graves.)
Even after the Yamnaya were shown to have come to Europe, disagreement still lingered about how they had managed to drive such a dramatic turnover in the gene pool—replacing up to 90% of the indigenous farmers’ genes in parts of the continent. Some researchers thought only violence could explain it, possibly even a genocide in which swathes of those farmers were wiped out. Over the past decade, genetic and archaeological tools have provided finer resolution, bringing a radical rethink of what happened.
One of the most important realizations, articulated by Thomas Booth, a bioarchaeologist at the Francis Crick Institute in London, among others, has been that the same outcome could have been achieved by small waves of mainly peaceful immigrants, interbreeding with locals over generations and managing to keep their children alive to puberty. This model fits much better with what archaeologists find in Yamnaya graves: very few weapons, and a low incidence of traumatic injury.
The papers from 2015 spawned headlines asking if the Yamnaya were the most murderous people of all time. At the meeting in Budapest in April, Martin Furholt, an archaeologist at the University of Kiel, suggested, provocatively, that they might actually have been “peace-loving hippies”.
Most experts would settle for something in between. One outstanding question concerns exactly who came west. Some have argued that the pioneers, at least, were overwhelmingly male—which conjures marauding warbands and violence. Dr Reich thinks it possible that there was no sex bias, in which case whole families may have come, and in peace. Other factors might have facilitated the Yamnaya’s success. Kristian Kristiansen, an archaeologist, who works with Eske Willerslev’s palaeogenetics group at the University of Copenhagen, thinks a deadly form of plague may have already been present in Europe before they arrived. The disease may have devastated farming communities, liberating pasturelands and clearing a path for the newcomers.
But if Europe’s last great transformation came about slowly, perhaps even imperceptibly, that has other implications. By the time the Yamnaya moved on from what is now Hungary, leaving the steppe for Europe’s temperate forests, they were no longer Yamnaya. Those migrants carried Yamnaya genes, but by now these were mixed with those of the indigenous farmers. Their culture had changed too, borrowing from local ones, and the blending continued as they moved west, until finally, around 4,500 years ago, the Yamnaya’s genetic signature showed up in the British Isles. Their descendants had expanded as far as they could, and in just a couple of centuries. “It was a proper revolution,” says Volker Heyd, an archaeologist at the University of Helsinki in Finland, one of the Budapest meeting’s organizers. It just was not as violent as was once thought.
Most European men alive today carry Y chromosomes that were brought in by the Yamnaya migrants of the Bronze Age, a legacy of the privileged access the latter managed to obtain, by fair means or foul, to local women. Millions of men in Central and South Asia carry the same Y chromosomes, since the Yamnaya expanded eastward too. In January Dr Willerslev’s group reported that a genetic predisposition to multiple sclerosis, an inflammatory disease of the central nervous system, arrived in Europe with the Yamnaya, and spread wherever their descendants did. It may have arisen as part of a package of immune changes that evolved in steppe herders, who lived close to their animals, to protect them against diseases of animal origin—including plague. In a modern context, it causes a different kind of disease.
Similarly, ancient DNA indicates that genes promoting lactose tolerance, the ability to drink milk without digestive malaise, became more prevalent in Europe after the Bronze Age migrations brought dairying practices with them. The Yamnaya themselves were probably not lactose-tolerant, even though milk was central to their diet. They are thought to have consumed it in fermented form, as cheese or yogurt, unknowingly recruiting the bacteria that drive fermentation to break down the lactose for them. But once milk became plentiful, lactose tolerance became advantageous, and the trait’s prevalence increased in their descendants. More of them could drink their milk raw.
What of the Indo-European languages? Language, like culture, does not require mass migration to spread, but as David Anthony, an archaeologist at Hartwick College in New York, explained, painstaking reconstructions of the vocabulary of early Indo-European languages, based on comparisons of their living descendants, indicate that their speakers knew wheeled transport, practised dairying and possibly rode horses. That constrains when and where they could have lived, and Dr Anthony finds the Yamnaya to be the best fit. Many are now convinced they spread these languages throughout the Old World.
They probably did not speak the first Indo-European language, however. Dr Reich’s group is not alone in thinking that would have been spoken closer to the Caucasus Mountains, reaching Yamnaya territory with those early waves of migration. The older language, and its speakers, remain dimly lit. But as far as the Yamnaya are concerned, Dr Nikitin thinks that the broad strokes of their story are now in place. The timing of the findings may be grimly fortuitous. For the foreseeable future, the ground near Mykhailivka will yield bullets and landmines more readily than more ancient evidence of the extraordinary Yamnaya culture.” [The Economist Article]
David Anthony mentioned in the article above had a couple more important additions in his other works. First, about Mikhailivka:
“That Mikhailovka is a settlement, not a kurgan cemetery, immediately identifies the western Yamnaya way of life as more residentially stable than that of eastern Yamnaya. The strategic hill fort at Mikhailovka (level I) on the lower Dnieper was occupied before 3400 BCE by people who had connections in the coastal steppes to the west (the Mikhailovka I culture).”
Second, it is about the boundaries of the Yamnaya Culture:
“Yamnaya settlements are known west of the Don in Ukraine, but east of the Don in Russia there are no significant Yamnaya settlements“.
Ukrainian Language is Likely the Closest to Original Proto-Indo-European Language >
The “Cradle of Civilizations” book has little-known facts about the archaeological discoveries predating the Yamnaya Culture.
