The highlands of western Asia, rather than the Pontic Caspian steppe to the north, were the original homeland of Indo-European languages, a study by geneticists suggests.
The findings, published in Science, come in one of three new papers that seek to provide a comprehensive genetic history of southeastern Europe and western Asia — a region the authors call the “Southern Arc”.
As well as weighing in on the vexed question of linguistic origins, the papers shed light on the Asian antecedents, the physical appearance and social organisation of the Yamnaya steppe pastoralists who changed the face of Eurasia thousands of years ago and were ancestors of billions of people alive today.
Among the findings relating to the historical era, the authors, including Dr Iosif Lazaridis and Professor David Reich, of Harvard University , said that Anatolia, in modern-day Turkey, was the “demographic engine” of imperial Rome, with people living around Rome in the early centuries AD different genetically to the earlier inhabitants and almost identical to Byzantine Anatolians living centuries later.
The first study involved sequencing the DNA of 727 individuals from across a 10,000-year span and examines gene-flow between peoples of the “Southern Arc” and the Yamnaya to the north. It fills in significant gaps in the genetic record.
The horse-riding Yamnaya swept out of the Pontic Caspian steppe north of the Black Sea in the third millennium BC. They are credited with having spread not only their genes but also a precursor of the Indo-European languages — which include English, Greek, Farsi and Hindi — across large parts of Europe and Asia, from Ireland to India.
The researchers estimate that, as well as being descended from Eastern European hunter-gatherers, the Yamnaya derived more than half their ancestry from two different streams of migration from West Asia that brought genes from the Caucasus, Anatolia and the Levant. Their analysis also indicates that all regions where Indo-European languages were spoken saw significant gene flow from the Yamnaya, with the exception of pre-Bronze Age Anatolia.
As a result, they suggest the original homeland of a Proto-Indo-European language — ancestral to all Indo-European languages including the extinct Anatolian languages such as Hittite and Lydian — was somewhere in the highlands of West Asia. The DNA indicates that this is a region ancestral to both the Yamnaya and Anatolian people such as the Hittites. The highlands include parts of modern-day Armenia, Turkey and Iran and the paper indicates that further sampling and analysis will be necessary to narrow down a location.
The location of a Proto-Indo-European homeland is hotly contested, with the Pontic Caspian Steppe and Anatolia among the regions frequently proposed.
Another of the new papers indicates that the Yamnaya contributed about 10 per cent of the ancestry of Mycenaean Greeks — the Bronze Age civilisation that inspired Homer. The remainder of the Mycenaeans’ ancestry resembled that of the Minoans of Crete who did not have Yamnaya ancestry and were related to the people of nearby Anatolia.
Significantly, the team note that, while most Mycenaeans, including ordinary working people, had some Yamnaya or “steppe” admixture, some of the elite did not. They said this finding challenged “narratives of social dominance”. It has previously been claimed by some researchers that the Yamnaya achieved vast conquests through genocide and brutal subjugation.
The researchers write: “Whatever the social role of early steppe migrants into the Aegean, they did not establish a system that precluded admixture with locals or prevented them from rising to positions of power. This inclusiveness may explain the substantial dilution of steppe ancestry in the Aegean, as migrants and locals blended to form the ancestors of the Mycenaean-era population, and may shed light on the genesis of the Greek language linked, on one hand, with the rest of Indo-Europeans through steppe ancestry and, on the other, with the people of the Aegean who preceded the Proto-Greek speakers.”
“Increased connectivity set the stage for Anatolians to become the demographic engine of imperial Rome”Iosif Lazaridis et al.
They also note that analysis of the Yamnaya’s genes contradicts “stereotypical characterisations of steppe peoples as being blue-eyed, pale-skinned and light-haired”, indicating that they resembled present-day people from the Mediterranean. “We find that the modal phenotype of eye, skin, and hair pigmentation in ancient West Eurasians was brown-eyed, of intermediate complexion, and brown-haired — even among Yamnaya steppe pastoralists — contradicting stereotypical characterisations of Steppe peoples as being blue-eyed, pale-skinned, and light-haired.”
They add: “Light pigmentation in West Eurasia was the result of selection across time, which continued into the historical period, and not of the survival of supposed ancient Indo-European phenotypes as some 19th- and 20th-century writers supposed or the product of the direct influence of climate that some Greco-Roman writers hypothesised to explain patterns they observed during their own time.”
The team also looked at the ancestry of residents of ancient Rome and its surroundings. Previous research has indicated that there was large-scale migration from the Near East during the imperial period and the new study suggests that most of the migrants were from Anatolia — a region that includes the site of Troy.
They write: “In an irony of history, although the Roman Republic prevailed in its existential military struggle against the Anatolians rallied by Mithridates VI of Pontus during the first century BCE, the final incorporation of Anatolia into the Roman Empire and the increased connectivity that ensued may have set the stage for the very same Anatolians to become the demographic engine of imperial Rome itself. This recreated, in historical time, the mythical journey of Aeneas and his Trojan exiles from Anatolia to the shores of Italy.”
The top image shows a Hittite-period relief in Konya, Anatolia. The Hittites’ language was distantly related to surviving Indo-European languages such as English and Farsi. Photo: Alamy