Ancient genomics support deep divergence between Eastern and Western Mediterranean IE languages

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https://www.biorxiv.org/content/10.1101/2024.12.02.626332v1


The Indo-European languages are among the most widely spoken in the world, yet their early diversification remains contentious (1-5). It is widely accepted that the spread of this language family across Europe from the 5th millennium BP correlates with the expansion and diversification of steppe-related genetic ancestry from the onset of the Bronze Age (6,7). However, multiple steppe-derived populations co-existed in Europe during this period, and it remains unclear how these populations diverged and which provided the demographic channels for the ancestral forms of the Italic, Celtic, Greek, and Armenian languages (8,9). To investigate the ancestral histories of Indo-European-speaking groups in Southern Europe, we sequenced genomes from 314 ancient individuals from the Mediterranean and surrounding regions, spanning from 5,200 BP to 2,100 BP, and co-analysed these with published genome data. We additionally conducted strontium isotope analyses on 224 of these individuals. We find a deep east-west divide of steppe ancestry in Southern Europe during the Bronze Age. Specifically, we show that the arrival of steppe ancestry in Spain, France, and Italy was mediated by Bell Beaker (BB) populations of Western Europe, likely contributing to the emergence of the Italic and Celtic languages. In contrast, Armenian and Greek populations acquired steppe ancestry directly from Yamnaya groups of Eastern Europe. These results are consistent with the linguistic Italo-Celtic (10, 11) and Graeco-Armenian (1, 12, 13) hypotheses accounting for the origins of most Mediterranean Indo-European languages of Classical Antiquity. Our findings thus align with specific linguistic divergence models for the Indo-European language family while contradicting others. This underlines the power of ancient DNA in uncovering prehistoric diversifications of human populations and language communities.

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On the Mycenaeans

The arrival of Mycenaean culture, along with the Greek
language, has been subject to divergent interpretations, ranging from gradual, peaceful
infiltration to more rapid acquisition of political control78–80. Neither of these models are
contradicted by the new genetic evidence: following the collapse of Early Helladic society,
the brief Middle Helladic period saw new migrants from the north. These eventually
consolidated political control with the advent of the Late Helladic period and the formation of
Early Mycenaean Culture around 3,700 BP81. The process also entailed a cultural and
linguistic encounter between newcomers and the residing population. Over time the original
steppe signal diminished due to admixture with local populations with farmer ancestry.
Archaeological evidence documents sustained contacts with the genetic source region in
Moldova and the surrounding Carpathian region, as reflected in the introduction of steppe
horses and chariots82 , as well as the trade in silver from Carpathian mines83.


Thus, a long-standing debate regarding the origins of Mycenaean culture can be resolved, at
least in part. Genetic links with Anatolia and Crete persisted, mirroring the cultural influences
that shaped the formation of Mycenaean society. Moreover, Mycenaean culture exhibits
striking similarities with the slightly earlier Trialeti culture of the Southern Caucasus68, which
likely contributed to processes behind the subsequent Armenian ethnogenesis. In the South
Caucasus, we see the rise of new Bronze Age elites in the mineral-rich regions of present-day
Georgia and Armenia. These elites had links to both steppe chariot traditions and the Hittite
civilization in Anatolia. Trialeti burial inventories, characterized by monumental tumulus
chamber burials featuring precious imports, exhibit parallels with both Hittite city-states and
early Mycenaean shaft graves. This suggests the formation of new commercial and military
networks linking steppe societies and Near Eastern civilizations68, as now also corroborated
by the genetics.

Cyprus

In Cyprus, the Arcadocypriot Greek dialect was spoken from at least the Early Iron Age, next
to Phoenician and one or more unknown languages attested through the Cypro-Minoan and
Cypriot syllabaries57. A diverse population is also suggested by genetic links between LBA
and EIA Cyprus with the Levant and the Aegean. Steppe ancestry is identified in a number of
unpublished individuals from Hala Sultan Tekke (CGG_2_022123, CGG_2_022924) and
from Lapithos (CGG_2_022517), reflecting an affiliation with Late Helladic (i.e. Mycenaean
Age) populations of the Peloponnese. This aligns with the appearance of Mycenaean pottery
imports in the Late Bronze Age58 and with the linguistic classification of Arcadocypriot as a
descendant of the same South Greek dialect as Mycenaean, in contrast to other Greek dialects
such as Doric and Ionic54,59. However, one other individual from Lapithos (CGG_2_22488),
although buried 4,100–4,000 BP, already clusters with LBA Greeks, suggesting Pre-
Mycenaean connectivity with steppe-impacted populations of the Aegean.