Indo-European Homeland and the Indo-Europeans

Indo-European Homeland

Modern linguists have placed the Proto-Indo-European homeland in the Pontic-Caspian Steppe, a distinct geographic and archeological region extending from the Danube estuary to the Ural mountains to the east and North Caucasus to the south.

The Neolithic, Eneolithic and early Bronze Age cultures in Pontic-Caspian steppe has been called the Kurgan culture (7000-2200 BCE) by Marija Gimbutas, due to the lasting practice of burying the deads under mounds (“kurgan”) among the succession of cultures in that region. It is now known that kurgan-type burials only date from the 4th millenium BCE and almost certainly originated south of the Caucasus.

Horses were first domesticated around 4600 BCE in the Caspian Steppe, perhaps somewhere around the Don or the lower Volga, and soon became a defining element of steppe culture. Nevertheless it is unlikely that R1b was already present in the eastern steppes at the time, so the domestication of the horse should be attributed to the indigenous R1a people.

Haplogroup R-M17, sometimes referred to as R-M198, is particularly common in a large region extending from South Asia and Southern Siberia to Central Europe and Scandinavia. It is the most common subclade within the family of Y DNA lineages referred to as R1a or R-M420, which share in common the M420 SNP mutation, and before the discovery of M420, R-M17 was itself referred to as R1a.

The decade-long debate as to which Eurasian region possessed the most diverse, hence oldest, STR values within R-M17, has been effectively put to an end with the discovery of R-M17 sub-clades. SNPs offer a clearer and more robust resolution than STRs. They shows that all their tested Indian R-M17 samples belong to the Z-93 sub-clade, which is a derivative, “daughter” branch of R-M17.

Exactly when and where R-M17 arose requires further elucidation. The major limitations precluding an equivocal conclusion include the need for: (i) greater population sampling (ii) more ancient DNA data, and (iii) more robust and consistent methodology in estimating haplogroup ages and their phylogeographic relationships. The observed data currently suggests that haplogroup R1a likely differentiated in the region between Eastern Europe and South Asia.

In contrast, Eastern European populations belong to different daughter branches of R-M17, namely Z- 280 and M-458. The former is widely distributed over south-eastern, central-eastern and eastern Europe, and as far as Central Asia. Indeed, Central Asia is an overlap zone for the R1a1-Z280 and R1a1-Z93″, being found in Mongol and Uzbek populations. On the other hand, M-458 is more geographically restricted to central-eastern Europe.

Furthermore, the undifferentiated, parental M-198 existed in the European populations, but was not found in the Indian groups. This pattern implies that an early differentiation zone of R1a1-M198 conceivably occurred somewhere within the Eurasian Steppes or the Middle East and Caucasus region as they lie between South Asia and Eastern Europe, from where South Asian Z-93 and European Z-283 sub-clades differentiated and spread in opposite directions.

Nearly all samples from Bronze and Iron Age graves in the Krasnoyarsk area in south Siberia belonged to R-M17 and appeared to represent an eastward migration from Europe. In central Europe, Corded Ware period human remains at Eulau from which Y-DNA was extracted appear to be R-M17(xM458) (which they found most similar to the modern German R-M17* haplotype.

Haplogroup R1b STR variance in Europe forms a cline from east to west, which is more consistent with an entry into Europe from Western Asia with the spread of farming. The proposal of a southeastern origin of R1b were supported by three detailed studies based on large datasets published in 2010. These detected that the earliest subclades of R1b are found in western Asia and the most recent in western Europe.

While age estimates in these articles are all more recent than the Last Glacial Maximum, all mention the Neolithic, when farming was introduced to Europe from the Middle East as a possible candidate period. The exact dating of the migration or migrations responsible for this distribution is unclear, not ruling out migrations as early as the Mesolithic or as late as Hallstatt, but more probably Late Neolithic.

Ancient DNA of human remains from the Late Neolithic Bell Beaker site of Kromsdorf, Germany, belong to the Y haplogroup R1b. However, analysis of ancient Y DNA from the remains of populations derived from early Neolithic settlements such as the Mediterranean Cardium and Central and North European LBK settlements have found an absence of males belonging to haplogroup R1b.

The Paleolithic origins of R1b are not entirely clear to this day. Haplogroup R1* and R2* might have originated in southern Central Asia (between the Caspian depression and the Hindu Kush). A branch of R1 would have developed into R1b, then R1b1 and R1b1a in the northern part of the Middle East around the time of the Last Glacial Maximum (circa 20,000 years ago), while R1a migrated north to Siberia. Some of the oldest forms of R1b are found around the Caucasus, in Iran and in southern Central Asia, a vast region where could have roamed the nomadic R1b hunter-gatherers during the Ice Age.

R1b1a presumptively moved to northern Anatolia and across the Caucasus during the Neolithic, where it split into R1b1a1 (M73) and R1b1a2 (M269). The Near Eastern leftovers evolved into R1b1c (V88), now found at low frequencies among the Lebanese, the Druze, and the Jews. The Phoenicians (who came from modern day Lebanon) spread this R1b1c to their colonies, notably Sardinia and the Maghreb.

R1b1a2 (the most common form in Europe) and R1b1a1 is closely associated with the diffusion of Indo-European languages, as attested by its presence in all regions of the world where Indo-European languages were spoken in ancient times, from the Atlantic coast of Europe to the Indian subcontinent, including almost all Europe (except Finland and Bosnia-Herzegovina), Anatolia, Armenia, European Russia, southern Siberia, many pockets around Central Asia (notably Xinjiang, Turkmenistan, Tajikistan and Afghanistan), without forgetting Iran, Pakistan, India and Nepal. The history of R1b and R1a are intricately connected to each others.

The Kura–Araxes culture or the early trans-Caucasian culture was a civilization that existed from 3400 BC until about 2000 BC, which has traditionally been regarded as the date of its end, but it may have disappeared as early as 2600 or 2700 BC. The earliest evidence for this culture is found on the Ararat plain; thence it spread to Georgia by 3000 BC (but never reaching Colchis), and during the next millennium it proceeded westward to the Erzurum plain, southwest to Cilicia, and to the southeast into an area below the Urmia basin and Lake Van, and finally down to the borders of present day Syria. Altogether, the early Trans-Caucasian culture, at its greatest spread, enveloped a vast area approximately 1,000 km by 500 km.

Inhumation practices are mixed. Flat graves are found, but so are substantial kurgan burials, the latter of which may be surrounded by cromlechs. This points to a heterogeneous ethno-linguistic population (see section below).

Late in the history of this culture, its people built kurgans of greatly varying sizes, containing greatly varying amounts and types of metalwork, with larger, wealthier kurgans surrounded by smaller kurgans containing less wealth. They are also remarkable for the production of wheeled vehicles (wagons and carts), which were sometimes included in burial kurgans. This trend suggests the eventual emergence of a marked social hierarchy.

The culture is closely linked to the approximately contemporaneous Maykop culture of Transcaucasia. The Kura-Araxes culture was contiguous, and had mutual influences, with the Maikop culture in the Northwest Caucasus. Similarities between some features and objects of the Maikop and Kura-Araxes cultures, such as large square graves, the bold-relief curvilinear ornamentation of pottery, ochre-coloured ceramics, earthen hearth props with horn projections, flint arrowheads, stone axes and copper pitchforks are indicative of a cultural unity that pervaded the Caucasus in the Neolithic Age.

Hurrian and Urartian elements are quite probable, as are Northeast Caucasian ones. Some authors subsume Hurrians and Urartians under Northeast Caucasian as well as part of the Alarodian theory. The presence of Kartvelian languages was also highly probable. Influences of Semitic languages and Indo-European languages are also highly possible, though the presence of the languages on the lands of the Kura–Araxes culture is more controversial. In the Armenian hypothesis of Indo-European origins, this culture (and perhaps that of the Maykop culture) is identified with the speakers of the Anatolian languages.

The Anatolian branch is generally considered the earliest to split from the Proto-Indo-European language, from a stage referred to either as Indo-Hittite or “Middle PIE”; typically a date in the mid-4th millennium BC is assumed. Statistical research by Quentin Atkinson and others using Bayesian inference and glottochronological markers favors an Indo-European origin in Anatolia, though the method’s validity and accuracy are subject to debate.

The oldest Indo-European language is Anatolian. Luwian (or, to English speakers, Luvian) may well have been the language of Homer’s Troy, destroyed ca. 1250 BC. Hittite, the oldest and most richly attested of these languages, was spoken in Central Anatolia by historical Hittite kings (ca. 1650-1180 BC) and, before that, probably as early as 2000 BC at Kanesh (Kultepe).

The Armenian language, the Indo-European language spoken by the Armenians, shows a large percentage of loans from Iranian languages, something that initially led linguists to erroneously classify Armenian as an Iranian language. The distinctness of Armenian was only recognized when Hübschmann (1875) used the comparative method to distinguish two layers of Iranian loans from the older Armenian vocabulary.

W. M. Austin (1942) concluded that there was an early contact between Armenian and Anatolian languages, based on what he considered common archaisms, such as the lack of a feminine and the absence of inherited long vowels. However, unlike shared innovations (or synapomorphies), the common retention of archaisms (or symplesiomorphy) is not necessarily considered evidence of a period of common isolated development.

Soviet linguist Igor Diakonov (1985) noted the presence in Old Armenian of what he calls a Caucasian substratum, identified by earlier scholars, consisting of loans from the Kartvelian and Northeast Caucasian languages such as Udi. Noting that the Hurro-Urartian peoples inhabited the Armenian homeland in the second millennium b.c., Diakonov identifies in Armenian a Hurro-Urartian substratum of social, cultural, and animal and plant terms such as ałaxin “slave girl” (< Hurr. al(l)a(e)ḫḫenne), cov “sea” (< Urart. ṣûǝ “(inland) sea”), ułt “camel” (< Hurr. uḷtu), and xnjor “apple(tree)” (< Hurr. ḫinzuri).

Some of the terms he gives admittedly have an Akkadian or Sumerian provenance, but he suggests they were borrowed through Hurrian or Urartian. Given that these borrowings do not undergo sound changes characteristic of the development of Armenian from Proto-Indo-European, he dates their borrowing to a time before the written record but after the Proto-Armenian language stage.

Graeco-Aryan (or Graeco-Armeno-Aryan) is a hypothetical clade within the Indo-European family, ancestral to the Greek language, the Armenian language, and the Indo-Iranian languages. Graeco-Aryan unity would have become divided into Proto-Greek and Proto-Indo-Iranian by the mid 3rd millennium BC. The Phrygian language would also be included. Conceivably, Proto-Armenian would have been located between Proto-Greek and Proto-Indo-Iranian, consistent with the fact that Armenian shares certain features only with Indo-Iranian (the satem change) but others only with Greek (s > h).

Graeco-Armeno-Aryan has comparatively wide support among Indo-Europeanists for the Indo-European Homeland to be located in the Armenian Highland. Early and strong evidence was given by Euler’s 1979 examination on shared features in Greek and Sanskrit nominal flection.

Used in tandem with the Graeco-Armeno-Aryan hypothesis, the Armenian language would also be included under the label Aryano-Greco-Armenic, splitting into proto-Greek/Phrygian and “Armeno-Aryan” (ancestor of Armenian and Indo-Iranian).

In the context of the Kurgan hypothesis, Greco-Aryan is also known as “Late PIE” or “Late Indo-European” (LIE), suggesting that Greco-Aryan forms a dialect group which corresponds to the latest stage of linguistic unity in the Indo-European homeland in the early part of the 3rd millennium BC. By 2500 BC, Proto-Greek and Proto-Indo-Iranian had separated, moving westward and eastward from the Pontic Steppe, respectively.

If Graeco-Aryan is a valid group, Grassmann’s law may have a common origin in Greek and Sanskrit. (Note, however, that Grassmann’s law in Greek postdates certain sound changes that happened only in Greek and not Sanskrit, which suggests that it cannot strictly be an inheritance from a common Graeco-Aryan stage. Rather, it is more likely an areal feature that spread across a then-contiguous Graeco-Aryan-speaking area after early Proto-Greek and Proto-Indo-Iranian had developed into separate dialects but before they ceased being in geographic contact.)

The Yamna culture is identified with the late Proto-Indo-Europeans (PIE) in the Kurgan hypothesis of Marija Gimbutas. It is the strongest candidate for the Urheimat (homeland) of the Proto-Indo-European language, along with the preceding Sredny Stog culture, now that archaeological evidence of the culture and its migrations has been closely tied to the evidence from linguistics.

Pavel Dolukhanov argues that the emergence of the Pit-Grave culture represents a social development of various local Bronze Age cultures, representing “an expression of social stratification and the emergence of chiefdom-type nomadic social structures”, which in turn intensified inter-group contacts between essentially heterogeneous social groups.

The linguistic composition of the Catacomb culture is unclear. Within the context of the Kurgan hypothesis expounded by Marija Gimbutas, an Indo-European component is hard to deny, particularly in the later stages. Placing the ancestors of the Greek, Armenian and Paleo-Balkan dialects here is tempting, as it would neatly explain certain shared features.

More recently, the Ukrainian archaeologist V. Kulbaka has argued that the Late Yamna cultures of ca. 3200–2800 BC, esp. the Budzhak, Starosilsk, and Novotitarovka groups, might represent the Greek-Armenian-“Aryan”(=Indo-Iranian) ancestors (Graeco-Aryan, Graeco-Armenian), and the Catacomb culture that of the “unified” (to ca. 2500 BC) and then “differentiated” Indo-Iranians.

Grigoryev’s (1998) version of the Armenian hypothesis connects Catacomb culture with Indo-Aryans, because catacomb burial ritual had roots in South-Western Turkmenistan from the early 4th millennium (Parkhai cemetery). The same opinion is supported by Leo Klejn in his various publications.

Little is known about the arrival of Proto-Greek speakers. The Mycenaean culture commenced circa 1650 BCE and is clearly an imported steppe culture. The close relationship between Mycenaean and Proto-Indo-Iranian languages suggest that they split fairly late, some time between 2500 and 2000 BCE.

Mycenaeans rose in prominence ca. 1600 BC and stayed in control of Greece until about 1100 BC. Evidence shows that they spoke an early form of Greek. They took control of Crete ca. 1450 BC. An abundance of Mycenaean pottery is found in Italy and Sicily, suggesting that they were in contact and traded with the Mycenaeans. Due to the influence of Minoan Crete the further south the site, the more the pottery is influenced by Minoan styles.

Mycenaean Greek, named after Mycenae, one of the major centres of Mycenaean Greece, is the most ancient attested form of the Greek language, spoken on the Greek mainland, Crete and Cyprus in the 16th to 12th centuries BC, before the hypothesised Dorian invasion which was often cited as the terminus post quem for the coming of the Greek language to Greece.

The language is preserved in inscriptions in Linear B, a script first attested on Crete before the 14th century BC. Most instances of these inscriptions are on clay tablets found in Knossos in central Crete, and in Pylos in the southwest of the Peloponnese. Other tablets have been found at Mycenae itself, Tiryns and Thebes and at Chania in Western Crete.

The tablets remained long undeciphered, and every conceivable language was suggested for them, until Michael Ventris deciphered the script in 1952 and by a preponderance of evidence proved the language to be an early form of Greek.

Compared with later Ancient Greek, Mycenaean preserves a number of archaic features of its Indo-European heritage. It also preserves PIE forms. This means that determining the actual pronunciation of written words is often difficult, and makes use of a combination of the PIE etymology of a word, its form in later Greek, and inconsistent spelling. Even so, for some words the pronunciation is not known exactly, esp. when the meaning is unclear from context or the word has no descendants in the later dialects.

The Dorian invasion is a concept devised by historians of Ancient Greece to explain the replacement of pre-classical dialects and traditions in southern Greece by the ones that prevailed in Classical Greece. The latter were named Dorian by the ancient Greek writers after the historical population that owned them, the Dorians.

Despite nearly 200 years of investigation, the historicity of the Dorian invasion has never been established. The meaning of the concept has become to some degree amorphous. The work done on it has mainly served to rule out various speculations. The possibility of a real Dorian invasion remains open.

Armenian Modal Haplotype, also known in the literature as Haplotype 35 (ht35), as opposed to the Western European ‘haplotype 15’, which comprises the Proto-Italo-Celtic P312/S116 and the Proto-Germanic U106/S21. It is associated with R1b1b2 characterized by DYS393=12.

This branch of R1b was the first that emerged from the Pontic Steppe. Greek and Anatolian branches of Indo-European people, including the Hittites, Lydians, Phrygians and Armenians, is included in the group. The Trojans also probably belonged to this group.

It includes R1b-L23/S141, its subclade L51/M412/S167, and its two subclades L11/S127/L151 (in central an northern Europe) and Z2103 (in Anatolia and Assyria). Altogether they are known as ‘haplotype 35’ (ht35)

Haplogroup R1b and R1a

It is not yet entirely clear when R1b crossed over from eastern Anatolia to the Pontic-Caspian steppe. This could have happened during or just after the Neolithic, or both. The genetic diversity of R1b being greater around the Caucasus it is hard to deny that R1b evolved there before entering the steppe world. It is possible that a first R1b migration from Anatolia in the 5th or even 6th millennium BCE introduced sheep into the steppe, an animal whose wool would play an important role in Celtic and Germanic (R1b branches of the Indo-Europeans) clothing traditions up to this day.

Another migration across the Caucasus happened shortly before 3700 BCE, when the Maykop culture, the world’s first Bronze Age society, appeared apparently out of nowhere in the north-west Caucasus. The origins of Maykop are still uncertain, but archeologists have linked it to contemporary Chalcolithic cultures in Assyria and western Iran.

Archeology also shows a clear diffusion of bronze working and kurgan-type burials from the Maykop culture to the Pontic Steppe, where the Yamna culture developed soon afterwards (from 3500 BCE). Kurgan (a.k.a. tumulus) burials would become a dominant feature of ancient Indo-European societies and were widely used by the Celts, Romans, Germanic tribes, and Scythians, among others.

Middle Eastern R1b people had been living and blending to some extent with the local R1a foragers and herders at the steppes for over a millennium, perhaps even two or three. The close cultural contact and interactions between R1a and R1b people all over the Pontic-Caspian Steppe resulted in the creation of a common vernacular, a new lingua franca, which linguists have called Proto-Indo-European (PIE).

Linguistic similarities exist between PIE and Caucasian and Hurrian languages in the Middle East on the one hand, and Uralic languages in the Volga-Ural region on the other hand, which makes the Pontic Steppe the perfect intermediary region.

During the Yamna period cattle and sheep herders adopted wagons to transport their food and tents, which allowed them to move deeper into the steppe, giving rise to a new mobile lifestyle that would eventually lead to the great Indo-European migrations. This type of mass migration in which whole tribes moved with the help of wagons was still common in Gaul at the time of Julius Caesar, and among Germanic peoples in the late Antiquity.

The Yamna horizon was not a single, unified culture. In the south, along the northern shores of the Black Sea coast until the the north-west Caucasus, was a region of open steppe, expanding eastward until the Caspian Sea, Siberia and Mongolia (the Eurasian Steppe).

The western section, between the Don and Dniester Rivers (and later the Danube), was the one most densely settled by R1b people, with only a minority of R1a people (5-10%). The eastern section, in the Volga basin until the Ural mountains, was inhabited by R1a people with a substantial minority of R1b people (whose descendants can be found among the Bashkirs, Turkmans, Uyghurs and Hazaras, among others).

The northern part of the Yamna horizon was forest-steppe occupied by R1a people, also joined by a small minority of R1b (judging from modern Russians and Belarussians, the frequency of R1b was from seven to nine times less lower than R1a).

The western branch would migrate to the Balkans and Greece, then to central and Western Europe, and back to their ancestral Anatolia in successive waves (Hittites, Phrygians, Armenians, etc.). The eastern branch would migrate to Central Asia, Xinjiang, Siberia, and South Asia (Iran, Pakistan, India). The northern branch would evolve into the Corded Ware culture and disperse around the Baltic, Poland, Germany and Scandinavia.

Recent studies suggest that haplogroup R1b1a2-M269, which is the most common lineage in the European populations, was spread with first farmers via Anatolia to Europe during the Neolithic transition. These studies, however, did not include indigenous populations from the Armenian plateau, though it has played a key role in the ancient human migrations since early Paleolithic.

Y-chromosomal data collected in three Armenian geographic groups from eastern and western parts of the Armenian plateau, and comparative datasets of various European populations used to assess the genetic contribution of the region, shows that the frequency of haplogroup R1b1a2-M269 in eastern Armenian populations is higher compared with eastern European populations (including Anatolia) and lower than in Western Europe.

The rate of the variance and age of the R1b1a2-M269 is the highest in western Armenian population among all datasets considered, and that this haplogroup has been spread of north- and westward. In addition, there is a strong correlation between the genetic and geographic distances of the populations studied thus reflecting the directions of pre-Neolithic and Neolithic migrations from the Near East.

The origins of R1b are not entirely clear to this day. Some of the oldest forms of R1b are found in the Near East and around the Caucasus. Haplogroup R1* and R2* might have originated in southern Central Asia (between the Caspian and the Hindu Kush). A branch of R1 would have developed into R1b* then R1b1* in the northern part of the Middle East during the Ice Age.

Whereas R1b1 is found is such places as the Levant or Cameroon, R1b1b mostly likely originated in north-eastern Anatolia. It presumptively moved to northern Anatolia and across the Caucasus during the early Neolithic, where it became R1b1b.

The Near Eastern leftovers evolved into R1b1a (M18), now found at low frequencies among the Lebanese and the Druze.The Phoenicians (who came from modern day Lebanon) spread this R1b1a and R1b1* to their colonies, notably Sardinia and the Maghreb.

The subclades R1b1b1 and R1b1b2 (the most common form in Europe) are closely associated with the spread of Indo-European languages, as attested by its presence in all regions of the world where Indo-European languages were spoken in ancient times, from the Atlantic coast of Europe to the Indian subcontinent, including almost all Europe (except Finland and Bosnia-Herzegovina), Anatolia, Armenia, Europan Russia, southern Siberia, many pockets around Central Asia (notably Xinjiang, Turkmenistan, Tajikistan and Afghanistan), without forgetting Iran, Pakistan, India and Nepal.

The R1b branch of the Indo-Europeans is thought to have originated in the southern Yamna culture (northern shores of the Black Sea). It was the first one to move from the steppes to Europe, invading the Danube delta around 4200 BCE, then making its way around the Balkans and the Hungarian plain in the 4th millennium BCE.

These cultures from the late Neolithic and into the Iron Age, with specific traits such as Kurgan burials and horse domestication, have been associated with the dispersal of Indo-European languages across Eurasia.

The dramatic expansion of the Proto-Indo-Europeans was possible thanks to an early adoption of bronze weapons and the domestication of the horse in the Eurasian steppes (circa 4000-3500 BCE). Archaeologists recognize a complex of inter-related and relatively mobile cultures living on the Eurasian steppe, part of which protrudes into Europe as far west as Ukraine.

The history of R1b and R1a are intricately connected to each others. While the southern Steppe culture is believed to have carried predominantly R1b (M269 and M73) lineages, the northern forest-steppe culture would have been essentially R1a-dominant.

Haplogroup R1a probably branched off from R1* around the time of the Last Glacial Maximum (19,000 to 26,000 years before present). Little is know for certain about its place of origin. Some think it might have originated in the Balkans or around Pakistan and Northwest India, due to the greater genetic diversity found in these regions.

The diversity can be explained by other factors though. The Balkans have been subject to 5000 years of migrations from the Eurasian Steppes, each bringing new varieties of R1a.

South Asia has had a much bigger population than any other parts of the world (occasionally equalled by China) for at least 10,000 years, and larger population bring about more genetic diversity. The most likely place of origin of R1a is Central Asia or southern Russia/Siberia.

The first forays of steppe people into the Balkans happened between 4200 BCE and 3900 BCE, when horse riders crossed the Dniester and Danube and apparently destroyed the towns of the Gumelnita, Varna and Karanovo VI cultures in Eastern Romania and Bulgaria.

A climatic change resulting in colder winters during this exact period probably pushed steppe herders to seek milder pastures for their stock, while failed crops would have led to famine and internal disturbance within the Danubian and Balkanic communities.

The ensuing Cernavoda culture (Copper Age, 4000-3200 BCE), Coțofeni culture (Copper to Bronze Age, 3500-2500 BCE) and Ezero culture (Bronze Age, 3300-2700 BCE), in modern Romania, seems to have had a mixed population of steppe immigrants and people from the old tell settlements. These steppe immigrants were likely a mixture of both R1a and R1b lineages, with a probably higher percentage of R1a than later Yamna-era invasions.

The steppe invaders would have forced many Danubian farmers to migrate to the Cucuteni-Trypillian towns in the eastern Carpathians, causing a population boom and a north-eastward expansion until the Dnieper valley, bringing Y-haplogroups G2a, I2a1 (probably the dominant lineage of the Cucuteni-Trypillian culture), E1b1b, J and T in what is now central Ukraine.

This precocious Indo-European advance westward was fairly limited, due to the absence of Bronze weapons and organised army at the time, and was indeed only possible thanks to climatic catastrophes which reduced the defences of the towns of Old Europe. The Carphatian, Danubian, and Balkanic cultures were too densely populated and technologically advanced to allow for a massive migration.

In comparison the forest-steppe R1a people successfully penetrated into the heart of Europe with little hindrance, due to the absence of developed agrarian societies around Poland and the Baltic. The Corded Ware (Battle Axe) culture (3200-1800 BCE) was a natural western expansion of the Yamna culture, reaching as far west as Germany and as far north as Sweden and Norway.

DNA analysis from the Corded Ware culture site of Eulau confirms the presence of R1a (but not R1b) in central Germany around 2600 BCE. The Corded Ware tribes expanded from the northern fringe of the Yamna culture where R1a lineages were prevalent over R1b ones.

The expansion of R1b people into Old Europe was slower, but proved inevitable. In 2800 BCE, by the time the Corded Ware had already reached Scandinavia, the Bronze Age R1b cultures had barely moved into the Pannonian steppe.

They established major settlements in the Great Hungarian Plain, the most similar habitat to their ancestral Pontic Steppes. Around 2500 BCE, the western branch of Indo-European R1b were poised for their next major expansion into modern Germany and Western Europe.

By that time, the R1b immigrants had blended to a great extent with the indigenous Mesolithic and Neolithic populations of the Danubian basin, where they had now lived for 1,700 years.

The strongly partriarchal Indo-European elite remained almost exclusively R1b on the paternal side, but absorbed a high proportion of non-Indo-European maternal lineages. Hybridised, the new Proto-Indo-European R1b people would have lost most of their remaining Proto-Europoid or Mongolid features inherited from their Caspian origins (which were still clearly visible in numerous individuals from the Yamna period). Their light hair, eye and skin pigmentation, once interbred with the darker inhabitants of Old Europe, became more like that of modern Southern Europeans.

The Indo-Europeans’s bronze weapons and horses would have given them a tremendous advantage over the autochthonous inhabitants of Europe, namely the native haplogroup I (descendant of Cro-Magnon), and the early Neolithic herders and farmers (G2a, J, E1b1b and T). This allowed R1a and R1b to replace most of the native male lineages, although female lineages seem to have been less affected.

A comparison with the Indo-Iranian invasion of South Asia shows that 40% of the male linages of northern India are R1a, but less than 10% of the female lineages could be of Indo-European origin. The impact of the Indo-Europeans was more severe in Europe because European society 4,000 years ago was less developed in terms of agriculture, technology (no bronze weapons) and population density than that of the Indus Valley civilization. This is particularly true of the native Western European cultures where farming arrived much later than in the Balkans or Central Europe.

Greece, the Balkans and the Carpathians were the most advanced of European societies at the time and were the least affected in terms of haplogroup replacement. Native European Y-DNA haplogroups (I1, I2) also survived better in regions that were more difficult to reach or less hospitable, like Scandinavia, southern Switzerland, Sardinia or the Dinaric Alps.

The R1a people of the Corded Ware culture would come across far less populous societies in Northern Europe, mostly descended from the lighter Mesolithic population (haplogroup I1 and I2), and therefore retain more of their original pigmentation (although facial traits evolved considerably in Scandinavia, where the I1 inhabitants were strongly dolicocephalic and long-faced, as opposed to the brachycephalic and broad-faced steppe people).

The forest-steppe origin of this culture is obvious from the introduction of corded pottery and the abundant use of polished battle axes, the two most prominent features of the Corded Ware culture.

The migration of the R1b people to central and Western Europe left a vacuum for R1a people in the southern steppe around the time of the Catacomb culture (2800-2200 BCE). The first expansion of the forest-steppe people occured with the Corded Ware Culture.

This is also probably when the satemisation process of the Indo-European languages began since the Balto-Slavic and Indo-Iranian language groups belong to the same Satem isogloss and both appear to have evolved from the the Catacomb culture.

Ancient DNA testing has confirmed the presence of haplogroup R1a1a in samples from the Corded Ware culture in Germany (2600 BCE), from Tocharian mummies (2000 BCE) in Northwest China, from Kurgan burials (circa 1600 BCE) from the Andronovo culture in southern Russia and southern Siberia, as well as from a variety of Iron-age sites from Russia, Siberia, Mongolia and Central Asia.

The first major expansion of R1a, thought to have been the dominant haplogroup among the northern and eastern Proto-Indo-European language speakers, that evolved into the Indo-Iranian, Thracian, Baltic and Slavic branches, took place with the westward propagation of the Corded Ware culture from the northern forest-steppe in the Yamna homeland. This was the first wave of R1a into Europe, the one that brought the Z283 subclade to Germany and the Netherlands, and Z284 to Scandinavia.

The Corded Ware R1a people would have mixed with the pre-Germanic I1 and I2 aborigines, which resulted in the first Indo-European culture in Germany and Scandinavia, although that culture could not be considered Proto-Germanic – it was simply Proto-Indo-European at that stage, or perhaps or Proto-Balto-Slavic.

Proto-Germanic language probably developed as a blend of two branches of Indo-European languages, namely the Proto-Balto-Slavic language of the Corded-Ware culture (R1a-Z283) and the later arrival of Proto-Italo-Celto-Germanic people from the Unetice culture (R1b-L11).

This is supported by the fact that Germanic people are a R1a-R1b hybrid, that these two haplogroups came via separate routes at different times, and that Proto-Germanic language is closest to Proto-Italo-Celtic, but also shares similarities with Proto-Slavic. Germanic languages probably did not appear before the Nordic Bronze Age (1800-500 BCE).

It is likely that a minority of R1a people accompanied this R1b migration. Those R1a men would have belonged to the L664 subclade, the first to split from the Yamna core. These early steppe invaders were not a homogeneous group, but a cluster of tribes.

It is possible that the R1a-L664 people were one or several separate tribes of their own, or that they mixed with some R1b lineages, notably R1b-U106, which would become the main Germanic lineage many centuries later.

The R1b conquest of Europe happened in two phases. For nearly two millennia, starting from circa 4200 BCE, steppe people limited their conquest to the rich Chalcolithic civilisations of the Carpathians and the Balkans. These societies possessed the world’s largest towns, notably the tell settlements of the Cucuteni-Tripolye culture.

Nothing incited the R1b conquerors to move further into Western Europe at such an early stage, because most of the land north and west of the Alps was still sparsely populated woodland. The Neolithic did not reach the British Isles and Scandinavia before circa 4000 BCE. Even northern France and most of the Alpine region had been farming or herding for less than a millennium and were still quite primitive compared to Southeast Europe and the Middle East.

North-west Europe remained a tribal society of hunter-gatherers practising only limited agriculture for centuries after the conquest of the Balkans by the Indo-Europeans. Why would our R1b “conquistadors” leave the comfort of the wealthy and populous Danubian civilisations for the harsh living conditions that lie beyond ? Bronze Age people coveted tin, copper, and gold, of which the Balkans had plenty, but that no one had yet discovered in Western Europe.

R1b-L51 is thought to have arrived in Central Europe (Hungary, Austria, Bohemia) around 2500 BCE, approximately two millennia after the shift to the Neolithic in these regions. Agrarian towns had started to develop. Gold and copper had begun to be mined. The prospects of a conquest were now far more appealing.

The archeological and genetic evidence (distribution of R1b subclades) point at several consecutive waves towards eastern and central Germany between 2800 BCE and 2300 BCE. The R1b-R1a contingent moved up the Danube to the Panonian plain around 2800 BCE, brought to an end the local Bell Beaker (circa 2200 BCE) and Corded Ware (c. 2400 BCE) cultures in Central Europe, and set up the Unetice culture (2300-1600 BCE) around Bohemia and eastern Germany. Unetice can be seen as the source of future Germanic, Celtic and Italic cultures, and is associated with the L11 subclade of R1b.

The Proto-Italo-Celto-Germanic R1b people had settled in what is now Germany by 2300 BCE, where they founded the Unetice culture, probably the first culture in which R1b-L11 lineages played a major role.

It is interesting to note that the Unetice period happen to correspond to the end of the Maykop (2500 BCE) and Kemi Oba (2200 BCE) cultures on the northern shores of the Black Sea, and their replacement by cultures descended from the northern steppes. It can therefore be envisaged that the (mostly) R1b population from the northern half of the Black Sea migrated westward due to pressure from other Indo-European people (R1a) from the north, for example that of the burgeoning Proto-Indo-Iranian branch, linked to the contemporary Poltavka and Abashevo cultures.

Judging from the propagation of bronze working to Western Europe, those first Indo-Europeans reached France and the Low Countries by 2200 BCE, Britain by 2100 BCE and Ireland by 2000 BCE, and Iberia by 1800 BCE.

It is doubtful that the Bell Beaker culture (2800-1900 BCE) in Western Europe was already Indo-European because its attributes are in perfect continuity with the native Megalithic cultures. The Beaker phenomenon started during the Late Neolithic and Early Chalcolithic in Portugal and propagated to the north-east towards Germany.

During the same period Bronze Age steppe cultures spread from Germany in the opposite direction towards Iberia, France and Britain. It is more likely that the beakers and horses found across Western Europe during that period were the result of trade with neighbouring Indo-European cultures, including the first wave of R1b into Central Europe.

It is equally possible that the Beaker people were R1b merchants or explorers who travelled across Western Europe and brought back tales of riches poorly defended by Stone Age people and waiting to be conquered by the more advanced Indo-Europeans, with their bronze weapons and horses.

What is undeniable is that the following Unetice (2300-1600 BCE), Tumulus (1600-1200 BCE), Urnfield (1300-1200 BCE) and Hallstatt (1200-750 BCE) cultures were linked to the diffusion of R1b to Europe, as they abruptly introduce new technologies and a radically different lifestyle.

This first wave of R1b presumably carried R1b-L21 lineages in great number (perhaps because of a founder effect), as these are found everywhere in western, northern and Central Europe. The early split of L21 from the main Proto-Celtic branch around Germany would explain why the Q-Celtic languages (Goidelic and Hispano-Celtic) diverged so much from the P-Celtic branch (La Tène, Gaulish, Brythonic), which appears to have expanded from the later Urnfield and Hallstat cultures.

Some L21 lineages from the Netherlands and northern Germany later entered Scandinavia (from 1700 BCE) with the dominant subclade of the region, R1b-S21/U106 (see below). The stronger presence of L21 in Norway and Iceland can be attributed to the Norwegian Vikings, who had colonised parts of Scotland and Ireland and taken slaves among the native Celtic populations, whom they brought to their new colony of Iceland and back to Norway. Nowadays about 20% of all Icelandic male lineages are R1b-L21 of Scottish or Irish origin.

In France, R1b-L21 is mainly present in historical Brittany (including Mayenne and Vendée) and in Lower Normandy. This region was repopulated by massive immigration of insular Britons in the 5th century due to pressure from the invading Anglo-Saxons. However, it is possible that L21 was present in Armorica since the Bronze age or the Iron age given that the tribes of the Armorican Confederation of ancient Gaul already had a distinct identity from the other Gauls and had maintained close ties with the British Isles at least since the Atlantic Bronze Age.

The late Unetice culture expanded to Scandinavia, founding the Nordic Bronze Age. R1a-L664 and R1b (L11 and U106) presumably reached Scandinavia at this time. People from the Nordic Bronze Age probably spoke a Proto-Germanic language, which for over a thousand years acquired vocabulary from the indigenous Corded Ware language, itself a mixture of Proto-Balto-Slavic and non-IE pre-Germanic.

The first genuine Germanic tongue has been estimated by linguists to have come into existence around (or after) 500 BCE, just as the Nordic Bronze Age came to an end, giving way to the Pre-Roman Iron Age.

The uniqueness of some of the Germanic vocabulary points at borrowing from native pre-Indo-European languages (Germanic substrate theory). The Celtic language itself is known to have borrowed from Afro-Asiatic languages spoken by Near-Eastern immigrants to Central Europe. The fact that present-day Scandinavia is composed of roughly 40% of I1, 20% of R1a and 40% of R1b reinforces the idea that the Germanic ethnicity and language had acquired a tri-hybrid character by the Iron Age.

The Bronze Age did not appear in Iberia until 1800 BCE, and was mostly confined to the cultures of El Argar and Los Millares in south-east Spain, with sporadic sites showing up in Castile by 1700 BCE and in Extremadura and southern Portugal by 1500 BCE.

These Early Bronze Age sites typically did not have more than some bronze daggers or axes and cannot be considered proper Bronze Age societies, but rather Copper Age societies with occasional bronze artefacts (perhaps imported).

These cultures might have been founded by small groups of R1b adventurers looking for easy conquests in parts of Europe that did not yet have bronze weapons. They would have become a small ruling elite, would have had children with local women, and within a few generations their Indo-European language would have been lost, absorbed by the indigenous languages.

Iberia did not become a fully-fledged Bronze Age society until the 13th century BCE, when the Urnfield culture (1300-1200 BCE) expanded from Germany to Catalonia via southern France, then the ensuing Hallstatt culture (1200-750 BCE) spread throughout most of the peninsula (especially the western half). This period belongs to the wider Atlantic Bronze Age (1300-700 BCE), when Iberia was connected to the rest of Western Europe through a complex trade network.

It is hard to say when exactly DF27 entered Iberia. Considering its overwhelming presence in the peninsula and in south-west France, it is likely that DF27 arrived early, during the 1800 to 1300 BCE period, and perhaps even earlier, if R1b adventurers penetrated the Bell Beaker culture, as they appear to have done all over Western Europe from 2300 BCE to 1800 BCE. The Atlantic Bronze Age could correspond to the period when DF27 radiated more evenly around Iberia and ended up, following Atlantic trade routes, all the way to the British Isles, the Netherlands and western Norway (where M153 and SRY2728 make up about 1% of the population).