View source for Alternative models of Indo-European expansion

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This model uses mainly SNP investigation to support the general view of Archaeologists whereby Yamna migrants did not directly form the Corded Ware culture[Anthony 2007][Harrison and Heyd 2007][Heyd 2007][Heyd 2012][Kristiansen et al. 2017][Heyd 2017], correcting thus assumptions based solely on recent genetic research.

Communities formed mainly by R1b1a1a2a-L23 and R1a1a1b-Z645 lineages, which clearly expanded during the Chalcolithic – associated to Yamna and Corded Ware cultures, respectively – are assumed to have evolved differently in eastern Europe, albeit in close contact (probably in a neighbouring region) in light of the common ancestry they share.

Other models are compatible with the state of the art of genetic investigation, though. Listed here are possibilities compatible with the current knowledge, in decreasing order of probability:

== ''Kurgan people'' ==

Yamna clans of R1a1a1b-Z645 lineages existed and migrated to the north, but have not been sampled yet. This seems to be the preferred model in recent genetic papers, which support a direct Yamna > Corded Ware migration[Haak et al. 2015][Allentoft et al. 2015][Lazaridis et al. 2016]. 

This framework seems compatible with Kristiansen’s traditional model of Corded Ware culture development[Kristiansen 1989][Kristiansen et al. 2017], and also partially with that of Gimbutas[Gimbutas 1965][Gimbutas 1977], involving a gradual cultural (and population) contribution of Indo-Europeans from the steppe to east-central Europe. Centuries of contact between the Indo-Europeans from the steppe and the Baden and Globular Amphora cultures should have formed the [[Corded Ware culture|third Corded Ware horizon]] that expanded after ca. 3000 BC. 

This seems in part supported by steppe ancestry found in individuals from the Balkans and from [[Neolithic-Chalcolithic transition|Ukraine Eneolithic cultures]] of the 5th-4th millennia BC. All of them clearly show such steppe ancestry before the main Chalcolithic expansion of the Yamna culture[Mathieson et al. 2017][Haak et al. 2015]. 

However, it is in contrast with the lack of steppe ancestry in sampled distant individuals from Baden and Globular Amphora cultures[Mathieson et al. 2017]. Also, from a linguistic point of view, this long-lasting framework does not allow for the adoption of a Late Indo-European language by the Corded Ware culture, and would still leave the most obvious [[Late Indo-European]]-speaking expansion to the south-eastern spread of [[Yamna migration|Yamna migrants]].

On the other hand, the model presented in this paper, which supports a Corded Ware Substratum Hypothesis, would be compatible with eastern Yamna clans of R1a1a1b-Z645 lineages expanding a language ancestral to Slavic and Indo-Iranian with the Corded Ware culture, and therefore the substrate language would correspond to the original east-central region where the culture originated in the Late Neolithic. In that case, Kortlandt’s late ''Satem'' or Indo-Slavonic dialect[Kortlandt 2016b] could also be supported, but the common unconnected substratum of Balto-Slavic and Germanic[Kortlandt 2016a] would probably need further assumptions, like the Agricultural Substrate Hypothesis[Kristiansen et al. 2017][Kroonen 2012][Iversen and Kroonen 2017]. 

Problems with the “Kurgan” model (and similar ones) include:

*This model assumes the existence of differentiated clans with a majority of R1a1a1b-Z645 lineages coexisting with clans with a majority of R1b1a1a2a1-L51 subclades, either in the east or in the west – or, exceptionally, in both, since they are different dialectal areas. Both of them would have expanded during the Chalcolithic: R1a1a1b-Z645 clans to the north (possibly via the Prut), to form the third Corded Ware horizon, and R1b1a1a2a1-L51 and R1b1a1a2a2-Z2103 clans to the east into the Afanasevo culture, and west to form Yamna settlements of the Balkans. 

*It would need a framework for a sudden and direct contribution of Yamna to the creation of the Corded Ware culture, which currently does not exist. 

*The coexistence of such differentiated communities is in contrast with the natural evolution of male-dominated steppe societies of R1b1a1a2-M269 and R1b1a1a2a-L23 lineages, which underwent at least two important expansions, and must have therefore undergone a decrease in Y-DNA variability since the Mesolithic. 

*It is also in contrast with the lack of R1a1a1b-Z645 lineages in Yamna, and in western and south-eastern European cultures related to the expansion of Indo-European languages. A potential explanation for this lack of R1a1a1b-Z645 would be a sample selection bias, whereby western Yamna migrants of R1a1a1b-Z645 subclades and central-east European Corded Ware samples of R1b1a1a2a-L23 subclades have not yet been sampled. 

A further assumption of this model is that Corded Ware contributed to the creation of the Bell Beaker culture[Haak et al. 2015][Kristiansen et al. 2017], which is in contrast with mainstream archaeological models, and was based mainly on the influence of the Corded Ware outlier of Esperstedt in assessing steppe ancestry of the Corded Ware culture. The closer position of Bell Beaker samples from the Balkans to Yamna samples – closer than any other sample of the Corded Ware in PCA,  safe for the Corded Ware outlier[Olalde et al. 2017] –, as well as their connection to Vučedol and western Yamna ancestry, makes such a direct connection more and more unlikely.

<span class="plainlinks">[https://indo-european.eu/human-ancestry/principal-component-analysis-pca-and-eigensoft/ https://indo-european.eu/wp-content/uploads/2017/09/olalde-pca.png]</span>

<small>''Image from [https://doi.org/10.1101/135962 Olalde et al. (2017)].  «Principal component analysis of 990 present-day West Eurasian individuals (grey dots), with previously published (pale yellow) and new ancient samples projected onto the first two principal components»”. Original images under a [http://creativecommons.org/licenses/by-nc/4.0/ CC-BY-NC 4.0 International license].''</small>

== Founder effect / resurgence of R1a lineages or cultural diffusion ==

West Yamna was mainly composed of clans of R1b1a1a2a-L23 subclades, as supported in this model, but the admixture seen in Corded Ware samples from central and north-eastern Europe comes precisely from original Yamna migrants of R1b1a1a2a-L23 subclades that have not been sampled. These first generations of northern migrants would have travelled west and north-west, maybe involving those known to have settled north up the Prut River, possibly beginning as early as 3100 BC, but probably from ca. 3000 BC. 

This framework could be compatible with Anthony’s proposal of elites from the steppe dominating over the Usatovo culture[Anthony 2007][Anthony 2010][Anthony and Ringe 2015].

On the other hand, Anthony’s model would still need a majority of the Usatovo population mainly composed of R1a1a1b-Z645 lineages, and with a previous ancestry closest to the east Yamna population, as well as a resurge of R1a1a1b-Z645 lineages within few generations, so that previous “native” admixture and Yamna lineages could go unnoticed in the Corded Ware population sampled. To sample individuals from only a few generations is difficult, apart from the indemonstrable proposal (advanced by Anthony) that the general Usatovo population would have adopted the prestige language of the elites (in this case Pre-Germanic) by way of cultural diffusion. It also leaves open the same possibility for multiple (as unlikely and as indemonstrable) cultural diffusions among Corded Ware groups due to the technological superiority of the Yamna culture, e.g. of Proto-Balto-Slavic to the Middle Dnieper culture.

== R1b-L51 from the west and cultural diffusion ==

West Yamna clans were mainly composed of clans of R1b1a1a2a2-Z2103 lineages, which expanded with Yamna migrants to the west. Subclade R1b1a1a2a1-L51 (and especially R1b1a1a2a1-L151 subclades) may have split after the Neolithic expansion associated with Middle Indo-European, and developed a society in central and south-eastern Europe.

It would have later adopted the ‘Yamna package’, developing the East Bell Beaker group that later expanded further to the west. That could be supported by the finding of a R1b1a1a2a2-Z2103 subclade in Vučedol, and by the lack of R1b1a1a2a1-L51 subclades in Yamna. This model could be linked with the proposed origin of Proto-Indo-European in western or central Europe[Cunliffe and Koch 2012].

This is in contrast with estimated dates of haplogroup formation, and the inferred history from ancient samples. The evolution of R1b1a1a2-M269 and R1b1a1a2a-L23 lineages within the steppe since the Mesolithic, the quite late TMRCA for R1b1a1a2a-L23, and the finding of an R1b1a1a2a-L23(xZ2013) subclade in eastern Yamna all point to an internal evolution of these subclades. This and the expansion of R1b1a1a2a1-L151 subclades (but not R1b1a1a2a1-L51) with the Bell Beaker culture, probably evolved from Yamna migrants in the westernmost region, makes the eventual appearance of R1b1a1a2a1-L51 subclades in west Yamna quite likely.

This model would also allow for a Yamna region hiding unsampled clans of R1a1a1b-Z645 lineages, as in the “Kurgan people” model.

== Anatolian hypothesis ==

An alternative hypothesis is that the Proto-Indo-European homeland was in the Caucasus or Iran, and expanded through Anatolia, which can be linked to the most recent proposals of the Anatolian hypothesis[Renfrew 2003]. 

The current genetic models are not, however, compatible with the Armenian homeland hypothesis[Gamkrelidze and Ivanov 1995], which suggests a more recent expansion of Late Indo-European from the Armenian highland. 

A westward movement associated with the CHG ancestry may have thus contributed to the dispersal of Anatolian languages, seen in the contribution of CHG to Anatolian peoples during different Neolithic and Chalcolithic waves. The northward mixture of CHG with EHG ancestry in the steppe may signal the formation of Indo-European-speaking steppe population associated with the Chalcolithic expansion of Late Indo-European[Mathieson et al. 2017][Lazaridis et al. 2017].

In line with this model, one could support the North Pontic Hypothesis, whereby the Proto-Indo-European homeland should be placed north of the Black Sea, linked to Old European cultures, and in contact with potentially related Uralic and Semitic languages[Vander Linden 2004].

However, haplogroup analysis reveals a prevalence of J-M304 lineages associated with CHG expansion into Anatolia, probably related to movements within the Fertile Crescent, which is not seen in the Yamna population. This suggests a different type of spread for this component in the steppe.

No archaeological models show such a strong wave of migrants from the south into the steppe, but it shows continuous contacts of steppe cultures with Transcaucasian cultures since the Mesolithic. It is therefore more likely that the CHG contribution came from a long-term inter-regional gene flow that began early, probably coinciding with Neolithic population movements within the steppe.

Controversial linguistic macro-families are also compatible with other mainstream models of expansion.

== References ==

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* [*Harrison and Heyd 2007] Harrison, Richard, and Volker Heyd. 2007. The Transformation of Europe in the Third Millennium BC: the example of ‘Le Petit-Chasseur I + III’ (Sion, Valais, Switzerland). Praehistorische Zeitschrift 82 (2).

* [*Heyd 2007] Heyd, Volker. 2007 [https://www.academia.edu/1249528/_2011_V._Heyd_Yamnaya_Groups_and_Tumuli_west_of_the_Black_Sea._In_Ancestral_Landscapes._Ed._by_E._Borgna_and_S._M%C3%BCller_Celka._TMO_58_Lyon_p._536-555 Yamnaya gropus and tumuli west of the Black Sea]. Travaux de la Maison de l'Orient et de la Méditerranée. Série recherches archéologiques 58 (1):535-555.

* [*Heyd 2012] Heyd, Volker. 2012. Yamnaya gropus and tumuli west of the Black Sea. Travaux de la Maison de l'Orient et de la Méditerranée. Série recherches archéologiques 58 (1):535-555.

* [*Heyd 2017] Heyd, Volker. 2017. Kossinna's smile. Antiquity 91 (356):348-359.

* [*Iversen and Kroonen 2017] Iversen, Rune, and Guus Kroonen. 2017. Talking Neolithic: Linguistic and Archaeological Perspectives on How Indo-European Was Implemented in Southern Scandinavia. American Journal of Archaeology 121 (4):511-525.

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* [*Gimbutas 1965] Gimbutas, Marija. 1965. Bronze Age cultures in Central and Eastern Europe. The Hague: Mouton & Co.

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* [*Kortlandt 2016b]Kortlandt, Frederik. 2016. Balto-Slavic and Indo-Iranian. Baltistica 51 (2):355-364.

* [*Kristiansen 1989] Kristiansen, Kristian. 1989. Prehistoric Migrations - the Case of the Single Grave and Corded Ware Cultures. Journal of Danish Archaeology 8 (1):211-225.

* [*Kristiansen et al. 2017] Kristiansen, Kristian, Morten E. Allentoft, Karin M. Frei, Rune Iversen, Niels N. Johannsen, Guus Kroonen, Łukasz Pospieszny, T. Douglas Price, Simon Rasmussen, Karl-Göran Sjögren, Martin Sikora, and Eske Willerslev. 2017. Re-theorising mobility and the formation of culture and language among the Corded Ware Culture in Europe. Antiquity 91 (356):334-347.

* [*Kroonen 2012] Kroonen, Guus. 2012. Non-Indo-European root nouns in Germanic: Evidence in support of the Agricultural Substrate Hypothesis. In A Linguistic Map of Prehistoric Northern Europe, edited by R. Grünthal and P. Kallio. Helsinki: Suomalais-Ugrilaisen Seura.

* [*Lazaridis et al. 2016] Lazaridis, I., D. Nadel, G. Rollefson, D. C. Merrett, N. Rohland, S. Mallick, D. Fernandes, M. Novak, B. Gamarra, K. Sirak, S. Connell, K. Stewardson, E. Harney, Q. Fu, G. Gonzalez-Fortes, E. R. Jones, S. A. Roodenberg, G. Lengyel, F. Bocquentin, B. Gasparian, J. M. Monge, M. Gregg, V. Eshed, A. S. Mizrahi, C. Meiklejohn, F. Gerritsen, L. Bejenaru, M. Bluher, A. Campbell, G. Cavalleri, D. Comas, P. Froguel, E. Gilbert, S. M. Kerr, P. Kovacs, J. Krause, D. McGettigan, M. Merrigan, D. A. Merriwether, S. O'Reilly, M. B. Richards, O. Semino, M. Shamoon-Pour, G. Stefanescu, M. Stumvoll, A. Tonjes, A. Torroni, J. F. Wilson, L. Yengo, N. A. Hovhannisyan, N. Patterson, R. Pinhasi, and D. Reich. 2016. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5003663/ Genomic insights into the origin of farming in the ancient Near East]. Nature 536 (7617):419-24. https://dx.doi.org/10.1038/nature19310

* [*Lazaridis et al. 2017] Lazaridis, Iosif, Alissa Mittnik, Nick Patterson, Swapan Mallick, Nadin Rohland, Saskia Pfrengle, Anja Furtwängler, Alexander Peltzer, Cosimo Posth, Andonis Vasilakis, P. J. P. McGeorge, Eleni Konsolaki-Yannopoulou, George Korres, Holley Martlew, Manolis Michalodimitrakis, Mehmet Özsait, Nesrin Özsait, Anastasia Papathanasiou, Michael Richards, Songül Alpaslan Roodenberg, Yannis Tzedakis, Robert Arnott, Daniel M. Fernandes, Jeffery R. Hughey, Dimitra M. Lotakis, Patrick A. Navas, Yannis Maniatis, John A. Stamatoyannopoulos, Kristin Stewardson, Philipp Stockhammer, Ron Pinhasi, David Reich, Johannes Krause, and George Stamatoyannopoulos. 2017. Genetic origins of the Minoans and Mycenaeans. Nature 548 (7666):214-218.

* [*Mathieson et al. 2017] Mathieson, Iain, Songül Alpaslan Roodenberg, Cosimo Posth, Anna Szécsényi-Nagy, Nadin Rohland, Swapan Mallick, Iñigo Olade, Nasreen Broomandkhoshbacht, Olivia Cheronet, Daniel Fernandes, Matthew Ferry, Beatriz Gamarra, Gloria González Fortes, Wolfgang Haak, Eadaoin Harney, Ben Krause-Kyora, Isil Kucukkalipci, Megan Michel, Alissa Mittnik, Kathrin Nägele, Mario Novak, Jonas Oppenheimer, Nick Patterson, Saskia Pfrengle, Kendra Sirak, Kristin Stewardson, Stefania Vai, Stefan Alexandrov, Kurt W. Alt, Radian Andreescu, Dragana Antonović, Abigail Ash, Nadezhda Atanassova, Krum Bacvarov, Mende Balázs Gusztáv, Hervé Bocherens, Michael Bolus, Adina Boroneanţ, Yavor Boyadzhiev, Alicja Budnik, Josip Burmaz, Stefan Chohadzhiev, Nicholas J. Conard, Richard Cottiaux, Maja Čuka, Christophe Cupillard, Dorothée G. Drucker, Nedko Elenski, Michael Francken, Borislava Galabova, Georgi Ganetovski, Bernard Gely, Tamás Hajdu, Veneta Handzhyiska, Katerina Harvati, Thomas Higham, Stanislav Iliev, Ivor Janković, Ivor Karavanić, Douglas J. Kennett, Darko Komšo, Alexandra Kozak, Damian Labuda, Martina Lari, Catalin Lazar, Maleen Leppek, Krassimir Leshtakov, Domenico Lo Vetro, Dženi Los, Ivaylo Lozanov, Maria Malina, Fabio Martini, Kath McSweeney, Harald Meller, Marko Menđušić, Pavel Mirea, Vyacheslav Moiseyev, Vanya Petrova, T. Douglas Price, Angela Simalcsik, Luca Sineo, Mario Šlaus, Vladimir Slavchev, Petar Stanev, Andrej Starović, Tamás Szeniczey, Sahra Talamo, Maria Teschler-Nicola, Corinne Thevenet, Ivan Valchev, Frédérique Valentin, Sergey Vasilyev, Fanica Veljanovska, Svetlana Venelinova, Elizaveta Veselovskaya, Bence Viola, Cristian Virag, Joško Zaninović, Steve Zäuner, Philipp W. Stockhammer, Giulio Catalano, Raiko Krauß, David Caramelli, Gunita Zariņa, Bisserka Gaydarska, Malcolm Lillie, Alexey G. Nikitin, Inna Potekhina, Anastasia Papathanasiou, Dušan Borić, Clive Bonsall, Johannes Krause, Ron Pinhasi, and David Reich. 2017. The Genomic History Of Southeastern Europe. bioRxiv. https://doi.org/10.1101/135616

* [*Olalde et al. 2017] Olalde, Iñigo, Selina Brace, Morten E. Allentoft, Ian Armit, Kristian Kristiansen, Nadin Rohland, Swapan Mallick, Thomas Booth, Anna Szécsényi-Nagy, Alissa Mittnik, Eveline Altena, Mark Lipson, Iosif Lazaridis, Nick J. Patterson, Nasreen Broomandkhoshbacht, Yoan Diekmann, Zuzana Faltyskova, Daniel M. Fernandes, Matthew Ferry, Eadaoin Harney, Peter de Knijff, Megan Michel, Jonas Oppenheimer, Kristin Stewardson, Alistair Barclay, Kurt W. Alt, Azucena Avilés Fernández, Eszter Bánffy, Maria Bernabò-Brea, David Billoin, Concepción Blasco, Clive Bonsall, Laura Bonsall, Tim Allen, Lindsey Büster, Sophie Carver, Laura Castells Navarro, Oliver Edward Craig, Gordon T. Cook, Barry Cunliffe, Anthony Denaire, Kirsten Egging Dinwiddy, Natasha Dodwell, Michal Ernée, Christopher Evans, Milan Kuchařík, Joan Francès Farré, Harry Fokkens, Chris Fowler, Michiel Gazenbeek, Rafael Garrido Pena, María Haber-Uriarte, Elżbieta Haduch, Gill Hey, Nick Jowett, Timothy Knowles, Ken Massy, Saskia Pfrengle, Philippe Lefranc, Olivier Lemercier, Arnaud Lefebvre, Joaquín Lomba Maurandi, Tona Majó, Jacqueline I. McKinley, Kathleen McSweeney, Mende Balázs Gusztáv, Alessandra Modi, Gabriella Kulcsár, Viktória Kiss, András Czene, Róbert Patay, Anna Endródi, Kitti Köhler, Tamás Hajdu, João Luís Cardoso, Corina Liesau, Michael Parker Pearson, Piotr Włodarczak, T. Douglas Price, Pilar Prieto, Pierre-Jérôme Rey, Patricia Ríos, Roberto Risch, Manuel A. Rojo Guerra, Aurore Schmitt, Joël Serralongue, Ana Maria Silva, Václav Smrčka, Luc Vergnaud, João Zilhão, David Caramelli, Thomas Higham, Volker Heyd, Alison Sheridan, Karl-Göran Sjögren, Mark G. Thomas, Philipp W. Stockhammer, Ron Pinhasi, Johannes Krause, Wolfgang Haak, Ian Barnes, Carles Lalueza-Fox, and David Reich. 2017. The Beaker Phenomenon And The Genomic Transformation Of Northwest Europe. bioRxiv. https://doi.org/10.1101/135962

* [*Renfrew 2003] Renfrew, Colin. 2003. Time Depth, Convergence Theory, and Innovation in Proto-Indo-European: 'Old Europe' as a PIE Linguistic Area. In Languages in Prehistoric Europe, edited by A. Bammesberger and T. Vennemann. Heidelberg: Universitätsverlag Winter.

* [*Vander Linden 2004] Vander Linden, Marc. 2004. The Roots of the Indo-European Diaspora: New Perspectives on the North Pontic Hypothesis. Paper read at Proceedings of the fifteenth Annual UCLA Indo-European conference, at Washington.

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