I published an essay (or “dissertation”) some weeks ago, about what seems to me one of the most likely models of expansion of Indo-European-speaking peoples, based on Y-DNA haplogroups. Recently J.P. Mallory had proposed* (although he was not the first) that North-West Indo-European (the ancestor of Italo-Celtic and Germanic, and Balto-Slavic**) expanded with the Bell Beaker culture, a hypothesis that is supported by the most recent radiocarbon data (and subsequent proposal of an eastern origin of the pre-Bell Beaker culture, linked to the Yamna expansion, by Volker and Heyd). As I outline in the paper, ancient DNA samples and genetic data from modern populations seem to support this new model.
(highly detailed diachronic maps with Indo-European cultures, peoples, languages, and Y-DNA samples)
The still most prevalent model followed by archaeologists, based on Gimbutas’ theory, links the Corded Ware culture expansion to an expansion of the Yamna culture. Gimbutas linked the expansion of Bell Beaker to the expansion of certain Indo-European dialects through Vucedol, and Corded Ware was associated with the expansion of Germano-Balto-Slavic. Even though linguistics has changed its mainstream view of the dialectalization of Late Indo-European in the past half century, the archaeological community (those who supported the steppe expansion, at least) has remained strongly linked to Gimbutas, and more recently David Anthony has supported a similar model (with a phylogenetic model of Proto-Indo-European dialects by Don Ringe), by explaining a dual expansion into Corded Ware by Pre-Germanic (through a mixed Old European / IE Usatovo culture) and Pre-Balto-Slavic (through the Middle Dnieper culture), while eastern Bell Beakers expanded with Italo-Celtic dialects. While a strong cultural connection between Yamna and Corded Ware is currently undeniable, and admixture analyses show a connection between steppe and both Bell Beaker and Corded Ware samples, the actual relationship is today far less clear than it was 10 years ago (when we would simply connect Yamna with a R1a-dominated Corded Ware), and far more ancient samples from the steppe, steppe-forest, and forest zone are needed to extract any strong conclusions.
During this time I have received some comments on the paper, and have discovered some interesting sources for more information, like BioRxiv (for the newest pre-print papers on Genetics), and Academia.edu (for papers on Archaeology), both of which I can’t hardly recommend enough for anyone interested in these topics. From what I have experienced, Linguistics – which seemed to me a quite closed, strongly conservative community, due to my proposal of speaking a reconstructed Proto-Indo-European dialect as a common language today – has been more open with my model than some archaeological/genetic tandems, and linguists have shown a clearer grasp of all anthropological disciplines involved in Indo-European studies than others… My model remains a theory that I expect to develop further with more details and more genetic data, as they are published.
There are some interesting upcoming samples (mainly from Bell Beaker) by the Reich Lab – and today its publication seems nearer. While the interpretation seems to be in line with what has been said in previous similar publications, the most interesting data will most likely be the actual samples, apparently already showing a lack of steppe ancestry in Iberian Bell Beaker, and a clear invasion of Bell Beaker peoples (hence R1b?) in Great Britain. Hopefully some new samples of Yamna and Corded Ware might give us interesting information.
It is always to be remembered that, when talking about Indo-European peoples, what matters is linguistics: after, all, the peoples whose place and time we want to find are defined by their language, Indo-European. Archaeology might be able to date some cultural developments potentially linked with Indo-European-speaking peoples, and genetics might give support to the expansion of peoples (and thus maybe languages) accompanying such cultural expansions. Recent genetic developments are quite interesting, in that we might be able to place Late Indo-European and North-West Indo-European speakers in place and time, but it seems to me that some people are trying to answer the Urheimat problem the other way around.
* J.P. Mallory, ‘The Indo-Europeanization of Atlantic Europe’, in Celtic From the West 2: Rethinking the Bronze Age and the Arrival of Indo-European in Atlantic Europe, eds J. T. Koch and B. Cunliffe (Oxford, 2013), p.17-40
** It has been proposed that Balto-Slavic derived partially from North-West Indo-European, and partially from a different Late Indo-European language, although there are different models to explain the pidginization of this dialect