Migration of the Bell Beakers—but not from Iberia (Olalde et al. 2018)

At last, after many months of waiting, the paper that I’ve been calling the Bell Beaker Behemoth will finally appear at Nature today or tomorrow, depending on your time zone [Update: the paper is here]. The accompanying dataset is already online, and it’s twice as big as what the paper’s bioRxiv preprint promised, packing 400 new samples from Neolithic, Copper Age and Bronze Age Europe (freely available via the Reich Lab here).
I’ll incorporate these samples into my collection of ancients very shortly, and then put them through their paces in the usual and new ways.
Nevertheless, despite the much larger and more varied new dataset, I know for a fact that the conclusions in the paper are the same as those in the preprint (which we discussed here). The authors tentatively accept the archaeologically-based academic consensus that the Bell Beaker phenomenon originated in Copper Age Iberia. But they admit that they can’t find evidence in their ancient DNA data that its expansion across much of the rest of Europe was accompanied by significant gene flow from Iberia, and thus driven by migration.
However, they do see in their data a large-scale migration of Central European Beakers to Western Europe around 2500 BC, bringing with them, amongst other things, steppe or Yamnaya-related admixture to the region for the first time. Many of the new samples are from the British Isles – where the impact of this migration was profound, resulting in roughly a 90% turnover of the population – and they appear to have been collected specifically to reaffirm this conclusion.
How exactly this massive population turnover came about isn’t known yet. But early indications from other parts of Europe, where similar population shifts have been inferred from ancient DNA for the Late Neolithic/Early Bronze Age period, are that plague epidemics and deadly violence may have been important factors (see here and here).
I don’t have a strong opinion about the place of origin of the Beaker cultural package, and I don’t find the Iberian model entirely satisfying, mostly because it doesn’t gel with the latest ancient DNA data. On the other hand, I’ve made up my mind as to who the Central European Beakers rich in steppe ancestry and also Y-haplogroup R1b-M269 were, and you can read about that here.
What are your thoughts after looking over the new samples? It’s a big dataset alright, but does it do justice to the massive and complex Bell Beaker phenomenon? If not, then what’s missing? Who’s actually happy that the puzzle of the origin of the Beakers has now been solved? Feel free to let me know in the comments below.
Update 21/02/2018: I’ve updated my Global 25 datasheets with most of the ancient samples from Olalde et al. 2018 and Mathieson et al. 2018 (see list here).

Global 25 datasheet
Global 25 datasheet (scaled)
Global 25 pop averages
Global 25 pop averages (scaled)

See also…
Who’s your (proto) daddy Western Europeans?

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