When was Proto-Celtic spoken (offtopic from Beaker-Bell R1b)

[Taranis]

Ireland is an endpoint and endpoints are good to test hypotheses.

The last of the four Megalithic building waves was the Wedge Tomb which briefly overlapped with the Bronze Age people. In this Bronze Age, the artifacts are Bell Beaker, which are found uniformly throughout the island in contrast to the Megaliths which are mostly in the north. The certifiably Celtic La Tène culture is also found entirely in the north, and the south is without any Iron Age artifacts at all.

No one has found any evidence of any "Celtic Invasions" of Ireland, yet the people are there. It has been pointed out that many of the pre-Christian royal sites (really more rex as in the Golden Bough, than king), are associated with Megalithic sites, especially Tara and the great Boyne Valley monuments. This seems to me to indicate a certain cultural continuity through the centuries, as opposed to some Celtic Invasion from Iberia who stumbled upon Newgrange.

So it has always seemed to me, that the only candidates for the presumed pre-Celts were the Bell Beakers, for if not them, then who?

These new R1b results are very intriguing.

You bring up some very interesting ideas there. I absolutely agree that the position of Ireland is intriguing, and the origin of the Celtic language in Ireland is puzzling.

As I mentioned before, there are several unanswered problems with the idea that Beaker-Bell was Proto-Celtic: first is the sheer area that it covered (since areas such southern Scandinavia, Sardinia, Sicily, Southeastern Iberia, North Africa, etc. were never Celtic), the second is the ancientness of Beaker-Bell.

Beaker-Bell existed circa 2,000 years before the earliest attestations of Celtic languages, and if we compare the Celtic languages in Antiquity (Lepontic, Celtiberian, Gaulish, Ogham Irish - especially the parallels between the latter two are particularly stunning), they are all fairly similar to each other (and paradoxially Oghamic Irish, from the 4th century AD is in many ways the most conservative of them all). If we compare language families that are of a roughly comparable age (ie, the Germanic and the Romance languages), they have diverged to a much greater degree. From that perspective, I find it highly dubious to argue that the Celtic languages began to diverge in the 3rd millennium BC if they are so similar to each other. As an analogy, this is like arguing that Vulgar Latin was spoken around 4000 years ago.

I absolutely agree however that the Celtic language presence in Ireland can be neither explained by a La-Tene invasion/immigration (this can be convincingly argued for P-Celtic Britain, but definitely not for Ireland!), nor by some kind of late immigration from Iberia (I'm talking about the Mil Espaine from the Book of Invasions, which are almost certainly a medieval fabrication - besides if anything I think this happened vice versa ).