Particularly interesting have been the links between Artenacian culture and the closely related Aquitani people ca. 2600 BCE (also here and here), geographical extents suggested by toponymns (also here), megalithic monuments (and also here), nearby and potentially relevant cultural complexes such as the Beaker culture, the Rossen culture and the Chasseen culture, and the culture of the Stele people (also here, and here), the role of RH negative genetics, lactase persistance genetics, Y-DNA genetics for R1b1b2, linguistic landscape considerations, outstanding academic issues in the Upper Paleolithic transition, and more.
Either in one of the links above, or somewhere else that I'll have to track down, was some discussion of the timing of the arrival of cattle herding and megalithic structures in Basque country (which was quite a bit later, at least in the case of the megalithic structures, than the rest of Iberia and close in time to the rise in cattle herding and the end of the Artenacian). The Artenacian also is quite a good fit to some guesses I'd made based on latase persistance genetics before I learned that it even existed, in terms of timing, geographical extent, and direction of migration, which is just the kind of thing you like to see happen.
The Stele people story unfolds close in time, and importantly pre-Bell Beaker, but post Cardial Pottery in Iberia. But, given that the oldest evidence of the Bell Beaker people is ca. 2900 BCE in Iberia, about three centuries after the Stele people are seen in Sardinia, it is hard to make out if they are proto-Bell Beaker people (and hence arguably Indo-Europeans, which would be consistent with their place of origin), or are a layer that comes earlier and integrates with the later megalithic culture.
Then come the complexities and question marks.
We have basically no pre-Neolithic Y-DNA samples from Europe that are R1b, and indeed, basically no pre-Neolithic Y-DNA samples anywhere in Europe. We do have lots of R1a from ca. 2000 BCE and a bit older in Eastern Europe and Central Asia, but that doesn't resolve the R1b timeline much at all.
To answer the question of Basque origins, you have to say what you mean by the Basque people (which in turn flows from why you want to know the answer to that question) and entertain the possibility of phenomena like language shift due to elite dominance, demic migration accompanied by admixture with existing populations (possibly on a sex biased basis), Iberian demic interactions with North Africa in each direction, transfers with technology and cultures with neighboring cultures (e.g. bow wave models in which cultures neighboring Indo-Europeans that have adopted IE technologies and cultural features migrate with expanding Indo-Europeans at their heels), the relationship of the Corded Ware (which the Artenacian held at bay in Western Europe) to proto-Indo-European culture, and the deeper roots of the immediate antecedents to the Basque people.
I haven't digested the information to my satisfaction enough to write a post reaching strong conclusions. My preliminary avenues of inquiry are (1) to see the time period from about 3500 BCE to 2500 BCE (and especially 3000 BCE to 2600 BCE) as central to the ethnogenesis of the Basque people in the region where they are found today, (2) to see them as arriving by land from what is now France with the Aternican which is probably an important source of the Y-DNA R1b and lactose persistence genes in modern Basque, (3) to see significant amounts Paleolithic era mtDNA as the product of admixture between proto-Basque and indigeneous hunter-gatherer or Cardial Pottery populations, (4) to see Basque society at a remote level going back to the early Neolithic as probably more culturally derived from the LBK than the Cardial Pottery Neolithic, (5) to see the Basque people as either derived from or significantly influenced by upon contact with the Atlantic megalithic culture in France, (6) to conclude that anything the Basque and Indo-European populations of Iberia differ in is probably largely attributable to the later waves of Indo-European migration (Bell Beaker, Celt, Roman and Reconquest), (7) to see strong suggestive connections between the Basque and Sardinians that nevertheless remain cryptic, and (8) to have continuing uncertainty regarding the linguistic affiliations of the Bell Beaker people.
Scenarios in which the Bell Beaker people are culturally Pre-Vasconic, with the Celts representing the first Indo-European migration wave, and those in which the Bell Beaker people are culturally Indo-European and are the first Indo-European migration wave both have some plausibility. Bell Beaker integration into megalithic culture by 2500BCE-2400 BCE argues for a Pre-Vasconic reading, but there are arguments that Celtic origins are too young to account for the spread of Indo-European culture. The Bell Beaker geographic distribution is a decent fit to the Old European toponym area. Bell Beaker is sometimes seen as having Funnelbeaker culture antecedents (TRB) which was a clearly megalithic culture, and at other times seen as having antecedents in Corded Ware to whom the Aternicians were opposed. Neither of these theories, however, is a fit to the oldest Bell Beaker wares being found in Iberia ca. 2900 BCE.
The Bell Beaker physical anthropology, a discipline with a good track record of predicting genetic links in these kinds of situations carries its own implications:
Historical craniometric studies found that the Beaker people appeared to be of a different physical type than those earlier populations in the same geographic areas. They were described as tall, heavy boned and brachycephalic. The early studies on the Beakers which were based on the analysis of their skeletal remains, were craniometric. This apparent evidence of migration was in line with archaeological discoveries linking Beaker culture to new farming techniques, mortuary practices, copper-working skills, and other cultural innovations. . . . Margaret Cox and Simon Mays sum up the position: "Although it can hardly be said that craniometric data provide an unequivocal answer to the problem of the Beaker folk, the balance of the evidence would at present seem to favour a migration hypothesis."
Non-metrical research concerning the Beaker people in Britain also cautiously pointed in the direction of immigration. Subsequent studies, such as one concerning the Carpathian Basin, and a non-metrical analysis of skeletons in central-southern Germany, have also identified marked typological differences with the pre-Beaker inhabitants.
Jocelyne Desideri examined the teeth in skeletons from Bell Beaker sites in Northern Spain, Southern France, Switzerland, the Czech Republic and Hungary for her thesis. Looking at inherited dental traits, she found that only in Northern Spain and the Czech Republic were there demonstrable genetic links between immediately previous populations and Bell Beaker populations. Elsewhere there was a genetic discontinuity.
These data points are suggestive of a possible identity in time and space between the Stele people and the proto-Bell Beaker people and with an Iberian origination of the Bell Beaker people. An Iberian origin Bell Beaker people also puts it in opposition to Corded Ware and aligned with the megalithic people, in accord with the alignment of the later Aternicians. From the same source: "A review of radiocarbon dates for Bell Beaker across Europe found that some of the earliest were found in Portugal, where the range from Zambujal and Cerro de la Virgen ran between 2900 BC and 2500 BC, in contrast to the rather later range for Andalusia (between 2500 BC to 2200 BC)."
My preliminary inclination is to see early megalithic culture (with separate Cardial Pottery and LBK branches), intermediate copper to bronze age Bell Beaker culture (recently found to have extended as far as the Baltics at its peak, which is the furthest extent of Old European topomyns) that was fusional with local neolithic cultures and has a meaningful demographic component, and Indo-European culture (which was culturally disruptive, but perhaps not as strongly disruptive demographically) as three separate migration waves, with Bell Beaker as a non-Indo-European copper age culture more prone to integrate with the megalithic culture, and the Urnfield culture as the first Indo-European culture that fully displaced the prior cultures of the region in Western Europe.
In the North, I am inclined to see Indo-European culture date not to the Funnelbeaker culture or the Bell Beaker, but to the Nordic Bronze Age (starting sometime 1700 BCE-1200 BCE) which is seen as synonymous with proto-Germanic in this frame, and the Urnfield Culture (as well as the Hallstat, La Tene, and Celtic cultures that grew out of it) would likewise have been an Indo-European one. This would also suggest that the Central European Tumulus culture that preceded the Urnfield Culture, and perhaps the Unetice culture before it, 2300-1600 BC, may also have been Indo-European, but casts doubt on the Unetice's culture's origins in the Bell Beaker culture. But, a Unetice culture source in the Southern Corded Ware culture seems like a better geographic fit and a more fitting to an Indo-European source culture.
But, this is problematic as well in a non-Indo-European read of Bell Beaker, because there is a good argument that the Stele people have roots in the Kemi oba culture very close to the kurgan proto-Indo-European urheimat.
On the other hand the Kemi oba culture had strong trade and cultural ties with, was contemporaneous with, and was adjacent to the Maykop culture, which eminent Indo-Europeanist Mallory identifies as probably non-Indo-European in unity with the Northwest Caucasus mountain region. In this view, the Kemi oba people would have had very little genetic contribution from the Northwest Caucasus but would have experienced language shift arising from cultural dominance arising from more advanced Northwest Caucasian technologies in areas like copper working.
In this scenario, then, we have Northwest Caucasian languages, with genetic and culture infusions from the Steppe, and ties to the some of the earliest centers of the copper industry. The Stele people migration was from about 3200 BCE to 3000 BCE, so the link that this would imply between Basque and Northwest Caucasian languages (influenced by existing substrates for a relatively fusional wave of migration), would be about as thin as the link between the most divergent branches of the Indo-European language family (e.g. Hindi and English) without the extant and documented intermediate branches to reveal the connections, particularly as the Basque people may have had origins from Southern Iberia to France and then back to Northern Iberia, rather than directly from Southern Iberia to Northern Iberia.
Rather than suggesting a common source of Indo-European and Basque languages, the two cultures might have represented similar technological complexes based on technological exchanges between two cultural and linguistic groups, the Indo-Europeans to the North, and the Caucasians to the South.
While it seems presumptuous, given that we know that there was a substantial demographic component to the Bell Beaker migration, it wouldn't be beyond plausibility to imagine that R1b, rather than being a Paleolithic or Indo-European marker (and how could R1b be predominant in the Basque if it was an Indo-European marker?), R1b might be a proto-Vasconic Bell Beaker marker, as its distribution fits the megalithic cultural region into which it integrated and spreads further at lower frequencies into areas were the Bell Beaker culture was in place for a shorter time period. This seems even less presumptuous when one digs down into accounts of just how primitive an existence pre-Bell Beaker Neolithic farmers in Western Europe endured. It wouldn't have taken much of an edge to become leading figures in this simple small villages.
It also provides a path for R1b with a likely origin around the Caspian Sea or Central Asia to make its way to Western Europe. This interpretation would leave, by process of elimination Y-DNA haplogroups I and T as the most plausible candidates for pre-Neolithic Y-DNA haplogroups, perhaps with T in place pre-LGM in Europe, and I in the Epipaleolithic or early Neolithic.
This could also help explain some of the cultural ambiguity of the Bell Beaker culture. Given that both Bell Beaker and Indo-Europeans are directly borrowing metallurgy and farming technologies and some other parts of the same cultural complex from each other before their respective expansions, it makes sense that artifacts found by archaeologists alone would have a hard time revealing an Indo-European or Vasconic affinity.
In this view, R1a really is an Indo-European marker and its relative absence from Western Europe is a direct consequence of the fact that the Vasconic R1b carrying Bell Beaker people beat them to it and delivered an equivalent technological package that allowed them to hold off the Indo-Europeans for a millenium. This scenario is also a good fit to the absence of early Neolithic R1b in Western Europe.
One down side of this interpretation of course, is that it suggests that the combined forces of the Indo-European and Vasconic expansions have utterly obliterated any distinguishable linguistic traces of either Upper Paleolithic Europeans or of early Neolithic Europeans from either the LBK or Cardial Pottery branches of that Neolithic expansion. Any trace of Upper Paleolithic languages would have become substrates of early Neolithic languages, which in turn would have become substrates in Vasconic and Indo-European languages.
In Basque, the lack of any way to parse substrate from superstate (except perhaps by remote comparisons to proto-Northwest Caucasian and purging Indo-European borrowings, that would still be highly conjectural) makes the task impossible. In Celtic and Germanic languages, the intervening Vasconic substrate would muddy the early Neolithic and hunter-gather substrates. In areas where Indo-European languages directly replaced early Neolithic and hunter-gatherer languages leaving perhaps identifiable substrates, subsequent Slavic language expansions would probably have obscured those substrates in the previous probably Indo-European languages of that region.
Basque, in this narrative, would be essentially equal in age to Indo-European, although it would have been the more ancient language in Western Europe and might be more directly descended from Northwest Caucasian than Indo-European is from its progenitors. My own inclination is to see Proto-Indo-European itself as a likely creole of an ancient variety of the Uralic language and the probably very different language of the LBK farmers.
This would also tend to place the origins of African R1b-V88, associated most strongly with the Chadic people, which is quite basal in the R1b clade, somewhat earlier in time than the Stele people migration of ca. 3200 BCE to 3000 BCE and to associate its likely place of origin as the Southern Steppe. Conveniently, this would put this migration before the invention of writing in Egypt and Sumeria, which would help to explain why there is no historical record of this migration.
It is also tempting to associate the G2a rich people of the Caucasus with the G2a rich source populations of early Cardial Potery and LBK Neolithic populations. Thus, the Bell Beaker people may have been linguistically separated linguistically from the older Neolithic populations of the region by only 1500-2500 years, little more than the separation of the Romance languages or the Sanskrit derived languages of India are from each other. Greater similarity in language and cultural roots between the Bell Beaker people and their Neolithic predecessors may have faciliated their greater fusion with the local people, as opposed to the far more complete lack of cultural continuity between Indo-European culture and its predecessor.