Maju has a post with a nice map on the extent of Bell Beaker archaeology in Iberia, and also a dedicated permanent page discussing the Iberian Chalcolithic (i.e. the copper age in what is currently Spain and Portugal, which is the time period in which the Bell Beaker culture appeared in Iberia).
Why is this such salient information?
Mostly because of the critical role that the Bell Beaker people may have played in the larger sweep of European prehistory and demographics. It was not nearly is plausible that the Bell Beaker people (or if not them, some other Copper Age or Bronze Age population) had to be so demographically influential in Europe until ancient DNA results started to force the question.
The European Transition From Hunter-Gatherers To Herders and Farmers
No one disputes that human civilization in Europe profoundly changed almost every place that the Neolithic revolution (i.e. farming, herding and sedentary living in communities other than fishing economies) arrived, when the Neolithic revolution arrived in Europe.
Ancient mtDNA data make fairly clear that, at least outside Southern Europe, this transition had a substantial demic component - i.e. it involved a major infusion of new immigrations from the general vicinity of West Asia and Anatolia (and perhaps Southeast Europe, Central Asia and the Near East), rather than merely involving a technology transfer absorbed by the existing residents. The demographic shift involved in hunter-gatherer to farmer and herder transitions may have been less abrupt in Southern Europe than in Northern Europe, however.
Except for a few places that are liminal between the Near East and West Asia on one hand, and Europe on the other, the Neolithic revolution arrived in Europe starting around 6000 B.C.E. or later, with a Danubian Linear Pottery Culture in the East, and a Cardial Pottery Culture in Southern Europe constituting the two main first waves of Neolithic expansion.
The Atlantic Megalithic Culture
In an area roughly described as "Atlantic Europe," with outposts as far east as Sardinia, as far west as the British Isles, and as far North as Denmark, the Neolithic cultures crystalized into a "megalithic culture" (think Stonehenge) linked by maritime trade. In some parts of Atlantic Europe, the megalithic culture is the initial Neolithic culture that can be discerned in the archaeological record. In other parts of Europe including Atlantic Europe, there may have been some pre-megalithic Neolithic period for as much as one or two thousand years.
Residual Hunter-Gatherers Of Northern Europe
Not all of Europe experienced the Neolithic Revolution at once, however. The Funnel Beaker culture (TBK) (more or less in Northern Continental Europe) and Comb Ceramic archaeological cultures (more or less in Slavic and Uralic Europe and Siberia) were some of the last hunter-gatherer-fishing cultures of Europe that did not practice farming or herding on a widespread basis and existed in areas that were marginal for agricultural food production at times contemporaneous with Neolithic European cultures.
The Genetic Evidence For A Demic Models
Ancient DNA evidence (combining mtDNA, Y-DNA and autosomal DNA), and evidence from skeletons of the respective cultures, shows both that the early Neolithic populations had substantial immigrant components, and that these early Neolithic populations, particularly on the Y-DNA and autosomal DNA side, were not typical of modern European populations. There was surely some assimilation of individuals from pre-Neolithic societies, and later from early Neolithic societies, but the amount of gene pool influence exerted by the earlier layers is a closer fit to a pure replacement model than to a cultural diffusion model.
So, somehow or other, there must have been one or more major demographic transitions between the early Neolithic era and the point at which ancient DNA starts to look quite similar in overall character to modern European DNA (realistically, no later than the Middle Ages in most places).
When Could Demographic Transitions Have Taken Place After The Neolithic?
The natural question to ask next is what candidate cultural transition(s) could have coincided with this major post-Neolithic demographic transitions. There are several plausible candidates. All of the non-Bell Beaker candidates are historic groups of expanding Indo-Europeans, often in several sucessive waves (e.g. Latin and its successor Romance languages, often replaced Indo-European Celtic languages, and the Slavic expansion probably also replaced existing Indo-European languages in the region that are now mostly lost; the case that the culture from which the Corded Ware archaeological culture emerged spoke a language that was Indo-European is also a reasonably plausible one).
The archaeological record shows relative continuity within the Neolithic era in Western and Northern Europe until the Bell Beaker culture of the Copper Age arrives ca. 3000 B.C.E. and exhibits a substantial break with past cultures. Craniographic evidence and very preliminary ancient DNA evidence suggest that the Bell Beaker culture had a meaningful migrant population component (at least in most places, the phenomena streched over a very large area and a quite lengthy time frame), and this view is coming to be the more widely held one as historical anthropology experienced ancient DNA driven paradigm shifts, contrary to a historical anthropological view that peaked around the 1970s that had tried to describe the phenomena as largely a technology transfer without meaningful migration.
At its greatest extent the Bell Beaker culture extended over most of Western Europe (with some holes where there is no archaeological evidence for it within that area) and well inland from the Baltic Sea coast pretty much to the Baltic states. Bell Beaker culture had a larger peak geographic range than the predecessor megalithic culture, although all or almost all megalithic cultural areas transitioned to the Bell Beaker culture.
Contemporaneously, in an area roughly corresponding to Cold War Eastern Europe, another European Copper Age culture, the Corded Ware Culture, prevailed.
The boundary between the two cultures overlapped somewhat, with distinctly Bell Beaker and Corded Ware archaeological sites found within dozens of miles from each other at approximately the same times, and also shifted over time. But, there was a divide for something on the order of a thousand years.
The thin ancient DNA evidence available from the European Chalcolithic, and other evidence from archaeology tenatively suggest that at least by this point in time, the modern European pattern in which Western Europe has a strong component of Y-DNA haplogroup R1b, very roughly in the geographic region of the Bell Beaker culture where a first ancient DNA sample reveales the oldest known European R1b ancient DNA, while the area roughly in the geographic region of the Corded Ware culture has produced ancient DNA samples from the culture of Y-DNA haplogroup R1a, similar to that found there today, in both cases, in a tenantive contrast with early Neolithic Y-DNA in both the LBK and Cardial Pottery areas. Thus, the Y-DNA landscape of modern Europe was starting to gel sometime around the European Chalcolithic, if not earlier (the ancient Y-DNA data gets much thinner at older date than the mtDNA data does because mtDNA is more easily preserved and sequenced from ancient sources).
The linguistic affinities of the Bell Beaker and Corded Ware cultures is a critical cutoff point in historical linguistics, because combined, these two cultures covered almost all of Europe at some point during the Chalcolithic. If these archaeological cultures were associated with language families (which a demic component to the Bell Beaker culture is suggestive of), then these cultures provide a foundation from which subsequent linguistic developments can be tracked. However, if this is the case, pre-Chalcolithic languages of Europe, other than proto-Indo-European or proto-Uralic, are irrevocably lost.
The Bell Beaker cultural area also appears to coincide with a region where some linguistic observers have pointed to the existence of a "Vasconic substrate" set of geographic proper names that appear to have no relationship of the Indo-European languages that prevail in all but a few regions of Europe (Basque country, Finland, Hungary, Latvia and a few Russian refugia) today. The megalithic culture didn't have the geographic extent to be a fit for this toponymic region, and the post-Bell Beaker linguistic layers are known well enough to rule them out. But, the evidence of a Vasconic substrate in typonymns is not terribly overwhelming either.
Legitimate arguments have been advanced that the Bell Beaker people may have been pre-Celtic Indo-Europeans linguistically rather than than speakers of a non-Indo-European language, and since there were no literate languages in Europe at the time (writing was just in its earliest days in Sumeria and Egypt at the time), and there aren't even any contemporaneous phonetic transcriptions of Bell Beaker speech from that era that have been deciphered, we have to make linguistic inferences based upon signs of substrate influences in later languages, proper names that survived, the known stories of other parts of the puzzle, like the reasonably well understood Bronze Age expansions of the Indo-European languages in the early historic era, and whatever hints we can derive from the existence of the Basque and Etruscan people's in the historic era, cryptic hints from the oldest surviving histories to discuss these areas, and evidence showing genetic and cultural ties that are suggestive that linguistic ties may have been present as well.
I personally believe at the time that I am writing this post that the Basque language is probably the last remaining survivor of a language family or subfamily that once encompassed all or almost all of the Vasconic substrate area and that the continental European branch of this language family has its roots in a near basal proto-language spoken by the earliest Portugese Bell Beaker peoples. I also strongly suspect that this proto-language in turn distantly and at great time depth derived from a non-Indo-European language probably spoken in the Caucusas mountains, Armenia or Anatolia at the time that the proto-Bell Beaker people migrated to Iberia and from there to the rest of Atlantic Europe and beyond. Most likely that language was related to the Northwest Caucuasian languages (e.g. Chechnyian) and spoken by proto-Bell Beaker people from the Steppe who acquired it via language shift from a relatively advanced for its time Caucasian superstrate metal culture. As I've noted in a prior post, I also personally believe that the Basque language probably arrived in its current local via France and not Iberia to the South. But, new evidence could easily shift the plausibility of this theory.