Predictions about the genetic change from Single Grave to the Late Neolithic in Denmark

germanic-early-bronze-age

New open access paper Mapping human mobility during the third and second millennia BC in present-day Denmark by Frei et al. PLOS One (2019), from the Copenhagen group (including Allentoft, Sikora, and Kristiansen) of samples whose genomic profile will probably be published soon.

Interesting excerpts (emphasis mine):

We present results of the largest multidisciplinary human mobility investigation to date of skeletal remains from present-day Denmark encompassing the 3rd and 2nd millennia BC. Through a multi-analytical approach based on 88 individuals from 37 different archaeological localities in which we combine strontium isotope and radiocarbon analyses together with anthropological investigations, we explore whether there are significant changes in human mobility patterns during this period. Overall, our data suggest that mobility of people seems to have been continuous throughout the 3rd and 2nd millennia BC. However, our data also indicate a clear shift in mobility patterns from around 1600 BC onwards, with a larger variation in the geographical origin of the migrants, and potentially including more distant regions. This shift occurred during a transition period at the beginning of the Nordic Bronze Age at a time when society flourished, expanded and experienced an unprecedented economic growth, suggesting that these aspects were closely related.

denmark-late-neolithic-bronze-age-sites
Map of present-day Denmark illustrating locations of the burial sites.
The dashed black line marks the maximum advance stage of the last glaciation (Weichselian). Drafted with public domain data from Natural Earth (https://www.naturalearthdata.com).

Strontium isotope analyses

The results of our strontium isotope analyses are presented in Table 2 and listed in chronological order according to the radiocarbon dates (in sites with multiple individuals we start with the oldest radiocarbon individual). The strontium isotope data set reveals a wide range of values from 87Sr/86Sr = 0.70871 (RISE 23, from the site of Debel) to 87Sr/86Sr = 0.71788 (RISE 20, from the site of Karlstrup). Despite the difficulties of establishing the baseline range some of the herein investigated individuals may be classified as non-locals. A few individuals have tooth enamel signatures that lie just above the upper baseline limit of 87Sr/86Sr = 0.711 and therefore, the classification of these humans as non-locals should be considered with caution. Nevertheless, the significant proportion of individuals with relatively radiogenic values suggest that about a quarter of the individuals studied herein seem to have originated from other places than from those they were buried, and hence implying a continuous degree of mobility during the 3rd and 2nd millennia BC.

strontium-isotope-denmark-neolithic-bronze-age
Diagram plotting results of strontium isotope ratios versus calibrated radiocarbon dates of the individuals investigated. The grey band shows the “local” baseline.

Middle Neolithic

From the Single Grave Culture (SGC) which is closely related to the Corded Ware Complex in central and eastern Europe and dates from c. 2800 BC to 2200 BC, we analyzed seven of the at least ten individuals who were buried at the site of Gjerrild in eastern Jutland (Fig 1). Gjerrild is a key SGC site, as to date it has provided the most substantial skeletal material pertaining to this culture from present-day Denmark. However, it is not a typical SGC grave, but a megalithic chamber of the so-called “Bøstrup type”. The SGC pottery was decorated with cord or stamp impressions and the stone battle axes were a common feature of male equipment. Such shared traits in the Corded Ware Complex probably reflected shared occupational, social and religious characteristics. Apart from one individual who yielded a Bronze Age date, five individuals date within the period that spans from c. 2600 BC to 2200 BC, hence representing the middle and late SGC phases (Table 1 and S1 File). Of the seven individuals, three males, one female, two infants and one adult (only represented by a disarticulated mandible, and dated to the Bronze Age), all but one yielded strontium isotope signatures that fall within the local baseline range. Only the female (RISE 1283) has a more radiogenic strontium isotope signature of 87Sr/86Sr = 0.7127, which is similar to that of the male from Kyndeløse and might indicate non-local provenance. One of the individuals at Gjerrild, a mature-old adult male, who yielded a local signature (RISE 432) was accompanied by a D-type arrowhead and an amber bead which lay on his right side. He showed signs of inflammation on his lower legs, in particular on the left one. He had a healed trepanation (Fig 2). Another individual (RISE 73a, 1282), an adult male, was found with a type D arrowhead in the sternum (Fig 3).

denmark-late-neolithic-bronze-age
Strontium isotope, 14C results and sex and age determinations from individuals from the 3rd and 2nd millennia BC from Denmark presented in chronological order. Modified from the paper, see full image.

Late Neolithic I

We sampled individuals from a total of twelve different sites that date to the Late Neolithic period (2300/2250-1700 BC).

One of these sites is Hellested on Zealand (Fig 1 and S1 File), with four flat graves containing five individuals, four young males and one mature adult female. We conducted strontium isotope analyses of enamel from all five individuals, and our results point to two individuals being characterized by local strontium isotope values. One of these individuals, the female, was buried with no grave goods (RISE 53, grave B) while the other, a young male, was buried with a fragmented bone pin (RISE 56, grave F). The other three male individuals (RISE 54, 55, 57) yielded similar strontium isotopic values that lie slightly above the local baseline range. All these individuals had been buried with early flint daggers (type I and II), and one of them (RISE 57, grave A) additionally had a ring-headed pin (Ringkopfnadel) [56]. On the basis of the presence of this ring-headed pin, Lomborg [56] suggested that these individuals had connections with the Únětice culture. Furthermore, three of them have radiocarbon dates that overlap (RISE 55, 56 and 57; Table 1).

Another Late Neolithic site is Juelsberg on the island of Funen (central Denmark, Fig 1 and S1 File) which is a gallery grave that contained at least 19 individuals. We conducted strontium isotope analyses of tooth enamel on 8 out of the 19 individuals and two of them, a male and female, yielded ratios that suggest a non-local origin (RISE 30 and 32). The grave goods comprise a (Lomborg) type I flint dagger but also some non-local type of artefacts. These consist of an early type of bone pin (type 7) mainly found in south-eastern Scandinavia, and a barbed and tanged flint arrowhead of the west-European Bell Beaker type suggesting western connections. The middle adult female (RISE 32) yielded an 87Sr/86Sr = 0.7121 and the mature to old adult male (RISE 30) yielded a 87Sr/86Sr = 0.7112. The different Sr isotope signatures of these individuals imply that they might have originated from different areas, albeit their radiocarbon dates are very similar.

The gallery grave of Marbjerg, Zealand (Fig 1), yielded 17 individuals (S1 File), and we conducted strontium isotope analyses of tooth enamel on 11 of them. The majority of the individuals were males, but females and children, too, were present. Anthropological investigations of the individuals from this site, males as well as females, indicate a relatively high life expectancy with respect to that typical for this period (S1 Table). Our radiocarbon dates revealed that this grave was in use for several hundred years from the Early Late Neolithic (2210–2030 cal BC, RISE 39) to the Late Neolithic /Early Nordic Bronze Age Period (1770–1620 cal BC, RISE 41). Despite the long-term use of this grave, 10 of the 11 individuals studied herein yielded a very narrow and overlapping range of strontium isotope values between 87Sr/86Sr = 0.7096–0.7101. Their values suggest not only that these individuals were local but that their food sources were derived from the same area over the course of several centuries. Only the tooth enamel sample of one individual, a middle to mature adult male (RISE 40), yielded a higher value of 87Sr/86Sr = 0.7117, which seems to suggest a non-local origin.

Predictions about these samples

Strontium isotope analyses only show potential movements during an individual’s lifetime, which is normally useless to assess relevant migrations if the sampling is not big enough (see more on investigating population movements). Still, if a sampling like this one shows many potentially non-local individuals from different parts of Denmark deviating from the baseline at a certain period, you can infer that something is happening within Denmark and in nearby regions.

strontium-isotope-denmark-late-neolithic-bronze-age
Strontium isotope results of the 88 investigated individuals including Late Bronze Age individuals investigated previously. The grey band shows the “local” baseline.

Based on what we know now, I bet these are the most likely events in Denmark that marked the Nordic Late Neolithic with its Bell Beaker-related Dagger Period ca. 2400/2300 BC on:

  1. Sudden appearance of R1b-L23 lineages (probably R1b-U106 among them), originally from the Northern European Plain, ultimately from the Danube River Basin. R1a-M417 subclades, possibly prevalent in the previous period, disappear or appear rarely, to resurge later during the Bronze Age probably mostly as hg R1a-Z284, originally from the Battle Axe culture in Sweden, together with I1 – these resurgence events might be shifted to a later phase, though, and there might be some isolated R1a cases in the Danish LN, too.
  2. Shift of Middle Neolithic to Late Neolithic in the PCA away from the Corded Ware cluster and closer to the Bell Beaker cluster – whatever that means exactly for Danish SGC relative to Northern European Beakers, visible especially when enough samples are available.
  3. Evident sign of new incoming ancestry ultimately from Yamnaya-related populations, compared to earlier peoples of Corded Ware ancestry. Yes, even this far north, despite heavy admixture of Yamnaya-like Bell Beakers through exogamy with Corded Ware-like populations all the way to the north from the Danube Basin.

All this will support, once again, the expansion of Bell Beakers from Yamnaya settlers of Central-East Europe. That is probably what I will be reporting about the data as related to the Pre-Proto-Germanic homeland of the Northern European Plain, unless there is some big surprise, for example that R1b-U106 expanded later from Northern Germany, more clearly associated with later Barbed Wire Beakers or even Únětice movements, although I find this very unlikely at this point.

The above predictions are more or less evident to everyone, despite the current mistrust in the Yamnaya – Bell Beaker expansion route of North-West Indo-European, due to the prevalent nativist and/or reactionary trends in hobby population genomics and among academics. My main prediction is therefore about human behaviour:

(1) Seeing how the Copenhagen group started to describe recently South Scandinavian genetic and linguistic prehistory, their conclusions are predictable. From the introduction of this paper:

The 3rd millennium BC stands out as a period of migrations in western Eurasia, as pastoral steppe populations settled in temperate Europe after 2800 BC e.g. [1, 2]. This was also a period of cultural and genetic admixture e.g. [3]. From 1600 BC onwards, southern Scandinavia became more closely linked to the existing European metal trade networks (…)

See what they did there? No mention of the radical change that the Dagger Period brought to Scandinavia, in cultural or genetic terms (see e.g. here or here). Strange how the only thing that Kristiansen has changed since the 1980s – and only after the 2015 genetic papers – is his previous emphasis on the Dagger Period as the most relevant unifying cultural and population movement in Scandinavia, responsible for the formation of a common Nordic language, which is suddenly given as little weight as possible in all his publications, to support some imaginary continuity with the Corded Ware culture (see e.g. here or here).

(2) Only a few males from the Single Grave period are described in this sampling, and they are quite close to the arrival of Bell Beakers, so if someone is looking for closure about the “R1b from Corded Ware”, I bet there won’t be any. As with conspiracy theories of native Vasconic R1b-L51 hidden somewhere in Western Europe even after Olalde et al. (2018) and Olalde et al. (2019), the mythic native Nordic R1b-U106 of Corded Ware will remain hidden in some unsampled Corded Ware group in the minds of many, despite being already found in Bell Beaker-derived European EBA cultures of Bohemia and possibly of Hungary, too (ca. 2500-2200 BC, see SNP calls), apart from the Late Neolithic sample from Lilla Beddinge in Scania (ca. 2275-2032 BC, see SNP calls)

I hope that I am wrong, and that some scholar in the Danish group is capable of reporting the data as it is, even if it contradicts the theories of its leading archaeologist, Kristian Kristiansen. The apparent downplay of the increase in non-local origins of individuals during the Late Neolithic I period as they appear in this paper, as well as their summary of foreign migrations into Denmark which mysteriously stop with the arrival of “Steppe ancestry” ca. 2800 BC, make me think that a change in their narrative is not very likely. The cons of working with academic divos, I guess…

Related

European hydrotoponymy (VI): the British Isles and non-Indo-Europeans

middle-bronze-age-british-isles

The nature of the prehistoric languages of the British Isles is particularly difficult to address: because of the lack of ancient data from certain territories; because of the traditional interpretation of Old European names simply as “Celtic”; and because Vennemann’s re-labelling of the Old European hydrotoponymy as non-Indo-European has helped distract the focus away from the real non-Indo-European substrate on the islands.

Alteuropäisch and Celtic

An interesting summary of hydronymy in the British Isles was already offered long ago, in British and European River-Names, by Kitson, Transactions of the Philological Society (1996) 94(2):73-118. In it, he discusses, among others:

  • Non-serial hydronyms: Drua-/Drav-/Dru-, from drew- sometimes reshaped as derw-; ab-; ag-; al-; alb-; alm-; am-; antjā-; arg-; aw-; dan-; eis-; el-/ol-; er-/or-; kar(r)a-, ker-; nebh-; ned-; n(e)id-; sal-; wig-; weis-/wis-; ur-, wer-; etc.
  • Serial elements: -went-, -m(e)no-, -nt-o-, -n-; -nā-, -tā-; -st-, -r-; etc.

Probably non-Celtic suffixes are found e.g. in Tamesis, paralelled in the Spey Tuesis, and also in Tweed (<*Twesetā?); or -no-/-nā- is also particularly frequent in Scottish river-names, but not in English ones. Another interesting case is the reverse suffix relative order into -r-st- instead of -st-r-.

Most if not all of them can be explained as of Old European nature. I will leave aside the discussion of particular formations – most of which may be found repeated, complemented, and updated in more modern texts.

hydronyms-ub-ob
Hydronyms ub-, ob-. Another Western European river name.

Bell Beakers as Old Europeans

(…) Bell-beakers are in fact the only archaeological phenomenon of any period of prehistory with a comparably wide spread to that of river-names in the western half of Europe. The presumption must I think be that Beaker Folk were the vector of alteuropäisch river-names to most of western Europe. Rivers in the base Arg-, which we have seen there is cause to think was not already in use at the earliest stage of the river-naming system, and which therefore should be associated with such a vector if one existed, fit their distribution exceptionally well.

That they were a single-speech community can be asserted more confidently of the Beaker Folk than of most archaeologically identified groups for the very reasons that have caused archaeologists difficulty in interpreting them. As McEvedy (1967:28) put it, ‘the bell-beaker folk march convincingly in every prehistorian’s text, but they do so from Spain to Germany in some and from Germany to Spain in others, while lately there has been a tendency to make them go from Spain to Germany and back again (primary and reflux movements)’. One ‘firm datum seems to be that the British beaker folk came from the Rhine-Elbe region.’

This confirms what the long chronology now indicated for Common Indo-European would suggest anyway, and what to me, as remarked above, the rareness of non-Indo-European names in England suggests, that the old dissenting minority of Celticists were right to see the arrival in Britain of Indo-Europeans, as evinced in river-names whether or not in ethnic proto-Celts, as early as the third millennium. McEvedy’s map of Beaker Folk identifies them linguistically with Celto-Ligurians, but in that his admirably tidy mind was, typically, a degree too tidy. Considerations of phonology indicate that more than one linguistic group was involved.

It is normal in reconstructed Indo-European for groups of related words not all to have the same vowel in the root syllable. The commonest vowel gradation is between e, o, and zero; (…) Language-groups that level short a and o include Germanic and Baltic, Slavonic, Illyrian, Hittite and Indo-Iranian; but Celtic and Italic like Greek and Armenian preserve the original distinction. It follows that Celts speaking normal Celtic sounds cannot have been wholly responsible for bringing alteuropäisch river-names to any area. It would seem to follow, as Professor Nicolaisen has consistently urged, that in Spain, Gaul, Britain, and Italy, where the only historically known early Indo-Europeans were speakers of non-levelling languages, they were preceded by speakers of levelling languages not historically known. This hypothesis, pretty well required by the linguistic evidence, finds so good an archaeological correlate in the Beaker People that I think it would now be flying in the face of the evidence not to accept those as bearers of the river-names to these countries.

bell-beaker-civilization
Bell Beaker Civilization (CAD O. Lemercier).

The funny note is the rejection of the steppe homeland by Kitson in favour of Central European Neolithic cultures, due in part to the ‘impossibility’ of proto-Finnic loans from East Indo-European, if Proto-Indo-European was spoken in the steppe. As I said recently, the lack of knowledge of Uralic languages and Indo-European – Uralic contacts has clearly conditioned the Urheimat question for both, Proto-Indo-European and Proto-Uralic researchers.

On the other hand, the identification of Bell Beakers with Old Europeans was not something new. Already in the 1950s Hugh Hencken talked about this, and J.P. Mallory (who described Bell Beakers more exactly in 2013 as North-West Indo-Europeans) is sure that this idea had been used even before the 1950s.

The question is, though, to what extent the reasoning of those researchers was as detailed so as to consider it a modern approach to the question, because Krahe in the 1940s seems to offer the first reliable data to make that assumption. In any case, Gimbutas’ idea of Kurgan warriors imposing Indo-European languages everywhere, so over-represented in Encyclopedia-like texts since the end of the 1990s, was not the only, and probably never the main hypothesis among many Indo-Europeanists.

Celts part of Bell Beakers?

Regarding Koch and Cunliffe’s revival of the autochthonous Celts idea, one can find a similar traditional view among British researchers of the early and mid-20th century – and a proper rejection based on hydrotoponymy. It seems that many fringe theories in Indo-European studies, from Nordic or Baltic homelands to autochthonous Celts to the Europa Vasconica, can be traced back to revivalist waves of romantic views of the 19th c.:

What the late Professor C. F. C. Hawkes called in British archaeology ‘cumulative Celticity’, built up by successions of comparatively small tribal migrations, will then have operated on the linguistic side as well. That the predecessors of the Celts proper for so long had in most of Britain been people of similar Indo-European speech explains why there is not a significant survival of recognizably non-Indo-European river-names, and why the few serious candidates for non-Indo-European among recorded place-names all seem to be in Scotland. That the river-names kept their north European non-Celtic phonology will be because the Celts proper took them over as names, with denotative not fully lexical meaning. (…)

(…) I think non-Celtic Indo-European-speakers are likely to have been involved in fact, whether or not they are the whole story, both because that it is the hypothesis which makes best sense of the archaeological evidence (…)

(…) because it is widely accepted that placenames in the Low Countries imply the existence of at least one group of not historically attested Indo-European-speakers, not the same as the ones we are concerned with. So do names in Spain, another country where the only historically attested early Indo-Europeans were Celtic. Comparing Spanish alteuropäisch names with British ones gives a glimpse of the dialectal range that must have characterized the Beaker phenomenon. Either group shares one feature with historical Celtic that the other lacks. The Spanish names like Celtic proper mostly keep Inda-European o. There the diagnostic feature is initial p (Schmoll 1959:93, 78-80; Rodriguez 1980), lost from Celtic and the alteuropäisch of Britain.

Interesting is also the early reaction against Vennemann’s much publicized interpretation of Krahe’s Old European as ‘Vasconic’. This is a useful comment which is still applicable to the same non-existent ‘problem’ found by some Indo-Europeanists, depending on their ideas about Indo-European dialectalization:

It is again naughty of Vennemann (1994:244) to call his laryngealist explanation ‘the only kind of explanation that I know’. At least he does not quite go so far in his laryngealism as to posit a proto-Indo-European in which the vowel a never existed, as Kuiper does.

NOTE. It is difficult to understand why the work of so many Indo-Europeanists is usually not known, while Vennemann’s far-fetched theory has been endlessly repeated. I reckon it must be the same phenomenon of personal and professional contacts, involvement in editorial decisions, and simplification in mass media which makes Kristiansen and his theories frequently published and cited nowadays.

Pre-Pritenic

Orkney

Based on these data, I entertained the idea of arguing for a Pre-Celtic Indo-European language in A Storm of Words, called Pre-Pritenic, with a tentative fable based on the data described below for the Insular Celtic substrate, but eventually deleted the whole text, because (unlike other tentative fables, like the Lusitanian or Venetic ones) it was pure speculation with not even fragmentary data to rely on. Here is a fragment of the discussion:

Among the main reasons adduced to reject the non-Celtic nature of Pritenic is Orkney, a region where Pictish carved stones have been found (indicator of a centralised Pictish power and identity). The name was attested first as Gk. Orkas / Orkádos (secondary source, from Pytheas of Massilia, ca. 322-285 BC, or possibly much later) and Lat. Orchades / Orcades (by Latin sources in the 1st century AD), and it was used to describe the northernmost promontory in Scotland, commonly identified as Dunnet Head in Caithness. It is supposed to derive its name from Cel. *φorko- ‘pig’, because speakers of Old Irish interpreted the name for the island later as Insi Orc ‘island of the pigs’. Therefore, Pritenic would have undergone the prototypical Common Celtic evolution of NWIE *p- → Ø- (see above).

This argument is flawed, in so far as it could have happened (with the interpretation of the name from a Celtic point of view) what happened later with Norwegian settlers, who reinterpreted the name according to Old Norse orkn ‘seal’, to identify it as ‘island of the seals’. In fact, texts published in the 19th and 20th century looked for an even closer etymology to the interpreter, who usually saw it as ‘island of the orcas’.

The region name orc- could be speculatively linked to NWIE *ork-i- ‘cut off, divide’, cf. Ita. *erk-i- (vowel analogically changed), Hitt. ārk- (<*hork-ei-), in Latin found with the meaning ‘divide (an inheritance)’, hence noun Lat. erctum ‘inheritance, inherited part’.

Maybe more interesting is a connection to *or-, as found in British rivers or streams Arrow, Oare Water (Som), Ayre , Armet Water, Arnot Burn, Ernan Water etc. for which cognates Skt. arvan(t)- ‘running, swift’, árṇa- ‘surging’, Gmc. *arnia- ‘lively, energetic’ have been proposed (Forster 1941; Nicolaisen 1976; Kitson 1996). Similar to these derivatives in -n-, -m-, one could argue for a denominative suffixation in *-ko-, not uncommon in Old European toponyms (Villar Liébana 2007), which could be interpreted originally as ‘(region) pertaining to the Or (river, stream)’. The a-vocalism of Old European does not need further explanation, being fairly common in the British Isles (Kitson 1996).

I tried to look for rivers and streams in Caithness that fit a potential border for an ancestral tribe, but after reading many (and I really mean too many) texts on Scotland’s hydronymy, which is a quite well-researched area, I didn’t like the idea of plunging into such a speculative task; not when I have this blog for that… I deleted the text from the book, seeing how it doesn’t really add anything of value and may have distracted from its real aim. If any reader wants to post potential candidates for this delimiting river ‘Or’ in Caithness, feel free to post that below.

or-hydronym
Or- hydronyms, mapped by Villar (2007). He considered it a variant of ur-, uro-, and only included one certain occurrence from old river-names in southern England.

Weak (if any) support of a non-Celtic nature of the names might also be found in the late description of Ptolemy’s Geographia (originally ca. 150 AD), Tauroedoúnou tēs kai Orkádos kaloumenēs, translated in Latin as Tarved(r)um, quod et Orcas promontorium dicitur. The original name seems to be formed from *tau-r-, as is common in Indo-European *taur-o- (compare also river Taum), whereas the commonly used Latin translation seems to rely on a Celtic *tarw-o-.

Always Celtic?

As with other Pictish material, these questions are unlikely to be settled without unequivocal sources pointing to the original names and their meaning. The autochthonous trend is set lately by Guto Rhys, whose work is thorough and methodologically sound, although his reviews tend to dismiss all evidence of a non-Celtic (or even non-Brittonic) layer in Pictland as described in previous works, mostly because of the lack of direct sources or uncontroverted data:

Where a supposed divergence is found in certain names, a lack of proper reading or interpretation of materials (or lack of enough cases to generalize them), combined with similar names in other (neighbouring or distant) Celtic languages, is adduced.

However, the same arguments can indeed be used to reject his proposal of a Celtic nature of many names which cannot be simply explained with other clearly Celtic examples: namely, that all similarities are due to later influences, re-analysis and modifications of Old European terms according to Celtic phonemic (or etymological) patterns, or that the Brittonic nature of many names are due to convergence of the attested Pritenic naming conventions with neighbouring dialects.

In the end, the only conclusion is that there is a clear impasse in hydrotoponymic research in the British Isles, particularly in Scotland, with an impossibility of describing non-Celtic or non-Indo-European Pre-Pritenic layers, due in great part – in my opinion – to the trend among many British Celticists to consider Celtic as autochthonous to the Atlantic. This hinders the proper investigation of the question, just like the trend among Basque studies to consider the western Pyrenees as the eternal Vasconic homeland hinders a fair investigation of the actual Vasconic proto-history.

pictland
Probable maximum extent of Pictland is also highlighted in blue and overlain on the modern outline of northern Britain. Image from Noble, G., Goldberg, M., & Hamilton, D. (2018).

Non-Indo-Europeans in Northern Europe

Insular Celtic substrate

Matasović, a specialist in Celtic languages and author of the famous Eytmological Dictionary of Proto-Celtic (IEED 2009), writes in The substratum in Insular Celtic (2009):

Syntactic evidence

The syntactic parallels between Insular Celtic and Afro-Asiatic languages (which used to be called Hamito-Semitic) were noted more than a century ago by Morris-Jones (1899), and subsequently discussed by a number of scholars. These parallels include the following.

  1. The VSO order, attested both in OIr. and in Brythonic from the earliest documents (…).
  2. The existence of special relative forms of the verb, (…).
  3. The existence of prepositions inflected for person (or prepositional pronouns), (…).
  4. Prepositional progressive verbal forms, (…).
  5. The existence of the opposition between the “absolute” and “conjunct” verbal forms. (…)

The aforementioned features of Old Irish and Insular Celtic syntax (and a few others) are all found in Afro-Asiatic languages, often in several branches of that family, but usually in Berber and Ancient Egyptian (see e.g. Isaac 2001, 2007a).

Orin Gensler, in his unpublished dissertation (1993) applied refined statistical methods showing that the syntactic parallels between Insular Celtic and Afro-Asiatic cannot be attributed to chance. The crucial point is that these parallels include features that are otherwise rare cross-linguistically, but co-occur precisely in those two groups of languages. This more or less amounts to a proof that there was some connection between Insular Celtic and Afro-Asiatic at some stage in prehistory, but the exact nature of that connection is still open to speculation.

“Atlantic” typology

Insular Celtic also shares a number of areal isoglosses with languages of Western Africa, sometimes also with Basque, which shows that the Insular Celtic — Afroasiatic parallels should be viewed in light of the larger framework of prehistoric areal convergences in Western Europe and NW Africa.

The text goes on with typologically rare features found in West Europe and West Africa, such as the inter-dental fricative /þ/ (also in English, Icelandic, Castillian Spanish); initial consonant mutations/regular alterations of initial consonants caused by the grammatical category of the preceding word; the common order demonstrative-noun (within the NP) reversed; the vigesimal counting system; or use of demonstrative articles.

Lexical evidence

(…) only 38 words shared by Brythonic and Goidelic without any plausible IE etymology. These words belong to the semantic fields that are usually prone to borrowing, including words referring to animals (…), plants (…), and elements of the physical world (…). Note that cognates of these words may be unattested in Gaulish and Celtiberian because these languages are poorly attested, so that the actual number of exclusive loanwords from substratum language(s) in Insular Celtic is probably even lower. In my opinion it is not higher than 1% of the vocabulary. The large majority of substratum words in Irish and Welsh (and, generally, in Goidelic and Brythonic) is not shared by these two languages, which probably means that the sources were different substrates of, respectively, Ireland and Britain; (…)

Conclusion

The thesis that Insular Celtic languages were subject to strong influences from an unknown, presumably non-Indo-European substratum, hardly needs to be argued for. However, the available evidence is consistent with several different hypotheses regarding the areal and genetic affiliation of this substratum, or, more probably, substrata. The syntactic parallels between the Insular Celtic and Afro-Asiatic languages are probably not accidental, but they should not be taken to mean that the pre-Celtic substratum of Britain and Ireland belonged to the Afro-Asiatic stock. It is also possible that it was a language, or a group of languages (not necessarily related), that belonged to the same macro-area as the Afro-Asiatic languages of North Africa. The parallels between Insular Celtic, Basque, and the Atlantic languages of the Niger-Congo family, presented in the second part of this paper, are consistent with the hypothesis that there was a large linguistic macro-area, encompassing parts of NW Africa, as well as large parts of Western Europe, before the arrival of the speakers of Indo-European, including Celtic.

tuk-language
Map of tuk-, tok-, tuch-, tug- (with India). Interestingly, the language of the -tuk- represents a more recent layer in Iberia than the earlier Old European serial elements, pointing to a west-european expansion from the north, although it may have an Indo-European etymology.

Language of the geminates

Further evidence of the potential presence of non-Indo-European speakers at the arrival of Insular Celtic may be found in Schrijver’s Non-Indo-European surviving in Ireland in the first millennium AD (2000), and his less enthusiastic revision More on Non-Indo-European surviving in Ireland in the first millennium AD (2005). Both are referred and enough summarized by Matasović (2009).

Even more interesting than the discussion of potential non-Indo-Europeans still lingering in Ireland until well into the Common Era, is the discussion on his paper Lost Languages in Northern Europe (2001). Apart from other non-Indo-European borrowings in northern Europe, most of which must clearly be included within the European agricultural substrate, Schrijver tries to interpret the relative chronology of a substratum language of northern Europe, described by Kuiper (1995) as A2, and by Schrijver as “language of geminates“.

This substrate language is heavily present in Germanic (see e.g. Boutkan 1998), but also in Celtic and Balto-Slavic:

A highly characteristic feature of words deriving from this language is the variation of the final root consonant, which may be single or double, voiced or voiceless, and prenasalized. (…)

Incidentally, the language of geminates cannot be Uralic, as another of its characteristics is the frequent occurrence of word-initial *kn- and *kl-, and Uralic languages do not allow consonant clusters at the beginning of the word. On the other hand, and at the risk of explaining obscura per obscuriora, one might consider the possibility that the consonant gradation of Lappish and Baltic Finnic is somehow connected with the alternation of consonants at the end of the first syllable in the “language of geminates”.

The idea that the Northern European language of geminates could play an intermediary role in loan contacts between Northern and Western Indo-European on the one hand and Finno-Ugric on the other may also account for the fact that Finno-Ugric words could end up as far away as Celtic, which as far as we know was never in direct contact with a branch of Uralic.

Schrijver later changed his view about certain aspects of this substrate, from a “language of geminates” influencing Balto-Finnic which in turn influenced Germanic, to Pre-Balto-Finnic speakers being the substrate of Germanic, and both evolving at the same time in contact in Scandinavia. In fact, we know that Pre-Proto-Germanic evolved in southern Scandinavia, with a core in Jutland that shifted to the south, so the location must have been close to the North European Plain.

Also fitting this model is the substrate behind Balto-Slavic (spoken in the West Baltic), which must have also been (Para-)Balto-Finnic. However, the frequent word-initial *kn- and *kl- and the loanwords appearing in the Celtic homeland (also including Early Balto-Finnic) must place this Uralic(± non-Indo-European) language contact also well into Central European Corded Ware groups.

Similarly, one of the shared features between Finnic and Mordvinic is precisely the presence of certain geminated consonants. A revision of the data in combination with these facts should shift of evidence to a (Para-)Balto-Finnic-speaking Baltic area during the Early Bronze Age, certainly encompassing the Battle Axe culture.

corded-ware-groups-europe
Corded Ware groups. “Classical funerary practices” found regularly, in darker shades. Modified from Furholt (2014).

Afroasiatic-like substrate and Vasconic

The only archaeological culture that could fit most of these data, in the currently known relative chronological time frame, would be the Megalithic expansion in Western Europe, or potentially (maybe in addition to this early layer) the expansion of the Proto-Beaker package, which could have spread a Basque-Iberian language (see e.g. my take on Basque-Iberians).

Whether the language behind the Insular Celtic substrate (or, rather, some of its dialects) had true Afroasiatic syntactic features or it was just a language with features which happened to be similar to Afroasiatic is irrelevant. It’s impossible to reconstruct with confidence a Pre-Proto-Basque language with the currently available information.

Interestingly, it is possible to argue for an Afroasiatic branch surviving among hunter-gatherers adopting Neolithic traits in northern Europe. This has been proposed many times in the past, and one could argue in palaeogenomics for indirect supporting data, such as the expansion of WHG ancestry from south-east Europe (close to Anatolia, forming a cline with AME), and in particular of hg. R1b-V88 from the steppe – potentially associated with the Afroasiatic expansion into Africa from a Nostratic community.

NOTE. I will not resort here to typologically-based arguments similar to the “Hamito-Semit(id)ic” and “Vasconic-Uralic” Europe that were commonly in use in the 1990s, because they are in great part based on the mere re-labelling of Old European layers as “Vasconic” and flawed mass lexical/grammatical comparisons. For linguists favourable to this kind of reasoning, the theory set forth here is probably easier, though, as will be for those supporting a Neolithic expansion of Indo-European from the Mediterranean. This, however, has its own set of problems, as I have already discussed.

megalithic-tradition-western-europe
Distribution of megaliths in western, central, and northern Europe (after Muller 2006; graphic: Holger Dieterich).

Single Grave culture

The non-Indo-European substrate of Insular Celtic, in combination with the oldest hydrotoponymic layers – almost exclusively of Old European nature – of Britain and likely all of Ireland, can more easily be explained as a first layer of North-West Indo-European speakers heavily influenced by an Afroasiatic(-like) substrate reaching the British Isles, possibly with a slightly richer set of non-Indo-European loanwords at the time. Their language would have been later replaced by the closely related Celtic dialects imposed by elites in the Early Iron Age, which could have then easily absorbed this (mainly syntactic) substrate.

There is little space to argue for a hypothetic non-Indo-European expansion from another region, or for an in situ substrate, due to:

  1. the radical population replacement (and Y-chromosome bottleneck) in Britain and northern Ireland stemming from the Lower Rhine;
  2. the lack of meaningful population movements during the Bronze Age (at least from out of the islands);
  3. the final east-west movements of Celtic languages;
  4. the presence of the same (mainly syntactic) substrate in both Goidelic and Brittonic; and
  5. the minimal non-Indo-European lexical borrowings and hydrotoponymy, different in each island;

Based on archaeological and palaeogenomic data, the only reasonable direct connection of north-western Bell Beakers and this substrate language would be then the Corded Ware groups from north-western Europe – i.e. the traditionally named Single Grave culture from northern Germany and Denmark, and the Protruding Foot Beaker culture from the Netherlands.

The main reasons for this are as follows:

1. Early Corded Ware wave

The earliest Corded Ware burials from northern Europe (ca. 2900-2800 BC) show important differences, so no strict funerary norms existed at first (Furholt 2014):

  • In southern Sweden the prevailing orientation is north-east–south-west, and south–north; contrary to the supposed rule, male individuals are regularly deposite on their left and females on their right side
  • In the Danish Isles and north-eastern Germany, the Final Neolithic / Single Grave Period is characterized by a majority of megalithic graves, with only some single graves from typical barrows.
  • In south Germany, west–east and collective burials prevail, while in Switzerland no graves are found.
  • In Kuyavia (south-eastern Poland), Hesse (Germany), or the Baltic, west–east orientation and gender differentiation cannot be proven statistically.
corded-ware-expansion
Corded Ware and neighbouring groups. Top: cultural map. Bottom: varied Y-chromosome haplogroups from ancient DNA samples. See full maps.

In genetics, the area that would become the ‘core Corded Ware province’ only after ca. 2700 BC also shows a surprising variability in the oldest samples in terms of haplogroups (which may indicate a recent departure of migrants from a mixed homeland); in terms of admixture, at least one sample clusters close to EEF groups, while later ones from Esperstedt – of hg. R1a-M417 (possibly xZ645) – show a likely admixture with Yamna vanguard groups expanding from the Carpathian Basin.

On the contrary, the slightly later eastern expansions as Battle Axe and Abashevo show long-lasting genetic continuity and a marked bottleneck under R1a-Z645 subclades, as well as a clear cultural connection through the Fatyanovo culture. The role of local populations, particularly females, in preserving local customs in the Single Grave culture (see Bourgeois and Kroon 2017) is also quite relevant to the continuity of the regionl culture in spite of migrations.

2. Single Grave culture in Denmark

The Corded Ware culture in Denmark was particularly weak in its human impact compared to previous farmers (see e.g. Feeser et al. 2019), and also in its cultural traits, adopting Funnel Beaker culture traits up to a point where even the Copenhagen group describes cultural continuity, likely entailing an important substrate language impact (see e.g. Iversen and Kroonen 2017).

It’s not difficult to realize that this same argument used for Semitic-like terms in Germanic by Kroonen (2012) – e.g. words for ‘lentil’, ‘pea’, and ‘turnip’ – and supported by the Copenhagen group may be used to support the adoption of non-Uralic substrate in a Uralic-speaking Corded Ware area (as Schrijver does), which later influenced incoming Bell Beakers that developed into the Pre-Proto-Germanic speakers.

From Iversen (2016):

As it appears from the analysis above, the situation in East Denmark during the 3rd millennium BC is culturally rather complex. The continued use of megalithic entombments and the almost total rejection of the Single Grave burial custom show a strong affiliation with old Funnel Beaker traditions even after the end of the Funnel Beaker culture. (…) With an almost total lack of the two defining elements of the Single Grave culture – interments in single graves and the prominent position of stone battle axes – one can hardly talk about a Single Grave culture in East Denmark. What we see is rather the adoption of various Single Grave, Battle Axe and Pitted Ware cultural traits into a setting that was basically a continuation of Funnel Beaker norms and traditions (Iversen 2015).

denmark-single-grave-battle-axe
Single Grave and Battle axe culture graves in Denmark and scania (dots). Grey colouring: Distribution of Jutland single Graves. Dark grey: Initial phase ca. 2850–2800 BC. Cross: Megalithic tombs with single Grave/Battle axe culture finds (Iversen 2013 fig. 3).

The reason why East Denmark so conservatively upheld the Funnel Beaker traditions must be found in the area’s old position as a ‘megalithic heartland’, which reaches back to the early 4th millennium BC when dolmens and passage graves were constructed in very large numbers. (…) The result was a cultural blend governed by old Funnel Beaker norms and the use of Pitted Ware, Single Grave and Battle Axe material culture. This situation continued until the beginning of the Late Neolithic (ca. 2350 BC) when cultural and social development took a new course and flint daggers and metal objects appeared/ re-appeared in South Scandinavia.

The radical change brought about in the Late Neolithic “Dagger Period” is commonly agreed to be associated with the arrival and expansion of the Pre-Proto-Germanic communtity (read more here).

3. Single Grave culture in the Netherlands

The Corded Ware culture in the Netherlands is particularly disconnected culturally from its eastern core areas, which is reflected in the likely survival of a non-Indo-European language around the Low Countries, in the so-called Nordwestblock area. From Kroon et al. (2019):

The connections between changes in ceramic production techniques and social changes (see Fig. 2) allow for the formulation of hypotheses about the technological impact of the scenarios that archaeologists have proposed for the introduction of the CWC. If migration (i.e. an influx of new communities that bring new material culture) causes the spread of the CWC, then CWC vessels should differ from the vessels of previous communities in all respects: resilient, group-related, and salient techniques. However, if the introduction of the CWC is the result of diffusion of stylistic traits and moving objects, both these imported objects (different raw materials and production sequences) and changes in salient techniques should be observed when comparing CWC vessels to VLC vessels. Network interactions should yield the same changes as diffusion, as the combined movement of people, objects and styles within existing networks leads to the introduction of CWC. However, network interactions should yield one additional characteristic. Given that new people are integrated into extant communities, the occurrence of vessels with different resilient techniques, but group-related techniques that are stable relative to previous communities, is to be expected.

culture-change-cwc-netherlands
Schematic representation of the hypothesised changes in ceramic technology for diffusion (above) and migration (below) scenarios for the spread of the CWC. Image from Kroon et al. (2019).

The over-arching transitional process in the Western coastal area of the Netherlands is local continuity with diffusion and network interaction traits. Interestingly, the supra-regional networks of the VLC communities in this region, as well as some of the defining technological practices within these networks, remain intact throughout the CWC transition.

In the absence of detailed genetic and isotopic data from Late Neolithic individuals from the western coastal areas of the Netherlands, direct conclusions on the relations between the migrations demonstrated by genetic analyses in other regions and the outcomes of this study remain speculative. However, if a similar shift in the late Neolithic gene pool from this area can be detected, this raises questions on the impact of such migrations on knowledge transmission and local traditions. If such a change cannot be attested, questions should be raised about the nature of the CWC in this particular area. Questions that will ultimately boil down to what we define as CWC.

In other words, the introduction of Corded Ware in the Netherlands, which we can assume were driven by migrations – evidenced by the arrival of “Steppe ancestry” (see below) – would need to be interpreted in light of the adoption of a different set of cultural traits in this region. Combining linguistic and archaeological data, there is strong evidence that the Corded Ware ideology and its internal coherence might have been broken in the westernmost territories, hence the likely survival of the local culture and language(s).

Further reasons for this independence from the Uralic homeland, supporting the advantages of a cultural and linguistic integration among regional groups, include:

  1. the gradual shift of the core Corded Ware territory to the east in the centuries leading to the mid-3rd millennium BC;
  2. the similar weakened grip in Jutland (see above);
  3. the development of an isolated “classical” package in western Europe disconnected from eastern groups; and
  4. the cultural and genetic impact of expanding vanguard Yamna settlers.
single-grave-netherlands
General distribution of SGC settlements in the Netherlands. A = the tidal area in the province of Noord-Holland; B = the coastal barriers and Older Dunes area; C = the central river district; D = the northern, central and southern Dutch Pleistocene areas. a = certain/probable settlement; b = possible settlement; c = wooden trackway. Legend Holocene: 1 = coastal barriers and dunes. 2 = marine clay. 3 = peat. 4 = river clay. 5 = river dunes. 6 = water. Image modified from Drenth, Brinkkemper, and Lauwerier (2006).

4. Old Europeans in Britain

This predominant non-Indo-European language would later be the substrate language of Bell Beakers from the Lower Rhine and the British Isles.

Culturally, the same process as in the previous Single Grave culture period may have happened in the Low Countries, due to the culturally favorable situation there. This might be inferred from the continuity of Protruding Foot Beaker into All-Over Ornamented Beaker, most likely an imitation of the expanding Proto-Beaker package by locals of the Single Grave culture.

Arguably, though, the same situation should have happened in all other Proto-Beaker regions favourable to cultural change and witnessing admixture with locals, such as Iberia, and the social relevance of this imitation is far from being accepted by almost anyone except for archaeologists working around the Rhine… From Heise (2014):

While in 1955 the Maritime Beaker was considered to be intrusive, the 1976 work seemed to prove that in the Netherlands a continuous development from Protruding Foot Beaker (PFB) to All-Over Ornamented (AOO) Beaker to Maritime Beaker occurred. Nevertheless, the authors stressed that it was not possible to identify ‘the’ origin of the ‘Bell Beaker Culture’ in the Lower Rhine Area since typical artefacts (wristguards, daggers) were not known to be associated with the early AOO and Maritime pottery. Furthermore they argued against the “misleading simplification” of a single point of origin (Lanting & van der Waals 1976, 2). However, this last observation was not appreciated or was simply ignored by large parts of the research community and the theory was subsequently applied as a universal solution in many parts of Europe.

all-over-ornamented-beakers
Typological development of Beakers in the Netherlands (PFB: Protruding Foot Beakers; AOO: All Over Ornamented Beakers; BB: Bell Beakers) (after Lanting & van der Waals 1976, 4, fig. 1).

In fact, most archaeologists have unequivocally rejected a Single Grave – Classical Bell Beaker continuity, and Heyd’s model has been recently confirmed in paleogenomics, which shows an evident expansion of East Bell Beakers from Yamna settlers in the Carpathian Basin (see here). We may nevertheless still save the following assertion, as particularly relevant for the continuity of non-Indo-European languages among the Single Grave groups of the Lower Rhine:

Marc Vander Linden argued that the “local validity of the Dutch sequence cannot […] be questioned” (2012, 76).

Olalde et al. (2019) showed how British, Dutch, and French Beakers have excess “Steppe ancestry” relative to Central European Beakers from Germany, who are in turn closest to the origin of Old Europeans in Iberia (i.e. Galaico-Lusitanian, “Ligurian”), the Lower Danube (i.e. Celtic), Italy (i.e. Italic, Venetic, Messapic), Sicily, and even Denmark (i.e. Germanic). This excess “Steppe ancestry” probably implies admixture with local Single Grave populations of the Lower Rhine, which is further supported by the position of these Lower Rhine Beakers in the PCA (using British Beakers and Netherlands BA as proxies), clustering – among Bell Beakers – closest to Corded Ware samples.

rhine-beakers
PCA of ancient Eurasian samples, with Corded Ware clusters drawn. Rhine/British Bell Beakers partially overlapping them. See full PCAs.

Futhermore, the emergence of Bell Beakers in the British Isles represents a radical replacement, with a population turnover of ca. 90% of the local population, and Yamna lineages representing more than 90% of the haplogroups of individuals in Chalcolithic and Bronze Age Britain and Ireland, apart from an evident Y-chromosome bottleneck under hg. R1b-S461 (and its subclade R1b-L21), maintained during the whole Bronze Age. The scarce non-Indo-European hydrotoponymy attests to the lack of integration of local populations or their languages into the new society. All this suggests an initial swift and massive intrusion marking the linguistic evolution of the British Isles until the Iron Age.

The arrival of Insular Celtic in the British Isles will be likely defined by an increase in ancestry related to Central Europe (and probably haplogroups, too). Since the Afroasiatic-like substrate is unrelated to Common Celtic, the non-Indo-European substrate must be associated with preceding Bronze Age populations of western Europe, most likely with Bronze Age Britons, who are in turn derived from Bell Beakers from the Lower Rhine admixed with Single Grave peoples. The latter, therefore, must have passed on their Afroasiatic-like language as the substrate of Lower Rhine Beakers.

5. Vasconic from the north

Another indirect proof to the survival of non-Indo-Europeans in northern Europe is offered by Basques. Vasconic speakers came originally from some place beyond Aquitaine, and very recently before the Roman conquests, because place- and river-names show an overwhelming Old European substratum to the north of the Pyrenees, and exclusively Old European to the south.

Their origin is potentially quite far away, since Modern Basques show a similar cluster to that found in Iron Age Celtiberians of the Basque country. This could essentially mean that Basques were peoples of north/central European ancestry (see below fitting models of origin populations), because they must have arrived to Aquitaine after the arrival of Celtiberians, and with a similar ancestry.

In words of Olalde et al. (2019):

(…) increases in Steppe ancestry were not always accompanied by switches to Indo-European languages. This is consistent with the genetic profile of present-day Basques who speak the only non-Indo-European language in Western Europe but overlap genetically with Iron Age populations showing substantial levels of Steppe ancestry.

olalde-iberia-chalcolithic

The Tollense Valley near Rügen in the West Baltic shows LBA people clustering with Modern Basques (see here). This is compatible with the arrival (or displacement) of Vasconic-speaking Northern/Central Europeans close to the Rhine, possibly originally from northern France, very likely close to the Atlantic area during the Final Bronze Age / Early Iron Age based on cultural interactions.

british-isles-basques-late-bronze-age
Population movements from central-northern Europe into western Europe. Top: Cultures of the Late Bronze Age. Bottom: PCA with Bronze Age samples and drawn clusters. Marked in red is the Tollense site (please note: the approximate Tollense cluster does not include outliers, among them those closer to Modern Basques). Also marked is the British Bell Beaker sample closest to CWC populations. See full maps and whole PCAs.

Pre-Steppe languages in Europe?

An alternative to Old Europeans of the British Isles would be to support some kind of non-Indo-European/Vasconic continuity in the Atlantic façade close to the English Channel and the North Sea, given the current lack of palaeogenomic data on Bell Beakers and later groups in the area, and the potential Vasconic nature of Megalithic/Proto-Beaker groups that might have survived there.

The main problems with this approach are the lack of such an Afroasiatic-like substrate in Gaulish, which should have shown the same substrate as Insular Celtic, and the impossibility of associating this Afroasiatic-like substrate with Vasconic, both potentially representing completely different languages. A counterargument would be that we don’t have that much information on Gaulish and its dialects – or on the syntax of Vasconic, for that matter – to reject this hypothesis straight away…

In any case, the survival of pockets of non-Indo-European, non-Uralic speakers in northern Europe, even after Steppe-related expansions, should not shock anyone:

If the survival of non-Indo-European-speaking groups happened despite the swift expansion and radical population replacement brought about by the Bell Beaker folk – so called traditionally because of its unitary culture suggesting a unitary language community -, and non-Uralic-speaking groups in areas dominated by Corded Ware peoples, it could certainly have happened, and even more so, with Corded Ware and Bell Beaker groups at the western and northern edges of their expansions, due to the early loss of contact with their respective core cultural regions.

Conclusion

Even obscure components of place or river names, like those from northern Europe, the Nordwestblock area, and the British Isles, might be better explained as Old European exceptions than any other alternative, i.e. either as an Indo-European layer over a non-Indo-European one or vice versa, or both in different periods, before the eventual unifying Celtic, Roman, and (later) Germanic expansions.

All in all, one could say about substrates and hydrotoponymy in the British Isles, the Lower Rhine, and in northern Europe as a whole, that the potentially interesting non-Indo-European forms are precisely those which do not interest either scholarly ‘faction’:

  • those supporting a non-Indo-European Western Europe, because it doesn’t represent the whole substrate, and can’t be used to argue for a Europa Vasconica or Europa Afroasiatica;
  • those supporting a Palaeo-Indo-European Western Europe, because their limited presence concentrated in isolated pockets doesn’t deny the Indo-Europeanness of the Old European layer anywhere.

However, these are the details that should be studied and that could define what happened exactly after steppe-related migrations, e.g. in the Single Grave cultural area before and after North-West Indo-Europeans admixed with its population, and thus what happened in the British Isles, too.

Ignoring the (mostly useless) typological comparisons, my bet would be for an ancient Uralic layer heavily admixed with local non-Uralic peoples, especially intense in the Single Grave culture. This Proto-Uralic layer would be of a dialect or dialects (assuming succeeding CWC waves and later local expansions) different from the known Late Proto-Uralic – which expanded with eastern Corded Ware groups.

Describing the phonetic features of this layer could improve our knowledge of Early Proto-Uralic, as well as some specifics of the evolution of Germanic, Balto-Slavic, and potentially Celtic and Balto-Finnic.

This would be similar to the relevance of Aquitanian toponyms for Proto-Basque reconstruction, or of the alteuropäische substratum when it conflicts with the Proto-Indo-European dialectal reconstruction of some linguists (e.g. the laryngeal Pre-Indo-Slavonic of Kortlandt) which, like Kitson implies, should question the dialectal reconstruction of this minority of Indo-Europeanists, and not the Indo-European nature of the substratum.

Related