Genetic study Geographic origin, ancestry, and death circumstances at the Cornaux/Les Sauges Iron Age bridge, Switzerland

[mount123]

Geographic origin, ancestry, and death circumstances at the Cornaux/Les Sauges Iron Age bridge, Switzerland - Scientific Reports

Cornaux/Les Sauges (Switzerland, Late Iron Age) revealed remnants of a wooden bridge, artifacts, and human and animal skeletal remains. The relationship between the collapsed structure and the skeletal material, whether it indicates a potential accident or cultural practices, remains elusive. We...

www.nature.com

 

[Maciamo]

La Tène genomes from Switzerland (probably Helveti tribes). 7 Y-DNA haplogroups: one R1b-P312, 4 R1b-U152 > L2, one G2a-L497 > Z1816 and one J2b2a-L283 > PH1602. Very similar haplogroups to the Hallstatt individuals from Baden-Wurttemberg and to the Etruscans.

 

[Riverman]

Table 11.

Finally a solid confirmation for my hypothesis of Hallstatt-La Tene dispersal of E-V13 to the West. I hypothesized in particular about branches of North Thracian/Dacian E-S2979 reaching the West from the sphere of East Hallstatt-Vekerzug. Well, here it is:
E1b1b1a1b1a10a1a1b~ = downstream of E-S2979
https://discover.familytreedna.com/y-dna/E-BY5400/tree
https://www.yfull.com/tree/E-Y95437/
Modern descendants in Russia (Chuvash people - Scythian dispersal?), which just underscores the Vekerzug-North Thracian affiliation of this branch. The branch origins dates exactly to the Hallstatt-Vekerzug phase. Would be nice to know how far apart the Chuvash and this Celt (?) are.

The sample had some contamination, but it was run through the tools, resulting in enough SNP's to verify it, but not enough for further processing with the analyses they claim:

After merging the shotgun and capture sequencing data, the average genome coverage in our samples ranged from 0.1193 to 0.9218 X, while 939,972 to 1,346,808 of targeted SNPs were covered, with a mean coverage spanning from 1.84 X to 10.46 X (Supplementary Table S9). Additionally, most samples (> 81%) show low contamination estimates from modern human DNA (≤ 5% on mtDNA for all samples and ≤ 3% on Y-Chromosome in males), except for two (COR-3 and COR-19; 6% and 24% of contamination on mtDNA level, respectively). After filtering the reads by PMDtools40, the two contaminated samples still retained enough human reads for sex determination (810,776 and 1,004,715, respectively)41,42 but not for further analyses (kinship, PCA, and clustering analysis).

Presumably for the same reason its not carbon dated, but looks legitimate from the context.

 

[Maciamo]

E-V13 it was already found in two La Tène samples from Hungary (I18527 and I18832) by Patterson et al. 2021. Both were E-BY3880.

 

[Maciamo]

I posted from my phone yesterday, but now that I am on my PC here is the summary table of the haplogroups from this study. Note that the COR-7 and COR-8 appear to be the same individual (say the authors), so I removed COR-8.

[TABLE=collapse]
[TR]
[TD]ID[/TD]
[TD]Y-DNA haplogroup[/TD]
[TD]Y-DNA SNP[/TD]
[TD]mtDNA[/TD]
[/TR]
[TR]
[TD]COR-19[/TD]
[TD]E1b1b1a1b1a10a1a1b~[/TD]
[TD]E-BY5400[/TD]
[TD]HV[/TD]
[/TR]
[TR]
[TD]COR-5[/TD]
[TD]female[/TD]
[TD]female[/TD]
[TD]U5a1a1[/TD]
[/TR]
[TR]
[TD]COR-2[/TD]
[TD]G2a2b2a1a1b1a1~[/TD]
[TD]G-CTS2100*[/TD]
[TD]V[/TD]
[/TR]
[TR]
[TD]COR-7[/TD]
[TD]J2b2a1a1a1b2~[/TD]
[TD]J-PH1601/etc[/TD]
[TD]HV0+195[/TD]
[/TR]
[TR]
[TD]COR-3[/TD]
[TD]R1b1a1b1a1a1c1b1[/TD]
[TD]R-S5556[/TD]
[TD]HV0+195[/TD]
[/TR]
[TR]
[TD]COR-21[/TD]
[TD]R1b1a1b1a1a1c2b2a1b1b1a4b[/TD]
[TD]R-S27458[/TD]
[TD]H13a1a1[/TD]
[/TR]
[TR]
[TD]COR-16[/TD]
[TD]R1b1a1b1a1a2b1[/TD]
[TD]R-L2*[/TD]
[TD]H3+152[/TD]
[/TR]
[TR]
[TD]COR-11[/TD]
[TD]R1b1a1b1a1a2b1a[/TD]
[TD]R-S255*[/TD]
[TD]H2a1k[/TD]
[/TR]
[TR]
[TD]COR-15/17[/TD]
[TD]R1b1a1b1a1a2b1a~[/TD]
[TD]R-S372*[/TD]
[TD]H95*[/TD]
[/TR]
[TR]
[TD]COR-9[/TD]
[TD]R1b1a1b1a1a2b1a1[/TD]
[TD]R-L20[/TD]
[TD]U5b1c2[/TD]
[/TR]
[/TABLE]

COR-13 is E-V13 > Z1057 > CTS1273 > BY3880 > Z5018 > S2979 > Z16659 > L241 > BY5500 (aka BY5400). So it's the same BY3880 branch as the two La Tène samples from Hungary, which would confirm that this clade of E-V13 at least was La Tène Celtic.

 

[MOESAN]

This change in paradygm among heirs of BB's and then what I think Celts seem showing effectively some input of Tells cultures from Hungary among the Tumuli people; so it's not Tumuli people who created Urnfields, they have been more or less (sometimes not at all) influenced by previously sedent poeple rich in EEF Y-haplo's and autoDNA. (that added to the EEF input by exogamy).
It's why me and others think that proto-Celtic and Celtic languages in their peculiarity were not born in Central Europe but rather in West-West-Central Europe, around eastern France. SW Germany at first. These tongues matured among Tumuli of West and even before among precedent cultures. Celtic language owes nothing to Urnfields, just Unrfields penetrated more than a culture and put some tribes on martch, allowing some of them to send celtic dialects farther.
THe Celtic-Italic (and other cousin) dialects found birth rather in western Europe, spite not on the Atlantic shores as proposed the "Celts of the West" theory (KOch and Co?)

 

[Vitruvius]

Geographic origin, ancestry, and death circumstances at the Cornaux/Les Sauges Iron Age bridge, Switzerland - Scientific Reports

Cornaux/Les Sauges (Switzerland, Late Iron Age) revealed remnants of a wooden bridge, artifacts, and human and animal skeletal remains. The relationship between the collapsed structure and the skeletal material, whether it indicates a potential accident or cultural practices, remains elusive. We...

www.nature.com

The samples look simplistically modern french-like to me, and are found at the southern end of the Central European cluster, which should come as no surprise given their ethnic affiliation. This is a nice starting point to gauge what preroman alpine celts would've resembled. Clearly there is a notable difference between themselves and the Etruscans of Felsina and the Picenes as one would expect.

 

[Pax Augusta]

La Tène genomes from Switzerland (probably Helveti tribes). 7 Y-DNA haplogroups: one R1b-P312, 4 R1b-U152 > L2, one G2a-L497 > Z1816 and one J2b2a-L283 > PH1602. Very similar haplogroups to the Hallstatt individuals from Baden-Wurttemberg and to the Etruscans.

Further confirmation, and this is really interesting, and it really seems once again to suggest that the earlier Bell Beaker played a very important role, even with subsequent movements up to the Urnfield culture, and that there is some truth in the Italo-Celtic linguistic theory, and that the split happened there in the Bell Beaker of Central Europe. It remains to be understand whether it is only true for the Latin-Faliscan branch, or also for the Osco-Umbrian branch (as I have said several times before, there are two theses about this among linguists, one that Latin-Faliscan and Osco-Umbrian arrived together, another that Osco-Umbrian is a much more recent arrival of the Latin-Faliscan branch and that the convergence occurred in Italy because of contacts).

The samples look simplistically modern french-like to me, and are found at the southern end of the Central European cluster, which should come as no surprise given their ethnic affiliation. This is a nice starting point to gauge what preroman alpine celts would've resembled. Clearly there is a notable difference between themselves and the Etruscans of Felsina and the Picenes as one would expect.

The difference is in autosomal DNA, and not in uniparental markers (at least with the Etruscans), because evidently there was a greater density of populations of Chalcolithic descent (EEF + WHG) in southern Europe than in northern Europe, with central Europe acting as a transition between the two areas.

 

[Pax Augusta]

This change in paradygm among heirs of BB's and then what I think Celts seem showing effectively some input of Tells cultures from Hungary among the Tumuli people; so it's not Tumuli people who created Urnfields, they have been more or less (sometimes not at all) influenced by previously sedent poeple rich in EEF Y-haplo's and autoDNA. (that added to the EEF input by exogamy).
It's why me and others think that proto-Celtic and Celtic languages in their peculiarity were not born in Central Europe but rather in West-West-Central Europe, around eastern France. SW Germany at first. These tongues matured among Tumuli of West and even before among precedent cultures. Celtic language owes nothing to Urnfields, just Unrfields penetrated more than a culture and put some tribes on martch, allowing some of them to send celtic dialects farther.
THe Celtic-Italic (and other cousin) dialects found birth rather in western Europe, spite not on the Atlantic shores as proposed the "Celts of the West" theory (KOch and Co?)

I agree with your observations but we should not forget that Bell Beaker, Tumuli, Urnfield... are not peoples or ethnic groups like those of the Iron Age, but first of all material cultures. For the area of the possible birthplace of the Italo-Celtic languages, before the split, an area between eastern France and neighboring western Germany (Rhine Valley, specifically near the Oberrhein?) is plausible.

 

[MOESAN]

I agree with your observations but we should not forget that Bell Beaker, Tumuli, Urnfield... are not peoples or ethnic groups like those of the Iron Age, but first of all material cultures. For the area of the possible birthplace of the Italo-Celtic languages, before the split, an area between eastern France and neighboring western Germany (Rhine Valley, specifically near the Oberrhein?) is plausible.

I agree. BB's at first were not a tight ethnic group, and the specific "kit" they carried (not always complete) was the adoption by elites. That doesn't imply there has not been real ethnic groups in the cultural horizon of BB's. Plus we may imagine some between or vehiulary group (the famous (often) brachycephals we find in everyplace at Chalco where BB's appeared very close in time, and which were dominant in Middle Rhine region at Chalco, even if this group is not by force the one which gave birth to the initial typical pottery.
Concerning this Tumuli group I'm tempted to see in them the more precise Italic and Celtic territory inhabitants. Uneasy to say. I "see" Italics differentiated rather among the Austria/Croatia group of Tumuli, whose more tight contacts with cultures of Hungary and surroundings between BA and IA could explain the linguistic evolution. An influence which may have reached as far as post-Mycenian Greece. If we rely on swords, Hungary places seem a "melting pot" atfirst and superficial sight. Let's keep in mind this is a try to roughly synthetise things and not a credo.

 

[Riverman]

If looking at cultureal groupings like Bell Beakers and Tumulus culture, we clearly see an ethnic group in the archaeological record, but the situation is more obvious in the core zone, the groups with the typical package. Especially at the fringes we get more kind of a variation and regional influences. So far, its exactly in those fringe groups we find more deviating genetic profiles (like Hungarian Bell Beakers). Usually, if a foreign ethnic group adopted some customs, they altered it and didn't take the full package or not abruptly so.

 

[Pax Augusta]

If looking at cultureal groupings like Bell Beakers and Tumulus culture, we clearly see an ethnic group in the archaeological record, but the situation is more obvious in the core zone, the groups with the typical package. Especially at the fringes we get more kind of a variation and regional influences. So far, its exactly in those fringe groups we find more deviating genetic profiles (like Hungarian Bell Beakers). Usually, if a foreign ethnic group adopted some customs, they altered it and didn't take the full package or not abruptly so.

If you go to an archaeology exam and tell the archaeology professor that if you look at cultural groupings like the Bell Beakers and the Tumulus culture, one clearly see an ethnic grouping in the archaeological record, you get slapped in the face. For a whole series of considerations made about the definition of ethnicity by cultural anthropologists and accepted by archaeologists.

 

[Pax Augusta]

I agree. BB's at first were not a tight ethnic group, and the specific "kit" they carried (not always complete) was the adoption by elites. That doesn't imply there has not been real ethnic groups in the cultural horizon of BB's. Plus we may imagine some between or vehiulary group (the famous (often) brachycephals we find in everyplace at Chalco where BB's appeared very close in time, and which were dominant in Middle Rhine region at Chalco, even if this group is not by force the one which gave birth to the initial typical pottery

Concerning this Tumuli group I'm tempted to see in them the more precise Italic and Celtic territory inhabitants. Uneasy to say. I "see" Italics differentiated rather among the Austria/Croatia group of Tumuli, whose more tight contacts with cultures of Hungary and surroundings between BA and IA could explain the linguistic evolution. An influence which may have reached as far as post-Mycenian Greece. If we rely on swords, Hungary places seem a "melting pot" atfirst and superficial sight. Let's keep in mind this is a try to roughly synthetise things and not a credo.

On the issue of ethnicities, Anthropologists and archaeologists usully do not believe that in such a remote time we can already speak of formed ethnic groups in the modern sense of the term in much of Europe, but all at most in the Bronze Age at the emergence of identities, particularly local identities, and traditions, because in order to be able to speak of ethnicity individuals must show ethnic self-consciousness, and a whole other set of conditions that are shown only later, roughly from the end of the Bronze Age, with the establishment of proper ethnic groups only from the Iron Age. Obviously exceptions to this are those areas in the world that develop earlier. Among European peoples, the Greeks are probably among the first of whom we can speak of ethnicity. Of course, it is a debate that continues and a widely discussed topic, with some proposing to backdate it. But unfortunately it is the spread of the alphabet that remains an important discriminator, because it is with writing that we have the first definite evidence of ethnic self-awareness and self-consciousness.

On the issue of the Tumuli, I will answer you tomorrow.

 

[Vitruvius]

On the issue of ethnicities, Anthropologists and archaeologists usully do not believe that in such a remote time we can already speak of formed ethnic groups in the modern sense of the term in much of Europe, but all at most in the Bronze Age at the emergence of identities, particularly local identities, and traditions, because in order to be able to speak of ethnicity individuals must show ethnic self-consciousness, and a whole other set of conditions that are shown only later, roughly from the end of the Bronze Age, with the establishment of proper ethnic groups only from the Iron Age. Obviously exceptions to this are those areas in the world that develop earlier. Among European peoples, the Greeks are probably among the first of whom we can speak of ethnicity. Of course, it is a debate that continues and a widely discussed topic, with some proposing to backdate it. But unfortunately it is the spread of the alphabet that remains an important discriminator, because it is with writing that we have the first definite evidence of ethnic self-awareness and self-consciousness.

On the issue of the Tumuli, I will answer you tomorrow.

It is impossible to speak of a lack of ethnic-self awareness when we have a lack of documentation or oral tradition from most of the bronze age. Why assume ethnic self consciousness did not exist where we haven't a clue as to how these people thought of themselves? Who are these anthropologists to make such assumptions for those they know nothing about beyond material artifacts? This type of thinking is fallacious and unreasonable. For those populations who could write we do see evidence of ethnic affiliation, so for what cause would we assume otherwise for illiterate cultures?

 

[Vitruvius]

The difference is in autosomal DNA, and not in uniparental markers (at least with the Etruscans), because evidently there was a greater density of populations of Chalcolithic descent (EEF + WHG) in southern Europe than in northern Europe, with central Europe acting as a transition between the two areas.

Yes and autosomal DNA is what counts if we want to look at the breadth of variance in makeup both between and within ethnic groups. Do we have evidence for this population density difference beyond inference from EEF-like contribution? Do we actually see larger villages and occupied living spaces in copper age southern Europe over Northern? It could be equally possible that Yamnaya migrations to southern Europe were simply smaller than that of corded ware movements throughout northern Europe, no? We also need to remember that southern Europe has received a bronze age Anatolian influx simultaneously during this era, which would in turn help to stabilize or fix an EEF like genetic signature to about 60% in whatever populations were being affected.

 

[Pax Augusta]

Yes and autosomal DNA is what counts if we want to look at the breadth of variance in makeup both between and within ethnic groups. Do we have evidence for this population density difference beyond inference from EEF-like contribution? Do we actually see larger villages and occupied living spaces in copper age southern Europe over Northern? It could be equally possible that Yamnaya migrations to southern Europe were simply smaller than that of corded ware movements throughout northern Europe, no? We also need to remember that southern Europe has received a bronze age Anatolian influx simultaneously during this era, which would in turn help to stabilize or fix an EEF like genetic signature to about 60% in whatever populations were being affected.

Yes, of course autosomal matters a lot, no doubt. I know you don't like it very much, but uniparental markers also counts, if you really want to fully understand the movements that occurred.

Of course, we know the final outcome but still do not know for sure how the ratio between the ancestral components that gave rise to the Iron Age populations was formed. Either hypothesis could be valid.

We also need to remember that southern Europe has received a bronze age Anatolian influx simultaneously during this era, which would in turn help to stabilize or fix an EEF like genetic signature to about 60% in whatever populations were being affected.

Bronze Age Anatolian influx marked by Iran_N/CHG? To date there is no evidence that all of southern Europe (from the Iberian Peninsula to the Balkans) received a Bronze Age Anatolian influx in the same proportions. It is worth remembering that southern Europe constitutes two clusters from Bronze age at least, one southwestern, and the other southeastern, from the autosomal point of view.

 

[Pax Augusta]

It is impossible to speak of a lack of ethnic-self awareness when we have a lack of documentation or oral tradition from most of the bronze age. Why assume ethnic self consciousness did not exist where we haven't a clue as to how these people thought of themselves? Who are these anthropologists to make such assumptions for those they know nothing about beyond material artifacts? This type of thinking is fallacious and unreasonable. For those populations who could write we do see evidence of ethnic affiliation, so for what cause would we assume otherwise for illiterate cultures?

There are attempts in fact, and not surprisingly usually by Indo-European scholars, to backdate the emergence of ethnic groups in Europe to the Bronze Age. On the other hand, that of calling the Prehistoric/Protohistoric people of the Steppes (who would have contributed later to the spread of Indo-European languages in Europe and Asia) Indo-Europeans as if they had been a people in the ethnic sense is an old adage of Indo-European scholars.

In fact the ethnic question is much more complicated, and several factors, linguistic, cultural, historical, biological etc., may play a role in defining it. Think of the consequences of considering Bronze Age material cultures as ethnic groups, when we talk about where the possible split of the hypothetical Italo-Celtic language family occurred (in this context it does not matter whether it occurred in the Bell Beaker or the Tumuli), are we suggesting that the two language families, the Italic and the Celtic, are descended from the same Bronze Age ethnicity? And thus consequently their ethnicities?

There are many books on these topics. I personally don't agree with everything they write but what I think is not so relevant. Anthony D. Smith, The Ethnic Origins of Nations. Ugo Fabietti, "Ethnic Identity" (in Italian, don't know if there is in English), Jonathan Hall, Ethnic Identity in Greek Antiquity, Patrick J. Geary, The Myth of Nations: The Medieval Origins of Europe, Eric Hobsbawm and Terence Ranger, The Invention of Tradition. Jean-Paul Demoule, Mais où sont passés les Indo-Européens ? : Le mythe d'origine de l'Occident ((in French, don't know if there is in English), or the collected book A Companion to Ethnicity in the Ancient Mediterranean, which contains different points of view. But then there are many others that I can't think of now.

 

[Riverman]

If you go to an archaeology exam and tell the archaeology professor that if you look at cultural groupings like the Bell Beakers and the Tumulus culture, one clearly see an ethnic grouping in the archaeological record, you get slapped in the face. For a whole series of considerations made about the definition of ethnicity by cultural anthropologists and accepted by archaeologists.

I'm aware of the "New Archaeology" dogma of cultural diffusion and "pots not people". I had discussion on the issue with my professor back then and I remember very well how they argued that "Bell Beakers are just a cultural phenomenon" and all that crap, even when we knew they were spreading not just a fully developed package in a short period of time, but even a specific physical anthropoligical type or variation.
We now have the data to prove them wrong, because even more than the autosomal similarity, ethnicity in patriarchal-patrilinear societies, like most developed cultures in the world and in Eurasia in particular were, Indoeuropeans even more so (even agnatic), direct paternal lineage matters a lot for the ethnic groups and identity, the tribal unity based on mythical and oftentimes real ancestors.
And we see time and time again that complete cultural shifts recognisable by the abrupt introduction of full archaeological packages like Corded Ware, Bell Beaker, Tumulus culture, resuled in population change on replacement level, with the introduction of closely related paternal lineage based clans. Most specifically, R-Z283 for Corded Ware, R-L51 for Bell Beaker and R-L51/R-U152/R-L2 for Tumulus culture.

Like in the area of the Encrusted Pottery people we see a complete and abrupt shift in the archaeological record with the Koszider horizon towards the Tumulus culture and soon after we find almost exclusively the Tumulus culture package, Bell Beaker ancestry and R-L2 in Transdanubia. If that's not a clear cut ethnic tribal identity, which was already visible in the archaeological record, what is?
Also, the Encrusted Pottery people fled down the Danube and appear with their full archaeological package, autosomal profile and lineages (I2+G2) in Northern Croatia and Bulgaria.

The only thing missing is the written record which tells us that the trives X displaced the tribe Y in Trandanubia, with tribe Y fleeing to the lower Middle/Lower Danube.

All that talk about cultural diffusion is largely irrelevant if its about complete, nearly unaltered packages. Then its in 9 of 10 cases a demic/ethnic diffusion up to the periods of state. The big partial expeption in the BA was Unetice, because Unetice did subjugate some clans (of Bell Beakers for example) without eliminating them completely. Which however didn't pay off, since they later took part in their very destruction with the Tumulus culture expansion.

 

[Vitruvius]

Yes, of course autosomal matters a lot, no doubt. I know you don't like it very much, but uniparental markers also counts, if you really want to fully understand the movements that occurred.

I don't have an issue with anyone following haplogroups, including yourself of course. I only take issue with those who try to posit them as more informative than autosomal DNA when it comes to population movements as they represent less than 1% of the expressed genome of any individual. They also suffer from sex based reproduction biases which do not reflect autosomal changes at the statistical level. Drawing too many inferences from such a tiny amount of genetic information is a common pitfall I keep seeing. There's no harm in noting them otherwise if we can agree on this.

Of course, we know the final outcome but still do not know for sure how the ratio between the ancestral components that gave rise to the Iron Age populations was formed. Either hypothesis could be valid.

The best way to determine this will be to wait for preceding bronze age populations to be sequenced and to note their changes over time I think. IIRC we do have some bronze age swiss samples from past studies, but I'd have to double check to verify.

Bronze Age Anatolian influx marked by Iran_N/CHG? To date there is no evidence that all of southern Europe (from the Iberian Peninsula to the Balkans) received a Bronze Age Anatolian influx in the same proportions. It is worth remembering that southern Europe constitutes two clusters from Bronze age at least, one southwestern, and the other southeastern, from the autosomal point of view.

Yes, marked by Armenian Neolithic like ancestry which is usually just blanket labelled as CHG/Iran_N. Sure, the ancestry took a predictable east to west path of impact in S. Europe but its influence cannot be ignored. We see it definitively in large proportion in Greece and we already see it in somewhat smaller proportions in the Sicilian bronze age. Right now it is beginning to look like it did not get too far up the Italian peninsula until at least the Iron age, but it was present at the very least in Italy.

 

[Vitruvius]

There are attempts in fact, and not surprisingly usually by Indo-European scholars, to backdate the emergence of ethnic groups in Europe to the Bronze Age. On the other hand, that of calling the Prehistoric/Protohistoric people of the Steppes (who would have contributed later to the spread of Indo-European languages in Europe and Asia) Indo-Europeans as if they had been a people in the ethnic sense is an old adage of Indo-European scholars.

In fact the ethnic question is much more complicated, and several factors, linguistic, cultural, historical, biological etc., may play a role in defining it. Think of the consequences of considering Bronze Age material cultures as ethnic groups, when we talk about where the possible split of the hypothetical Italo-Celtic language family occurred (in this context it does not matter whether it occurred in the Bell Beaker or the Tumuli), are we suggesting that the two language families, the Italic and the Celtic, are descended from the same Bronze Age ethnicity? And thus consequently their ethnicities?

There are many books on these topics. I personally don't agree with everything they write but what I think is not so relevant. Anthony D. Smith, The Ethnic Origins of Nations. Ugo Fabietti, "Ethnic Identity" (in Italian, don't know if there is in English), Jonathan Hall, Ethnic Identity in Greek Antiquity, Patrick J. Geary, The Myth of Nations: The Medieval Origins of Europe, Eric Hobsbawm and Terence Ranger, The Invention of Tradition. Jean-Paul Demoule, Mais où sont passés les Indo-Européens ? : Le mythe d'origine de l'Occident ((in French, don't know if there is in English), or the collected book A Companion to Ethnicity in the Ancient Mediterranean, which contains different points of view. But then there are many others that I can't think of now.

I've seen the attempts of Indo European Scholars attempting to refer to all IE speakers as some sort of single, macroethnic group after their dispersal which I think is a bit silly given the scope of their movements. I think it's perhaps more realistic to consider this possibility before their movements, but not so much afterwards.

When I speak of the possible existence of bronze age ethnic groups I don't mean to imply they would've definitively existed upon hard lines of material cultural horizons. I simply mean to say that i would be surprised if collections of villages which spoke the same languages and were born of the same population movements on a localized level would not identify with one another as an ethnic basis. As to your question, if an Italo-Celtic macrolanguage group ever did exist in great quantity (which I seriously question), I would personally have a hard time believing this would constitute a single ethnic group. I would presume this would more of be a range of rather complex dialects with shifting verbiage based off varied degrees of isolated geography and trade routes as opposed to a unified language such as what we have today with standard Italian, standard french and so on. What I could see as more likely is certain parts of such types of dialectal continuums sharing enough commonalities (linguistic and otherwise) to enable participation in local tribal confederations of villages which would become identified on an ethnic basis (think of the confederation of Etruscan cities as a sort of iron age equivalent of this social phenomenon). The construction of ethnic identity upon these lines has utilitarian use cases in terms of increased defense and continuity of a localized population and their specific systems of survival and organization.

To put it more bluntly, I find it hard to imagine ethnic identity was something limited to literate cultures, but I also think it was much more complex than simply material horizons or participation in any given IE language family.