Polygyny as a potential reason for Y-DNA bottlenecks among agropastoralists

polygyny-estimates

Open access Greater wealth inequality, less polygyny: rethinking the polygyny threshold model by Ross et al. Journal of the Royal Society Interface (2018).

Interesting excerpts, from the discussion (emphasis mine):

We use cross-cultural data and a new mutual mate choice model to propose a resolution to the polygyny paradox. Following Oh et al. [17], we extend the standard polygyny threshold model to a mutual mate choice model that accounts for both female supply to, and male demand for, polygynous matchings, in the light of the importance of, and inequality in, rival and non-rival forms of wealth. The empirical results presented in figures 5 and 6 demonstrate two phenomena that are jointly sufficient to generate a transition to more frequent monogamy among populations with a co-occurring transition to a more unequal, highly stratified, class-based social structure. In such populations, fewer men can cross the wealth threshold required to obtain a second wife, and those who do may be fabulously wealthy, but—because of diminishing marginal fitness returns to increasing number of marriages—do not acquire wives in full proportion to their capacity to support them with rival wealth. Together, these effects reduce the population-level fraction of wives in polygynous marriages.

Our model demonstrates that a low population-level frequency of polygyny will be an equilibrium outcome among fitness maximizing males and females in a society characterized by a large class of wealth-poor peasants and a small class of exceptionally wealthy elite. Our mutual mate choice model thus provides an empirically plausible resolution to the polygyny paradox and the transition to monogamy which co-occurred with the rise of highly unequal agricultural populations.

polygyny-pastoralists
(a) Mean frequency of married women who are married polygynously by production system (+2 s.e.) using the Standard Cross-Cultural Sample [30]. Rates of polygyny are measured with variable ]872, per cent of wives with co-wives. (b) Rates of monogamy and polygyny by production system are measured with variable ]861, the standard polygamy code. Data on subsistence come from variable ]858, categorized subsistence. In general, agricultural populations show reduced rates of polygyny and increased rates of monogamy relative to other subsistence systems. See electronic supplementary material for more information. (c) Gini of wealth by production system in our sample.

The reasons for this decrease in marginal fitness returns are explained as either a) a potential missing of important rival forms of wealth in the statistical model, or b) one or more of the following reasons:

  • [A] male’s time and attention are rival inputs to his own fitness (…) A single rich man will have to defend his 10 wives from nine unmarried men on average.”As the wealth ratio grows even more skewed, this situation could become increasingly difficult to manage (e.g. requiring the use of eunochs to defend harems [74]).
  • A related possibility is that a growing number of unmarried men could socially censure wealthy polygynous males, imposing costs on them that reduce male demand for and/or female supply to polygynous marriage [23,24]. (…)
  • A third possibility is that sexually transmitted infection (STI) burden [22,75] could diminish returns to polygyny, if polygyny enhances infection rates [76,77]. (…)
  • Finally, impediments to cooperation or even outright conflict among co-wives can be greater as the number of wives increases. Interference competition among co-wives could impose significant fitness costs in settings where effective child rearing benefits from cooperation [79,80].(…)
polygyny-agropastoralists
between the Gini coefficient on completed rival wealth and per cent completed female polygyny.

I have previously argued against some reasons traditionally given to explain the replacement of native male populations after migrations (i.e. polygyny, slavery, targeted male extermination, etc.), because I believe that a gradual successful expansion of patrilineal clans over some generations based on wealth alone is enough to explain the obvious Y-DNA bottlenecks that happened in many different prehistoric and historic cultures (especially among steppe pastoralists, including Indo-Europeans).

I realize that I haven’t really used any study to support my opinion, though, and data from modern and ancient pastoralists from different regions seem to contradict it, so maybe ancient DNA can show that Indo-Europeans had often children with more than one woman at the same time. I don’t remember seeing that kind of information in supplementary materials to date. From memory I can think of maybe two or three examples of agnate siblings published, but I doubt the archaeological age estimation (based on simple observation of skeletal remains) combined with radiocarbon age (usually given with broad CI) could be enough to prove a similar age of conception. Maybe a case of many siblings clearly of the same age and from many different mothers in the same burial could be a strong proof of this…

I recently read that theoretical models are actually trusted by no one except for the researchers who propose them, and experimental data are trusted by everyone except for the researchers who worked with them. I cannot agree more. However, we lack information about this question (as far as I know), so we may have to rely on indirect estimations, like the kind of models presented in the paper (or the one proposed for Post-Neolithic Y-chromosome bottlenecks).

The Late Proto-Indo-European word for bride comes from a root meaning ‘drive, lead’, hence literally ‘deportation’, so the bride was transferred from her father’s family to her husband’s house. Marriage was certainly an asymmetrical contract for its members, and the reconstructible word for ‘dowry’ further supports the weaker position of the wife in it. Also, ancient marriage could differ from a family agreement, because marriage by elopement, bride kidnapping or hostage was probably common (more or less socially regulated) for people belonging the same culture. Apart from this, I don’t know about reconstructed linguistic data pointing to polygyny, and I doubt archaeological data alone – without genetics – can help.

Related

About Scepters, Horses, and War: on Khvalynsk migrants in the Caucasus and the Danube

steppe-horse-sceptre-khvalynsk

dergachev-scepters-khavlynsk-horsesAbout two months ago I stumbled upon a gem in archaeological studies related to Proto-Indo-Europeans, the book О скипетрах, о лошадях, о войне: этюды в защиту миграционной концепции М.Гимбутас (On sceptres, on horses, on war: Studies in defence of M. Gimbutas’ migration concepts), 2007, by V. A. Dergachev, from the Institute of Cultural Heritage of the Moldavian Republic.

Dergachev’s work dedicates 488 pages to a very specific Final Neolithic-Eneolithic period in the Pontic-Caspian steppe, and the most relevant parts of the book concern the nature and expansion of horses and horse domestication, horse-head scepters, and other horse-related symbology – arguably the most relevant cultural signs associated with Proto-Indo-European speakers in this period.

I haven’t had enough time to read the whole book, but I have read with interest certain important chapters.

About Scepters

Typological classification

The genetic and chronological relationship of horse-head pommel-scepters is classified with incredible detail, to the extent that one could divide subregions among those cultures using them.

khvalynsk-horse-head-scepters
Scheme of regional distribution – chronological – typological development of the carved horse-head stone scepters.

Simplified conclusions of this section include (emphasis mine):

  1. The [horse-head pommel-]scepters arose originally in the depth of the Khvalynsk culture. Following the now well-known finds, they are definitely related to those of the Middle Volga group.
  2. horse-head-pommel-scepters-distribution
    General scheme of genetic and chronological development of carved scepters by visual assessment of morphological details.
  3. In their next modifications, these scepters continued to evolve and develop into the area of the Khvalynsk culture in its latest stages, and possibly later.
  4. Simultaneously, with the same modifications, these scepters “are introduced” into common usage in the Novodanilovka culture, which in its spread by one wing was in contact and interspersed immediately with the area of Khvalynsk remains; and on the other hand, far in the south – in the Pre-Kuban and Ciscaucasian regions – within the range of the Domaikopska culture; and in the west – in the Carpathian – Post-Kuban – with the areas of early agricultural cultures Cucuteni A – Trypillia B1, Gumelnița-Karanovo VI.
  5. The simultaneous presence in the areas of the Ciscaucasian, Carpatho-Danubian, and especially Novodinilovka cultures, whose carriers continue the Khvalynian traditions of making stone scepters, and the scepters themselves (in their non-functional implication in the local cultural environment), all definitely allow us to view these findings as imported Novodanilovka objects.
distribution-horse-scepters
Schematic depiction of the spread of horse-head scepters in the Middle Eneolithic. See a full version with notes here.

Cultural relevance of scepters

The text goes on to make an international comparison of scepters and their relevance as a cultural phenomenon, with its strong symbolic functions as divine object, its use in times of peace, in times of war, and in a system of ritual power.

horse-scepters-steppe
Restoration of V. A. Dergachev: a) model for restoration – Paleolithic and Neolithic wands; b) the expected appearance of the Eneolithic scepter on the handle with a coupling (according to Dergachev 2007).
Especially interesting is the section dedicated to Agamemnon’s scepter in the Iliad, one of the oldest Indo-European epics. Here is an excerpt from Illiad II.100-110 (see here the Greek version) with the scepter’s human and divine genealogy:

Then among them lord Agamemnon uprose, bearing in his hands the sceptre which Hephaestus had wrought with toil. Hephaestus gave it to king Zeus, son of Cronos, and Zeus gave it to the messenger Argeïphontes; and Hermes, the lord, gave it to Pelops, driver of horses, and Pelops in turn gave it to Atreus, shepherd of the host; and Atreus at his death left it to Thyestes, rich in flocks, and Thyestes again left it to Agamemnon to bear, that so he might be lord of many isles and of all Argos.

About the horse

His studies on horse remains show an interesting, detailed quantitative and statistical approach to the importance and (cultural and chronological) origin of horses (and likely horse domestication) in each culture.

Although the part on horse remains is probably a bit outdated today, after many recent studies of Eneolithic steppe sites (see here one example), it still shows the relative distribution of horse bone remains among different steppe cultures, which is probably similar to what could be reported today:

distribution-horses-steppe-eneolithic
Territorial distribution of horse remains in the Middle Eneolithic period. Absolute and relative numbers.

Even more interesting is the relationship of the distribution of horse remains with archaeological complexes and horse-related symbols. Some excerpts from the conclusions of this section:

  1. Accounting and analysis of archeo-zoological and archaeological data proper for a horse for a vast area from the Tisza and the Middle Danube to the Caucasus and the Urals (which includes the main cultures of the western agricultural, Caucasian, and Eastern European cultural zones) clearly points to the eastern cultural zone as a zone of the originally the most important social significance of a horse as the only possible zone of the earliest domestication, horseback riding and all-round use of a horse. In relation to the eastern, the western land – the ancient Carpatho-Danubian or the Caucasian cultural zones – are secondary and subordinate to the first on the phenomenon under consideration.
  2. horse-symbols
    Horse-shaped hanger-amulets made of bone.
  3. The first quantitative leap in the manifestation of the remnants of a horse, marking itself and the first qualitative changes in the social status of this animal, is due mainly to the Middle Volga culture of the developed Neolithic of the Middle Volga region (in part, the Southwest Urals), which, accordingly, determine the cultural context, time and geographic region – or, the initial, single and main epicenter of the process of taming and domestication of a horse.
  4. On the one hand, the subsequent substantial increase in the number of horse remnants, and, on the other, the wide inclusion of the horse in cults, rituals, funerary rituals (horse pendants, ornamented metacarpus, horse bones, sacrificial altars) in the Samara culture of the Early Eneolithic of the same region definitely indicates the continuing increase in the social significance of this species of animal, which was most likely expressed in the final design of a specialized horse breeding culture and, accordingly, in a wide range of applications using a horse for riding. At the same time, we can observe the beginning of the transfer of the already domesticated horse from the original historical and geographic epicenter to other cultures of the eastern cultural zone and, in part, the cultures closest to the periphery of this zone, into the western agricultural zone (Bolgrad-Aldeni P, Pre-CuCuteni-Trypillya A) .
  5. expansion-horse-steppe
    Schematic depiction of cultures and regional-chronological distribution of percentage of horse remains. (Depicted are arrows from Middle Volga and Samara culture to the rest)
  6. Middle Eneolithic – early stages. One of the leading places in the remnants of the horse is in the Middle Volga region, the Khvalynsk culture. Genetically related to the Samara, the Khvalynsk I culture preserves the traditions of the ritual, cultural meaning, the treatment of the image of a horse in funerals (altars, horse bones, funerary rituals). But, At the same time, it is in this precise culture that the image of the horse, included in the social symbolism (horse-head pommel-scepter), for the first time it acquires a special, maximum social significance. That is why the appearance and subsequent widespread distribution of the social symbols in Novodanilovka-type objects can definitely be considered as another qualitative leap in the social significance of a horse – its use for military purposes for close and distant expeditions. And such an interpretation is fully confirmed from the analysis of Novodanilovka-type objects, which is the subject of discussion.
  7. Judging by the osteological data and the typological evolution of the horse-head scepters, the Khvalynian culture and remains of the Novodanilovka type are already associated with the relatively widespread and intensive findings of domesticated horses in various areas of the eastern cultural zone (semi-desert regions of the Lower Volga and the Caspian region – Khvalynsk culture, forest-steppe and steppe from the Volga to the Dnieper – Sredni Stog, Repin cultures), and the western – agricultural (Gumelnitsa, Cucuteni A-Tripolye Bl), and the Caucasus (Pre-Maykop) zones, where, however, the horse played a very modest role.
  8. samara-khvalynsk-horses
    Schematic depiction of cultures and regional-chronological distribution of zooarchaeological and ritual data on horses. (Shadowed are from top to bottom the Middle Volga, Samara, Khvalynsk, and Novodanilovka; in bold, other percentages of unrelated cultures: e.g. to the left of Khvalynsk and Novodanilovka, Sredni Stog with 29.65% overall horse bone remains, but 0% of horse symbolism)
  9. From the functional point of view, according to the sum of the data, there is no reason to doubt that in the eastern zone the horse is already present in the Late Neolithic period. Since its domestication and the emergence of a specialized horse breeding, it has been also widely used for meat, milk and dairy products (including the traditional hippace tradition of the later Scythians), and since the beginning of the early Eneolithic for transport and for riding purposes. Another thing is the horse as a means of war, a means of distant travel and expansion. The beginning of the use of a horse for these purposes, in the opinion of the author, is determined by the appearance of social symbolism in the form of horse-head scepters, and is most fully reflected in the memories of the Khvalynsk culture and, in particular, the Novodanilovka type. Concerning western or Caucasian cultural zones related to Khvalynsk, the horse is thought to have been linked to the eastern region, used mainly for riding, as a means of transport and for communication, which, however, does not exclude its use for meat.

These are the main conclusions-interpretations, suggesting the analysis and archaeological and other sources containing information about the horse. And as for our pommel-scepters, then, as can be seen from these sources, the main thing is that the culture of the Middle Volga region, according to all the data, definitely accumulates in itself the longest traditions associated with the gradual increase of social significance of the horse. And if so, this circumstance motivates the possibility or necessity of appearing in the environment of the bearers of this culture of unique signs-symbols that carry within themselves or reflect the image of this animal as an extremely significant social reality. The revealed and characterized quality, as a matter of fact, fill or open by themselves the hypothetical elements we have previously identified, the meanings of that particularity, folded in the social sign-symbol, in our case – the horse-head-shaped scepter.

horse-symbolism-rituals-steppe
Archaeological sites with objects (signs-symbols) related to horses. Horse-head scepters included in other maps are excluded from this one (notice the conspicuous absence of such objects in Sredni Stog and neighbouring North Pontic regions).

The relevance of Dergachev’s work

As you certainly know by now if you are a usual reader of this blog, there were two other seminal publications that same year correcting and expanding Gimbutas’ model:

Each one of these works taken independently (especially the books) may give a different version of Proto-Indo-European migrations; Anthony and Dergachev are heirs of Gimbutas’ simplistic kurgan-based model, and of other previous, now rejected ideas, and they reflect them whenever they don’t deal with first-hand investigation (and even sometimes when interpreting their own data). Taken together – and especially in combination with recent genetic studies – , though, they describe a clearer, solider model of how Proto-Indo-Europeans developed and expanded.

distribution-scepters-steppe
Distribution of horse-head scepters, according to Dergachev, Sorokin (1986).

Anthony’s publication overshadowed the importance of Dergachev’s work for the English-speaking world – and by extension for the rest of us. However, V. A. Dergachev’s updated study of his previous work on steppe cultures shows the right, thorough, and diligent way of describing the expansion of early Khvalynsk-Novodanilovka chieftains with the horse and horse symbolism into the Caucasus and the Lower Danube (like the seminal work of Harrison & Heyd 2007 described the expansion of Yamna settlers with East Bell Beakers, culturally opposed to Corded Ware and to the Proto-Beakers). On the other hand, Anthony’s broad-brush, superficial description of thousands of years of potential Indo-European-speaking peoples gave a migration picture that – although generally right (like radiocarbon-based Iberian origin of the Bell Beaker culture was right) – was bound to be wrong in some essential details, as we are seeing in archaeology and genetics.

NOTE. As I have said before, Anthony’s interpretations of Sredni Stog culture representing a sort of ‘peasants’ under the rule of Novodanilovka chiefs was based on old theories of Telegin, who changed his mind – as did the rest of the Russian school well before the publication of Dergachev’s book, considering both as distinct cultural phenomena. Anthony selected the old interpretation, not to follow a Gimbutas / Kristiansen model of Sredni Stog being Indo-European and expanding with GAC into Corded Ware (because, for him, Corded Ware peoples were originally non-Indo-European speakers): he seems to have done it to prove that Proto-Anatolian traveled indeed through the North Pontic area, i.e. to avoid the regional ‘gap’ in the maps, if you like. Then with the expansion of Repin over the area, Sredni Stog peoples would have been absorbed. With genetic investigation, as we know, and with this kind of detailed archaeological studies, the traditional preference for “large and early” IE territories – proper of the mid-20th century – are no longer necessary.

sredni-stog-suvorovo-novodanilovka-cernavoda
Anthony (2007): “Steppe and Danubian sites at the time of the Suvorovo-Novodanilovka intrusion, about 4200-3900 BC.”

Steppe Eneolithic

We already had in 2016 a Samara hunter-gatherer sample dated ca. 5600 BC, representative of EHG ancestry, of haplogroup R1b1a. We also had three early Khvalynsk samples from Samara Eneolithic dated ca. 4600 BC, with a drift towards (what we believe now is) a population from the Caucasus, showing haplogroups Q1a, R1a1(xM198), and R1b1a, the last one described in its paper as from a high-status burial, similar to high-status individuals buried under kurgans in later Yamna graves (of R1b-L23 lineages), and therefore likely a founder of an elite group of patrilineally-related families, while the R1a1 sample showed scarce decoration, and does not belong to the M417 lineage expanded later in Sredni Stog or Corded Ware.

In 2017 we knew of the Ukraine_Eneolithic sample I6561, from Alexandria, of a precise subclade (L657) of haplogroup R1a-Z93, dated ca. 4000 BC, and likely from the Sredni Stog (or maybe Kvitjana) culture. This sample alone makes it quite likely that the expansion of R1a-Z645 subclades happened earlier than expected, and that it was associated with movements along forest-steppe cultures, most likely along the Upper Dniester or Dnieper-Dniester corridor up to the Forest Zone.

We have now confirmation that Khvalynsk samples from the Yekaterinovka Cape settlement ca. 4250-4000 BC were reported by a genetic lab (to the archaeological team responsible) as being of R1b-L23 subclades, although the precise clades (reported as P312 and U106) are possibly not accurate.

NOTE. Curiously enough, and quite revealing for the close relationship of scepters to the ritual source of power for Khvalynsk chieftains (political and/or religious leaders), the scepter found in the elite burial 45 of the Ekaterinovka cape (a riverine settlement) shows a unique zoomorphic carving, possibly resembling a toothed fish or reptile, rather than the most common horse-related motifs of the time.

ekaterinovka-cape-scepter
Zoomorphic carved stone scepter of the Ekaterinovka Cape burial 45: photos (left) and schematic depiction (right).

With Wang et al. (2018), a real game-changer in the Khvalynsk – Sredni Stog (and also in the Yamna/Bell Beaker – Corded Ware) opposition, we also know that two Steppe Eneolithic samples from the Northern Caucasus Piedmont, dated ca. 4300-4100 BC, show haplogroup R1b1. Although its direct connection to the expansion of early Khvalynsk with horse-related symbolism is not clear from the archaeological information shared (none), this is what the paper has to say about them:

The two distinct clusters are already visible in the oldest individuals of our temporal transect, dated to the Eneolithic period (~6300-6100 yBP/4300-4100 calBCE). Three individuals from the sites of Progress 2 and Vonjuchka 1 in the North Caucasus piedmont steppe (‘Eneolithic steppe’), which harbor Eastern and Caucasian hunter-gatherer related ancestry (EHG and CHG, respectively), are genetically very similar to Eneolithic individuals from Khalynsk II and the Samara region19, 27. This extends the cline of dilution of EHG ancestry via CHG/Iranian-like ancestry to sites immediately north of the Caucasus foothills.

In contrast, the oldest individuals from the northern mountain flank itself, which are three first degree-related individuals from the Unakozovskaya cave associated with the Darkveti-Meshoko Eneolithic culture (analysis label ‘Eneolithic Caucasus’) show mixed ancestry mostly derived from sources related to the Anatolian Neolithic (orange) and CHG/Iran Neolithic (green) in the ADMIXTURE plot (Fig. 2C). While similar ancestry profiles have been reported for Anatolian and Armenian Chalcolithic and Bronze Age individuals20, 23, this result suggests the presence of the mixed Anatolian/Iranian/CHG related ancestry north of the Great Caucasus Range as early as ~6500 years ago.

On the specific burials, we have e.g. the recent open access paper New cases of trepanations from the 5th to 3rd millennia BC in Southern Russia in the context of previous research: Possible evidence for a ritually motivated tradition of cranial surgery?, by Gresky et al. J Am Phys Anthropol (2016):

During the late 5th millennium BC, cultural groups of the Eneolithic occupied the northern circumpontic area and the areas between the North Caucasus and the Lower Volga. For the first time, individual inhumations were placed below low burial mounds (Rassamakin, 2011). During the 4th millennium BC, the area split into two cultural spheres. In the northern steppe area communities continued with the burial practice of crouched inhumations below low mounds, with this culturally transforming into the early Pit Grave culture. In contrast, in the Caucasian foothill zone and the neighbouring steppe, the Majkop-Novosvobodnaya culture emerged (Kohl and Trifonov, 2014). Similarly, during the 3rd millennium BC, two cultural spheres influenced the area: The North Caucasian Culture dominated the Caucasian foothills for the next five centuries, while in the steppe area between the Lower Don and the Caucasus, regional groups of the Catacomb Culture existed side-by-side.

Burials of the Eneolithic epoch (late 5th millennium BC)

The oldest group of individuals with trepanations are found in the North Caucasian variant of the late circumpontic Eneolithic and date to the last third of the 5th millennium BC (Korenevsky, 2012). Burials of this epoch are inhumations in shallow pits, chiefly without burial goods, but covered with large quantities of red ochre. Of special interest is a collective burial of seven individuals from VP 1/12, who were interred together in a secondary burial ritual. The sites of Tuzluki, Mukhin, Voinuchka, Progress, and Sengileevskii all belong to this period.

PCA-caucasus-khvalynsk-sredni-stog
Image modified from Wang et al. (2018). Samples projected in PCA of 84 modern-day West Eurasian populations (open symbols). Previously known clusters have been marked and referenced. An EHG and a Caucasus ‘clouds’ have been drawn, leaving Pontic-Caspian steppe and derived groups between them.See the original file here.

Without the datasets to test different models, you can only imagine what is happening with the processed, secondary data we have. The position of Eneolithic Steppe cluster in the PCA (probably Khvalynsk-related peoples already influenced by the absorbed, previous Caucasus population), as well as other potential Caucasus groups intermediate between Steppe Maykop and Caucasus Maykop (as suggested by other ancient and modern Caucasus samples), may indicate that Yamna is between Khvalynsk and such intermediate Caucasus populations (as the source of the additional CHG-related ancestry) and – as the paper itself states – that it also received additional EEF contribution, probably from the western cultures absorbed during these Khvalynsk-Novodanilovka migrations (or later during Khvalynsk/Repin migrations).

Also interpreted in light of these early Khvalynsk-Novodanilovka migrations of horse riding chieftains (and their close contacts with the Caucasus), you can clearly see where the similar CHG-like contribution to Ukraine Eneolithic and other North Pontic forest-steppe cultures (which later contributed to Proto-Corded Ware peoples) must have come from. The simplistically reported proportions of EHG:CHG:EEF ancestry might be similar in many of these groups, but the precise origin and evolution of such ancestral components is certainly not the same: statistical methods will eventually show this, when (and if) we have many more samples, but for the moment Y-DNA is the most obvious indicator of such differences.

There was no steppe people speaking a steppe language AKA immutable Proto-Indo-European: the glottochronological models spanning thousands of years are not valid for the steppe, just as they are not valid for an Anatolian homeland, nor for a Caucasus homeland. The actual cultural-historical early Sredni Stog – Khvalynsk community, formed earlier than ca. 5000 BC, is a thousand years older than the expansion of Khvalynsk with the horse, and some two thousand years older than the expansion of Khvalynsk-Repin/Early Yamna migrants (see here for the latest genetic research).

What lies between the formation of that early Eneolithic cultural-historical community, and what we see in archaeology and genetics in Middle and Late Eneolithic steppe cultures, is the radical differentiation of western (Ukraine Eneolithic, mainly forest-steppe) and eastern (Samara and Khvalynsk/Repin, mainly steppe) cultures and peoples, i.e. precisely the period of differentiation of an eastern, Proto-Indo-Hittite-speaking early Khvalynsk community (that expanded with the horse and horse-related symbols) from a western, probably Early Proto-Uralic speaking community of the North Pontic forest-steppe cultural area.

NOTE. I am not against a Neolithic ‘steppe’ language. But this steppe language was spoken before and/or during the first Neolithisation wave, and should be associated with Indo-Uralic. If there was no Indo-Uralic language, then some communities would have developed Early Proto-Indo-European and Early Proto-Uralic side by side, in close contact to allow for dozens of loanwords or wanderwords to be dated to this period (where, simplistically, PIH *H corresponds to EPU *k, with some exceptions).

steppe-forest-change
Map of a) steppe – forest-steppe border during the Eneolithic in the Pontic-Caspian region and b) the border today, showing a more limited steppe zone in the North Pontic area (reason for the specific ways of expansion of horse-related cultures and horse-related nomadic pastoralism during the Eneolithic).

The convergence that we see in PCA and Admixture of Yamna and the earliest Baltic LN / Corded Ware ‘outlier’ samples (if not directly related exogamy of some Baltic LN/CWC groups with Yamna migrants, e.g. those along the Prut), must be traced back to the period of genetic drift that began precisely with these Khvalynsk-Novodanilovka expansions, also closely associated with populations of the Caucasus, thus bringing North Pontic forest-steppe cultures (probably behind Proto-Corded Ware peoples) nearer to Khvalynsk, and both by extension to Yamna.

We have seen this problem arise in Bell Beaker samples expanding all over Europe, turning from a fully Yamnaya-like population to something else entirely in different regions, from more EEF-like to more CWC-like, sharing one common trait: Y-DNA. We are seeing the same happen with Balkan groups and Mycenaeans, with Old Hittites, and with steppe MLBA from Andronovo peoples expanding over Central and South Asia, and we know that patrilineal clans and thus Y-chromosome bottlenecks were common after Neolithisation, especially with nomadic pastoralist steppe clans (and probably also with many previous population expansions).

Steppe Eneolithic peoples were thus no different to other previous and posterior expanding groups, and ancestry is going to be similar for people living in neighbouring regions, so Y-DNA will remain the essential tool to distinguish different peoples (see here a summary of Proto-Indo-Europeans expanding R1b-L23).

We are nevertheless still seeing “R1b zombies” (a quite appropriate name I read on Anthrogenica) still arguing for a Western European origin of R1b-L23 based on EEF-like ancestry and few steppe-related contribution found in Iberian Bell Beakers (read what David Reich has to say on this question); and “OIT zombies” still arguing for IVC representing Proto-Indo-European, based on Iran_N ancestry and the minimal steppe ancestry-related impact on certain ancient Asian cultures, now partly helped by “Caucasus homeland zombies” with the new PIE=CHG model; apart from many other pet theory zombies rising occasionally from their graves here and there. Let’s hope that this virus of the undead theories does not spread too strongly to the R1a-Indo-European association, when the official data on Khvalynsk, West Yamna, and Yamna Hungary come out and show that they were dominated by R1b-L23 lineages.

Because we need to explore in detail the continuation of Khvalynsk-related (potential Proto-Anatolian) cultures in the Lower Danube and the Balkans, e.g. from Cernavoda I to Cernavoda III, then maybe to Ezero, and then to Troy; as well as the specific areas of Late Indo-European expansions associated with Early Yamna settlers turning into Bell Beakers, Balkan EBA, and Steppe MLBA-associated cultures. There is a lot of work to do on proper definition of Bronze Age cultures and their potential dialects, as well as convergence and divergence trends, and not only of Indo-European, but also of Uralic-speaking communities derived from Corded Ware cultures.

If we let the narratives of the 2000s in Genetics (in combination with the 1960s in Archaeology) dominate the conversation, then a lot of time will be absurdly lost until reality imposes itself. And it will.

EDIT (2 JUL 2018): Some sentences corrected, and some information added to the original post.

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Domestication spread probably via the North Pontic steppe to Khvalynsk… but not horse riding

Interesting paper Excavation at the Razdolnoe site on the Kalmius river in 2010, by N. Kotova, D. Anthony, D. Brown, S. Degermendzhy, P. Crabtree, In: Archaeology and Palaeoecology of the Ukrainian Steppe / IA NAS of Ukraine, Kyiv 2017.

Nothing new probably to those who have read Anthony (2007), but this new publication of his research on the North Pontic region seems to contradict recent papers which cast doubts on the presence of early forms of domestication in the North Pontic steppe, and would reject thus also the arrival of domestication to Khvalynsk from a southern route.

Interesting excerpts discussing recent research and results of this one (emphasis mine):

A brief comment about the fauna is required. A separate international archaeological project studied sites dated to the mid — 6th millennium BC in the Severskiy Donets basin (Starobelsk I, Novoselovka III) northeast of Razdolnoe, and found that they had hunting and gathering economies that made use of Unio shellfish, fish, and turtles, like the Neolithic occupation at Razdolnoe. But the Donets sites had no domesticated animal species. The author argued that the cultures of the Donets and lower Don basins in the 6th millennium BC probably had no domesticated animals, and that the domesticated sheep-goat bones identified at Semenovka, west of Razdolnoe, and dated to 5500 calBC, probably were mis-identified and actually came from wild saiga antelope (Motuzaite- Matuzeviciute 2012: 14). This suggestion was made on the basis of a single bone identified as sheep-goat at Semenovka by O.P. Zhuravlev (not N.S. Kotova as Motuzaite-Matuzeviciute wrote) and sent out for radiocarbon dating, that was re-examined by Cambridge University archaeozoologists.

Regardless of which identification is correct, a single bone is insufficient to cast doubt on sheep-goat bones identified at Sredni Stog 1, Sobachki, and other Neolithic sites in the Dnieper valley. Nevertheless, yet another international collaboration that studied the economy of Dereivka in the Dnieper valley argued that the economy of Eneolithic Dereivka site, which they dated to about 3500 calBC (ignoring 10 radiocarbon dates between 4200—3700 calBC), was still at an «initial phase of animal domestication» and that the Dereivka occupants of 3500 calBC were still largely dependent on hunting and fishing (Mileto et al. 2017: 67—68).

The dated Bos calf in the lower occupation level at Razdolnoe shows that domesticated animals were present in the Kalmius river valley in the Azov steppes in 5500 calBC, at a time when the cultures of the Donets valley were still hunters and gatherers just 200 km to the northeast of Razdolnoe. Sheep-goat and Bos bones were found in all Neolithic and Eneolithic levels at Razdolnoe. Because it was a small excavation, this evidence should not be over-interpreted. We cannot say how important domesticated animals were in the daily diet. But domesticated sheep-goat and cows had reached the Azov steppes by 5500 calBC. The appearance of cattle and sheep-goat as sacrificial animals in graves of the Khvalynsk Culture on the Volga by the early 5th millennium BC probably was a continuation of the spread of animal herding eastward from the Azov steppes.

neolithic_steppe-anatolian-migrations
Most likely route of expansion of horse domestication and horse riding (including Suvorovo-Novodanilovka chiefs) from Khvalynsk into the North Pontic steppe and the Balkans.

Re-reading the papers on this subject – in which researchers seem to be fighting among each other for a radical interpretation of few animal bones – , I would suggest that the key concept they should be emphasizing is probably not the ‘presence’ vs. ‘absence’ of domestication in North Pontic steppe cultures in absolute terms.

Since there were clearly domesticated animals to the east and west of North Pontic cultures in the Neolithic, and thus the finding there of domesticated animals is more than likely, what is of great interest is the relative measure in which domesticated animals were relied upon by forest-steppe economies, compared to the use of available natural resources.

After all, many researchers currently agree that the North Pontic steppe and forest-steppe peoples formed communities of mainly hunter-fishers and gatherers, and findings of this paper do not seem to contradict this.

NOTE. In fact, there was a more recent paper I referenced which argues in such general terms with detail – probably written at the same time as this one -, by one of the authors they discuss, Mileto et al. (2018).

Also, as the paper states,

we want to emphasize that even a small excavation in the steppe zone, where only scanty number of the Neolithic and Eneolithic sites have been known yet, is very important and always gives very interesting materials.

Hence by confirming Anthony’s account of early domestication spreading eastwards during the Neolithic expansion, and without horses’ remains in any of the periods investigated (including Sredni Stog I-III), it also supports his hypothesis of horse riding emerging in Khvalynsk and expanding westward.

The Razdolnoe site lies near modern-day Donetsk, and its latest layer investigated (ca. 4300-4150 BC) represents thus the eastern variant of Sredni Stog III, being consequently the one more in contact with expanding early Khvalynsk.

Given the absence of horse remains in all layers, these results would also suggest that Novodanilovka and Suvorovo horse-riding chiefs (emerging ca. 4400-4200 BC to the west of this region) were indeed unrelated to the surrounding Sredni Stog population, and most likely migrants from the horse-riding Khvalynsk culture.

Featured image: Expansion of domestication in the Pontic-Caspian steppe, according to Anthony (2007).

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