Cereal cultivation and processing in Trypillian mega-sites

New paper (behind paywall) Where are the cereals? Contribution of phytolith analysis to the study of subsistence economy at the Trypillia site Maidanetske (ca. 3900-3650 BCE), central Ukraine, by Dal Corso et al. Journal of Arid Environments (2018).

Interesting excerpts (only introduction and conclusions, emphasis mine):

Archaeological setting at the site of Maidanetske, Ukraine

From ca. 4800 to 3350 BCE, Trypillia settlements were widespread over parts of eastern Romania, Moldova and Ukraine (Menotti and Korvin-Piotrovskiy, 2012; Müller et al., 2016; Videiko, 2004). Maidanetske (Fig. 1B) is one of the so-called “mega-sites” which developed during ca. 3900–3400 BCE in central Ukraine, in the Uman region (Cherkasy district) (Müller and Videiko, 2016; Müller et al., 2017). In this region, nine of these “mega-sites” have been found. Mega-sites are characterized by a regular plan with concentric rings of houses around a large empty central space, additional quartiers, with radial and peripheral track ways (Fig. 1B). The three mega-sites Maidanetske, Taljanky and Dobrovody, lay ca. 15 km apart from each other (Fig. 1A); other mega-sites are located within a 50 km radius around Maidanetske. Archaeologically, these mega-sites consist of the remains of buildings most of them burnt, although a minority of unburnt buildings is known of as well (Burdo and Videiko, 2016; Müller and Videiko, 2016; Ohlrau, 2015). Most of these buildings have a standardized regular size (average 6×12 m) and architecture including domestic installations and a standardized assemblage of artifacts. At Maidanetske beside normal sized houses there are few larger rectangular buildings that are located regularly along the main pathways. Further archaeological contexts include pits, pottery kilns, and peripheral ditches. A huge variety of mostly painted pottery (including many with figurative animal and plant motives), some flint artifacts, rare copper objects, querns, adzes and a broad range of anthropomorphic and zoomorphic figurines are attested within houses and mega-structures. In terms of organic remains, animal bones are fairly common, while botanical macro-remains appear to be scarce and poorly preserved (Kirleis and Dal Corso, 2016; Pashkevich and Videjko, 2006).

trypillia-maidanetske-north-pontic-steppe-forest
The location of the Chalcolithic site of Maidanetske and of other sites mentioned in the text within the map of the natural vegetation (modified after Kirleis
and Dreibrodt, 2016, graphic K. Winter, Kiel University).

Environmental setting at Maidanetske

The Trypillia sites in central Ukraine, including Maidanetske, are located in a semi-arid forest-steppe ecozone, a mosaic-like ecosystem stretched between the dry steppe grasslands in the south and temperate woodland biomes in the north (Fig. 1A). In this transitional zone the natural vegetation is supposed to be patchy and sensitive to climate and topography (Feurdean et al., 2015; Molnàr et al., 2012; Walter, 1974). Since most of the accessible plateaus are converted to agricultural land and the scarce broadleaf woodlands are managed, the natural landscape heterogeneity is difficult to trace within the current landscape (Kuzemko et al., 2014). Besides agricultural fields and villages, narrow river valleys incised into the loess plateaus are present, with riparian vegetation and artificial lakes. This western Pontic area has a humid continental climate with wet winters and warm summers (Köppen and Geiger, 1939), which corresponds to a semi-arid 0.2–0.5 aridity index value according to UNEP (1997). Nevertheless, the reconstruction of past climatic as well as environmental conditions is not straightforward, since undisturbed archives for pollen analysis are lacking in the region and published climatic reconstructions combine evidences from peripheral areas (Gerasimenko, 1997; Harper, 2017; Kirleis and Dreibrodt, 2016). In the Transylvanian forest-steppe region, palynological investigations suggest that dry grasslands have expanded since the end of the 4th millennium BCE, fostered by Bronze Age forest clearance, while before this the area was largely forested (Feurdean et al., 2015). In the Hungarian forest-steppe, the mixed oak forest on Loess almost disappeared by the end of the 18th century AD, hampered by factors such as fragmentation, slow regeneration, spread of invasive species and lowering of the water table due to increased aridity (Molnàr et al., 2012). It is clear that forest-steppe environments are very sensitive to aridity and land use practices. To understand whether similar landscape change can have occurred in central Ukraine already at the time of Chalcolithic mega-sites, an understanding of the extent of crop growing and deforestation is crucial.

The site of Maidanetske is situated on a plateau covered by Loess deposited during the Last Glaciation. This plateau is dissected by valleys of different sizes with perennial rivers present within the large valleys. One of these rivers passes the site in a distance of less than 500 m. The soils that are present nowadays are Chernozems. They show dark greyish-brown A-horizons of thicknesses between 30 and 50 cm and a texture dominated by silt. Numerous filled crotowinas indicate an intensive bioturbation during the formation of these soils. The Chernozems cover the archaeological record. The variations in thickness of the A-horizon are probably reflecting post-depositional soil erosion processes. Buried soils discovered at lower slope positions below colluvial layers show properties of Cambisols, thus pointing towards a forested past of the surrounding landscape (Kirleis and Dreibrodt, 2016).

trypillia-maidanetske-mega-city-settlement-old-europe
The reconstruction of Maidanetske based on geomagnetic survey (modern and from the 1970s by
Dudkin), with the position of the trenches mentioned in this study.

Conclusion

At the site of Maidanetske, the phytolith record from different contexts including multiple houses, was studied, which confirmed cereal cultivation as part of the subsistence economy of the site. Furthermore, phytoliths gave information about wild grasses, whereas dicotyledonous material was scarce. For the house structures cereal byproducts, chaff and straw were identified as material selected for tempering daub for the wall construction. Ash layers in a pit filled with house remains show similar pattern. Daub fragments and pit filling are the most promising archives for further phytolith work on cereals at Trypillia sites. The sediment inside four burnt houses and the areas outside two houses, where also grinding stones were sampled, showed little presence of the remains of final cereal processing, suggesting that either the surfaces were cleaned and the chaff was collected after dehusking, or the cereal processing activity took place somewhere else. Specific archaeological contexts, such as vessels and grinding stones, did not differ much from the control samples from archaeological sediment nearby, suggesting disturbance of the record.(…)

Related

Expansion of domesticated goat echoes expansion of early farmers

goat-neolithic

New paper (behind paywall) Ancient goat genomes reveal mosaic domestication in the Fertile Crescent, by Daly et al. Science (2018) 361(6397):85-88.

Interesting excerpts (emphasis mine):

Thus, our data favor a process of Near Eastern animal domestication that is dispersed in space and time, rather than radiating from a central core (3, 11). This resonates with archaeozoological evidence for disparate early management strategies from early Anatolian, Iranian, and Levantine Neolithic sites (12, 13). Interestingly, our finding of divergent goat genomes within the Neolithic echoes genetic investigation of early farmers. Northwestern Anatolian and Iranian human Neolithic genomes are also divergent (14–16), which suggests the sharing of techniques rather than large-scale migrations of populations across Southwest Asia in the period of early domestication. Several crop plants also show evidence of parallel domestication processes in the region (17).

PCA affinity (Fig. 2), supported by qpGraph and outgroup f3 analyses, suggests that modern European goats derive from a source close to the western Neolithic; Far Eastern goats derive from early eastern Neolithic domesticates; and African goats have a contribution from the Levant, but in this case with considerable admixture from the other sources (figs. S11, S16, and S17 and tables S26 and 27). The latter may be in part a result of admixture that is discernible in the same analyses extended to ancient genomes within the Fertile Crescent after the Neolithic (figs. S18 and S19 and tables S20, S27, and S31) when the spread of metallurgy and other developments likely resulted in an expansion of inter-regional trade networks and livestock movement.

goat-middle-east
Maximumlikelihood phylogeny and geographical distributions of ancient mtDNA haplogroups. (A) A phylogeny placing ancient whole mtDNA sequences in the context of known haplogroups. Symbols denoting individuals are colored by clade membership; shape indicates archaeological period (see key). Unlabeled nodes are modern bezoar and outgroup sequence (Nubian ibex) added for reference.We define haplogroup T as the sister branch to the West Caucasian tur (9). (B and C) Geographical distributions of haplogroups show early highly structured diversity in the Neolithic period (B) followed by collapse of structure in succeeding periods (C).We delineate the tiled maps at 7250 to 6950 BP, a period >bracketing both our earliest Chalcolithic sequence (24, Mianroud) and latest Neolithic (6, Aşağı Pınar). Numbered archaeological sites also include Direkli Cave (8), Abu Ghosh (9), ‘Ain Ghazal (10), and Hovk-1 Cave (11) (table S1) (9).

Our results imply a domestication process carried out by humans in dispersed, divergent, but communicating communities across the Fertile Crescent who selected animals in early millennia, including for pigmentation, the most visible of domestic traits.

Related

Ancient genomes from North Africa evidence Neolithic migrations to the Maghreb

BioRxiv preprint now published (behind paywall) Ancient genomes from North Africa evidence prehistoric migrations to the Maghreb from both the Levant and Europe, by Fregel et al., PNAS (2018).

NOTE. I think one of the important changes in this version compared to the preprint is the addition of the recent Iberomaurusian samples.

Abstract (emphasis mine):

The extent to which prehistoric migrations of farmers influenced the genetic pool of western North Africans remains unclear. Archaeological evidence suggests that the Neolithization process may have happened through the adoption of innovations by local Epipaleolithic communities or by demic diffusion from the Eastern Mediterranean shores or Iberia. Here, we present an analysis of individuals’ genome sequences from Early and Late Neolithic sites in Morocco and from Early Neolithic individuals from southern Iberia. We show that Early Neolithic Moroccans (∼5,000 BCE) are similar to Later Stone Age individuals from the same region and possess an endemic element retained in present-day Maghrebi populations, confirming a long-term genetic continuity in the region. This scenario is consistent with Early Neolithic traditions in North Africa deriving from Epipaleolithic communities that adopted certain agricultural techniques from neighboring populations. Among Eurasian ancient populations, Early Neolithic Moroccans are distantly related to Levantine Natufian hunter-gatherers (∼9,000 BCE) and Pre-Pottery Neolithic farmers (∼6,500 BCE). Late Neolithic (∼3,000 BCE) Moroccans, in contrast, share an Iberian component, supporting theories of trans-Gibraltar gene flow and indicating that Neolithization of North Africa involved both the movement of ideas and people. Lastly, the southern Iberian Early Neolithic samples share the same genetic composition as the Cardial Mediterranean Neolithic culture that reached Iberia ∼5,500 BCE. The cultural and genetic similarities between Iberian and North African Neolithic traditions further reinforce the model of an Iberian migration into the Maghreb.

north-africa-genomes-pca
Ancestry inference in ancient samples from North Africa and the Iberian Peninsula. PCA analysis using the Human Origins panel (European, Middle Eastern, and North African populations) and LASER projection of aDNA samples.

Relevant excerpts:

FST and outgroup-f3 distances indicate a high similarity between IAM and Taforalt. As observed for IAM, most Taforalt sample ancestry derives from Epipaleolithic populations from the Levant. However, van de Loosdrecht et al. (17) also reported that one third of Taforalt ancestry was of sub-Saharan African origin. To confirm whether IAM individuals show a sub-Saharan African component, we calculated f4(chimpanzee, African population; Natufian, IAM) in such a way that a positive result for f4 would indicate that IAM is composed both of Levantine and African ancestries. Consistent with the results observed for Taforalt, f4 values are significantly positive for West African populations, with the highest value observed for Gambian and Mandenka (Fig. 3 and SI Appendix, Supplementary Note 10). Together, these results indicate the presence of the same ancestral components in ∼15,000-y old and ∼7,000-y-old populations from Morocco, strongly suggesting a temporal continuity between Later Stone Age and Early Neolithic populations in the Maghreb. However, it is important to take into account that the number of ancient genomes available for comparison is still low and future sampling can provide further refinement in the evolutionary history of North Africa.

Genetic analyses have revealed that the population history of modern North Africans is quite complex (11). Based on our aDNA analysis, we identify an Early Neolithic Moroccan component that is (i) restricted to North Africa in present-day populations (11); (ii) the sole ancestry in IAM samples; and (iii) similar to the one observed in Later Stone Age samples from Morocco (17). We conclude that this component, distantly related to that of Epipaleolithic communities from the Levant, represents the autochthonous Maghrebi ancestry associated with Berber populations. Our data suggests that human populations were isolated in the Maghreb since Upper Paleolithic times. Our hypothesis is in agreement with archaeological research pointing to the first stage of the Neolithic expansion in Morocco as the result of a local population that adopted some technological innovations, such as pottery production or farming, from neighboring areas.

By 3,000 BCE, a continuity in the Neolithic spread brought Mediterranean-like ancestry to the Maghreb, most likely from Iberia. Other archaeological remains, such as African elephant ivory and ostrich eggs found in Iberian sites, confirm the existence of contacts and exchange networks through both sides of the Gibraltar strait at this time. Our analyses strongly support that at least some of the European ancestry observed today in North Africa is related to prehistoric migrations, and local Berber populations were already admixed with Europeans before the Roman conquest. Furthermore, additional European/ Iberian ancestry could have reached the Maghreb after KEB people; this scenario is supported by the presence of Iberian-like Bell-Beaker pottery in more recent stratigraphic layers of IAM and KEB caves. Future paleogenomic efforts in North Africa will further disentangle the complex history of migrations that forged the ancestry of the admixed populations we observe today.

north-africa-iberia-admixture
Ancestry inference in ancient samples from North Africa and the Iberian Peninsula. (B) ADMIXTURE analysis using the Human Origins dataset (European, Middle Eastern, and North African populations) for modern and ancient samples (K = 8). (D) Detail of ADMIXTURE analysis using the Human Origins dataset (European, Middle Eastern, North African, and sub-Saharan African populations) for modern and ancient samples, including Taforalt.

Also, from the main author’s Twitter account:

I just realized that the paragraph with information on data availability is missing! Sequence data in the European Nucleotide Archive (PRJEB22699). Consensus mtDNA sequences are available at the National Center of Biotechnology Information (Accession Numbers MF991431-MF991448).

I find it hard to believe that this genetic continuity from Upper Palaeolithic to Late Neolithic could be representative of an autochthonous development of Afroasiatic. An important population movement – likely more than one – must be found in ancient DNA influencing North-Central and North-East Africa, probably during the time of the Green Sahara corridor.

See here:

Improving environmental conditions favoured higher local population density, which favoured domestication

agricultural-origins

New paper (behind paywall) Hindcasting global population densities reveals forces enabling the origin of agriculture, by Kavanagh et al., Nature Human Behaviour (2018)

Abstract (emphasis mine):

The development and spread of agriculture changed fundamental characteristics of human societies1,2,3. However, the degree to which environmental and social conditions enabled the origins of agriculture remains contested4,5,6. We test three hypothesized links between the environment, population density and the origins of plant and animal domestication, a prerequisite for agriculture: (1) domestication arose as environmental conditions improved and population densities increased7 (surplus hypothesis); (2) populations needed domestication to overcome deteriorating environmental conditions (necessity hypothesis)8,9; (3) factors promoting domestication were distinct in each location10 (regional uniqueness hypothesis). We overcome previous data limitations with a statistical model, in which environmental, geographic and cultural variables capture 77% of the variation in population density among 220 foraging societies worldwide. We use this model to hindcast potential population densities across the globe from 21,000 to 4,000 years before present. Despite the timing of domestication varying by thousands of years, we show that improving environmental conditions favoured higher local population densities during periods when domestication arose in every known agricultural origin centre. Our results uncover a common, global factor that facilitated one of humanity’s most significant innovations and demonstrate that modelling ancestral demographic changes can illuminate major events deep in human history.

cultural-variables-population-densities
Path diagram for piecewise-SEM exploring the effects of environmental and cultural variables on population densities of foraging societies. Measured variables are represented by the large boxes and R2 GLMM values (see Methods) are provided for response variables. n = 220. Red arrows depict negative relationships among variables, black arrows positive relationships, and dashed grey arrows depict non-significant paths (P ≥ 0.05). Standardized coefficients are presented for all paths (small boxes) and arrow widths are scaled to reflect the magnitude of path coefficients.

Interesting excerpts:

(…) our results are consistent with the surplus hypothesis, which suggests that improving environmental conditions and the potential for increased population density may have facilitated the domestication of plants and animals in agricultural origin centres4,7 (Fig. 3). Several factors may explain the links between environmental conditions, potential population density and the origin of domestication. For one, rates of innovation may scale positively with the number of potential innovators13,14. In turn, the likelihood of domestication innovations may have increased in environments that could support increasingly higher densities of foraging people.

In addition, foraging societies may have become more sedentary to take advantage of locally abundant resources, some of which were later domesticated35. Our results indicate that residential mobility scales negatively with population density in foraging societies (Fig. 1). Therefore, increasingly sedentary lifestyles may have contributed further to increases in population density and the potential for innovation. Increases in the productivity of wild progenitors of important domesticates may have also facilitated growing population densities and the viability of cultivation for food production15,16.

population-density-foragers
Predictions of potential population density for foragers. a–c, Predicted population densities at 4,000 (a), 10,000 (b) and 21,000 (c) YBP. Blue hues depict potential population densities below the median population density of observed foraging societies, and red hues depict potential population densities above the median. The second red hue and above are greater than the mean population density of observed foraging societies. Note the increase in area, through time, with potential population densities greater than the mean of observed foraging societies (number of 0.5° × 0.5° cells: 21,000 YBP = 3,027; 4,000 YBP = 4,673). For example, a notable increase in the number of red cells in the Sudanic savannah and Ganges of East India (Northeast India) between panels c and a.

It is also possible that improving environmental conditions may have resulted in a situation where necessity drove the origins of domestication. For example, population densities may have increased in foraging societies that occupied productive, coastal areas, causing an outflow of groups into regions with less ideal conditions where the cultivation of plants and animals was required to secure adequate food resources6,17,18. Our results cannot support, or refute, the possible influence the outflow of people from hospitable locations to less ideal environments may have played. A detailed understanding of the movements of ancient populations is required for more rigorous testing of the role that forced habitation of marginal environments may have played in the origins of domestication at particular sites.

See also:

Bayesian estimation of partial population continuity by using ancient DNA and spatially explicit simulations

europe-palaeolithic-neolithic

Open access Bayesian estimation of partial population continuity by using ancient DNA and spatially explicit simulations, by Silva et al., Evolutionary Applications (2018).

Abstract (emphasis mine):

The retrieval of ancient DNA from osteological material provides direct evidence of human genetic diversity in the past. Ancient DNA samples are often used to investigate whether there was population continuity in the settlement history of an area. Methods based on the serial coalescent algorithm have been developed to test whether the population continuity hypothesis can be statistically rejected by analysing DNA samples from the same region but of different ages. Rejection of this hypothesis is indicative of a large genetic shift, possibly due to immigration occurring between two sampling times. However, this approach is only able to reject a model of full continuity model (a total absence of genetic input from outside), but admixture between local and immigrant populations may lead to partial continuity. We have recently developed a method to test for population continuity that explicitly considers the spatial and temporal dynamics of populations. Here we extended this approach to estimate the proportion of genetic continuity between two populations, by using ancient genetic samples. We applied our original approach to the question of the Neolithic transition in Central Europe. Our results confirmed the rejection of full continuity, but our approach represents an important step forward by estimating the relative contribution of immigrant farmers and of local hunter‐gatherers to the final Central European Neolithic genetic pool. Furthermore, we show that a substantial proportion of genes brought by the farmers in this region were assimilated from other hunter‐gatherer populations along the way from Anatolia, which was not detectable by previous continuity tests. Our approach is also able to jointly estimate demographic parameters, as we show here by finding both low density and low migration rate for pre‐Neolithic hunter‐gatherers. It provides a useful tool for the analysis of the numerous aDNA datasets that are currently being produced for many different species.

central-european-neolithic
A) Different zones defined for computing proportions of ancestry in Central Europeans 4,500 BP. B) Schematic representation of various population contributions. C) Mean proportions of ancestry from the various PHG zones (A+B+C+D) in Central European populations from zone A at the end of the Neolithic transition 4,500 BP, computed for autosomal and mitochondrial markers.

Relevant excerpts:

Our results are in general accordance with two distinct ancestry components that have previously been detected at the continental scale by Lazaridis, Patterson et al. (2014): the “early European farmer” (EEF), which corresponds here to the NFA from Anatolia (zone C in Figure 3), and the “West European hunter-gatherer” (WHG), which corresponds here to the PHG from zones A and B in Figure 3. Notably, the contribution of an Ancient North Eurasians (ANE) component is not included in our model as we did not consider potential post-Neolithic immigration waves, which could have contributed to the modern European genetic pool, such as the wave that came from the Pontic steppes and was associated with the Yamnaya culture (Haak, Lazaridis et al. 2015). Without considering the ANE ancestry component, our estimate of the autosomal genetic contribution of Early farmers to the gene pool of Central European populations (25%) tends to be lower than the EEF ancestry estimated in most modern Western European populations, but is of the same order than the estimations in modern Estonians and in the ancient Late Neolithic genome “Karsdorf” from Germany (Lazaridis, Patterson et al. 2014, Haak, Lazaridis et al. 2015). Note that the contribution of hunter-gatherers to Neolithic communities appears to be variable in different regions of Europe (Skoglund, Malmstrom et al. 2012, Brandt, Haak et al. 2013, Lazaridis, Patterson et al. 2014), while we computed an average value for Central Europe. Moreover, we computed the ancestry of the two groups at the end of the Neolithic period while previous studies estimated it in modern times. Finally, previous studies used molecular information to directly estimate admixture proportions, while we use molecular information to estimate the model parameters and, then, we computed the expected genetic contributions of both groups using the best parameters, without using molecular information during this second step. Model assumptions may thus influence the inferences on the relative genetic contribution of both groups. In particular, we made the assumption of a uniform expansion of NFA with constant and similar assimilation of PHG over the whole continent but spatio-temporally heterogeneous environment, variable assimilation rate and long distance dispersal may have played an important role. The effects of those factors should be investigated in future studies.

FADS1 and the timing of human adaptation to agriculture

fads1-farmers

Open access FADS1 and the timing of human adaptation to agriculture, by Sara Mathieson & Iain Mathieson, bioRxiv (2018).

Abstract:

Variation at the FADS1/FADS2 gene cluster is functionally associated with differences in lipid metabolism and is often hypothesized to reflect adaptation to an agricultural diet. Here, we test the evidence for this relationship using both modern and ancient DNA data. We document pre-out-of-Africa selection for both the derived and ancestral FADS1 alleles and show that almost all the inhabitants of Europe carried the ancestral allele until the derived allele was introduced approximately 8,500 years ago by Early Neolithic farming populations. However, we also show that it was not under strong selection in these populations. Further, we find that this allele, and other proposed agricultural adaptations including variants at LCT/MCM6, SLC22A4 and NAT2, were not strongly selected until the Bronze Age, 2,000-4,000 years ago. Similarly, increased copy number variation at the salivary amylase gene AMY1 is not linked to the development of agriculture although in this case, the putative adaptation precedes the agricultural transition. Our analysis shows that selection at the FADS locus was not tightly linked to the development of agriculture. Further, it suggests that the strongest signals of recent human adaptation may not have been driven by the agricultural transition but by more recent changes in environment or by increased efficiency of selection due to increases in effective population size.

Interesting excerpt for the steppe-related expansion:

agricultural-adaptation-allele-frequency
Allele frequency trajectories for other putative agricultural adaptation variants. As in Figure 2C, estimated allele frequency trajectories and selection coefficients in different ancient European populations. Significant selection coefficients are labelled.

In the case of FADS1 and all the other examples we investigated, the proposed agricultural adaption was either not temporally linked with agriculture or showed no evidence of selection in agricultural populations. Instead, most of the variants with any evidence of selection were only strongly selected at some point between the Bronze Age and the present day, that is, in a period starting 2000-4000 BP and continuing until the present. This time period is one in which there is relatively limited ancient DNA data, and so we are unable to determine the timing of selection any more accurately. Future research should address the question of why this recent time period saw the most rapid changes in apparently diet associated genes. One plausible hypothesis is that the change in environment at this time was actually more dramatic than the earlier change associated with agriculture. Another is that effective population sizes were so small before this time that selection did not operate efficiently on variants with small selection coefficients. For example, analysis of present-day genomes from the United Kingdom suggests that effective population size increased by a factor of 100-1000 in the past 4500 years (Browning and Browning 2015). Ancient effective population sizes less that 104 would suggest that those populations would not be able to efficiently select for variants with selection coefficients on the order of 10-4 or smaller. Larger ancient DNA datasets from the past 4,000 years will likely resolve this question.

This complexity of the reasons for selection reminded me of the comment by Narasimhan on lactase persistence expanding with steppe populations into Central Asia (based on data of the paper where he is the first author):

I always thought that to argue for natural selection in humans (viz. skin color, lactase persistence, etc.) was possible for archaic groups over tens of thousands of years, but that more recent selections would be very difficult to prove, in so far as historical population expansions involve more ‘artificial’ (i.e. man-made or man-caused) societal changes.

NOTE. I am probably more inclined to think about regional outbreaks (especially of new diseases) as one of the few potential short-term selection mechanisms in historical societies, because of their potential to create sudden bottlenecks of better fitted survivors.

I think recent works like these are showing a mixed situation, where maybe some traits were strongly selected for environmental reasons; but most of the time they were probably – like, say, Y-DNA haplogroup bottlenecks in Europe after the steppe-related expansions – due mostly to chance.

Steppe and Caucasus Eneolithic: the new keystones of the EHG-CHG-ANE ancestry in steppe groups

indo-uralic-ehg-chg-ane-ancestry

Some interesting excerpts from Wang et al. (2018):

An interesting observation is that steppe zone individuals directly north of the Caucasus (Eneolithic Samara and Eneolithic steppe) had initially not received any gene flow from Anatolian farmers. Instead, the ancestry profile in Eneolithic steppe individuals shows an even mixture of EHG and CHG ancestry, which argues for an effective cultural and genetic border between the contemporaneous Eneolithic populations in the North Caucasus, notably Steppe and Caucasus. Due to the temporal limitations of our dataset, we currently cannot determine whether this ancestry is stemming from an existing natural genetic gradient running from EHG far to the north to CHG/Iran in the south or whether this is the result of farmers with Iranian farmer/ CHG-related ancestry reaching the steppe zone independent of and prior to a stream of Anatolian farmer-like ancestry, where they mixed with local hunter-gatherers that carried only EHG ancestry.

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 Eastern European (blue) and a Caucasus (brown) ‘clouds’ have been drawn in dotted circles, leaving Pontic-Caspian steppe and derived groups between them.See the original file here.

Concerning the influences from the south, our oldest dates from the immediate Maykop predecessors Darkveti-Meshoko (Eneolithic Caucasus) indicate that the Caucasus genetic profile was present north of the range ~6500 BP, 4500 calBCE. This is in accordance with the Neolithization of the Caucasus, which had started in the flood plains of the great rivers in the South Caucasus in the 6th millennium BCE from where it spread to the West and Northwest Caucasus during the 5th millennium BCE9, 49. It remains unclear whether the local CHG ancestry profile (represented by Late Upper Palaeolithic/Mesolithic individuals from Kotias Klde and Satsurblia in today’s Georgia) was also present in the North Caucasus region before the Neolithic. However, if we take the Caucasus hunter-gatherer individuals from Georgia as a local baseline and the oldest Eneolithic Caucasus individuals from our transect as a proxy for the local Late Neolithic ancestry, we notice a substantial increase in Anatolian farmer-related ancestry. This in all likelihood is linked to the process of Neolithization, which also brought this type of ancestry to Europe. As a consequence, it is possible that Neolithic groups could have reached the northern flanks of the Caucasus earlier50 (Supplementary Information 1) and in contact with local hunter gatherers facilitated the exploration of the steppe environment for pastoralist economies. Hence, additional sampling from older individuals is needed to fill this temporal and spatial gap.

The newest paper of the Reich/Jena group has brought samples (probably) much nearer to the actual CHG and ANE contribution seen in Eneolithic steppe peoples than the previously available Kotias Klde, Satsurblia, Afontova Gora 3, or Mal’ta.

It is impossible to say without direct access to the samples, but it is very likely that we will soon be able to break down different gross contributions from groups similar to these Steppe/Caucasus Neolithic ancestral groups into the diverse Eneolithic cultures of the Pontic-Caspian steppe, and thus trace more precisely each of these cultures to their genetic (and thus ethnolinguistic) heirs.

qpgraph-eneolithic-steppe
Admixture Graph modelling of the population history of the Caucasus region. We started with a skeleton tree without admixture including Mbuti, Loschbour and MA1. We grafted onto this EHG, CHG, Globular_Amphora, Eneolithic_steppe, Maykop, and Yamnaya_Caucasus, adding them consecutively to all possible edges in the tree and retaining only graph solutions that provided no differences of |Z|>3 between fitted and estimated statistics. The worst match is |Z|=2.824 for this graph. We note that the maximum discrepancy is f4(MA1, Maykop; EHG, Eneolithic_steppe) = -3.369 if we do not add the 4% EHG ancestry to Maykop. Drifts along edges are multiplied by 1000 and dashed lines represent admixture.”

Some more representative samples from Eneolithic steppe, steppe-forest and forest zone cultures of Eastern Europe will probably help with the fine-scale structure of different Chalcolithic groups, especially the homeland of early Corded Ware groups.

These new samples seem another good reason (like the Botai and R1b-M73) to rethink the role of (what I assumed were) different westward Mesolithic Eurasian waves of expansion influencing the formation of an Indo-Uralic and Indo-European community in Eastern Europe, and return to the simpler idea of local contributions from North Caucasus and steppe peoples absorbed by expanding EHG-like groups.

Related:

No large-scale steppe migration into Anatolia; early Yamna migrations and MLBA brought LPIE dialects in Asia

eurasian-hittite-samples

Another, simultaneous paper with the Eurasian samples from Nature, The first horse herders and the impact of early Bronze Age steppe expansions into Asia, by de Barros Damgaard et al., Science (2018).

A lot of interesting data, I will try to analyse its main implications, if only superficially, in sections.

Anatolian samples

Anatolia_EBA from Ovaören, and Anatolia_MLBA (this including Assyrian and Old Hittite samples), all from Kalehöyük, show almost no change in Y-DNA lineages (three samples J2a, one G2a), and therefore an origin of these people in common with CHG and Iranian Neolithic populations is likely. No EHG ancestry is found. And PCA cluster is just somehow closer to Europe, but not to EHG populations.

NOTE. Hittite is attested only in the late first half of the 2nd millennium, although the authors cite (in the linguistic supplement) potential evidence from the palatial archives of the ancient city of Ebla in Syria to argue that Indo-European languages may have been already spoken in the region in the late 3rd millennium BCE.

Regarding the Assyrian samples (one J2a) from Ovaören:

Layer V of GT-137 was the richest in terms of architectural finds and dates to the Early Bronze Age II. In this layer, 2 different structures and a well were uncovered. The well was filled with stones, pottery, and human skeletons (Figs. S2 and S3). In total, skeletons belonging to 22 individuals, including adults, young adults, and children, must belong to the disturbed Early Bronze Age II graves adjacent to the well (103). Pottery and stones found below the skeletons demonstrate that the water well was consciously filled and closed. The fill consists of dumped stones, sherds and skeletons, and the closing stones demonstrate that the water well was consciously filled and cancelled.

Regarding the site most likely associated with the emergence of Old Hittite (two samples J2a1, one G2a2b1), this is what we know:

The Middle Bronze Age at Kaman-Kalehöyük represented by stratum IIIc yields material remains (seals and ceramics) contemporary with the international trade system managed by expatriate Assyrian merchants evidenced at the nearby site of Kültepe/Kanesh. It is therefore also referred to as belonging to the “Assyrian Colony Period” (98). The stratum has revealed three burned architectural units, and it has been suggested that the seemingly site-wide conflagration might be connected to a destruction event linked with the emergence of the Old Hittite state (99). (…) Omura (100) suggests that the rooms could belong to a public building, and that it might even be a small trade center based on the types of artifacts recovered. Omura (100) has concluded that the evidence from the first complex indicates a battle between 2 groups took place at the site. It is possible that a group died inside the buildings, mostly perishing in the fire, while another group died in the courtyard.

NOTE. For more on the Old Hittite period, you can read this for example.

Regarding PCA:

The PCA (Fig. 2B) indicates that all the Anatolian genome sequences from the Early Bronze Age ( -2200 BCE) and Late Bronze Age (-1600 BCE) cluster with a previously sequenced Copper Age ( -3900- 3700 BCE) individual from Northwestern Anatolia and lie between Anatolian Neolithic (Anatolia_ N) samples and CHG samples but not between Anatolia_N and EHG samples.

(…) we are not able to reject a two-population qpAdm model in which these groups derive -60% of their ancestry from Anatolian farmers and -40% from CHG-related ancestry (p-value = 0.5). This signal is not driven by Neolithic Iranian ancestry.

pca-ancient-modern-eurasians
Principal Component Analysis estimated with ancient and modern Eurasians.

NOTE. Anatolian Iron Age samples, from the Hellenistic period, which was obviously greatly influenced by different, later Indo-European migrations, does show a change in PCA.

Regarding CHG ancestry:

Ancient DNA findings suggest extensive population contact between the Caucasus and the steppe during the Copper Age (-5000-3000 BCE) (1, 2, 42). Particularly, the first identified presence of Caucasian genomic ancestry in steppe populations is through the Khvalynsk burials (2, 47) and that of steppe ancestry in the Caucasus is through Armenian Copper Age individuals (42). These admixture processes likely gave rise to the ancestry that later became typical of the Yamnaya pastoralists (7), whose IE language may have evolved under the influence of a Caucasian language, possibly ‘from the Maykop culture (50, 55). This scenario is consistent with both the “Copper Age steppe” (4) and the “Caucasian” models for the origin of the Proto-Anatolian language (56).

The CHG specific ancestry and the absence of EHG-related ancestry in Bronze Age Anatolia would be in accordance with intense cultural interactions between populations in the Caucasus and Anatolia observed during the late 5th millennium BCE that seem to come to an end in the first half of the 4th millennium BCE with the village-based egalitarian Kura-Araxes society (59, 60), thus preceding the emergence and dispersal of Proto-Anatolian.

Our results indicate that the early spread of IE languages into Anatolia was not associated with any large-scale steppe-related migration, as previously suggested (61). Additionally, and in agreement with the later historical record of the region (62), we find no correlation between genetic ancestry and exclusive ethnic or political identities among the populations of Bronze Age Central Anatolia, as has previously been hypothesized ( 63).

The Anatolian question

There is no steppe ancestry or R1b-M269 lineages near early historic Hittites. Yet.

Nevertheless, we already know about potentially similar cases:

So there seems to be thus no theoretical problem in accepting:

  • That neither steppe ancestry nor R1b-M269 subclades, already diminished in Bulgaria in the mid-5th millennium, did reach Anatolia, but only those Common Anatolian-speaking Aegean groups over whose ancestors Proto-Anatolians (marked by incoming EHG ancestry) would have previously dominated in the Balkans.
  • That steppe ancestry and R1b-M269 subclades did in fact arrive in the Aegean, but EHG was further diluted among the CHG-related population by the time of the historic Anatolian-speaking peoples in central Anatolia. Or, the most likely option, that their trace have not been yet found. Probably the western Luwian peoples, near Troy, were genetically closer to Common Anatolians.

Both of these scenarios are interesting, in that they show potential links between Pre-Greek peoples of Hellas (related to Anatolians) and the Pelasgian substrate of early Greek dialects, since they show a similar recent CHG-related wave from the East.

What we can assert right now is that Proto-Anatolian must have separated quite early for this kind of data to show up. This should mean an end to the Late PIE origin of Anatolian, if there was some lost soul from the mid-20th century still rooting for this.

As I said in my review of Lazaridis’ latest preprint, we will have to wait for the appropriate potential routes of expansion of Proto-Anatolian to be investigated. As he answered, the lack of EHG poses a problem for steppe expansion into Anatolia, but there is still no better alternative model proposed.

Eurasian-CHG-ancestry
Model-based clustering analysis of present-day and ancient individuals assuming K = 6 ancestral components. The main ancestry components at K = 6 correlate well with CHG (turquoise), a major component of Iran_N, Namazga_CA and South Asian dines; EHG (pale blue), a component of the steppe dine and present in South Asia; East Asia (yellow ochre), the other component of the steppe d ine also in Tibeto-Burman South Asian populations; South Indian (pink), a core component of South Asian populations; Anatolian_N (purple), an important component of Anatolian Bronze Age and Steppe_MLBA; Onge (dark pink) forms its own component.

This is what the authors have to say:

Our findings are thus consistent with historical models of cultural hybridity and “Middle Ground” in a multi-cultural and multi-lingual but genetically homogeneous Bronze Age Anatolia (68, 69). Current linguistic estimations converge on dating the Proto-Anatolian split from residual PIE to the late 5th or early 4th millennia BCE (58, 70) and place the breakup of Anatolian IE inside Turkey prior to the mid-3rd millennium (53, 71,72).

We cannot at this point reject a scenario in which the introduction of the Anatolian IE languages into Anatolia was coupled with the CHG-derived admixture prior to 3700 BCE, but note that this is contrary to the standard view that PIE arose in the steppe north of the Caucasus (4) and that CHG ancestry is also associated with several non-IE-speaking groups, historical and current. Indeed, our data are also consistent with the first speakers of Anatolian IE coming to the region by way of commercial contacts and small-scale movement during the Bronze Age. Among comparative linguists, a Balkan route for the introduction of Anatolian IE is generally considered more likely than a passage through the Caucasus, due, for example, to greater Anatolian IE presence and language diversity in the west (73). Further discussion of these options is given in the archaeological and linguistic supplementary discussions (48, 49).

If you are asking yourselves why the Danish school (of Allentoft, Kristiansen, and Kroonen, co-authors of this paper) was not so fast to explain the findings the same way the proposed their infamous Indo-European – steppe ancestry association (i.e. ancestry = language, ergo CHG = PIE in this case), and resorted to mainstream anthropological models instead to explain the incongruence, I can think of two main reasons:

The possibility of having an early PIE around the Caucasus, potentially closely related not only to Uralic to the north, but also to Caucasian languages, Sumerian, Afroasiatic, Elamo-Dravidian, etc. could be a good reason for those excited with these few samples to begin dealing with macro-language proposals, such as Eurasiatic and Nostratic. If demonstrated to be true, a Northern Iranian origin of Middle PIE would also help relieve a little bit the pressure that some are feeling about the potentially male-driven Indo-European continuity (even if not “autochthonous”) associated with the expansion of R1b-L23 subclades.

On the other hand, I am a firm supporter of solid anthropological models of migration, and of “late and small” language expansions, usually accompanied by demic diffusion, which has been demonstrated to be linked with haplogroup expansion and reduction in variability.

Therefore, for the moment, even if it is weak – as weak as it always was (but still stronger than Gimbutas’ Maykop route) – the Balkan route seems like the best fit for all the data combined.

In fact, we already have steppe ancestry moving into the Lower Danube and Bulgaria in the mid-5th millennium. Let’s not forget that.

Yamna expansion to the East

Interesting data from an early East Yamna offshoot at Karagash, ca. 3018-2887 BC, of R1b-Z2106 lineage, which shows some ancestry, lineage, and cultural continuity in Sholpan, ca. 2620-2468 BC, in Kazakhstan.

This sample might be part of another descendant group from the migration waves that reached Afanasevo, and can thus be related to other early Asian R1b-L23 samples found in Narasimhan et al. (2018).

On the formation of Yamna and its CHG contribution, from the supplementary material:

  1. An admixture event, where Yamnaya is formed from a CHG population related to KK1 [=Kotias, dated ca. 7800 BC] and an ANE population related to Sidelkino and Botai. We inferred 54% of the Yamnaya ancestry to come from CHG and the remaining 46% to come from ANE.
  2. A split event, where the CHG component of Yamnaya splits from KK1. The model inferred this time at 27 kya (though we note the larger models in Sections S2.12.4 and S2.12.5 inferred a more recent split time [see below graphic]).
  3. A split event, where the ANE component of Yamnaya splits from Sidelkino. This was inferred at about about 11 kya.
  4. A split event, where the ANE component of Yamnaya splits from Botai. We inferred this to occur 17 kya. Note that this is above the Sidelkino split time, so our model infers Yamnaya to be more closely related to the EHG Sidelkino, as expected.
  5. An ancestral split event between the CHG and ANE ancestral populations. This was inferred to occur around 40 kya.
yamnaya-chg-ancestry
A 10-leaf model based on combining the models in Fig. S16 and Fig. S19 and re-estimating the model parameters.

On the expansion of domestication

CHG is not found in Botai, no gene flow from Yamna is found in its samples, and they are more related to East Asians, while Yamna is related to West Eurasians:

The lack of evidence of admixture between Botai horse herders and western steppe pastoralists is consistent with these latter migrating through the central steppe but not settling until they reached the Altai to the east (4). More significantly, this lack of admixture suggests that horses were domesticated by hunter-gatherers not previously familiar with farming, as were the cases for dogs (38) and reindeer (39). Domestication of the horse thus may best parallel that of the reindeer, a food animal that can be milked and ridden, which has been proposed to be domesticated by hunters via the “prey path” (40); indeed anthropologists note similarities in cosmological beliefs between hunters and reindeer herders (41). In contrast, most animal domestications were achieved by settled agriculturalists (5).

NOTE. I am not sure, but they seem to hint that there were separate events of horse domestication and horse-riding technique by the Botai and Yamna populations due to their lack of genetic contribution from the latter to the former. I guess they did not take into account farming spreading to the steppe without genetic contribution beyond the Dnieper… In fact, the superiority in horse-riding shown by the expanding Yamna peoples – as they state – should also serve to suggest from where the original technique expanded.

Indo-Iranian migrations

On the expansion of Yamna, and the different expansion of Steppe MLBA (with Indo-Iranian speakers) into Asia, further supporting Narasimhan et al. (2018), they have this to say:

However, direct influence of Yamnaya or related cultures of that period is not visible in the archaeological record, except perhaps for a single burial mound in Sarazm in present-day Tajikistan of contested age (44, 45). Additionally, linguistic reconstruction of proto-culture coupled with the archaeological chronology evidences a Late (-2300-1200 BCE) rather than Early Bronze Age (-3000-2500 BCE) arrival of the Indo-Iranian languages into South Asia (16, 45, 46). Thus, debate persists as to how and when Western Eurasian genetic signatures and IE languages reached South Asia.

Samples from the Namazga region (current Turkmenistan) from the Iron Age show an obvious influence from steppe MLBA (ca. 2300-1200 BC), and not steppe EBA (i.e. Yamna), population, in contrast with samples from the Chalcolithic (ca. 3300 BC), which don’t show this influence. This helps distinguish prior contacts with Iran Neolithic from the actual steppe population that expanded Indo-Iranian into Asia.

Very interesting therefore the Namazga CA sample (ca. 855 BC), of R1a-Z93 subclade, showing the sign of immigrant Indo-Aryans in the region. For more on this we will need an evaluation in common with the corrected data from Narasimhan et al. (2018), and all, including de Barros (Nature 2018), in combination with statistical methods to ascertain differences between early Indo-Aryans and Iranians.

namazga-expansion-south-asia
A summary of the four qpAdm models fitted for South Asian populations. For each modern South Asian population. we fit different models with qpAdm to explain their ancestry composition using ancient groups and present the f irst model that we could not reject in the following priority order: 1. Namazga_CA + Onge, 2. Namazga_CA + Onge + Late Bronze Age Steppe, 3. Namazga_CA + Onge + Xiongnu_lA (East Asian proxy). and 4. Turkmenistan_lA + Xiongnu_lA. Xiongnu_lA were used here to represent East Asian ancestry. We observe that while South Asian Dravidian speakers can be modeled as a mixture of Onge and Namazga_CA. an additional source related to Late Bronze Age steppe groups is required for IE speakers. In Tibeto-Burman and Austro-Asiatic speakers. an East Asian rather than a Steppe_MLBA source is required.

Siberian peoples and N1c lineages

We have already seen how the paper on Eurasian steppe samples tries to assign Uralic to Neolithic peoples east of the Urals. The association with Okunevo is unlikely, since most are of haplogroup Q1a2, but they seem to suggest (combining both papers) that they accompanied N lineages from Siberian hunter-gatherers (present e.g. in Botai or Shamanka II, during the Early Neolithic), and formed part of (or suffered from) different demic diffusion waves:

These serial changes in the Baikal populations are reflected in Y-chromosome lineages (Fig. SA; figs. S24 to S27, and tables S13 and SI4). MAI carries the R haplogroup, whereas the majority of Baikal_EN males belong to N lineages, which were widely distributed across Northern Eurasia (29), and the Baikal_LNBA males all carry Q haplogroups, as do most of the Okunevo_EMBA as well as some present-day Central Asians and Siberians.

NOTE. Also interesting to see no R1a in Baikal hunter-gatherers after ca. 3500 BC, and a prevalence of N lineages as supported in a previous paper on the Kitoi culture, which some had questioned in the past.

In fact, the only N1c1 sample comes from Ust’Ida Late Neolithic, 180km to the north of Lake Baikal, apparently before the expansion of Q1a2a lineages during the EBA period. While this sample may be related to those expanded later in Finno-Ugric territory (although it may only be related to those expanded much later with Yakuts), other samples are not clearly from those found widely distributed among North-East Europeans only after the Iron Age, or – as in the case of Shamanka II (N1c2), they are clearly not of the same haplogroup.

eurasian-n-subclades
Geographical location of ancient samples belonging to major clade N of the Y-chromosome.

Wrap-up

It is great to see the paper and the supplementary material deal with Y-DNA haplogroups and their relevance for migrations with such detail. Especially because this paper comes from the same Copenhagen-based research group that originally associated ancestry with language, creating thus today’s mess based on steppe ancestry.

Regarding Y-DNA data, once again almost 100% of samples from late Khvalynsk/Yamna and derived cultures (like Afanasevo and Bell Beaker) are R1b-L23, no single R1a-M417 lineage found, and few expected by now, if any, within Late Proto-Indo-European territory.

While they claim to take Y-DNA into account to assess migrations – as they do for example with Asian cultures – , their previous model of a Yamna “R1a-R1b community” remains oddly unchanged, and they even insist on it in the supplementary materials, as they do in their parallel Nature paper.

They have also expressly mitigated the use of ancestral components to assess populations, citing the ancestral and modern association of CHG ancestry with different ethnolinguistic groups in the Middle East, to dismiss any rushed conclusions on the origin of Anatolian, and consequently of Middle PIE. And they did so evidently because it did not fit the anthropological data that is mainstream today (supporting a Balkan route), which is the right thing to do.

However, they have apparently not stopped to reconsider the links of CWC and steppe ancestry to ancestral and modern Uralic peoples – although they expressly mention the strong connection with modern Karelians in the supplementary material.

Also, after Narasimhan et al. (2018), there is a clear genetic continuity with East Yamna (in ancestry as in R1b-L23 subclades), so their interpretations about Indo-Iranian in this paper and especially de Barros (Nature 2018) – regarding the Abashevo -> Sintashta/Srunba/Andronovo connection – come, again, too late.

Related:

The Lower Danube during the Eneolithic, and the potential Proto-Anatolian community

zhivotilovka-type-burials

Local cultural settings and transregional phenomena: on the impact of a funerary ritual in the Lower Danube in the 4th millennium BC, by Frinculeasa & Mirea, In: Buletinul Muzeului Judetean Teleorman, Seria Arheologie, 9, 2017, p. 75-116.

Interesting excerpts (emphasis mine):

1. In the area under discussion, around 4300-4200 BC – a chronological segment marking the evolutionary peak of ‘Old Europe’ (Anthony 2007: 225), represented by the Cucuteni A/ Tripolie BI, Aldeni-Bolgrad, Gumelniţa-Karanovo VI cultures – the first tumular burials appeared (Govedarica 2016: 85). However, flat burials, marked by the existence of some allogeneous elements in the local Eneolithic milieu, were also present. These finds have been linked to the presence (in terms of both trade and conflicts) of Suvorovo/Suvorovo-Novodanilovka communities (Anthony 2007: 251ff.; Govedarica and Manzura 2011: 46ff.; Reingruber and Rassamakin 2016) or of some groups from the ‘western part of the Skelia culture’ (Anthony 2007: 251ff.; Govedarica and Manzura 2011: 46ff.; Reingruber and Rassamakin 2016). (…) The zoomorphic sceptres and the four-knobbed stone mace heads found east of the Prut/the Lower Danube are also related to this topic (Govedarica 2004; Govedarica and Manzura 2011: abb. 5; Gogâltan 2013).

2. The next chronological segment intersects the ‘hiatus’ recorded between the end of the Gumelniţa-Karanovo VI cultural complex and the beginning of the Cernavoda I culture (Rassamakin 2011a: 85ff.; Govedarica and Manzura 2011: 51). We should also mention the existence of a small set of absolute dates ranging within the interval 4200/ 4150 – 3900/ 3850 BC that come from the sites of Sultana, Vităneşti, Pietrele, Bucşani, Ploieşti ‘Triaj’, Ovcarovo, Hotnica etc. (Reingruber 2015; Reingruber and Rassamakin 2016; Frînculeasa 2016; Bem and Haită 2016: 63; Krause et al. 2016). The examples of Sărăteni and Krasnoe15 and the abovementioned dates seem to fill out a part of this chronological segment. It is still difficult to say whether they reflect the presence of some communities that led to the disappearance of the Gumelniţa-Karanovo VI complex or are connected with an early Cernavoda I, or possibly late Suvorovo evolution. If we refer to the absolute dates obtained for samples taken from mammal bones found in Cernavoda I settlements, we notice that the appearance of this culture in the abovementioned chronological interval is not yet confirmed (Frînculeasa 2016, tab. 3).

3. The Cernavoda I discoveries (approximately 3850/3800 – 3550/3500 BC) are represented in the Lower Danube by settlements and flat graves (the presence of tumular burials should not be completely excluded, see Brăiliţa). In the Bugeac area, the Cernavoda I culture was until recently defined only by tumular burials (Manzura 1999). The presence at Orlovka of flat graves and of a settlement (with two habitation levels, in which the Cucuteni B painted pottery occurs in association with the unpainted pottery with crushed shells into the paste) (Govedarica and Manzura 2015; Manzura 2018) shows that we are dealing with the same cultural phenomenon both west and east of the Prut, beyond the so-called ‘Bessarabian version’. North of the Danube there are flat burials, with individuals in side-crouched position. Unlike the tumular graves (including the early ones), in the flat graves there are no ornaments, only (unpainted) pottery items, including at Orlovka cemetery.

kvityana-cernavoda
Map of funerary finds with skeletons in extended position from the 4th millennium BC and
contemporaneous cultural areas.

Therefore, the presence of tumular graves east of the Prut, in the same chronological interval, may be related to phenomena located east of the Dniester. In fact, Y. Rassamakin associates these finds with the Lower Mikhailovka culture, which precedes here the ritual that is specific to Kvityana communities (Rassamakin 1994: 42, 44; 1999: 92). He establishes a chronological relation between a number of findings such as the plastic anthropomorphic representations from Cernavoda, Râmnicelu, Târpeşti, Folteşti and Satu Nou (Neagu et al. 1982) and Dereivka (Rassamakin 1994: 41; 1999: 90), which seems to point to a revival of contacts between the North Pontic area and the Lower Danube, contacts which had been interrupted with the dissolution of the Gumelniţa-Karanovo VI cultural complex (Reingruber and Rassamakin 2016).

4. At the middle of the 4th millennium BC (we do not exclude that it could reach the end of the chronological interval in which the Cernavoda I culture evolves), we can establish the occurrence (in secondary position) in tumuli – located in the Prut-Dniester interfluve – of graves with deceased laid in extended position. It is a period in which the Kvityana funeral traditions transcend their place of origin. The painted pottery culture provides evidence for, indirectly or directly through the presence of vessels in graves, including east of the Dniester (Rassamakin 2011b; 2013a), the contact and the chronological relationship. Placing the constructions with rings later towards the last third of the 4th millennium BC is supported by the Usatovo finds (Tripolie CII) which are posterior to the Cernavoda I ones (Govedarica and Manzura 2011). The relationship and direct chronological relation between the Kvityana and the (early) Usatovo is also supported by the discovery of Sadovoe (Maljukevich and Petrenko 1993: fig. 5/2). (…)

5. Another horizon with burials of individuals in supine position is stratigraphically recorded between Zhivotilovka and Yamnaya (the last third of the 4th millennium BC); however, a coexistence of both cultural/ funerary groups with specific ritual elements (side-crouched and supinely with knees folded and raised) is not excluded either. The absence of inventory and of ochre and the presence of oval-elongated pits are specific elements.

6. (…) The extended position disappeared in the Early Bronze Age/ 3rd millennium BC (Rassamakin 2013a: 116), but is to be found again in the Katacombnaya ritual (Frînculeasa et al. 2017a). Ascertaining the many discrepancies regarding the contexts and radiocarbon dates, we maintain our reservations on this matter as well. Therefore, the two samples do not represent a solid basis for a possible discussion

From the conclusions:

If the Kvityana evolution covers a significant part of the first half of the 4th millennium BC, and partially the second half, west of the Prut we are dealing with Cernavoda I and later Usatovo communities in the same chronological time frame. The relationship between this ritual/ Kvityana and the Cernavoda I culture, which is stratigraphically unclear, and the absence of items to prove direct contacts show a slight chronological gap in favour of the Cernavoda I culture and the side-crouched ritual, at least in the Prut-Dniester interfluve. This ritual continues to be present, crosses the evolution of Zhivotilovka communities and continues as far as the start of the Yamnaya. The extended position is a late occurrence within the tumular burials in the Lower Danube, but here it is also a rather discreet ritual, one that seems to be of secondary importance. The presence of this ritual (and the accurate interpretation of stratigraphic situations) is an additional element for establishing a better chronological and chorological relationship between the West Pontic area and realities located in the North Pontic steppe, amidst a phenomenon which seems to have rewritten history in other parameters, initially of the Lower Danube and then of Western Europe.

If someone was still relying on Gimbutas – and mostly anything before the 2000s, like “kurgans”, in general terms – to assess cultural developments, and particularly ethnolinguistic identifications, it is time to let it go. The situation in the North Pontic area reveals itself far more complex with each new assessment of recent findings and radiocarbon dates.

By now it is evident that the LPIE-speaking community, formed in the Khvalynsk/Repin -> Yamna period, became dominated by R1b-M269 subclades early during its formation and expansion, based on what we have already seen in the Afanasevo expansion to the east, in the Bell Beaker migrants to the west, and in the admixed lineages (with incoming Abashevo peoples) in the North Caspian steppe that formed the Early Indo-Iranian community. While we don’t have much data on the Balkan region, especially Yamna migrants leading to the Proto-Greek migration, it is quite likely to support this, too.

Therefore, earlier PIE stages are the most likely objects of controversy for the future. Just like proponents of the Anatolian and Armenian homeland theories have surreptitiously shifted their proposal of “farmers expanding LPIE languages” to “farmers expanding earlier PIE stages”, we will see many different accounts of how late Khvalynsk/Repin came to be, and especially of what new culture now represents Middle PIE, be it early Sredni Stog, Northern Iran, or the Lower Danube.

I am not a priori radically opposed to any of those territories as potential earlier ‘original’ (i.e. Early PIE) homelands, although none of them is a likely Middle PIE Urheimat. The fact that such renewed proposals seem to be mostly based on haplogroups or ancestral components mixed into newly formed pet theories, instead of sound linguistic and archaeological models of cultural continuity (following late Khvalynsk/Repin backwards to their most likely forming cultures) does not help their cause.

neolithic_steppe-anatolian-migrations
Most likely Pre-Proto-Anatolian migration with Suvorovo-Novodanilovka chiefs in the North Pontic steppe and the Balkans.

I am certainly not opposed to a strong influence on the formation of a Middle PIE-speaking community (in terms of Y-DNA lineages and potentially language, since genomics cannot change our knowledge of prehistoric cultures) due to immigrants from the Caucasus. After all:

  1. There seems to be a Northern Caucasian (phonetic) substrate in Middle PIE compared to Uralic;
  2. There is an obvious genetic contribution to both North Pontic and North Caspian steppe communities (probably greater in the latter); and
  3. If you defend an Indo-Uralic community – e.g. in a Neolithic steppe cultural-historical community, as I would be inclined to support – , a sizeable migration from the south – whether driven by female exogamy, male migrants, or both – would explain that influence.

Nevertheless, even in this case of an obvious migration (e.g. by R1b-M269 lineages) from the Caucasus, we could be talking about a Caucasian group influencing the formation of a Middle PIE community, represented by Khvalynsk, i.e. not necessarily about a Maykop-Khvalynsk community.

That is, peoples from the Caucasus could have admixed with the (already diverse) North Caspian steppe community to form the Middle PIE-speaking peoples whose expansion developed both known dialectal splits:

  1. Proto-Anatolian, probably represented by Suvorovo-Novodanilovka chiefs, but possibly by Maykop; and
  2. Late PIE, undoubtedly represented by the community forming in late Khvalynsk/Repin -> Yamna.

The Lower Danube remains thus the most important region to investigate, looking for traces of a Proto-Anatolian migration out of the steppe. Today this route seems more likely than Gimbutas’ original idea of Maykop representing a steppe offshoot, since the culture and thus its contacts with the steppe are older than she expected, Anatolian is dated earlier than she could have known based on the works available then, and even the latest available language guesstimates and radiocarbon dates don’t fit quite right in light of the known cultural contacts.

Until some proof appears of a different origin than what archaeologists have described to date, we need more than a simple one-paragraph informal pet theory to change the mainstream model.

A) Given that data from Mesolithic and Eneolithic Pontic-Caspian steppe shows a mixed population in terms of haplogroups, and R1b-M269 lineages are still nowhere to be seen – in the three samples from the Samara region of the Khvalynsk culture -, I can still only guess that it is precisely the expansion of Middle PIE (Pre-Proto-Anatolian and Pre-LPIE) the event associated with the expansion of chiefs of R1b-M269 lineages, especially R1b-L23 subclades, and the general reduction in haplogroup variability, as is obviously seen later in Yamna.

B) If this haplogroup is found first in the Caucasus, and then in Maykop and Khvalynsk during and after their known contacts, though, instead of in Suvorovo-Novodanilovka chiefs, then the question may be settled as Reich recently proposed, and we may have to revise the language split (or, rather, the loss of contact between both MPIE dialects) to a slightly later date.

C) As a third, more complex alternative, if such haplogroup reduction actually happened slightly later – which is unlikely based on modern R1b-M269* and R1b-L23* haplogroup distribution – , say during the expansion of Khvalynsk and Repin as a Yamna community, then

C.1.) any lineage up to that point with steppe ancestry (including the R1b-V88 sample found in Varna, the same lineage apparently found in a likely early chief from Samara) could be the smoking gun of a potential Proto-Anatolian community spreading through the Balkans.

C.2) Alternatively, if it’s the Caucasus or Northern Iran the origin of Middle PIE formation, then any haplogroup or admixture from Maykop to Anatolia could represent Proto-Anatolians…

We just need more samples near the steppe in time and space to depict a clearer genetic image.

EDIT 28-29 APR 2018: Changes made to the text, including the possibility of a Maykop route.

Featured image: Distribution of burial sites of the Zhivotilovka type.

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Agricultural origins on the Anatolian plateau

anatolia-neolithic-agriculture

New paper (behind paywall) Agricultural origins on the Anatolian plateau, by Baird et al. PNAS (2018), published ahead of print (March 19).

Abstract (emphasis mine):

This paper explores the explanations for, and consequences of, the early appearance of food production outside the Fertile Crescent of Southwest Asia, where it originated in the 10th/9th millennia cal BC. We present evidence that cultivation appeared in Central Anatolia through adoption by indigenous foragers in the mid ninth millennium cal BC, but also demonstrate that uptake was not uniform, and that some communities chose to actively disregard cultivation. Adoption of cultivation was accompanied by experimentation with sheep/goat herding in a system of low-level food production that was integrated into foraging practices rather than used to replace them. Furthermore, rather than being a short-lived transitional state, low-level food production formed part of a subsistence strategy that lasted for several centuries, although its adoption had significant long-term social consequences for the adopting community at Boncuklu. Material continuities suggest that Boncuklu’s community was ancestral to that seen at the much larger settlement of Çatalhöyük East from 7100 cal BC, by which time a modest involvement with food production had been transformed into a major commitment to mixed farming, allowing the sustenance of a very large sedentary community. This evidence from Central Anatolia illustrates that polarized positions explaining the early spread of farming, opposing indigenous adoption to farmer colonization, are unsuited to understanding local sequences of subsistence and related social change. We go beyond identifying the mechanisms for the spread of farming by investigating the shorter- and longer-term implications of rejecting or adopting farming practices.

anatolia-neolithic
Map of central Anatolia showing the principal sites mentioned in the text.

Interesting excerpts:

The persistence of foraging and rejection of farming at Pınarbaşı is also worthy of further consideration. Pınarbaşı’s longevity as a settlement locale in the early Holocene appears to have been based on hunting of wild mammals, wetland exploitation, and significant focus on nut exploitation, all afforded by its ecotonal setting between the hills, plain, and wetland. Perhaps this existing diversity, including nutritious storable plant resources, was a key factor in a lack of interest in adopting cultivation. Another factor may have been a conscious desire to maintain traditional identities and long-standing distinctions with other communities, in part reflected in its particular way of life and its specific connections with particular elements in landscape, for example the almond and terebinth woodlands whose harvests underwrote the continuity of the Pınarbaşı settlement.

The variability in response to the possibilities of early food production in a relatively small geographical area demonstrated here is notable and provides an example useful in evaluating the spread of farming in other regions. It shows the possible role of indigenous foragers, the potential patchwork and diffuse nature of the spread of farming, the lack of homogeneity likely in the communities caught up in the process, the probability of significant continuities in local cultural traditions within the process, and the potentially long-term stable adaptation offered by lowlevel food production. The strength of identities linked to exploitation of particular foods and particular parts of the landscape may have been a major factor contributing to rejection or adoption of food production by indigenous foragers.

The results are also relevant for understanding the processes that underpinned the initial development of farming within the Fertile Crescent itself: that is, the region in which the wild progenitors of the Old World founder crops and stock animals are found. Recent research has rejected the notion of a core area for farming’s first appearance in southwest Asia and demonstrated that farming developed in diverse ways over the Fertile Crescent zone from the southern Levant to the Zagros, very analogous to the situation just described for Central Anatolia (2). Cultivation, herding, and domestication developed in that region, and it seems inescapable that exchange of crops and herded animals occurred between communities (2), involving a spread of farming within the Fertile Crescent, leading eventually to the Neolithic farming package that was so similar across the region and which spread into Europe (5). Central Anatolia was clearly linked to the Fertile Crescent, with significant evidence of exchange and some shared cultural traditions from at least the Epipaleolithic (22). The evidence presented here demonstrates very clearly the movement of crops between settlements and regions in early phases of the Neolithic through exchange, and thus allows us to identify episodes of crop exchange that were probably taking place within the Fertile Crescent itself, but are difficult, if not impossible, to distinguish due to the presence of crop progenitors across much of the region.

A very interesting read in combination with 14C-radiometric data and climatic conditions showing potential triggers of dispersal of Neolithic lifeways from Turkey to Southeast Europe, e.g. Dispersal of Neolithic Lifeways: Absolute Chronology and Rapid Climate Change in Central and West Anatolia, by Lee Clare & Bernhard Weninger, in The Neolithic in Turkey, Vol.6 (2014), Edited by Mehmet Özdogan, Nezih Basgelen, Peter Kuniholm.

anatolian-neolithic-aegean
The Late Neolithic (6600-6000 cal. BC) witnesses the rapid westward dispersal of Neolithic communities, apparently reaching the Aegean in the space of a very short time (ca. 6600 cal. BC). This process is linked to the demand of individuals, groups, and communities for less vulnerable conditions in the face of climate fluctuation associated with RCC. Coastal areas not only offered respite from more frequently occurring physical impacts (extreme winters and high drought risk) in inner Anatolia, they may also have provided refuge for weaker (more vulnerable) social groups (…).

Featured image, from the latter: “In the Early Pottery Neolithic (7000-6600 cal. BC) there occurs a clear break with precedeing (PPN) traditions, attested by abandonment and decreasing size of settlements, albeit that evidence for migration of groups westwards towards the Aegean is still ambiguous (black arrows: human migrations; white arrows: Anatolian obsidian)”

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