Sorry for the last weeks of silence, I have been rather busy lately. I am having more projects going on, and (because of that) I also wanted to finish a project I have been working on for many months already.
I have therefore decided to publish a provisional version of the text, in the hope that it will be useful in the following months, when I won’t be able to update it as often as I would like to:
Don’t forget to check out the maps included in the supplementary materials (I have added Y-DNA, mtDNA, and ADMIXTURE data using GIS software).
NOTE. Right now the files are only in my server. I will try to upload them to Academia.edu and Research Gate when I have time, in case the websites are too slow.
I would have preferred to wait for a thorough revision of the section on archaeology and the linguistic sections on Uralic, but I doubt I will have time when the reviews come, so it was either now or maybe next December…
I say so in the introduction, but it is evident that certain aspects of the book are tentative to say the least: the farther back we go from Late Proto-Indo-European, the less clear are many aspects. Also, linguistically I am not convinced about Eurasiatic or Nostratic, although they do have a certain interest when we try to offer a comprehensive view of the past, including ethnolinguistic identities.
I cannot be an expert in everything, and these books cover a lot. I am bound to publish many corrections as new information appears and more reviews are sent. For example, just days ago (before SNP calls of Wang et al. 2018 were published) some paragraphs implied that AME might have expanded Nostratic from the Middle East. Now it does not seem so, and I changed them just before uploading the text. That’s how tentative certain routes are, and how much all of this may change. And that only if we accept a Nostratic phylum…
NOTE. Since the first book I wrote was the linguistic one, and I have spent the last months updating the archaeology + genetics part, now many of you will probably understand 1) why I am so convinced about certain language relationships and 2) how I used many posts to clarify certain ideas and receive comments. Many posts offer probably a good timeline of what I worked with, and when.
I did not add this section to the books, because they are still not ready for print, but I think this is due somewhere now. It is impossible to reference all who have directly or indirectly contributed to this, so this is a list of those I feel have played an important role.
I am indebted to the following people (which does not mean that they share my views, obviously):
First and foremost, to Fernando López-Menchero, for having the patience to review with detail many parts on Indo-European linguistics, knowing that I won’t accept many of his comments anyway. The additional information he offers is invaluable, but I didn’t want to turn this into a huge linguistic encyclopaedia with unending discussions of tiny details of each reconstructed word. I think it is already too big as it is.
I would not have thought about doing this if it were not for the interest of Wekwos (Xavier Delamarre) in publishing a full book about the Indo-European demic diffusion model (in the second half of 2017, I think). It was them who suggested that I extended the content, when all I had done until then was write an essay and draw some maps in my free time between depositing the PhD thesis and defending it.
Sadly, as much as I would like to publish a book with a professional publisher, I don’t think ancient DNA lends itself for the traditional format, so my requests (mainly to have free licenses and being able to review the text at will, as new genetic papers are published) were logically not acceptable. Also, the main aim of all volumes, especially the linguistic one, is the teaching of essentials of Late Proto-Indo-European and related languages, and this objective would be thwarted by selling each volume for $50-70 and only in printed format. I prefer a wider distribution.
At first I didn’t think much of this proposal, because I do not benefit from this kind of publications in my scientific field, but with time my interest in writing a whole, comprehensive book on the subject grew to the point where it was already an ongoing project, probably by the start of 2018.
I would not have been in contact with Wekwos if it were not for user Camulogène Rix at Anthrogenica, so thanks for that and for the interest in this work.
I would not have thought of writing this either if not for the spontaneous support (with an unexpected phone call!) of a professor of the Complutense University of Madrid, Ángel Gómez Moreno, who is interested in this subject – as is his wife, a professor of Classics more closely associated to Indo-European studies, and who helped me with a search for Indo-Europeanists.
EDIT (1 JAN 2019): I remembered that Karin Bojs sent me her book after reading the demic diffusion model. I may have also thought about writing a whole book back then, but mid-2017 is probably too early for the project.
Professor Kortlandt is still to review the text, but he contributed to both previous essays in some very interesting ways, so I hope he can help me improve the parts on Uralic, and maybe alternative accounts of expansion for Balto-Slavic, depending on the time depth that he would consider warranted according to the Temematic hypothesis.
The maps are evidently (for those who are interested in genetics) in part the result of the effort of the late Jean Manco: As you can see from the maps including Y-DNA and mtDNA samples, I have benefitted from her way of organising data and publishing it. Similarly, the work of Iain McDonald in assessing the potential migration routes of R1b and R1a in Europe with the help of detailed maps was behind my idea for the first maps, and consequently behind these, too.
Readers of this blog with interesting comments have also been essential for the improvement of the texts. You can probably see some of your many contributions there. I may not answer many comments, because I am always busy (and sometimes I just don’t have anything interesting to say), but I try to read all of them.
Users of other sites, like Anthrogenica, whose particular points of view and deep knowledge of some very specific aspects are sometimes very useful. In particular, user Anglesqueville helped me to fix some issues with the merging of datasets to obtain the PCAs and ADMIXTURE, and prepared some individual samples to merge them.
Even without posting anything, Google Analytics keeps sending me messages about increasing user fidelity (returning users), and stats haven’t really changed (which probably means more people are reading old posts), so thank you for that.
We analyzed teeth from two individuals 63 recovered from Dzudzuana Cave, Southern Caucasus, from an archaeological layer previously dated to ~27-24kya (…). Both individuals had mitochondrial DNA sequences (U6 and N) that are consistent with deriving from lineages that are rare in the Caucasus or Europe today. The two individuals were genetically similar to each other, consistent with belonging to the same population and we thus analyze them jointly.
(…) our results prove that the European affinity of Neolithic Anatolians does not necessarily reflect any admixture into the Near East from Europe, as an Anatolian Neolithic-like population already existed in parts of the Near East by ~26kya. Furthermore, Dzudzuana shares more alleles with Villabruna-cluster groups than with other ESHG (Extended Data Fig. 5b), suggesting that this European affinity was specifically related to the Villabruna cluster, and indicating that the Villabruna affinity of PGNE populations from Anatolia and the Levant is not the result of a migration into the Near East from Europe. Rather, ancestry deeply related to the Villabruna cluster was present not only in Gravettian and Magdalenian-era Europeans but also in the populations of the Caucasus, by ~26kya. Neolithic Anatolians, while forming a clade with Dzudzuana with respect to ESHG, share more alleles with all other PGNE (Extended Data Fig. 5d), suggesting that PGNE share at least partially common descent to the exclusion of the much older samples from Dzudzuana.
Our co-modeling of Epipaleolithic Natufians and Ibero-Maurusians from Taforalt confirms that the Taforalt population was mixed, but instead of specifying gene flow from the ancestors of Natufians into the ancestors of Taforalt as originally reported, we infer gene flow in the reverse direction (into Natufians). The Neolithic population from Morocco, closely related to Taforalt is also consistent with being descended from the source of this gene flow, and appears to have no admixture from the Levantine Neolithic (Supplementary Information 166 section 3). If our model is correct, Epipaleolithic Natufians trace part of their ancestry to North Africa, consistent with morphological and archaeological studies that indicate a spread of morphological features and artifacts from North Africa into the Near East. Such a scenario would also explain the presence of Y-chromosome haplogroup E in the Natufians and Levantine farmers, a common link between the Levant and Africa.
(…) we cannot reject the hypothesis that Dzudzuana and the much later Neolithic Anatolians form a clade with respect to ESHG (P=0.286), consistent with the latter being a population largely descended from Dzudzuana-like pre-Neolithic populations whose geographical extent spanned both Anatolia and the Caucasus.Dzudzuana itself can be modeled as a 2-way mixture of Villabruna-related ancestry and a Basal Eurasian lineage.
In qpAdm modeling, a deeply divergent hunter-gatherer lineage that contributed in relatively unmixed form to the much later hunter-gatherers of the Villabruna cluster is specified as contributing to earlier hunter-gatherer groups (Gravettian Vestonice16: 35.7±11.3% and Magdalenian ElMiron: 60.6±11.3%) and to populations of the Caucasus (Dzudzuana: 199 72.5±3.7%, virtually identical to that inferred using ADMIXTUREGRAPH). In Europe, descendants of this lineage admixed with pre-existing hunter-gatherers related to Sunghir3 from Russia for the Gravettians and GoyetQ116-1 from Belgium for the Magdalenians, while in the Near East it did so with Basal Eurasians. Later Europeans prior to the arrival of agriculture were the product of re-settlement of this lineage after ~15kya in mainland Europe, while in eastern Europe they admixed with Siberian hunter-gatherers forming the WHG-ANE cline of ancestry [See PCA above]. In the Near East, the Dzudzuana-related population admixed with North African-related ancestry in the Levant and with Siberian hunter-gatherer and eastern non-African-related ancestry in Iran and the Caucasus. Thus, the highly differentiated populations at the dawn of the Neolithic were primarily descended from Villabruna Cluster and Dzudzuana-related ancestors, with varying degrees of additional input related to both North Africa and Ancient North/East Eurasia whose proximate sources may be clarified by future sampling of geographically and temporally intermediate populations.
Interesting excerpts from the supplementary materials:
From our analysis of Supplementary Information section 3, we showed that these sources are indeed complex, and only one of these (WHG, represented by Villabruna) appears to be a contributor to all the remaining sources. This should not be understood as showing that hunter-gatherers from mainland Europe migrated to the rest of West Eurasia, but rather that the fairly homogeneous post-15kya population of mainland Europe labeled WHG appear to represent a deep strain of ancestry that seems to have contributed to West Eurasians from the Gravettian era down to the Neolithic period.
Villabruna is representative of the WHG group. We also include ElMiron, the best sample from the Magdalenian era as we noticed that within the WHG group there were individuals that could not be modeled as a simple clade with Villabruna but also had some ElMiron-related ancestry. Ddudzuana is representative of the Ice Age Caucasus population, differentiated from Villabruna by Basal Eurasian ancestry. AG3 represents ANE/Upper Paleolithic Siberian ancestry, sampled from the vicinity of Lake Baikal, while Russia_Baikal_EN related to eastern Eurasians and represents a later layer of ancestry from the same region of Siberia as AG3 Finally, Mbuti are a deeply diverged African population that is used here to represent deep strains of ancestry (including Basal Eurasian) prior to the differentiation between West Eurasians and eastern non-Africans that are otherwise not accounted for by the remaining five sources. Collectively, we refer to this as ‘Basal’ or ‘Deep’ ancestry, which should be understood as referring potentially to both Basal Eurasian and African ancestry.
It has been suggested that there is an Anatolia Neolithic-related affinity in hunter-gatherers from the Iron Gates. Our analysis confirms this by showing that this population has Dzudzuana-related ancestry as do many hunter-gatherer populations from southeastern Europe, eastern Europe and Scandinavia. These populations cannot be modeled as a simple mixture of Villabruna and AG3 but require extra Dzudzuana-related ancestry even in the conservative estimates, with a positive admixture proportion inferred for several more in the speculative ones. Thus, the distinction between European hunter-gatherers and Near Eastern populations may have been gradual in pre-Neolithic times; samples from the Aegean (intermediate between those from the Balkans and Anatolia) may reveal how gradual the transition between Dzudzuana-like Neolithic Anatolians and mostly Villabruna-like hunter-gatherers was in southeastern Europe.
Villabruna: This type of ancestry differentiates between present-day Europeans and non-Europeans within West Eurasia, attaining a maximum of ~20% in the Baltic in accordance with previous observations and with the finding of a later persistence of significant hunter-gatherer ancestry in the region. Its proportion drops to ~0% throughout the Near East. Interestingly, a hint of such ancestry is also inferred in all North African populations west of Libya in the speculative proportions, consistent with an archaeogenetic inference of gene flow from Iberia to North Africa during the Late Neolithic.
ElMiron: This type of ancestry is absent in present-day West Eurasians. This may be because most of the Villabruna-related ancestry in Europeans traces to WHG populations that lacked it (since ElMiron-related ancestry is quite variable within European hunter-gatherers). However, ElMiron ancestry makes up only a minority component of all WHG populations sampled to date and WHG-related ancestry is a minority component of present-day Europeans. Thus, our failure to detect it in present day people may be simply be too little of it to detect with our methods.
Dzudzuana: Our analysis identifies Dzudzuana-related ancestry as the most important component of West Eurasians and the one that is found across West Eurasian-North African populations at ~46-88% levels. Thus, Dzudzuana-related ancestry can be viewed as the common core of the ancestry of West Eurasian-North African populations. Its distribution reaches its minima in northern Europe and appears to be complementary to that of Villabruna, being most strongly represented in North Africa, the Near East (including the Caucasus) and Mediterranean Europe. Our results here are expected from those of Supplementary Information section 3 in which we modeled ancient Near Eastern/North African populations (the principal ancestors of present-day people from the same regions) as deriving much of their ancestry from a Dzudzuana-related source. Migrations from the Near East/Caucasus associated with the spread of the Neolithic, but also the formation of steppe population introduced most of the Dzudzuana-related ancestry present in Europe, although (as we have seen above) some such ancestry was already present in some pre-agricultural hunter-gatherers in Europe.
AG3: Ancestry related to the AG3 sample from Siberia has a northern distribution, being strongly represented in both central-northern Europe and the north Caucasus.
Russia_Baikal_EN: Ancestry related to hunter-gatherers from Lake Baikal in Siberia (postdating AG3) appears to have affected primarily northeastern European populations which have been previously identified as having East Eurasian ancestry; some such ancestry is also identified for a Turkish population from Balıkesir, likely reflecting the Central Asian ancestry of Turkic speakers which has been recently confirmed directly in an Ottoman sample from Anatolia.
So, to try and sum up:
Dzudzuana shares ancestry with ‘Common West Eurasian’ (CWE). the ancestor cluster of Villabruna.
Dzudzuana diverges from CWE because of a Basal Eurasian ancestry contribution [which supports that Basal Eurasian ancestry was a deep Middle Eastern lineage].
Dzudzuana is closest to Anatolia Neolithic, and close to Gravettian.
Aurignacian: First West Eurasians arrive ca. 36,000 BP, Goyet cluster expands probably with C1a2 lineages.
After that, the early or ‘unmixed’ Villabruna cluster (‘hidden’ somewhere probably east of Europe, either North Eurasia or South Eurasia), lineages unknown (possibly IJ), contributes to:
Gravettian (ca. 30,000 BP): Věstonice cluster expands, probably with IJ lineages.
A (hidden) ‘Common West Eurasian’ population.
Dzudzuana ca. 26,000 BP derived from Common West Eurasian (curiously, haplogroup G seems to split in today’s subclades ca. 26,000 BP).
During the Gravettian (ca. 26,000 BP), an Anatolian Neolithic-like population exists already in the Near East. Both Věstonice and this Anatolian HG are close to Dzudzuana; in turn, Dzudzuana from CWE.
Magdalenian (ca. 20,000 BP): El Mirón cluster expands, probably with more specific I lineages.
Bølling-Allerød warming period (ca. 14,000 BP): ‘late’ Villabruna cluster or WHG (=CWE with greater affinity to Near Eastern populations) expands, probably spreading with R1b in mainland Europe and to the east (admixing with Siberian HG), creating the WHG — ANE ancestry cline, as reflected in Iron Gates HG, Baltic HG, etc.
[Here we have the possible “bidirectional gene flow between populations ancestral to Southeastern Europeans of the early Holocene and Anatolians of the late glacial or a dispersal of Southeastern Europeans into the Near East” inferred from Anatolian hunter-gatherers]
The paper talks about possibilities for Common West Eurasian:
Migration from mainland Europe to Near East or vice versa (not very likely);
Migration from a geographically intermediate Ice Age refugium in southeast Europe, Anatolia, or the circum-Pontic region that explain post-glacial affinity of post-glacial Levantine and Anatolian populations.
I would say that the distinct CHG vs. Dzudzuana ancestry puts CHG probably to the south, within the Iranian Plateau, during the Gravettian, expanding probably later.
Also important, Ancestral North African probably accompanied by haplogroup E. Early expansion of North Africans into the Near East further confirms the impossibility of Afroasiatic (much younger) to be associated with these expansions, and confirms that the still unclear Green Sahara migrations are the key.
Scythian population genetics and settlement patterns
Genetic continuity in the western Eurasian Steppe broken not due to Scythian dominance, but rather at the transition to the Chernyakhov culture (Ostrogoths), by Järve et al.
The long-held archaeological view sees the Early Iron Age nomadic Scythians expanding west from their Altai region homeland across the Eurasian Steppe until they reached the Ponto-Caspian region north of the Black and Caspian Seas by around 2,900 BP1. However, the migration theory has not found support from ancient DNA evidence, and it is still unclear how much of the Scythian dominance in the Eurasian Steppe was due to movements of people and how much reflected cultural diffusion and elite dominance. We present new whole-genome results of 31 ancient Western and Eastern Scythians as well as samples pre- and postdating them that allow us to set the Scythians in a temporal context by comparing the Western Scythians to samples before and after within the Ponto-Caspian region. We detect no significant contribution of the Scythians to the Early Iron Age Ponto-Caspian gene pool, inferring instead a genetic continuity in the western Eurasian Steppe that persisted from at least 4,800–4,400 cal BP to 2,700–2,100 cal BP (based on our radiocarbon dated samples), i.e. from the Yamnaya through the Scythian period.
However, the transition from the Scythian to the Chernyakhov culture between 2,100 and 1,700 cal BP does mark a shift in the Ponto-Caspian genetic landscape, with various analyses showing that Chernyakhov culture samples share more drift and derived alleles with Bronze/Iron Age and modern Europeans, while the Scythians position outside modern European variation. Our results agree well with the Ostrogothic origins of the Chernyakhov culture and support the hypothesis that the Scythian dominance was cultural rather than achieved through population replacement.
Detail of the slide with admixture of Scythian groups in Ukraine:
Interesting to read in combination with yesterday’s re-evaluation of Scythian mobility and settlement patterns in the west (showing adaptation to the different regional cultures), The Steppe was Sown – multi-isotopic research changes our understandings of Scythian diet and mobility, by Ventresca Miller et al.
Nomadic pastoralists conventionally known as the Scythians occupied the Pontic steppe during the Iron Age, c. 700-200 BC, a period of unprecedented pan-regional interaction. Popular science accounts of the Scythians promote narratives of roving bands of nomadic warriors traversing the steppe from the Altai Mountains to the Black Sea coastline. The quantity and scale of mobility in the region is usually emphasized based on the wide distribution of material culture and the characterization of Iron Age subsistence economies in the Pontic steppe and forest-steppe as mobile pastoralism. Yet, there remains a lack of systematic, direct analysis of the mobility of individuals and their animals. Here, we present a multi-isotopic analysis of humans from Iron Age Scythian sites in Ukraine. Mobility and dietary intake were documented through strontium, carbon and oxygen isotope analyses of tooth enamel. Our results provide direct evidence for mobility among populations in the steppe and forest-steppe zones, demonstrating a range of localized mobility strategies. However, we found that very few individuals came from outside of the broader vicinity of each site, often staying within a 90 km radius. Dietary intake varied at the intrasite level and was based in agro-pastoralism.
While terrestrial protein did form a portion of the diet for some individuals, there were also high levels of a 13C-enriched food source among many individuals, which has been interpreted as millet consumption. Individuals exhibiting 87Sr/86Sr ratios that fell outside the local range were more likely to have lower rates of millet consumption than those that fell within the local range. This suggests that individuals moving to the site later in life had different economic pursuits and consumed less millet. There is also strong evidence that children and infants moved at the pan-regional scale. Contrary to the popular narrative, the majority of Scythians engaged in localized mobility as part of agricultural lifeways while pan-regional movements included family groups.
Only small component of these pops highly mobile (in range of early childhood to adolescence), w/ interesting dietary composition correlates. Ongoing turn in Eurasian steppe archaeology towards seeing many of the iconically Scythian expressions of personal & warrior prestige…
North-Africans show ancestry from the ancient Near East and sub-Saharan Africa
Pleistocene North Africans show dual genetic ancestry from the ancient Near East and sub-Saharan Africa, by van de Loosdrecht et al.
North Africa, connecting sub-Saharan Africa and Eurasia, is important for understanding human history. However, the genetic history of modern humans in this region is largely unknown before the introduction of agriculture. After the Last Glacial Maximum modern humans, associated with the Iberomaurusian culture, inhabited a wide area spanning from Morocco to Libya. The Iberomaurusian is part of the early Later Stone Age and characterized by a distinct microlithic bladelet technology, complex hunter-gathering and tooth evulsion.
Here we present genomic data from seven individuals, directly dated to ~15,000-year-ago, from Grotte des Pigeons, Taforalt in Morocco. Uni-parental marker analyses show mitochondrial haplogroup U6a for six individuals and M1b for one individual, and Y-chromosome haplogroup E-M78 (E1b1b1a1) for males. We find a strong genetic affinity of the Taforalt individuals with ancient Near Easterners, best represented by ~12,000 year old Levantine Natufians, that made the transition from complex hunter-gathering to more sedentary food production. This suggests that genetic connections between Africa and the Near East predate the introduction of agriculture in North Africa by several millennia. Notably, we do not find evidence for gene flow from Paleolithic Europeans into the ~15,000 year old North Africans as previously suggested based on archaeological similarities. Finally, the Taforalt individuals derive one third of their ancestry from sub-Saharan Africans, best approximated by a mixture of genetic components preserved in present-day West Africans (Yoruba, Mende) and Africans from Tanzania (Hadza). In contrast, modern North Africans have a much smaller sub-Saharan African component with no apparent link to Hadza. Our results provide the earliest direct evidence for genetic interactions between modern humans across Africa and Eurasia.
Exploring the genomic impact of colonization in north-eastern Siberia by Seguin-Orlando et al.
Yakutia is the coldest region in the northern hemisphere, with winter record temperatures below minus 70°C. The ability of Yakut people to adapt both culturally and biologically to extremely cold temperatures has been key to their subsistence. They are believed to descend from an ancestral population, which left its original homeland in the Lake Baykal area following the Mongol expansion between the 13th and 15th centuries AD. They originally developed a semi-nomadic lifestyle, based on horse and cattle breeding, providing transportation, primary clothing material, meat, and milk. The early colonization by Russians in the first half of the 17th century AD, and their further expansion, have massively impacted indigenous populations. It led not only to massive epidemiological outbreaks, but also to an important dietary shift increasingly relying on carbohydrate-rich resources, and a profound lifestyle transition with the gradual conversion from Shamanism to Christianity and the establishment of new marriage customs. Leveraging an exceptional archaeological collection of more than a hundred of bodies excavated by MAFSO (Mission Archéologique Française en Sibérie Orientale) over the last 15 years and naturally kept frozen by the extreme cold temperatures of Yakutia, we have started to characterize the (epi)genome of indigenous individuals who lived from the 16th to the 20th century AD. Current data include the genome sequence of approximately 50 individuals that lived prior to and after Russian contact, at a coverage from 2 to 40 fold. Combined with data from archaeology and physical anthropology, as well as microbial DNA preserved in the specimens, our unique dataset is aimed at assessing the biological consequences of the social and biological changes undergone by the Yakut people following their neolithisation by Russian colons.
“Exploring the genomic impact of colonization in North-Eastern #Siberia” – Andaine Seguin-Orlando #ISBA8#aDNA with shotgun data from 110 #Yakut individuals over 4 regions and multiple archaeological phases of #Yakutia including 71 >1x coverage and 2 sequenced to high depth. pic.twitter.com/BGpecQPcGE
Interesting excerpts (emphasis mine, reference numbers deleted for clarity):
The material culture of the Late Chalcolithic period in the southern Levant contrasts qualitatively with that of earlier and later periods in the same region. The Late Chalcolithic in the Levant is characterized by increases in the density of settlements, introduction of sanctuaries, utilization of ossuaries in secondary burials, and expansion of public ritual practices as well as an efflorescence of symbolic motifs sculpted and painted on artifacts made of pottery, basalt, copper, and ivory. The period’s impressive metal artifacts, which reflect the first known use of the “lost wax” technique for casting of copper, attest to the extraordinary technical skill of the people of this period.
The distinctive cultural characteristics of the Late Chalcolithic period in the Levant (often related to the Ghassulian culture, although this term is not in practice applied to the Galilee region where this study is based) have few stylistic links to the earlier or later material cultures of the region, which has led to extensive debate about the origins of the people who made this material culture. One hypothesis is that the Chalcolithic culture in the region was spread in part by immigrants from the north (i.e., northern Mesopotamia), based on similarities in artistic designs. Others have suggested that the local populations of the Levant were entirely responsible for developing this culture, and that any similarities to material cultures to the north are due to borrowing of ideas and not to movements of people.
Previous genome-wide ancient DNA studies from the Near East have revealed that at the time when agriculture developed, populations from Anatolia, Iran, and the Levant were approximately as genetically differentiated from each other as present-day Europeans and East Asians are today. By the Bronze Age, however, expansion of different Near Eastern agriculturalist populations — Anatolian, Iranian, and Levantine — in all directions and admixture with each other substantially homogenized populations across the region, thereby contributing to the relatively low genetic differentiation that prevails today. Showed that the Levant Bronze Age population from the site of ‘Ain Ghazal, Jordan (2490–2300 BCE) could be fit statistically as a mixture of around 56% ancestry from a group related to Levantine Pre-Pottery Neolithic agriculturalists (represented by ancient DNA from Motza, Israel and ‘Ain Ghazal, Jordan; 8300–6700 BCE) and 44% related to populations of the Iranian Chalcolithic (Seh Gabi, Iran; 4680–3662 calBCE). Suggested that the Canaanite Levant Bronze Age population from the site of Sidon, Lebanon (~1700 BCE) could be modeled as a mixture of the same two groups albeit in different proportions (48% Levant Neolithic-related and 52% Iran Chalcolithic-related). However, the Neolithic and Bronze Age sites analyzed so far in the Levant are separated in time by more than three thousand years, making the study of samples that fill in this gap, such as those from Peqi’in, of critical importance.
This procedure produced genome-wide data from 22 ancient individuals from Peqi’in Cave (4500–3900 calBCE) (…)
We find that the individuals buried in Peqi’in Cave represent a relatively genetically homogenous population. This homogeneity is evident not only in the genome-wide analyses but also in the fact that most of the male individuals (nine out of ten) belong to the Y-chromosome haplogroup T, a lineage thought to have diversified in the Near East. This finding contrasts with both earlier (Neolithic and Epipaleolithic) Levantine populations, which were dominated by haplogroup E, and later Bronze Age individuals, all of whom belonged to haplogroup J.
Our finding that the Levant_ChL population can be well-modeled as a three-way admixture between Levant_N (57%), Anatolia_N (26%), and Iran_ChL (17%), while the Levant_BA_South can be modeled as a mixture of Levant_N (58%) and Iran_ChL (42%), but has little if any additional Anatolia_N-related ancestry, can only be explained by multiple episodes of population movement. The presence of Iran_ChL-related ancestry in both populations – but not in the earlier Levant_N – suggests a history of spread into the Levant of peoples related to Iranian agriculturalists, which must have occurred at least by the time of the Chalcolithic. The Anatolian_N component present in the Levant_ChL but not in the Levant_BA_South sample suggests that there was also a separate spread of Anatolian-related people into the region. The Levant_BA_South population may thus represent a remnant of a population that formed after an initial spread of Iran_ChL-related ancestry into the Levant that was not affected by the spread of an Anatolia_N-related population, or perhaps a reintroduction of a population without Anatolia_N-related ancestry to the region. We additionally find that the Levant_ChL population does not serve as a likely source of the Levantine-related ancestry in present-day East African populations.
These genetic results have striking correlates to material culture changes in the archaeological record. The archaeological finds at Peqi’in Cave share distinctive characteristics with other Chalcolithic sites, both to the north and south, including secondary burial in ossuaries with iconographic and geometric designs. It has been suggested that some Late Chalcolithic burial customs, artifacts and motifs may have had their origin in earlier Neolithic traditions in Anatolia and northern Mesopotamia. Some of the artistic expressions have been related to finds and ideas and to later religious concepts such as the gods Inanna and Dumuzi from these more northern regions. The knowledge and resources required to produce metallurgical artifacts in the Levant have also been hypothesized to come from the north.
Our finding of genetic discontinuity between the Chalcolithic and Early Bronze Age periods also resonates with aspects of the archeological record marked by dramatic changes in settlement patterns, large-scale abandonment of sites, many fewer items with symbolic meaning, and shifts in burial practices, including the disappearance of secondary burial in ossuaries. This supports the view that profound cultural upheaval, leading to the extinction of populations, was associated with the collapse of the Chalcolithic culture in this region.
I think the most interesting aspect of this paper is – as usual – the expansion of peoples associated with a single Y-DNA haplogroup. Given that the expansion of Semitic languages in the Middle East – like that of Anatolian languages from the north – must have happened after ca. 3100 BC, coinciding with the collapse of the Uruk period, these Chalcolithic north Levant peoples are probably not related to the posterior Semitic expansion in the region. This can be said to be supported by their lack of relationship with posterior Levantine migrations into Africa. The replacement of haplogroup E before the arrival of haplogroup J suggests still more clearly that Natufians and their main haplogroup were not related to the Afroasiatic expansions.
On the other hand, while their ancestry points to neighbouring regional origins, their haplogroup T1a1a (probably T1a1a1b2) may be closely related to that of other Semitic peoples to the south, as found in east Africa and Arabia. This may be due either to a northern migration of these Chalcolithic Levantine peoples from southern regions in the 5th millennium BC, or maybe to a posterior migration of Semitic peoples from the Levant to the south, coupled with the expansion of this haplogroup, but associated with a distinct population. As we know, ancestry can change within certain generations of intense admixture, while Y-DNA haplogroups are not commonly admixed in prehistoric population expansions.
Without more data from ancient DNA, it is difficult to say. Haplogroup T1a1 is found in Morocco (ca. 3780-3650 calBC), which could point to a recent expansion of a Berbero-Semitic branch; but also in a sample from Balkans Neolithic ca. 5800-5400 calBCE, which could suggest an Anatolian origin of the specific subclades encountered here. In any case, a potential origin of Proto-Semitic anywhere near this wide Near Eastern region ca. 4500-3500 BC cannot be discarded, knowing that their ancestors came probably from Africa.
Interesting from this paper is also that we are yet to find a single prehistoric population expansion not associated with a reduction of variability and expansion of Y-DNA haplogroups. It seems that the supposedly mixed Yamna community remains the only (hypothetical) example in history where expanding patrilineal clans will not share Y-DNA haplogroup…
The Sahara was wetter and greener during multiple interglacial periods of the Quaternary, when some have suggested it featured very large (mega) lakes, ranging in surface area from 30,000 to 350,000 km2. In this paper, we review the physical and biological evidence for these large lakes, especially during the African Humid Period (AHP) 11–5 ka. Megalake systems from around the world provide a checklist of diagnostic features, such as multiple well-defined shoreline benches, wave-rounded beach gravels where coarse material is present, landscape smoothing by lacustrine sediment, large-scale deltaic deposits, and in places, tufas encrusting shorelines. Our survey reveals no clear evidence of these features in the Sahara, except in the Chad basin. Hydrologic modeling of the proposed megalakes requires mean annual rainfall ≥1.2 m/yr and a northward displacement of tropical rainfall belts by ≥1000 km. Such a profound displacement is not supported by other paleo-climate proxies and comprehensive climate models, challenging the existence of megalakes in the Sahara. Rather than megalakes, isolated wetlands and small lakes are more consistent with the Sahelo-Sudanian paleoenvironment that prevailed in the Sahara during the AHP. A pale-green and discontinuously wet Sahara is the likelier context for human migrations out of Africa during the late Quaternary.
The whole review is an interesting read, but here are some relevant excerpts:
Various researchers have suggested that megalakes coevally covered portions of the Sahara during the AHP and previous periods, such as paleolakes Chad, Darfur, Fezzan, Ahnet-Mouydir, and Chotts (Fig. 2, Table 2). These proposed paleolakes range in size by an order of magnitude in surface area from the Caspian Sea–scale paleo-Lake Chad at 350,000 km2 to Lake Chotts at 30,000 km2. At their maximum, megalakes would have covered ~ 10% of the central and western Sahara, similar to the coverage by megalakes Victoria, Malawi, and Tanganyika in the equatorial tropics of the African Rift today. This observation alone should raise questions of the existence of megalakes in the Sahara, and especially if they developed coevally. Megalakes, because of their significant depth and area, generate large waves that become powerful modifiers of the land surface and leave conspicuous and extensive traces in the geologic record.
Lakes, megalakes, and wetlands
Active ground-water discharge systems abound in the Sahara today, although they were much more widespread in the AHP. They range from isolated springs and wet ground in many oases scattered across the Sahara (e.g., Haynes et al., 1989) to wetlands and small lakes (Kröpelin et al., 2008). Ground water feeding these systems is dominated by fossil AHP-age and older water (e.g., Edmunds and Wright 1979; Sonntag et al., 1980), although recently recharged water (<50 yr) has been locally identified in Saharan ground water (e.g., Sultan et al., 2000; Maduapuchi et al., 2006).
In our view, Lake Chad is the only former megalake in the Sahara firmly documented by sedimentologic and geomorphic evidence. Mega-Lake Chad is thought to have covered ~ 345,000 km2, stretching for nearly 8° (10–18°N) of latitude (Ghienne et al., 2002) (Fig. 2). The presence of paleo- Lake Chad was at one point challenged, but several—and in our view very robust—lines of evidence have been presented to support its development during the AHP. These include: (1) clear paleo-shorelines at various elevations, visible on the ground (Abafoni et al., 2014) and in radar and satellite images (Schuster et al., 2005; Drake and Bristow, 2006; Bouchette et al., 2010); (2) sand spits and shoreline berms (Thiemeyer, 2000; Abafoni et al., 2014); and (3) evaporites and aquatic fauna such as fresh-water mollusks and diatoms in basin deposits (e.g., Servant, 1973; Servant and Servant, 1983). Age determinations for all but the Holocene history of mega- Lake Chad are sparse, but there is evidence for Mio-Pliocene lake (s) (Lebatard et al., 2010) and major expansion of paleo- Lake Chad during the AHP (LeBlanc et al., 2006; Schuster et al., 2005; Abafoni et al., 2014; summarized in Armitage et al., 2015) up to the basin overflow level at ~ 329m asl.
Insights from hydrologic mass balance of megalakes
Using these conservative conditions (i.e., erring in the direction that will support megalake formation), our hydrologic models for the two biggest central Saharan megalakes (Darfur and Fezzan) require minimum annual average rainfall amounts of ~ 1.1 m/yr to balance moisture losses from their respective basins (Supplementary Table S1). Lake Chad required a similar amount (~1 m/yr; Supplementary Table S1) during the AHP according to our calculations, but this is plausible, because even today the southern third of the Chad basin receives ≥1.2 m/yr (Fig. 2) and experiences a climate similar to Lake Victoria. A modest 5° shift in the rainfall belt would bring this moist zone northward to cover a much larger portion of the Chad basin, which spans N13° ±7°. Estimated rainfall rates for Darfur and Fezzan are slightly less than the average of ~ 1.3 m/yr for the Lake Victoria basin, because of the lower aw values, that is, smaller areas of Saharan megalakes compared with their respective drainage basins (Fig. 15).
Estimates of paleo-rainfall during the AHP
Here major contradictions develop between the model outcomes and paleo-vegetation evidence, because our Sahelo-Sudanian hydrologic model predicts wetter conditions and therefore more tropical vegetation assemblages than found around Lake Victoria today. In fact, none of the very wet rainfall scenarios required by all our model runs can be reconciled with the relatively dry conditions implied by the fossil plant and animal evidence. In short, megalakes cannot be produced in Sahelo-Sudanian conditions past or present; to form, they require a tropical or subtropical setting, and major displacements of the African monsoon or extra-desert moisture sources.
If not megalakes, what size lakes, marshes, discharging springs, and flowing rivers in the Sahara were sustainable in Sahelo-Sudanian climatic conditions? For lakes and perennial rivers to be created and sustained, net rainfall in the basin has to exceed loss to evapotranspiration, evaporation, and infiltration, yielding runoff that then supplies a local lake or river. Our hydrologic models (see Supplementary Material) and empirical observations (Gash et al., 1991; Monteith, 1991) for the Sahel suggest that this limit is in the 200–300 mm/yr range, meaning that most of the Sahara during the AHP was probably too dry to support very large lakes or perennial rivers by means of local runoff. This does not preclude creation of local wetlands supplied by ground-water recharge focused from a very large recharge area or forced to the surface by hydrologic barriers such as faults, nor megalakes like Chad supplied by moisture from the subtropics and tropics outside the Sahel. But it does raise a key question concerning the size of paleolakes, if not megalakes, in the Sahara during the AHP. Our analysis suggests that Sahelo-Sudanian climate could perhaps support a paleolake approximately ≤5000 km2 in area in the Darfur basin and ≤10,000–20,000 km2 in the Fezzan basin. These are more than an order of magnitude smaller than the megalakes envisioned for these basins, but they are still sizable, and if enclosed in a single body of water, should have been large enough to generate clear shorelines (Enzel et al., 2015, 2017). On the other hand, if surface water was dispersed across a series of shallow and extensive but partly disconnected wetlands, as also implied by previous research (e.g., Pachur and Hoelzmann, 1991), then shorelines may not have developed.
One of the underdeveloped ideas of my Indo-European demic diffusion model was that R1b-V88 had migrated through South Italy to Northern Africa, and from it using the Sahara Green Corridor to the south, from where the “upside-down” view of Bender (2007) could have occurred, i.e. Afroasiatic expanding westwards within the Green Sahara, precisely at this time, and from a homeland near the Megalake Chad region (see here).
Whether or not R1b-V88 brought the ‘original’ lineage that expanded Afroasiatic languages may be contended, but after D’Atanasio et al. (2018) it seems that only two lineages, E-M2 and R1b-V88, fit the ‘star-like’ structure suggesting an appropriate haplogroup expansion and necessary regional distribution that could explain the spread of Afroasiatic languages within a reasonable time frame.
This review shows that the hypothesized Green Sahara corridor full of megalakes that some proposed had fully connected Africa from west to east was actually a strip of Sahelo-Sudanian steppe spread to the north of its current distribution, including the Chad megalake, East Africa and Arabia, apart from other discontinuous local wetlands further to the north in Africa. This greenish belt would have probably allowed for the initial spread of early Afroasiatic proto-languages only through the southern part of the current Sahara Desert. This and the R1b-V88 haplogroup distribution in Central and North Africa (with a prevalence among Chadic speakers probably due to later bottlenecks), and the Near East, leaves still fewer possibilities for an expansion of Afroasiatic from anywhere else.
If my proposal turns out to be correct, this Afroasiatic-like language would be the one suggested by some in the vocabulary of Old European and North European local groups (viz. Kroonen for the Agricultural Substrate Hypothesis), and not Anatolian farmer ancestry or haplogroup G2, which would have been rather confined to Southern Europe, mainly south of the Loess line, where incoming Middle East farmers encountered the main difficulties spreading agriculture and herding, and where they eventually admixed with local hunter-gatherers.
NOTE. If related to attested languages before the Roman expansion, Tyrsenian would be a good candidate for a descendant of the language of Anatolian farmers, given the more recent expansion of Anatolian ancestry to the Tuscan region (even if already influenced by Iran farmer ancestry), which reinforces its direct connection to the Aegean.
The fiercest opposition to this R1b-V88 – Afroasiatic connection may come from:
Traditional Hamito-Semitic scholars, who try to look for any parent language almost invariably in or around the Near East – the typical “here it was first attested, ergo here must be the origin, too”-assumption (coupled with the cradle of civilization memes) akin to the original reasons behind Anatolian or Out-of-India hypotheses; and of course
autochthonous continuity theories based on modern subclades, of (mainly Semitic) peoples of haplogroup E or J, who will root for either one or the other as the Afroasiatic source no matter what. As we have seen with the R1a – Indo-European hypothesis (see here for its history), this is never the right way to look at prehistoric migrations, though.
I proposed that it was R1a-M417 the lineage marking an expansion of Indo-Uralic from the east near Lake Baikal, then obviously connected to Yukaghir and Altaic languages marked by R1a-M17, and that haplogroup R could then be the source of a hypothetic Nostratic expansion (where R2 could mark the Dravidian expansion), with upper clades being maybe responsible for Borean.
However, recent studies have shown early expansions of R1b-297 to East Europe (Mathieson et al. 2017 & 2018), and of R1b-M73 to East Eurasia probably up to Siberia, and possibly reaching the Pacific (Jeong et al. 2018). Also, the Steppe Eneolithic and Caucasus Eneolithic clusters seen in Wang et al. (2018) would be able to explain the WHG – EHG – ANE ancestry cline seen in Mesolithic and Neolithic Eurasia without a need for westward migrations.
Dravidian is now after Narasimhan et al. (2018) and Damgaard et al. (Science 2018) more and more likely to be linked to the expansion of the Indus Valley civilization and haplogroup J, in turn strongly linked to Iranian farmer ancestry, thus giving support to an Elamo-Dravidian group stemming from Iran Neolithic.
NOTE. This Dravidian-IVC and Iran connection has been supported for years by knowledgeable bloggers and commenters alike, see e.g. one of Razib Khan’s posts on the subject. This rather early support for what is obvious today is probably behind the reactionary views by some nationalist Hindus, who probably saw in this a potential reason for a strengthened Indo-Aryan/Dravidian divide adding to the religious patchwork that is modern India.
I am not in a good position to judge Nostratic, and I don’t think Glottochronology, Swadesh lists, or any statistical methods applied to a bunch of words are of any use, here or anywhere. The work of pioneers like Illich-Svitych or Starostin, on the other hand, seem to me solid attempts to obtain a faithful reconstruction, if rather outdated today.
NOTE. I am still struggling to learn more about Uralic and Indo-Uralic; not because it is more difficult than Indo-European, but because – in comparison to PIE comparative grammar – material about them is scarce, and the few available sources are sometimes contradictory. My knowledge of Afroasiatic is limited to Semitic (Arabic and Akkadian), and the field is not much more developed here than for Uralic…
If one wanted to support a Nostratic proto-language, though, and not being able to take into account genome-wide autosomal admixture, the only haplogroup right now which can connect the expansion of all its branches is R1b-M343:
R1b-L278 expanded from Asia to Europe through the Iranian Plateau, since early subclades are found in Iran and the Caucasus region, thus supporting the separation of Elamo-Dravidian and Kartvelian branches;
R1b-V88 expanding everywhere in Europe, and especially the branch expanding to the south into Africa, may be linked to the initial Afroasiatic expansion through the Pale-Green Sahara corridor (and even a hypothetic expansion with E-M2 subclades and/or from the Middle East would also leave open the influence of V88 and previous R1b subclades from the Middle East in the emergence of the language);
R1b-297 subclades expanding to the east may be linked to Eurasiatic, giving rise to both Indo-Uralic (M269) and Macro- or Micro-Altaic (M73) expansions.
This is shameless, simplistic speculation, of course, but not more than the Nostratic hypothesis, and it has the main advantage of offering ‘small and late’ language expansions relative to other proposals spanning thousands (or even tens of thousands) of years more of language separation. On the other hand, that would leave Borean out of the question, unless the initial expansion of R1b subclades happened from a community close to lake Baikal (and Mal’ta) that was also at the origin of the other supposedly related Borean branches, whether linked to haplogroup R or to any other…
NOTE. If Afroasiatic and Indo-Uralic (or Eurasiatic) are not genetically related, my previous simplistic model, R1b-Afroasiatic vs. R1a-Eurasiatic, may still be supported, with R1a-M17 potentially marking the latest meaningful westward population expansion from which EHG ancestry might have developed (see here). Without detailed works on Nostratic comparative grammar and dialectalization, and especially without a lot more Palaeolithic and Mesolithic samples, all this will remain highly speculative, like proposals of the 2000s about Y-DNA-haplogroup – language relationships.
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.
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.
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.
In order to improve the phylogeography of the male-specific genetic traces of Greek and Phoenician colonizations on the Northern coasts of the Mediterranean, we performed a geographically structured sampling of seven subclades of haplogroup J in Turkey, Greece and Italy. We resequenced 4.4 Mb of Y-chromosome in 58 subjects, obtaining 1079 high quality variants. We did not find a preferential coalescence of Turkish samples to ancestral nodes, contradicting the simplistic idea of a dispersal and radiation of Hg J as a whole from the Middle East. Upon calibration with an ancient Hg J chromosome, we confirmed that signs of Holocenic Hg J radiations are subtle and date mainly to the Bronze Age. We pinpointed seven variants which could potentially unveil star clusters of sequences, indicative of local expansions. By directly genotyping these variants in Hg J carriers and complementing with published resequenced chromosomes (893 subjects), we provide strong temporal and distributional evidence for markers of the Greek settlement of Magna Graecia (J2a-L397) and Phoenician migrations (rs760148062). Our work generated a minimal but robust list of evolutionarily stable markers to elucidate the demographic dynamics and spatial domains of male-mediated movements across and around the Mediterranean, in the last 6,000 years.
Two features of our tree are at odds with the simplistic idea of a dispersal of Hg J as a whole from the Middle East towards Greece and Italy and an accompanying radiation26. First, there is little evidence of sudden diversification between 15 and 5 kya, a period of likely population increase and pressure for range expansion, due to the Agricultural revolution in the Fertile Crescent. Second, within each subclade, lineages currently sampled in Turkey do not show up as preferentially ancestral. Both findings are replicated and reinforced by examining the previous landmark studies. Our Turkish samples do not coalesce preferentially to ancestral nodes when mapped onto these studies’ trees.
Additional relevant information on the entire Hg J comes from the discontinuous distribution of J2b-M12. The northern fringe of our sample is enriched in the J2b-M241 subclade, which reappears in the gulf of Bengal38,45, with low frequencies in the intervening Iraq46 and Iran47. No J2b-M12 carriers were found among 35 modern Lebanese, as contrasted to one of two ancient specimens from the same region35.
In summary, a first conclusion of our sequencing effort and merge with available data is that the phylogeography of Hg J is complex and hardly explained by the presence of a single population harbouring the major lineages at the onset of agriculture and spreading westward. A unifying explanation for all the above inconsistencies could be a centre of initial radiation outside the area here sampled more densely, i.e. the Caucasus and regions North of it, from which different Hg J subclades may have later reached mainland Italy, Greece and Turkey, possibly following different routes and times. Evidence in this direction comes from the distribution of J2a-M41045,48 and the early-49 or mid-Holocene50 southward spread of J1.
The lineage defined by rs779180992, belonging to J2b-M205, and dated at 4–4.5 kya, has a radically different distribution, with derived alleles in Continental Italy, Greece and Northern Turkey, and two instances in a Palestinian and a Jew. The interpretation of the spread of this lineage is not straightforward. Tentative hypotheses are linked to Southward movements that occurred in the Balkan Peninsula from the Bronze Age29,53, through the Roman occupation and later54.
The slightly older (5.6–6.3 kya) branch 98 lineage displays a similar trend of a Eastward positioning of derived alleles, with the notable difference of being present in Sardinia, Crete, Cyprus and Northern Egypt. This feature and the low frequency of the parental J2a-M92 lineage in the Balkans27 calls for an explanation different from the above.
Finally, we explored the distribution of J2a-L397 and three derived lineages within it. J2a-L397 is tightly associated with a typical DYS445 6-repeat allele. This has been hypothesized as a marker of the Greek colonizations in the Mediterranean55, based on its presence in Greek Anatolia and Provence (France), a region with attested Iron Age Greek contribution. All of our chromosomes in this clade were characterized also by DYS391(9), confirming their Anatolian Greek signature. We resolved the J2a-L397 clade to an unprecedented precision, with three internal markers which allow a finer discrimination than STRs. The ages of the three lineages (2.0–3.0 kya) are compatible with the beginning of the Greek colonial period, in the 8th century BCE. The three subclades have different distributions (Fig. 2B), with two (branches 57, 59) found both East and West to Greece, and one only in Italy (branch 58). As to Mediterranean Islands, J2a-L397 was found in Cyprus56 and Crete43. Its presence as one of the three branches 57–59 will represent an important test. In Italy all three variants were found mainly along the Western coast (18/25), which hosted the preferred Greek trade cities. The finding of all three differentiated lineages in Locri excludes a local founder effect of a single genealogy. Interestingly, an important Greek colony was established in this location, with continuity of human settlement until modern times. The sample composed of the same subjects displayed genetic affinities with Eastern Greece and the Aegean also at autosomal markers57. In summary, the distributions of branches 57–59 mirror the variety of the cities of origin and geographic ranges during the phases of the colonization process58.
So, there you have it, another proof that haplogroup J and CHG-related ancestry in the Mediterranean was mainly driven by different (and late) expansions of historic peoples.
In the last three decades, genetic studies have played an increasingly important role in exploring human history. They have helped to conclusively establish that anatomically modern humans first appeared in Africa roughly 250,000–350,000 years before present and subsequently migrated to other parts of the world. The history of humans in Africa is complex and includes demographic events that influenced patterns of genetic variation across the continent. Through genetic studies, it has become evident that deep African population history is captured by relationships among African hunter–gatherers, as the world’s deepest population divergences occur among these groups, and that the deepest population divergence dates to 300,000 years before present. However, the spread of pastoralism and agriculture in the last few thousand years has shaped the geographic distribution of present-day Africans and their genetic diversity. With today’s sequencing technologies, we can obtain full genome sequences from diverse sets of extant and prehistoric Africans. The coming years will contribute exciting new insights toward deciphering human evolutionary history in Africa.
Regarding potential Afroasiatic origins and expansions:
It is currently believed that farming practices in northeastern and eastern Africa developed independently in the Sahara/Sahel (around 7,000 BP) and the Ethiopian highlands (7,000–4,000 BP), while farming in the Nile River Valley developed as a consequence of the Neolithic Revolution in the Middle East (84). Northeastern and eastern African farmers today speak languages from the Afro-Asiatic and Nilo-Saharan linguistic groups, which is also reflected in their genetic affinities (Figure 3, K=6). In the northern parts of East Africa (South Sudan, Somalia, and Ethiopia), Nilo-Saharan and Afro-Asiatic speakers with farming lifeways have completely replaced hunter–gatherers. It is still largely unclear how farming and herding practices influenced the northeastern African prefarming population structure and whether the spread of farming is better explained by demic or cultural diffusion in this part of the world. Genetic studies of contemporary populations and aDNA have started to provide some insights into population continuity and incoming gene flow in this region of Africa.
For example, studies have shown that a back-migration from Eurasia into Africa affected most of northeastern and eastern Africa (36, 46, 53, 89, 132) (Figure 1b). A genetic baseline of eastern African ancestral genetic variation unaffected by recent Eurasian admixture and farming migrations within the last 4,500 years has been suggested in the form of the genome sequence of a 4,500-year-old individual from Mota, Ethiopia (36). Based on comparisons with the ancient Mota genome, we know that certain populations from northeastern Africa show deep continuity in their local area with very limited gene flow resulting from recent population movements. For example, the Nilotic herder populations from South Sudan (e.g., Dinka, Nuer, and Shilluk) appear to have remained relatively isolated over time and received little to no gene flow from Eurasians, West African Bantu-speaking farmers, and other surrounding groups (53) (Figures 2 and 3). By contrast, the Nubian and Arab populations to their north show gene flow with Eurasians, which has been connected to the Arab expansion (53). The Nubian, Arab, and Beja populations of northeastern Africa roughly display equal admixture fractions from a local northeastern African gene pool (similar to the Nilotic component) and an incoming Eurasian migrant component (53) (Figure 3). The Eurasian component has been linked to the Middle East and the Arab migration, but only the Arab groups shifted to the Semitic languages; the Nubians and Beja groups kept their original languages. The Eurasian gene flow appears to have spread from north to south along the Nile and Blue Nile in a succession of admixture events (53).