Sea Peoples behind Philistines were Aegeans, including R1b-M269 lineages

New open access paper Ancient DNA sheds light on the genetic origins of early Iron Age Philistines, by Feldman et al. Science Advances (2019) 5(7):eaax0061.

Interesting excerpts (modified for clarity, emphasis mine):

Here, we report genome-wide data from human remains excavated at the ancient seaport of Ashkelon, forming a genetic time series encompassing the Bronze to Iron Age transition. We find that all three Ashkelon populations derive most of their ancestry from the local Levantine gene pool. The early Iron Age population was distinct in its high genetic affinity to European-derived populations and in the high variation of that affinity, suggesting that a gene flow from a European-related gene pool entered Ashkelon either at the end of the Bronze Age or at the beginning of the Iron Age. Of the available contemporaneous populations, we model the southern European gene pool as the best proxy for this incoming gene flow. Last, we observe that the excess European affinity of the early Iron Age individuals does not persist in the later Iron Age population, suggesting that it had a limited genetic impact on the long-term population structure of the people in Ashkelon.

philistines-pca
Ancient genomes (marked with color-filled symbols) projected onto the principal components inferred from present-day west Eurasians (gray circles). The newly reported Ashkelon populations are annotated in the upper corner.

Genetic discontinuity between the Bronze Age and the early Iron Age people of Ashkelon

In comparison to ASH_LBA, the four ASH_IA1 individuals from the following Iron Age I period are, on average, shifted along PC1 toward the European cline and are more spread out along PC1, overlapping with ASH_LBA on one extreme and with the Greek Late Bronze Age “S_Greece_LBA” on the other. Similarly, genetic clustering assigns ASH_IA1 with an average of 14% contribution from a cluster maximized in the Mesolithic European hunter-gatherers labeled “WHG” (shown in blue in Fig. 2B) (15, 22, 26). This component is inferred only in small proportions in earlier Bronze Age Levantine populations (2 to 9%).

In agreement with the PCA and ADMIXTURE results, only European hunter-gatherers (including WHG) and populations sharing a history of genetic admixture with European hunter-gatherers (e.g., as European Neolithic and post-Neolithic populations) produced significantly positive f4-statistics (Z ≥ 3), suggesting that, compared to ASH_LBA, ASH_IA1 has additional European-related ancestry.

We find that the PC1 coordinates positively correlate with the proportion of WHG ancestry modeled in the Ashkelon individuals, suggesting that WHG reasonably tag a European-related ancestral component within the ASH_IA1 individuals.

philistines-admixture
We plot the ancestral proportions of the Ashkelon individuals inferred by qpAdm using Iran_ChL, Levant_ChL, and WHG as sources ±1 SEs. P values are annotated under each model. In cases when the three-way model failed (χ2P < 0.05), we plot the fitting two-way model. The WHG ancestry is necessary only in ASH_IA1.

The best supported one (χ2P = 0.675) infers that ASH_IA1 derives around 43% of ancestry from the Greek Bronze Age “Crete_Odigitria_BA” (43.1 ± 19.2%) and the rest from the ASH_LBA population.

(…) only the models including “Sardinian,” “Crete_Odigitria_BA,” or “Iberia_BA” as the candidate population provided a good fit (χ2P = 0.715, 49.3 ± 8.5%; χ2P = 0.972, 38.0 ± 22.0%; and χ2P = 0.964, 25.8 ± 9.3%, respectively). We note that, because of geographical and temporal sampling gaps, populations that potentially contributed the “European-related” admixture in ASH_IA1 could be missing from the dataset.

The transient impact of the “European-related” gene flow on the Ashkelon gene pool

The ASH_IA2 individuals are intermediate along PC1 between the ASH_LBA ones and the earlier Bronze Age Levantines (Jordan_EBA/Lebanon_MBA) in the west Eurasian PCA (Fig. 2A). Notably, despite being chronologically closer to ASH_IA1, the ASH_IA2 individuals position closer, on average, to the earlier Bronze Age individuals.

philistines-y-dna
See more information on Y-DNA SNP calls, including ASH067 as R1b-M269 (xL151).

The transient excess of European-related genetic affinity in ASH_IA1 can be explained by two scenarios. The early Iron Age European-related genetic component could have been diluted by either the local Ashkelon population to the undetectable level at the time of the later Iron Age individuals or by a gene flow from a population outside of Ashkelon introduced during the final stages of the early Iron Age or the beginning of the later Iron Age.

By modeling ASH_IA2 as a mixture of ASH_IA1 and earlier Bronze Age Levantines/Late Period Egyptian, we infer a range of 7 to 38% of contribution from ASH_IA1, although no contribution cannot be rejected because of the limited resolution to differentiate between Bronze Age and early Iron Age ancestries in this model.

Hg. R1b-M269 and the Aegean

I already predicted this relationship of Philistines and Aegeans (Greeks in particular) months ago, based on linguistics, archaeology, and phylogeography, although it was (and still is) yet unclear if these paternal lineages might have come from other nearby populations which might be descended from Common Anatolians instead, given the known intense contacts between Helladic and West Anatolian groups.

luwian-civilization-sea-peoples
The alternative view: The Sea Peoples can be traced back to the Aegean, so they could also have consisted of Luwian petty kingdoms, who had formed an alliance and attacked Hatti from the south.

The deduction process for the Greek connection was quite simple:

Palaeo-Balkan populations

We know that R1b-Z2103 expanded with Yamna, including West Yamna settlers: they appear in Vučedol, which means they formed part of the earliest expansion waves of Yamna settlers into the Carpathian Basin, and they also appear scattered among Bell Beakers (apart from dominating East Yamna and Afanasevo), which suggests that they were possibly one of the most successful lineages during the late Repin/early Yamna expansion.

The “Steppe ancestry” associated with I2a-L699 samples among Balkan BA peoples may have also been associated with recent Bronze Age expansions, and this haplogroup’s presence among modern Balkan peoples may also suggest that it expanded with Palaeo-Balkan languages. Nevertheless, we don’t know which specific lineages and “Steppe ancestry” they represent, sadly.

These samples may well be related to remnants of previous Balkan populations like Cernavodă or Ezero, because there has been no peer-reviewed attempt at distinguishing Khvalynsk-/Novodanilovka- from Sredni Stog- from Yamnaya-related populations (see here), and some groups that are associated with this ancestry, like Corded Ware, are known to be culturally distinct from Yamna.

In any case, Proto-Greeks from the southern Balkans (say, Sitagroi IV and related groups) are probably going to show, based on Palaeo-Balkan substrate and Pre-Greek substrate and on the available Mycenaean samples, a process of decreasing proportion of R1b-Z2103 lineages relative to local ones, and a relatively similar cline of Yamna:EEF ancestry from northern to southern areas, at least in the periods closest to the Yamna expansion.

NOTE. The finding of “archaic” R1b-L389 (R1b-V1636) and R1a-M198 subclades among modern Greeks and the likely Neolithic origin of these paternal lineages around the Caucasus suggest that their presence in Greece may be from any of the more recent migrations that have happened between Anatolia and the Balkans, especially during the Common Era, rather than Indo-Anatolian migrations; probably very very recently.

-chalcolithic-late-balkans
Bronze Age cultures in the Balkans and the Aegean. See full map including ancient samples with Y-DNA, mtDNA, and ADMIXTURE.

Minoans and haplogroup J

In the Aegean, it is already evident that the population changed language partly through cultural diffusion, probably through elite domination of Proto-Greek speakers. Whether that happened before the invasion into the Greek Peninsula or after it is unclear, as we discussed recently, because we only have one reported Y-chromosome haplogroup among Mycenaeans, and it is J (probably continuing earlier lineages).

Now we have more samples from the so-called Emporion 2 cluster in Olalde et al. (2019), which shows Mycenaean-like eastern Mediterranean ancestry and 3 (out of 3) samples of haplogroup J, which – given the origin of the colony in Phocea – may be interpreted as the prevalence of West Anatolian-like ancestry and lineages in the eastern part of the Aegean (and possibly thus south Peloponnese), in line with the modern situation.

NOTE. It does not seem likely that those R or R1b-L23 samples from the Emporion 1 cluster are R1b-Z2103, based on their West European-like ancestry, although they still may be, because – as we know – ancestry (unlike haplogroup) changes too easily to interpret it as an ancestral ethnolinguistic marker.

anatolia-greek-aegean
PCA of ancient samples related to the Aegean, with Minoans, Mycenaeans (including the Emporion 2 cluster in the background) Anatolia N-Ch.-BA and Levantine BA-LBA populations, including Tel Shadud samples. See more PCAs of ancient Eurasian populations.

Greeks and haplogroup R1b-M269

Therefore, while the presence of R1b-Z2103 among ancient Balkan peoples connected to the Yamna expansion is clear, one might ask if R1b-Z2103 really spread up to the Peloponnese by the time of the Mycenaean Civilization. That has only one indirect answer, and it’s most likely yes.

We already had some R1b-Z2103 among Thracians and around the Armenoid homeland, which offers another clue at the migration of these lineages from the Balkans. The distribution of different “archaic” R1b-Z2103 subclades among modern Balkan populations and around the Aegean offered more support to this conclusion.

But now we have two interesting ancient populations that bear witness to the likely intrusion of R1b-M269 with Proto-Greeks:

An Ancient Greek of hg. R1b

A single ancient sample supports the increase in R1b-Z2103 among Greeks during the “Dorian” invasions that triggered the Dark Ages and the phenomenon of the Aegean Sea Peoples. It comes from a Greek lab study, showing R1b1b (i.e. R1b-P297 in the old nomenclature) as the only Y-chromosome haplogroup obtained from the sampling of the Gulf of Amurakia ca. 470-30 BC, i.e. before the Roman foundation of Nikopolis, hence from people likely from Anaktorion in Ancient Acarnania, of Corinthian origin.

ancient-greeks-y-dna-mtdna

Even with the few data available – and with the caution necessary for this kind of studies from non-established labs, which may be subject to many different kinds of errors – one could argue that the western Greek areas, which received different waves of migrants from the north and shows a higher distribution of R1b-Z2103 in modern times, was probably more heavily admixed with R1b-Z2103 than southern and eastern areas, which were always dominated by Greek-speaking populations more heavily admixed with locals.

The Dorian invasion and the Greek Dark Ages may thus account for a renewed influx of R1b-Z2103 lineages accompanying the dialects that would eventually help form the Hellenic Koiné. In a sense, it is only natural that demographically stronger populations around the Bronze Age Aegean would suffer a limited (male) population replacement with the succeeding invasions, starting with a higher genetic impact in the north-west and diminishing as they progressed to the south and the east, coupled with stepped admixture events with local populations.

This would be therefore the late equivalent of what happened at the end of the 3rd millennium BC, with Mycenaeans and their genetic continuity with Minoans.

pre-greek-ssos
Distribution of Pre-Greek place-names ending in -ssos/-ssa or -sos/-sa. See original images and more on the south/east cline distribution of Pre-Greek place-names here.

Sea peoples of hg. R1b-M269

Thanks to Wang et al. (2018) supplementary materials we knew that one of the two Levantine LBA II samples from Tel Shadud (final 13th–early 11th c. BC) published in van den Brink (2017) was of hg. R1b-M269 – in fact, the one interpreted as a Canaanite official residing at this site and emulating selected funerary aspects of Egyptian mortuary culture.

Both analyzed samples, this elite individual and a commoner of hg. J buried nearby, were genetically similar and indistinguishable from local populations, though:

Principal Components Analysis of L112 and L126 was carried out within the framework described in Lazaridis et al. (2016). This analysis showed that the two individuals cluster genetically, with similar estimated proportions of ancestry from diverse West Eurasian ancestral sources. These results are consistent with the hypothesis that they derive from the same population, or alternatively that they derive from two quite closely related populations.

We know that ancestry changes easily within a few generations, so there was not much information to go on, except for the fact that – being R1b-M269 – this individual could trace his paternal ancestor at some point to Proto-Indo-Europeans.

One might think that, because many haplogroups in this spreadsheet were wrong, this is also wrong; nevertheless, many haplogroups are correctly identified by Yleaf, and finding R1b-M269 in the Levant after the expansion of Sea Peoples could not be that surprising, because they were most likely related to populations of the Aegean Sea. Any other related hg. R1b (R1b-M73, R1b-V88, even R1b-V1636) wouldn’t fit as well as R1b-M269.

sea-peoples-egypt-rameses-iii

However, the early expansion of Proto-Indo-Aryans into the Middle East, as well as the later expansion of Armenians from the Balkans through Anatolia and of West Iranians from the east may have all potentially been related to this sample. But still, the previous linguistic and archaeological theories concerning the Philistines and the expansion of Sea Peoples in the Levant made this sample a likely (originally) Greek “Dorian” lineage, rather than the other (increasingly speculative) alternatives.

In any case, it was obvious to anyone – that is, to anyone with a minimum knowledge of how population genomics works – that just the two samples from van den Brink (2017) couldn’t be used to get to any conclusions about the ancestral origin of these individuals (or their differences) beyond Levantine peoples, because their ancestry was essentially (i.e. statistically) the same as the other few available ancient samples from nearby regions and similar periods.

If anything, the PCA suggested an origin of the R1b sample closer to Aegean populations relative to the J individual (see PCA above), and this should have been supported also by amateur models, without any possible confirmation (as with the ASH_IA2 cluster in this paper). However, if you have followed online discussions of Tel Shadud R1b-M269 sample since it was mentioned first on Eupedia months ago – including another wave of misguided speculation based on the ancestry of both individuals triggered by a discussion on this blog -, you have once more proof of how misleading ancestry analyses can be in the wrong hands.

NOTE. This is the Nth proof (and that only in 2019) of how it’s best to just avoid amateur analyses and interpretations altogether, as I did in the recent publication of the books. All those who didn’t take into account whatever was commented about the ancestry of these samples haven’t lost a single bit of relevant information on Levantine peoples, and have had more time for useful reads, compared to those dedicated to endless void speculation, once again gone awfully wrong, as does everything related to cocky ancient DNA crackpottery 😉

bronze-age-late-aegean
Late Bronze Age population movements in the Eastern Mediterranean and the Middle East. See full map including ancient DNA samples with Y-DNA, mtDNA, and ADMIXTURE.

Admittedly, though, even accepting the evident Mediterranean origin of this lineage, one could have argued that this sample may have been of R1b-L151 subclade, if one were inclined to support the theory that Italic peoples were behind Sea Peoples expanding east – and consequently that the ancestors of Etruscans had migrated eastward into the Aegean (e.g. into Lemnos), so that it could be asserted that Tyrsenian might have been a remnant language of an ancient population of northern Italy.

Philistines

Fortunately, some of the samples recovered in Feldman et al. (2019) that could be analyzed (those of the cluster ASH_IA1) offer a very specific time frame where European ancestry appeared (ca. 1250 BC) before it subsequently became fully diluted (as seen in cluster ASH_IA2) among the prevalent Levantine ancestry of the area.

Also fortunately, this precise cluster shows another R1b-M269 sample, likely R1b-Z2103 (because it is probably xL151), and this sample together with others from the same cluster prove that the ancestry related to the original southern European incomers was:

  1. Recent, related thus to LBA population movements, as expected; and
  2. More closely related to coeval Aegeans, including Mycenaeans with Steppe-related ancestry.

NOTE. I say “fortunately” because, as you can imagine if you have dealt with amateurish discussions long enough, without this cluster with evident Aegean ancestry and the R1b-M269 (Z2103) sample precisely associated to it, some would enter again in endless comment loops created by ancestry magicians, showing how Aegean peoples were not behind Sea Peoples, or not behind Philistines, or not behind the R1b-M269 among Philistines, depending on their specific agendas.

aegean-sea-peoples
Map of the Sea People invasions in the Aegean Sea and Eastern Mediterranean at the end of the Late Bronze Age (blue arrows).. Some of the major cities impacted by the raids are denoted with historical dates. Inland invasions are represented by purple arrows. From Kaniewski et al. (2011). Some of the major cities impacted by the raids are denoted with historical dates. Inland invasions are represented by purple arrows.

The results of the paper don’t solve the question of the exact origin of all Sea Peoples (not even that of Philistines), but it is quite clear that most of those forming this seafaring confederation must have come from sites around the Aegean Sea. This supports thus the traditional origin attributed to them, including a hint at the likely expansion of Eastern Mediterranean ancestry and lineages into the Italian Peninsula precisely from the Aegean, as some oral communications have already disclosed.

As an indirect conclusion from the findings in this paper, then, we can now more confidently support that Tyrsenian speakers most likely expanded into the Appenines and the Alps originally from a Tyrsenian-speaking LBA population from Lemnos, due to the social unrest in the whole Aegean region, and might have become heavily admixed with local Italic peoples quite quickly, as it happened with Philistines, resulting in yet another case of language expansion through (the simplistically called) elite domination.

Conclusion

Even more interesting than these specific findings, this paper confirms yet another hypothesis based on phylogeography, and proves once again two important starting points for ancient DNA interpretation that I have discussed extensively in this blog:

  • The rare R1b-M269 Y-chromosome lineage of Tel Shadud offered ipso facto the most relevant clue about the ancestral geographical origin of this Canaanite elite male’s paternal family, most likely from the north-west based on ancient phylogeography, which indirectly – in combination with linguistics and archaeology – supported the ancestral ethnolinguistic identification of Philistines with the Aegean and thus with (a population closest to) Ancient Greeks.
  • Ancestry analyses are often fully unreliable when assessing population movements, especially when few samples from incomplete temporal-geographical transects are assessed in isolation, because – unlike paternal (and maternal) haplogroups – ancestry might change fully within a few generations, depending on the particular anthropological setting. Their investigation is thus bound by many limitations – of design, statistical, and anthropological (i.e. archaeological and linguistic) – which are quite often not taken into account.

These cornerstones of ancient DNA interpretation have been already demonstrated to be valid not only for Levantine populations, as in this case, but also for Balkan peoples, for Bell Beakers, for steppe populations (like Khvalynsk, Sredni Stog, Yamna, Corded Ware), for Basques, for Balto-Slavs, for Ugrians and Samoyeds, and for many other prehistoric peoples.

I rest my case.

Related

Genetic landscape and past admixture of modern Slovenians

slovenes-snp

Open access Genetic Landscape of Slovenians: Past Admixture and Natural Selection Pattern, by Maisano Delser et al. Front. Genet. (2018).

Interesting excerpts (emphasis mine):

Samples

Overall, 96 samples ranging from Slovenian littoral to Lower Styria were genotyped for 713,599 markers using the OmniExpress 24-V1 BeadChips (Figure 1), genetic data were obtained from Esko et al. (2013). After removing related individuals, 92 samples were left. The Slovenian dataset has been subsequently merged with the Human Origin dataset (Lazaridis et al., 2016) for a total of 2163 individuals.

Y chromosome

First, Y chromosome genetic diversity was assessed. A total of 52 Y chromosomes were analyzed for 195 SNPs. The majority of individuals (25, 48.1%) belong to the haplogroup R1a1a1a (R-M417) while the second major haplogroup is represented by R1b (R-M343) including 15 individuals (28.8%). Twelve samples are assigned to haplogroup I (I M170): five and two samples belong to haplogroup I2a (I L460) and I1 (I M253), respectively, while the remaining five samples did not have enough information to be further assigned.

pca-slovenes
PCA of Slovenian samples with European populations (Slovenian_HO_EU dataset). For details regarding the populations included, see Supplementary Table 1.

PCA

Considering the unbalanced sample size of the Slovenian population compared to the other populations included in the dataset, a subset of 20 Slovenian individuals randomly sampled was used.

All Slovenian samples group together with Hungarians, Czechs, and some Croatians (“Central-Eastern European” cluster) as also suggested by the PCA. All Basque individuals with few French and Spanish cluster together (“Basque” cluster) while a “Northern-European” cluster is made of the majority of French, English, Icelanders, Norwegians, and Orcadians. Five populations contributed to the “Eastern-European” cluster including Belarusians, Estonians, Lithuanians, Mordovians, and Russians. Western and South Europe is split into two cluster: the first (“Western European” cluster) includes all Spanish individuals, few French, and some Italians (North Italy) while the second (“Southern-European” cluster) groups Sicilians, Greeks, some Croatians, Romanians, and some Italians (North Italy).

Admixture Pattern and Migration

admixture-slovenians
Modified image, from the paper (Central-East Europeans marked). Unsupervised admixture analysis of Slovenians. Results for K = 5 are showed as it represents the lowest cross-validation error. Slovenian samples show an admixture pattern similar to the neighboring populations such as Croatians and Hungarians. The major ancestral components are: the blue one which is shared with Lithuanians and Russians, followed by the dark green one that is mostly present in Greek samples and the light blue which characterizes Orcadians and English. For population acronyms see Supplementary Table 1.

All Slovenian individuals share common pattern of genetic ancestry, as revealed by ADMIXTURE analysis. The three major ancestry components are the North East and North West European ones (light blue and dark blue, respectively, Figure 3), followed by a South European one (dark green, Figure 3). Contribution from the Sardinians and Basque are present in negligible amount. The admixture pattern of Slovenians mimics the one suggested by the neighboring Eastern European populations, but it is different from the pattern suggested by North Italian populations even though they are geographically close.

Using ALDER, the most significant admixture event was obtained with Russians and Sardinians as source populations and it happened 135 ± 9.31 generations ago (Z-score = 11.54). (…) When tested for multiple admixture events (MALDER), we obtained evidence for one admixture event 165.391 ± 17.1918 generations ago corresponding to ∼2620 BCE (CI: 3101–2139) considering a generation time of 28 years (Figure 4), with Kalmyk and Sardinians as sources.

We then modeled the Slovenian population as target of admixture of ancient individuals from Haak et al. (2015) while computing the f3(Ancient 1, Ancient 2, Slovenian) statistic. The most significant signal was obtained with Yamnaya and HungaryGamba_EN (Z-score = -10.66), followed by MA1 with LBK_EN (Z-score -9.7) and Yamnaya with Stuttgart (Z-score = -8.6) used as possible source populations (Supplementary Figure 5).

We found a significant signal of admixture by using both pairs as ancient sources. Specifically, for the pair Yamnaya and Hungary_EN the admixture event is dated at 134.38 ± 23.69 generations ago (Z-score = 5.26, p-value of 1.5e-07) while for Yamnaya and LBK_EN at 153.65 ± 22.19 generations ago (Z-score = 6.92, p-value 4.4e-12). Outgroup f3 with Yamnaya put Slovenian population close to Hungarians, Czechs, and English, indicating a similar shared drift between these population with the Steppe populations (Supplementary Figure 6).

admixture-events-slovenes
Admixture events identified with ALDER and MALDER. The gray dots represent significant admixture events detected with ALDER using Slovenians as target, the solid line represents the single admixture event detected using MALDER, dashed lines represent the confidence interval. Only the significant results after multiple testing correction are plotted. For ALDER results see Supplementary Table 5.

Not that any of this would come as a surprise, but:

  • R1a-M458 and some R1a-Z280 (xR1a-Z92) lineages (found among Slovenes) were associated with the Slavic expansion, likely with the Prague-Korchak culture, originally stemming probably from peoples of the Lusatian culture. Other R1a-Z280 lineages remained associated with Uralic peoples, and some became Slavicized only recently.
  • PCA keeps supporting the common cluster of certain West, South, and East Slavs in a “Central-Eastern European” cluster, distinct from the “North-Eastern European” cluster formed by modern Finno-Ugrians, as well as ancient Finno-Ugrians of north-eastern Europe who were only recently Slavicized.
  • Admixture supports the same ancient ‘western’ (a core West+South+East Slavic) cluster, and the admixture event with Yamna + Hungary_EN is logically a proxy for Yamna Hungary being at the core of ancestral Central-East population movements related to Bell Beakers in the mid- to late 3rd millennium.

The theory that East Slavs are at the core of the Slavic expansion makes no sense, in terms of archaeology (see Florin Curta’s dismissal of those recent eastern ‘Slavic’ finds, his commentary on 19th century Pan-Slavic crap, or his book on Slavic migrations), in terms of ancient DNA (the earliest Slavs sampled cluster with modern West Slavs, distant from the steppe cluster, unlike Finno-Ugrians), or in terms of modern DNA.

I don’t know where exactly this impulse for the theory of Russia being the cradle of Slavs comes from today (although there are some obvious political trends to revive 19th c. ideas), but it was always clear for everyone, including Russians, that East Slavs had migrated to the east and north and assimilated indigenous Finno-Ugrians, apart from Turkic-, Iranian-, and Caucasian-speaking peoples to the east. Genetics is only confirming what was clear from other disciplines long ago.

Related

Expansion of haplogroup G2a in Anatolia possibly associated with the Mature Aceramic period

anatolian-hunter-gatherer-sampling

Preprint Late Pleistocene human genome suggests a local origin for the first farmers of central Anatolia, by Feldman et al. bioRxiv (2018).

Interesting excerpts (emphasis mine):

Anatolian hunter-gatherers experienced climatic changes during the last glaciation and inhabited a region that connects Europe to the Near East. However, interactions between Anatolia and Southeastern Europe in the later Upper Palaeolithic/Epipalaeolithic are so far not well documented archaeologically. Interestingly, a previous genomic study showed that present-day Near-Easterners share more alleles with European hunter-gatherers younger than 14,000 BP (‘Later European HG’) than with earlier ones (‘Earlier European HG’). With ancient genomic data available, we could directly compare the Near-Eastern hunter-gatherers (AHG and Natufian) with the European ones. As is the case for present-day Near-Easterners, the Near-Eastern hunter-gatherers share more alleles with the Later European HG than with the Earlier European HG, shown by the significantly positive statistic D(Later European HG, Earlier European HG; AHG/Natufian, Mbuti). Among the Later European HG, recently reported Mesolithic hunter-gatherers from the Balkan peninsula, which geographically connects Anatolia and central Europe (‘Iron Gates HG’), are genetically closer to AHG when compared to all the other European hunter-gatherers, as shown in the significantly positive statistic D(Iron_Gates_HG, European hunter-gatherers; AHG, Mbuti/Altai). Iron Gates HG are followed by Epigravettian and Mesolithic individuals from Italy and France (Villabruna and Ranchot respectively) as the next two European hunter-gatherers genetically closest to AHG. Iron Gates HG have been suggested to be genetically intermediate between WHG and eastern European hunter-gatherers (EHG) with an additional unknown ancestral component.

anatolian-hunter-gatherer-pca
Ancient genomes (marked with color-filled symbols) projected onto the principal components 5 computed from present-day west Eurasians (grey circles) (fig. S4). The geographic location of each ancient group is marked in (A). Ancient individuals newly reported in this study are additionally marked with a black dot inside the symbol

We find that Iron Gates HG can be modeled as a three-way mixture of Near-Eastern hunter-gatherers (25.8 ± 5.0 % AHG or 11.1 ± 2.2 % Natufian), WHG (62.9 ± 7.4 % or 78.0 ± 4.6 % respectively) and EHG (11.3 ± 3.3 % or 10.9 ± 3 % respectively). The affinity detected by the above D-statistic can be explained by gene flow from Near-Eastern hunter-gatherers into the ancestors of Iron Gates or by a gene flow from a population ancestral to Iron Gates into the Near-Eastern hunter-gatherers as well as by a combination of both. To distinguish the direction of the gene flow, we examined the Basal Eurasian ancestry 5 component (α), which is prevalent in the Near East but undetectable in European hunter-gatherers. Following a published approach, we estimated α to be 24.8 ± 5.5 % in AHG and 38.5 ± 5.0 % in Natufians, consistent with previous estimates for the latter. Under the model of unidirectional gene flow from Anatolia to Europe, 6.4 % is expected for α of Iron Gates by calculating (% AHG in Iron Gates HG) × (α in AHG). However, Iron Gates can be modeled without any Basal Eurasian ancestry or with a non-significant proportion of 1.6 ± 2.8 %, suggesting that unidirectional gene flow from the Near East to Europe alone is insufficient to explain the extra affinity between the Iron Gates HG and the Near-Eastern hunter-gatherers. Thus, it is plausible to assume that prior to 15,000 years ago there was either a 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. Presumably, this Southeastern European ancestral population later spread into central Europe during the post-last-glacial maximum (LGM) period, resulting in the observed late Pleistocene genetic affinity between the Near East and Europe.

near-eastern-european-hg
Basal Eurasian ancestry proportions (α) as a marker for Near-Eastern gene flow. Mixture proportions inferred by qpAdm for AHG and the Iron Gates HG are schematically represented. The lower schematic shows the expected α in Iron Gates HG under 10 assumption of unidirectional gene flow, inferred from α in the AHG source population. The observed α for Iron Gates HG is considerably smaller than expected thus, the unidirectional gene flow from the Near East to Europe is not sufficient to explain the above affinity.

While ancestry is not always relevant to distinguish certain population movements (see here), especially – as in this case – when there are few samples (thus neither geographically nor chronologically representative) and no previous model to test, it seems that ancestry and Y-DNA show a great degree of continuity in Anatolia since the Palaeolithic until the Neolithic, at least in the sampled regions. C1a2 appears in Europe since ca. 40,000 years ago (viz. Kostenki, Goyet, Vestonice, etc., and later emerges again in the Balkans after the Anatolian Neolithic expansion, probably a resurge of European groups).

The potential transition of a G2a-dominated agricultural society – that is later prevalent in Anatolian and European farmers – may have therefore happened during the Aceramic III period (ca. 8000 BC), a process of haplogroup expansion probably continuing through the early part of the Pottery Neolithic, as the society based on kinship appeared (Rosenberg and Erim-Özdoğan 2011). There is still much to know about the spread of ceramic technology and southwestern Asia domesticate complex, though.

anatolian-palaeolithic-hg

Without a proper geographical sampling, representative of previous and posterior populations, it is impossible to say. But the expansion of R1b-L754 through Anatolia to form part of the Villabruna cluster (and also the Iron Gates HG) seems perfectly possible with this data, although this paper does not help clarify the when or how. We have seen significant changes in ancestry happen within centuries with expanding populations admixing with locals. Palaeolithic sampling – like this one – shows few individuals scattered geographically over thousands of km and chronologically over thousands of years…

Related

Mitogenomes suggest rapid expansion of domesticated horse before 3500 BC

Open access Origin and spread of Thoroughbred racehorses inferred from complete mitochondrial genome sequences: Phylogenomic and Bayesian coalescent perspectives, by Yoon et al. PLOS One (2018).

Abstract (emphasis mine)

The Thoroughbred horse breed was developed primarily for racing, and has a significant contribution to the qualitative improvement of many other horse breeds. Despite the importance of Thoroughbred racehorses in historical, cultural, and economical viewpoints, there was no temporal and spatial dynamics of them using the mitogenome sequences. To explore this topic, the complete mitochondrial genome sequences of 14 Thoroughbreds and two Przewalski’s horses were determined. These sequences were analyzed together along with 151 previously published horse mitochondrial genomes from a range of breeds across the globe using a Bayesian coalescent approach as well as Bayesian inference and maximum likelihood methods. The racing horses were revealed to have multiple maternal origins and to be closely related to horses from one Asian, two Middle Eastern, and five European breeds. Thoroughbred horse breed was not directly related to the Przewalski’s horse which has been regarded as the closest taxon to the all domestic horses and the only true wild horse species left in the world. Our phylogenomic analyses also supported that there was no apparent correlation between geographic origin or breed and the evolution of global horses. The most recent common ancestor of the Thoroughbreds lived approximately 8,100–111,500 years ago, which was significantly younger than the most recent common ancestor of modern horses (0.7286 My). Bayesian skyline plot revealed that the population expansion of modern horses, including Thoroughbreds, occurred approximately 5,500–11,000 years ago, which coincide with the start of domestication. This is the first phylogenomic study on the Thoroughbred racehorse in association with its spatio-temporal dynamics. The database and genetic history information of Thoroughbred mitogenomes obtained from the present study provide useful information for future horse improvement projects, as well as for the study of horse genomics, conservation, and in association with its geographical distribution.

horse-domestication
Bayesian skyline plot (BSP) based on mitochondrial genome sequences from 167 modern horses.
The dark line in the BSP represents the estimated effective population size through time. The green area represents the 95% highest posterior density confidence intervals for this estimate.

Interesting excerpts:

We carried out a Bayesian coalescent approach using extended mitochondrial genome sequences from 167 horses in order to further assess the timescale of horse domestication. Here, we first calculated the time of the most recent common ancestor of Thoroughbred horses. Our analysis revealed the age of the most recent common ancestor of the racing horse to be around 8,100–111,500 years old. This estimate is much younger than that of the most recent common ancestor of the global horses, which has been estimated at 0.7286 Mys old.

phylogenetic-tree-horses
Bayesian maximum clade credibility phylogenomic tree on the ground of the mitochondrial genome sequences of 167 modern horses.
The data set (16,432 base pairs) was also analyzed phylogenetically using Bayesian inference (BI) and maximum likelihood (ML) methods which showed the same topologies. 95% Highest Posterior Density of node heights are shown by blue bars. Groups are marked by a “G”. Numbers at the nodes represent (left to right): posterior probabilities (≥0.80) for the BI tree and bootstrap values (≥70%) for the ML tree. The racing horses were revealed to have multiple maternal origins and to be closely related to horses from one Asian, two Middle Eastern, and five European breeds. Results of phylogenomic analyses also uncovered no apparent association between geographic origin or breed and heterogeneity of global horses. The most recent common ancestor of the Thoroughbreds lived approximately 8,100–111,500 years ago, which was significantly younger than the most recent common ancestor of modern horses (0.7286 My).

On the domestication time of modern horses, there have been several publications derived from both archaeological [49–51] and molecular [11–12, 23, 48] evidences. D’Andrade [49] reported that the origin of domestic horses was around 4,000 years ago. Ludwig et al. [50] stated the domestication time to be about 5,000 years ago, while Anthony [51] noted that horse rearing by humans may have occurred approximately 6,000 years ago. Subsequently, on the basis of mitochondrial genome sequences, Lippold et al. [11] and Achilli et al. [12] postulated domestication time to be about 6,000–8,000 and 6,000–7,000 years ago, respectively. Warmuth [48] dated domestication time to 5,500 years ago based on autosomal genotype data, while Orlando et al. [23] claimed that Przewalski’s and domestic horse populations diverged 38,000–72,000 years ago based on analysis of genome sequences. In contrast to the previous hypothesized date of horse domestication, the results of our Bayesian skyline plot (BSP) analysis depict a rapid expansion of the horse population approximately 5,500–11,000 years ago, which coincides with the start of domestication.

It seems that we will not have an update on horse aDNA from the ISBA 8, so we will have to make do with this for the moment.

Related

Global demographic history inferred from mitogenomes

Open access Global demographic history of human populations inferred from whole mitochondrial genomes, by Miller, Manica, and Amos, Royal Society Open Science (2018).

Relevant excerpts (emphasis mine):

Material

The Phase 3 sequence data from 20 populations, comprising five populations for each of the four main geographical regions of Europe, East Asia, South Asia and Africa, were downloaded from the 1000 Genomes Project website (www.1000genomes.org/data, [8]), including whole mitochondrial genome data for 1999 individuals. We decided not to analyse populations from the Americas due to the region’s complex history of admixture [13,14].

The European populations were as follows: Finnish sampled in Finland (FIN); European Caucasians resident in Utah, USA (CEU); British in England and Scotland (GBR); an Iberian population from Spain (IBS) and Toscani from Italy (TSI). Representing East Asia were the Han Chinese in Beijing (CHB); Southern Han Chinese (CHS); Dai Chinese from Xishuangbanna, China (CDX); Kinh population from Ho Chi Minh City, Vietnam (KHV) and Japanese from Tokyo (JPT). The South Asian populations were Punjabi Indians from Lahore, Pakistan (PJL); Gujarati Indians in Houston, USA (GIH) as well as Indian Telugu sampled in the UK (ITU); Bengali from Bangladesh (BEB) and Sri Lankan Tamil from the UK (STU). (…)

Method

We analysed our mtDNA data with the extended Bayesian skyline plot (EBSP) method, a Bayesian, non-parametric technique for inferring past population size fluctuations from genetic data. Building on the previous Bayesian skyline plot (BSP) approach, EBSP uses a piecewise-linear model and Markov chain Monte Carlo (MCMC) methods to reconstruct a populations’ demographic history [17] and is implemented in the software package BEAST v. 2.3.2 [11]. Alignments for each of the 20 populations were loaded separately into the Bayesian Evolutionary Analysis Utility tool (BEAUti v. 2.3.2) in NEXUS format.

1000-genomes-similarity-fst
Relationship between profile similarity and genetic distance, measured as Fst. Comparisons between regions, circles, are colour-coded: black ¼ AFR-EA; yellow ¼ AFR-EUR; blue ¼ AFR-SA; orange ¼ EUR-EA; green ¼ EA-SA; red ¼ EUR-SA. Comparisons within regions, squares, are coded: peach ¼ EUR; pink ¼ EA; dark blue ¼ EA; light blue ¼ AFR. Profile similarity is calculated as inferred size difference summed over 20 evenly spaced intervals (see Material and methods).

Regional demographic histories

Europe:

The five European profiles are presented in figure 2. The four southerly populations all show profiles with a stable size up to approximately 14 ka followed by a sudden, rapid increase that becomes progressively less steep towards the present. There is also a north-south trend, with confidence intervals becoming broader towards the north, particularly for the oldest time-points. The Finnish population profile appears rather different, but this is to be expected both because it is so far north and because previous studies have identified Finns as a strong genetic outlier in Europe [19–22].

europe-mtdna
Inferred demographic histories of five European populations. Dotted line is the median estimate of Ne and the thin grey lines show the boundary of the 95% CPD interval. The x-axis represents time from the present in years and all plots are on the same scale. Map shows origins of sampled populations.

South Asia:

The five profiles for South Asia are shown in figure 3. All populations reveal a period of rapid growth approximately 45–40 ka which then slows. Near the present the two southerly populations, GIH and STU both show evidence of a decline. However, this may be due to these samples being drawn from populations no longer living on the subcontinent, with the downward trend capturing a bottleneck associated with moving to Europe/America, perhaps accentuated by the tendency for immigrant populations to group by region, religion and race [23].

asia-mtdna
Inferred South Asian population demographic histories. Dotted line is the median Ne estimate and the thin grey lines show the boundary of the 95% CPD intervals. The x-axis represents time from the present in thousands of years and all plots are on the same scale. The map shows location of sampled populations.

Related

Origin of horse domestication likely on the North Caspian steppes

Open access Late Quaternary horses in Eurasia in the face of climate and vegetation change, by Leonardi et al. Science Advances (2008) 4(7):eaar5589.

Interesting excerpts (emphasis mine):

Here, we compiled an extensive continental-scale database, consisting of 3070 radiocarbon dates associated to horse paleontological and archeological finds across the whole of Eurasia, that has been analyzed in association with coarse-scale paleoclimatic reconstructions. We further collected the number of identified specimens (NISP) frequency data for horses versus other ungulates in 1120 archeological layers in Europe (…) This ma.ssive amount of data allowed us to track,with unprecedented details, how the geographic distribution of the species changed through time

Geographic range through time

For most analyses, the data have been divided into climatic periods: pre-LGM(older than 27 ka B.P.), LGM(27 to 18 ka B.P.), Late Glacial (18 to 11.7 ka B.P.), Preboreal (11.7 to 10.6 ka B.P.), Boreal (10.6 to 9.1 ka B.P.), Early Atlantic (9.1 to 7.5 ka B.P.), Late Atlantic (7.5 to 5.5 ka B.P.), and Recent (younger than 5.5 ka B.P.) (Fig. 1, A and B). The spatial and temporal distribution of horse remains compiled in our database reveals a strong imbalance in Eurasia (Fig. 1, A and B).

We found a common trend in both regions for a high number of occurrences at the end of the Pleistocene (with a decrease during the LGM, only visible in Europe), followed by a drastic reduction in the Early and Middle Holocene, and a relative increase toward more recent times. These included both the Early Atlantic in Europe, which started ~9.1 ka B.P., and the time range after 5.5 ka B.P. for Asia. The horse fossil record appears ubiquitous throughout Europe in the Late Pleistocene, while in the Early and Middle Holocene the finds are concentrated in central-western Europe and Iberia. From 7.5 ka B.P., the number of finds increases markedly, and the geographical distribution extends toward the east and southeast.

horse-distribution-climate
Horse occurrences through time. (A) Horse occurrences through time. Histograms showing the number of horse observations in Europe (left panel) and Asia (right panel) for each time bin (top) and for climatic period (bottom). Only time bins with more than 10 observations (black horizontal line) have been considered for the SDM analyses. From 22 ka B.P. backward (gray vertical line), time bins cover 2 ka following the available paleoclimatic reconstructions. The central map shows the boundaries considered while defining European and Asian regions, with the black line representing the Urals. The zoomed area shows the geographical resolution of the climatic reconstructions, with each pixel representing a grid cell. (B) Geographic distribution of horse occurrences. Maps showing horse occurrences for each climatic period in Europe (left) and Asia (right).

Different Asian and European niches

This analysis revealed that, in both continents, horses occupied only a portion of the climatic space available. The range covered by random locations shows that the paleoecological conditions present in Europe were only a subset of those found in Asia. However, European horses occupied a much wider climatic space than in Asia, with only limited overlap between the two ranges.

Horses conquered temperate environments from a European source

There is no evidence of climatic barriers between those two populations through time because the forecasts from Europe and Asia always overlap in central Eurasia, except 5 ka B.P. (figs. S3 and S4). An alternative explanation is the role of the Urals as a potential constraint for the dispersal of horses between Europe and north central Asia.

climatic-suitability-horses
Climatic suitability. (A) Cumulative climatic suitability for the past 44 ka based on simulation on the European (left), Eurasian (middle), and Asian (right) data sets. To correct for sampling bias in the Eurasian data set, for each time slice, all estimates and projections for Eurasia are performed considering 100 random resampling of European occurrences in the same number as Asian occurrences. The darker the colors, themore stable the climatic suitability for horses (climatic niche = p-Hor) through time. (B) Projection of climatic suitability across Eurasia in different climatic periods based on occurrences in Europe (left), Eurasia (middle), and Asia (right). Because of the scarcity of data available for Asia, no models for the Holocene have been possible for both Asia and Eurasia, with the exception of 5 and 3 ka B.P. (both included in the “Recent” period).

Climatic and habitat association patterns for horses in Europe support increasing habitat fragmentation

The decrease of horse remains in Europe is not characterized by a geographic reduction in the overall extent of the area occupied by the species but in a drop of frequencies in a geographic extent that does not vary much between the Late Glacial and the Early Atlantic (Figs. 1B and 4B). This pattern is more likely to result from habitat fragmentation than from a geographic shift in the climatic range suitable for the species, as observed for many animals during the LGM (23).

In the whole period ranging from the Preboreal (11.7 to 10.6 ka B.P.) to the Late Atlantic (7.5 to 5.5 ka B.P.), the total amount of land space most and likely suitable to horses is wider than in the Late Glacial, and only between 8 to 7 ka ago the European range appears patchy and fragmented (Fig. 4C). When comparing each of four successive time bins during the Holocene (8, 7, 6, and 5 ka B.P., respectively) (Fig. 4E), the difference in successive p-Hor values in Europe shows that the suitability for the species in Iberia, northeastern France, Italy, the Balkans, and eastern Europe steadily increased, while in Central Europe strong differences can be observed between neighboring regions.

horse-europe-asia
Analyses of the European data set and biomefrequency. (A) Distribution through time of the frequency of horse remains in Europe calculated as NISP of horses versus other ungulates. (B) Density of horse remains through time in Europe, calculated as NISP of horses versus other ungulates. The numbers at the bottom of each bar represent the number of observations falling in each class, from 0 to >5%. (C) Climatic suitability for horses in Europe between 10 and 3 ka B.P. (D) Climatic suitability per time period. Percentage of land cells in Europe with a value of suitability for horses (p-Hor) > 0.5 and p-Hor > 0.8. (E) Holocene climatic amelioration. Difference in p-Hor in Europe comparing five successive time bins during the Holocene: 9, 8, 7, 6, and 5 ka B.P. Eachmap shows the difference in themore recent distribution compared to the previous one. (F) Environmental reconstructions in themacro area surrounding horse finds in Europe (left) and Asia (right) per climatic period. The lighter the color, the less forested is the region. The numbers at the bottom of the bars show the number of occurrences in closed environments over all the observations. The dotted line represents a frequency of 0.5.

Taken at face value, this pattern would suggest that horses were not restricted to open environments but could equally well inhabit closed, forested environments, as previously suggested (18). However, as others recently emphasized (19), the faunal associations inHolocene sites from Europe suggest a different pattern. The PCAs based on faunal assemblages (figs. S1 and S2) separate on the second principal component sites characterized by ungulates associated to forested areas (red deer, wild boar, and roe deer) and all other animals, associated to semi-open and open environments, including horses for most records.

Together, the contrast between the reconstructed microscale and macroscale vegetable coverage in Europe, the increase of horses in mainly forested macroregions, and the spatial pattern of extinction suggest that, from the beginning of the Holocene, the suitable environment became more and more patchy, with open areas increasingly fragmented by forests, where wild populations of horses could have survived in isolation until one or several waves of arrivals of domestic horses, leading to either local admixture or a full replacement of the preexisting local populations.

Conclusion

Our data show that, up to 5.5 ka ago, horse finds do not show association with species characteristic of forested areas such as wild boar and roe deer. We infer that the open and semi-open habitats occupied by horses on a narrow geographic scale appear less and less frequent at a macroenvironmental scale, supporting the possibility of increasing fragmentation of open habitats. This event is also likely to have led to an intensification of genetic isolation for the remaining horse populations, a pattern that still needs to be tested on genomic data.

The suitability of both Iberia and eastern Europe appears constant throughout the entire post-LGM period, in line with these regions being hotspots of genetic diversity and, possibly, the refugia sources for the recolonization of the continent (11). While the Pontic-Caspian region appears not suitable for European horses around the time when horses where first domesticated some 5.5 ka ago (6), part of this region appears suitable for the Asian horses (with the Caspian Sea as the westernmost boundary). This may suggest that horse domestication started from a population background related to an Asian ancestry and that the further spread of the domesticated horses in Europe involved either adaptation to novel niches (possibly through selective breeding) or the application of domestication techniques to local horse populations pre-adapted to these environmental conditions. Testing this scenario will require mapping the genetic structure of the Eurasian horse population within the fifth to third millennium BCE.

Some remarks

Cultural-anthropological research and archaeological remains (see here), genetics (see here and here), and now also thorough palaeoclimatic and archaeological models point to the North Caspian region, settled by the Khvalynsk culture, as the most likely earliest origin of horse domestication. The paper also supports the favorable conditions of western Europe up to Iberia for the introduction of a horse-riding culture.

I intended to write a post about the myth of Corded Ware horse riders, but for the moment I haven’t found the time. Not that Corded Ware pastoralists didn’t have horses, or could not ride them: they were a highly mobile culture of pastoralists stemming from eastern Poland / western Ukraine, so they must have known horses, like many other European cultures of the late 4th / early 3rd millennium influenced by expanding Yamna settlers. But it just cannot be said to have formed an essential part of their culture, as it was for Khvalynsk-Novodanilovka, and especially Yamna and later East Bell Beaker, Sintashta, etc.

A mere look at these maps suffices to assess the limited role of the horse in north-eastern Europe, the only region where groups of late Corded Ware-derived cultures survived the expansion of Yamna, and especially East Bell Beakers after ca. 2500 BC, which transformed Western, Northern, and Central Europe, and even East Europe reaching the modern Baltic countries, Belarus, and Romania. Even Trzciniec was born out of the influence from expanding Bell Beakers into earlier Corded Ware territory, although the later (Iron Age) relevance of this culture was probably quite limited.

As you can imagine, without horses and horse symbolism, horse riding, carts, and intensive cattle-breeding (associated with Yamna and the broad, east-central European grasslands typical of steppe regions), there can be no Proto-Indo-European, whose reconstructed vocabulary is particulary rich in horse-related words, and whose reconstructed culture, society, and religion cannot be understood without the domesticated horse. In forest regions to the north-east and eastern Europe, there was apparently little space for horses, but plenty of room for other ungulates and thus hunting, and indeed Uralic languages

In the upcoming months we will see R1a-fans associating Proto-Indo-Europeans more and more with wool, and sheep, and corded ware, and forest regions, until the proposed homeland shifts to the Baltic and Finland, instead of dat boring horse-riding people of the steppes…No wait, it’s already happening.

NOTE. Also open access is the recent Horse Y chromosome assembly displays unique evolutionary features and putative stallion fertility genes, by Janečka et al. Nature Communications (2018).

Related

Mitogenomes show Longobard migration was socially stratified and included females

antiquity-germanic-migrations

New bioRxiv preprint A genetic perspective on Longobard-Era migrations, by Vai et al. (2018).

Interesting excerpts (emphasis mine):

In this study we sequenced complete mitochondrial genomes from nine early-medieval cemeteries located in the Czech Republic, Hungary and Italy, for a total of 87 individuals. In some of these cemeteries, a portion of the individuals are buried with cultural markers in these areas traditionally associated with the Longobard culture (hereby we refer to these cemeteries as LC), as opposed to burial communities in which no artifacts or rituals associated by archaeologists to Longobard culture have been found in any graves. These necropolises, hereby referred as NLC, may represent local communities or other Barbaric groups previously migrated to this region. This extended sampling strategy provides an excellent condition to investigate the degree of genetic affinity between coeval LC and NLC burials, and to shed light on early-medieval dynamics in Europe.

lombard-hungary-czech
Geographical and genetic relationship between the newly sequenced individuals. (A) Location of the sampled necropolises. Here and through the other figures LC cemeteries are represented by a circle while NLC ones are indicated by a square. C) DAPC Scatterplot of the most supported K (7) highlighted by the kmeans analysis

Social rank

There is also no clear geographical structure between samples in our dataset, with individuals from Italy, Hungary and Czech Republic clustering together. However, the first PC clearly separates a group of 12 LC individuals found at Szólád, Collegno and Mušov from a group composed by both LC and NLC individuals. The same pattern is also found when pairwise differences among individuals are plotted by multidimensional scaling (…)

The presence in this group of LC sequences belonging to macrohaplogroups I and W, commonly found at high frequencies in northern Europe (e.g. Finland 32), suggests (although certainly does not prove) the existence of a possible link between these 12 LC individuals and northern Europe. The peculiarity of this group is strengthened by archaeological information from the Szólád cemetery, where 8 of the 12 individuals in this group originated, indicating that all these samples were found buried with typical Longobard artifacts and grave assemblages. We do not find the same tight association for the 3 samples from Collegno, where the 3 graves are indeed devoid of evident Germanic cultural markers; however they are not placed in a separate and marginal location—as for the tombs without grave goods found in Szólád —but among graves with wooden chambers and weapons. It is worth noting that weapon burials were quite scarce in 5th century Pannonia and 6th century Italy (e.g. Goths never buried weapons), and an increase in weapon burials started in Italy only after the Longobard migration. In this light, the individuals buried in this manner may have been members of the same community as well, but belonging to the lowest social level. This social condition could explain the absence of artifacts and could be related to mixed marriages, whose offspring had an inferior social rank. Finally, this group also includes an individual from the Musov graveyard. This finding is particularly interesting in light of the fact that the Musov necropolis has been only tentatively associated with Longobard occupation (see Supplementary Text for details), based on the presence of but a few archaeological markers.

Female migration

We hence estimated that about 70% of the lineages found in Collegno actually derived from the Hungarian LC groups, in agreement with previous archaeological and historical hypotheses. This supports the idea that the spread of Longobards into Italy actually involved movements of fairly large numbers of people, who gave a substantial contribution to the gene pool of the resulting populations. This is even more remarkable thinking that, in many studied cases, military invasions are movements of males, and hence do not have consequences at the mtDNA level. Here, instead, we have evidence of changes in the composition of the mtDNA pool of an Italian population, supporting the view that immigration from Central Europe involved females as well as males.

Related

Native American genetic continuity and oldest mtDNA hg A2ah in the Andean region

Native American gene continuity to the modern admixed population from the Colombian Andes: Implication for biomedical, population and forensic studies by Criollo-Rayo et al., Forensic Sci Int Genet (2018), in press, corrected proof.

Abstract (emphasis mine):

Andean populations have variable degrees of Native American and European ancestry, representing an opportunity to study admixture dynamics in the populations from Latin America (also known as Hispanics). We characterized the genetic structure of two indigenous (Nasa and Pijao) and three admixed (Ibagué, Ortega and Planadas) groups from Tolima, in the Colombian Andes. DNA samples from 348 individuals were genotyped for six mitochondrial DNA (mtDNA), seven non-recombining Y-chromosome (NRY) region and 100 autosomal ancestry informative markers. Nasa and Pijao had a predominant Native American ancestry at the autosomal (92%), maternal (97%) and paternal (70%) level. The admixed groups had a predominant Native American mtDNA ancestry (90%), a substantial frequency of European NRY haplotypes (72%) and similar autosomal contributions from Europeans (51%) and Amerindians (45%). Pijao and nearby Ortega were indistinguishable at the mtDNA and autosomal level, suggesting a genetic continuity between them. Comparisons with multiple Native American populations throughout the Americas revealed that Pijao, had close similarities with Carib-speakers from distant parts of the continent, suggesting an ancient correlation between language and genes. In summary, our study aimed to understand Hispanic patterns of migration, settlement and admixture, supporting an extensive contribution of local Amerindian women to the gene pool of admixed groups and consistent with previous reports of European-male driven admixture in Colombia.

andean-y-dna-mtdna
Ancestral uniparental haplogroups and diversity in Tolima. Geography of sampling locations. The
top and middle sections show the frequency of Native American mtDNA haplogroups and NRY lineages for all
populations. Gene diversity is shown below their respective pie chart. The lower part depicts the geography of the
region where the sampling sites of Ortega and Pijao are closely located in Tolima’s Magdalena river valley and
Ibague, Planadas and Nasa located in the Andes cordilleras (additional geographic details are shown in SF1).

Highlights from the paper:

  • MtDNA suggest a pre/post Columbian genetic continuity in the Colombian Andes.
  • Y-chromosome diversity follows a clinal gradient in the studied region.
  • Sex-biased/male-driven admixture process, involving Pijao women with European men.
  • Admixed closer to Indigenous resguardos have a higher Native American ancestry.

Also interesting is the recent paper Mitochondrial lineage A2ah found in a pre‐Hispanic individual from the Andean region, by Russo et al., in American Journal of Human Biology (2018), with an interesting sample from the Regional Developments II period (540 ± 60 BP).

phylogeny-a2ah-mtdna
Phylogeny of the A2ah mitochondrial lineage based on HVR I sequences. Both MaximumParsimony andMaximumLikelihood reconstructions led to the same typology. The tree was rooted with the RSRS. Sample ID: Cueva: Pukara de La Cueva, STACRUZ: Santa Cruz, BNI: Beni, BR: South-eastern Brazil, TobaChA: TobaGranChaco

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