Ancient Sardinia hints at Mesolithic spread of R1b-V88, and Western EEF-related expansion of Vasconic

nuragic-sardinia-neolithic

New preprint Population history from the Neolithic to present on the Mediterranean island of Sardinia: An ancient DNA perspective, by Marcus et al. bioRxiv (2019)

Interesting excerpts (emphasis mine, edited for clarity):

On the high frequency of R1b-V88

Our genome-wide data allowed us to assign Y haplogroups for 25 ancient Sardinian individuals. More than half of them consist of R1b-V88 (n=10) or I2-M223 (n=7).

Francalacci et al. (2013) identi fied three major Sardinia-specifi c founder clades based on present-day variation within the haplogroups I2-M26, G2-L91 and R1b-V88, and here we found each of those broader haplogroups in at least one ancient Sardinian individual. Two major present-day Sardinian haplogroups, R1b-M269 and E-M215, are absent.

Compared to other Neolithic and present-day European populations, the number of identi fied R1b-V88 carriers is relatively high.

(…)ancient Sardinian mtDNA haplotypes belong almost exclusively to macro-haplogroups HV (n = 16), JT (n = 17) and U (n = 9), a composition broadly similar to other European Neolithic populations.

r1b-v88-europe
Geographic and temporal distribution of R1b-V88 Y-haplotypes in ancient European samples. We plot the geographic position of all ancient samples inferred to carry R1b-V88 equivalent markers. Dates are given as years BCE (means of calibrated 2s radio-carbon dates). Multiple V88 individuals with similar geographic positions are vertically stacked. We additionally color-code the status of the R1b-V88 subclade R1b-V2197, which is found in most present-day African R1b-V88 carriers.

On the origin of a Vasconic-like Paleosardo with the Western EEF

(…) the Neolithic (and also later) ancient Sardinian individuals sit between early Neolithic Iberian and later Copper Age Iberian populations, roughly on an axis that differentiates WHG and EEF populations and embedded in a cluster that additionally includes Neolithic British individuals. This result is also evident in terms of absolute genetic differentiation, with low pairwise FST ~ 0.005 +- 0.002 between Neolithic Sardinian individuals and Neolithic western mainland European populations. Pairwise outgroup-f3 analysis shows a very similar pattern, with the highest values of f3 (i.e. most shared drift) being with Neolithic and Copper Age Iberia, gradually dropping off for temporally and geographically distant populations.

In explicit admixture models (using qpAdm, see Methods) the southern French Neolithic individuals (France-N) are the most consistent with being a single source for Neolithic Sardinia (p ~ 0:074 to reject the model of one population being the direct source of the other); followed by other populations associated with the western Mediterranean Neolithic Cardial Ware expansion.

sardinians-ancient-eef
Principal Components Analysis based on the Human Origins dataset. A: Projection of ancient individuals’ genotypes onto principal component axes de fined by modern Western Eurasians (gray labels).

Pervasive Western Hunter-Gatherer ancestry in Iberian/French/Sardinian population

Similar to western European Neolithic and central European Late Neolithic populations, ancient Sardinian individuals are shifted towards WHG individuals in the top two PCs relative to early Neolithic Anatolians Admixture analysis using qpAdm infers that ancient Sardinian individuals harbour HG ancestry (~ 17%) that is higher than early Neolithic mainland populations (including Iberia, ~ 8%), but lower than Copper Age Iberians (~ 25%) and about the same as Southern French Middle-Neolithic individuals (~ 21%).

sardinia-modern-ancient-nuragic-pca
Principal Components Analysis based on the Human Origins dataset. B: Zoom into the region most relevant for Sardinian individuals.

Continuity from Sardinia Neolithic through the Nuragic

We found several lines of evidence supporting genetic continuity from the Sardinian Neolithic into the Bronze Age and Nuragic times. Importantly, we observed low genetic differentiation between ancient Sardinian individuals from various time periods.

A qpAdm analysis, which is based on simultaneously testing f-statistics with a number of outgroups and adjusts for correlations, cannot reject a model of Neolithic Sardinian individuals being a direct predecessor of Nuragic Sardinian individuals (…) Our qpAdm analysis further shows that the WHG ancestry proportion, in a model of admixture with Neolithic Anatolia, remains stable at ~17% throughout three ancient time-periods.

sardinians-modern-ancient-pca-admixture
Present-day genetic structure in Sardinia reanalyzed with aDNA. A: Scatter plot of the rst two principal components trained on 1577 present-day individuals with grand-parental ancestry from Sardinia. Each individual is labeled with a location if at least 3 of the 4 grandparents were born in the same geographical location (\small” three letter abbreviations); otherwise with \x” or if grand-parental ancestry is missing with \?”. We calculated median PC values for each Sardinian province (large abbreviations). We also projected each ancient Sardinian individual on to the top two PCs (gray points). B/C: We plot f-statistics that test for admixture of modern Sardinian individuals (grouped into provinces) when using Nuragic Sardinian individuals as one source population. Uncertainty ranges depict one standard error (calculated from block bootstrap). Karitiana are used in the f-statistic calculation as a proxy for ANE/Steppe ancestry (Patterson et al., 2012).

Steppe influx in Modern Sardinians

While contemporary Sardinian individuals show the highest affinity towards EEF-associated populations among all of the modern populations, they also display membership with other clusters (Fig. 5). In contrast to ancient Sardinian individuals, present-day Sardinian individuals carry a modest “Steppe-like” ancestry component (but generally less than continental present-day European populations), and an appreciable broadly “eastern Mediterranean” ancestry component (also inferred at a high fraction in other present-day Mediterranean populations, such as Sicily and Greece).

Related

Arrival of steppe ancestry with R1b-P312 in the Mediterranean: Balearic Islands, Sicily, and Iron Age Sardinia

steppe-balearic-sicily-sardinia

New preprint The Arrival of Steppe and Iranian Related Ancestry in the Islands of the Western Mediterranean by Fernandes, Mittnik, Olalde et al. bioRxiv (2019)

Interesting excerpts (emphasis in bold; modified for clarity):

Balearic Islands: The expansion of Iberian speakers

Mallorca_EBA dates to the earliest period of permanent occupation of the islands at around 2400 BCE. We parsimoniously modeled Mallorca_EBA as deriving 36.9 ± 4.2% of her ancestry from a source related to Yamnaya_Samara; (…). We next used qpAdm to identify “proximal” sources for Mallorca_EBA’s ancestry that are more closely related to this individual in space and time, and found that she can be modeled as a clade with the (small) subset of Iberian Bell Beaker culture associated individuals who carried Steppe-derived ancestry (p=0.442).

Suppl. Materials: The model used was with Bell_Beaker_Iberia_highsteppe, a group of outliers from Iberia buried in a Bell Beaker mortuary context who unlike most individuals from this context in that region had high proportions of Steppe ancestry (p=0.442).

Our estimates of Steppe ancestry in the two later Balearic Islands individuals are lower than the earlier one: 26.3 ± 5.1% for Formentera_MBA and 23.1 ± 3.6% for Menorca_LBA, but the Middle to Late Bronze Age Balearic individuals are not a clade relative to non-Balearic groups. Specifically, we find that f4(Mbuti.DG, X; Formentera_MBA, Menorca_LBA) is positive when X=Iberia_Chalcolithic (Z=2.6) or X=Sardinia_Nuragic_BA (Z=2.7). While it is tempting to interpret the latter statistic as suggesting a genetic link between peoples of the Talaiotic culture of the Balearic islands and the Nuragic culture of Sardinia, the attraction to Iberia_Chalcolithic is just as strong, and the mitochondrial haplogroup U5b1+16189+@16192 in Menorca_LBA is not observed in Sardinia_Nuragic_BA but is observed in multiple Iberia_Chalcolithic individuals. A possible explanation is that both the ancestors of Nuragic Sardinians and the ancestors of Talaiotic people from the Balearic Islands received gene flow from an unsampled Iberian Chalcolithic-related group (perhaps a mainland group affiliated to both) that did not contribute to Formentera_MBA.

This sample, like another one in El Argar, is of hg. R1b-P312. So there you are, the data that connects the Proto-Iberian expansion (replacing IE-speaking Bell Beakers) to the Iberian Chalcolithic population, signaled by the increase in Iberian Chalcolithic ancestry after the arrival of Bell Beakers, most likely connected originally to the Argaric and post-Argaric expansions during the MBA.

balearic-sicily-sardinia-pca
PCA with previously published ancient individuals (non-filled symbols), projected onto variation from present-day populations (gray squares).

Steppe in Sardinia IA: Phocaeans from Italy?

Most Sardinians buried in a Nuragic Bronze Age context possessed uniparental haplogroups found in European hunter-gatherers and early farmers, including Y-haplogroup R1b1a[xR1b1a1a] which is different from the characteristic R1b1a1a2a1a2 spread in association with the Bell Beaker complex. An exception is individual I10553 (1226-1056 calBCE) who carried Y-haplogroup J2b2a, previously observed in a Croatian Middle Bronze Age individual bearing Steppe ancestry, suggesting the possibility of genetic input from groups that arrived from the east after the spread of first farmers. This is consistent with the evidence of material culture exchange between Sardinians and mainland Mediterranean groups, although genome-wide analyses find no significant evidence of Steppe ancestry so the quantitative demographic impact was minimal.

Another interesting data, these (Mesolithic) remnant R1b-V88 lineages closely related to the Italian Peninsula, the most likely region of expansion of these lineages into Africa, in turn possibly connected to the expansion of Proto-Afroasiatic.

We detect definitive evidence of Iranian-related ancestry in an Iron Age Sardinian I10366 (391-209 calBCE) with an estimate of 11.9 ± 3.7.% Iran_Ganj_Dareh_Neolithic related ancestry, while rejecting the model with only Anatolian_Neolithic and WHG at p=0.0066 (Supplementary Table 9). The only model that we can fit for this individual using a pair of populations that are closer in time is as a mixture of Iberia_Chalcolithic (11.9 ± 3.2%) and Mycenaean (88.1 ± 3.2%) (p=0.067). This model fits even when including Nuragic Sardinians in the outgroups of the qpAdm analysis, which is consistent with the hypothesis that this individual had little if any ancestry from earlier Sardinians.

yamnaya-samara
Proportions of ancestry using a distal qpAdm framework on an individual basis (a), and based on qpWave clusters

Sicily EBA: The Lusitanian/Ligurian connection?

(…) While a previously reported Bell Beaker culture-associated individual from Sicily had no evidence of Steppe ancestry, (…) we find evidence of Steppe ancestry in the Early Bronze Age by ~2200 BCE. In distal qpAdm, the outlier Sicily_EBA11443 is parsimoniously modeled as harboring 40.2 ± 3.5% Steppe ancestry, and the outlier Sicily_EBA8561 is parsimoniously modeled as harboring 23.3 ± 3.5% Steppe ancestry. (…) The presence of Steppe ancestry in Early Bronze Age Sicily is also evident in Y chromosome analysis, which reveals that 4 of the 5 Early Bronze Age males had Steppe-associated Y-haplogroup R1b1a1a2a1a2. (Online Table 1). Two of these were Y-haplogroup R1b1a1a2a1a2a1 (Z195) which today is largely restricted to Iberia and has been hypothesized to have originated there 2500-2000 BCE. This evidence of west-to-east gene flow from Iberia is also suggested by qpAdm modeling where the only parsimonious proximate source for the Steppe ancestry we found in the main Sicily_EBA cluster is Iberians.

What’s this? An ancestral connection between Sicel Elymian and Galaico-Lusitanian or Ligurian (based on an origin in NE Iberia)? Impossible to say, especially if the languages of these early settlers were replaced later by non-Indo-European speakers from the eastern Mediterranean, and by Indo-European speakers from the mainland closely related to Proto-Italic during the LBA, but see below.

Regarding the comment on R1b-Z195, it is associated with modern Iberians, as DF27 in general, due to founder effects beyond the Pyrenees. It is a very old subclade, split directly from DF27 roughly at the same time as it split from the parent P312, i.e. it can be found anywhere in Europe, and it almost certainly accompanied the expansion of Celts from Central Europe under the subclade R1b-M167/SRY2627.

The connection is thus strong only because of the qpAdm modeling, since R1b-DF27 and subclade R1b-Z195 are certainly lineages expanded quite early, most likely with Yamna settlers in Hungary and East Bell Beakers.

In this case, if stemming from Iberia, it is most likely of subclade R1b-Z220 – or another Z195 (xM167) lineage – originally associated with the Old European substrate found in topo-hydronymy in Iberia, whose most likely remnants attested during the Iron Age were Lusitanians.

r1b-df27-z195
Left: Modern distribution of R1b-Z195 (YFull estimate 2700 BC); Right: Modern distribution of DF27. Both include later founder effects within Iberia, so the increase in the Basque country and the Crown of Aragon and the decrease in Portugal can safely be ignored. Contour maps of the derived allele frequencies of the SNPs analyzed in Solé-Morata et al. (2017).

We detect Iranian-related ancestry in Sicily by the Middle Bronze Age 1800-1500 BCE, consistent with the directional shift of these individuals toward Mycenaeans in PCA. Specifically, two of the Middle Bronze Age individuals can only be fit with models that in addition to Anatolia_Neolithic and WHG, include Iran_Ganj_Dareh_Neolithic. The most parsimonious model for Sicily_MBA3125 has 18.0 ± 3.6% Iranian-related ancestry (p=0.032 for rejecting the alternative model of Steppe rather than Iranian-related ancestry), and the most parsimonious model for Sicily_MBA has 14.9 ± 3.9% Iranian-related ancestry (p=0.037 for rejecting the alternative model).

The modern southern Italian Caucasus-related signal identified in Raveane et al. (2018) is plausibly related to the same Iranian-related spread of ancestry into Sicily that we observe in the Middle Bronze Age (and possibly the Early Bronze Age).

The non-Indo-European Sicanians and Elymians were possibly then connected to eastern Mediterranean groups before the expansion of the Sea Peoples.

For the Late Bronze Age group of individuals, qpAdm documented Steppe-related ancestry, modeling this group as 80.2 ± 1.8% Anatolia_Neolithic, 5.3 ± 1.6% WHG, and 14.5 ± 2.2% Yamnaya_Samara. Our modeling using sources more closely related in space and time also supports Sicily_LBA having Minoan-related ancestry or being derived from local preceding populations or individuals with ancestries similar to those of Sicily_EBA3123 (p=0.527), Sicily_MBA3124 (p=0.352), and Sicily_MBA3125 (p=0.095).

This increase in Steppe-related ancestry in a western site during the LBA most likely represents either an expansion from the Aegean or – maybe more likely, given the archaeological finds – a regional population similar to Sicily EBA re-emerging or rather being displaced from the eastern part of the island because of a westward movement from nearby Calabria.

Whether this population sampled spoke Indo-European or not at this time is questionable, since the Iron Age accounts show non-IE Elymians in this region.

Actually, Elymians seem to have spoken Indo-European, which fits well with the increase in steppe ancestry.

EDIT (21 MAR): Interesting about a proposed incoming Minoan-like ancestry is the potential origin of the Iran Neolithic-related ancestry that is going to appear in Central Italy during the LBA. This could then be potentially associated with Tyrsenians passing through the area, although the traditional description may be more more compatible with an arrival of Sea Peoples from the Adriatic.

Sad to read this:

This manuscript is dedicated to the memory of Sebastiano Tusa of the Soprintendenza del Mare in Palermo, who would have been an author of this study had he not tragically died in the crash of Ethiopia Airlines flight 302 on March 10.

Related

Y-chromosome mixture in the modern Corsican population shows different migration layers

mesolithic-europe

Open access Prehistoric migrations through the Mediterranean basin shaped Corsican Y-chromosome diversity, by Di Cristofaro et al. PLOS One (2018).

Interesting excerpts:

This study included 321 samples from men throughout Corsica; samples from Provence and Tuscany were added to the cohort. All samples were typed for 92 Y-SNPs, and Y-STRs were also analyzed.

Haplogroup R represented approximately half of the lineages in both Corsican and Tuscan samples (respectively 51.8% and 45.3%) whereas it reached 90% in Provence. Sub-clade R1b1a1a2a1a2b-U152 predominated in North Corsica whereas R1b1a1a2a1a1-U106 was present in South Corsica. Both SNPs display clinal distributions of frequency variation in Europe, the U152 branch being most frequent in Switzerland, Italy, France and Western Poland. Calibrated branch lengths from whole Y chromosome sequencing [44,45] and ancient DNA studies [46] both indicated that R1a and R1b diversification began relatively recently, about 5 Kya, consistent with Bronze Age and Copper Age demographic expansion. TMRCA estimations are concordant with such expansion in Corsica.

corsica-haplogroups
Spatial frequency maps for haplogroups with frequencies above 3%, their Y-STR based phylogenetic networks in Corsican populations (Blue: North, Green: West, Orange: South, Black: Center and Purple: East) and their TMRCA (in years, +/- SE).

Haplogroup G reached 21.7% in Corsica and 13.3% in Tuscany. Sub-clade G2a2a1a2-L91 accounted for 11.3% of all haplogroups in Corsica yet was not present in Provence or in Tuscany. Thirty-four out of the 37 G2a2a1a2-L91 displayed a unique Y-STR profile, illustrated by the star-like profile of STR networks (Fig 1). G2a2a1a2-L91 and G2a2a-PF3147(xL91xM286) show their highest frequency in present day Sardinia and southern Corsica compared to low levels from Caucasus to Southern Europe, encompassing the Near and Middle East [21,47–50]. Ancient DNA results from Early and Middle Neolithic samples reported the presence of haplogroup G2a-P15 [51–53], consistent with gene flow from the Mediterranean region during the Neolithic transition. Td expansion time estimated by STR for P15-affiliated chromosomes was estimated to be 15,082+/-2217 years ago [49]. Ötzi, the 5,300-year-old Alpine mummy, was derived for the L91 SNP [21]. A genetic relationship between G haplogroups from Corsica and Sardinia is further supported by DYS19 duplication, reported in North Sardinia [14], and observed in the southern part of the Corsica in 9 out of 37 G2a2a1a2-L91 chromosomes and in 4 out of 5 G2a2a-PF3147(xL91xM286) chromosomes, 3 of which displayed an identical STR profile (S4 Table).

This lineage has a reported coalescent age estimated by whole sequencing in Sardinian samples of about 9,000 years ago. This could reflect common ancestors coming from the Caucasus and moving westward during the Neolithic period [48], whereas their continental counterparts would have been replaced by rapidly expanding populations associated with the Bronze Age [46,54,55]. Estimated TMRCA for L91 lineage in Corsica is 4529 +/- 853 years. G-L497 showed high frequencies in Corsica compared to Provence and Tuscany, and this haplogroup was common in Europe, but rare in Greece, Anatolia and the Middle East. Fifteen out of the 17 Corsican G2a2b2a1a1b-L497 displayed a unique Y-STR profile (S4 Table) with an estimated TMRCA of 6867 +/- 1294 years. Haplogroup G2a2b1-M406, associated with Impressed Ware Neolithic markers, along with J2a1-DYS445 = 6 and J2a1b1-M92 [22,49], had very low levels in Corsica. Conversely, G2a2b2a-P303was highly represented and seemed to be independent of the G2a2b1-M406 marker. The 7 G2a2b2a-P303(xL497xM527) Corsican chromosomes displayed a unique Y-STR profile (S4 Table).

pca-corsica
First and second axes of the PCA based on 12 Y-chromosome haplogroup frequencies in 83 west Mediterranean populations.

Haplogroup J, mainly represented by J2a1b-M67(xM92), displayed intermediate frequencies in Corsica compared to Tuscany and Provence. J2a1b-M67(xM92) derived STR network analysis displayed a quite homogeneous profile across the island with an estimated TMRCA of 2381 +/- 449 years (Fig 1) and individuals displaying M67 were peripheral compared to Northwestern Italians (S2 Fig). The haplogroup J2a1-Page55(xM67xM530), characteristic of non-Greek Anatolia [22], was found in the north-west of Corsica. Haplogroup J2a1-DYS445 = 6 was found in the north-west with DYS391 = 10 repeats, and in the far south with DYS391 = 9 repeats, the former was associated with Anatolian Greek samples, whereas the second was found in central Anatolia [22]. The 7 J2b2a-M241 displayed a unique Y-STR profile (S4 Table), they were only detected in the Cap Corse region, this sub-haplogroup shows frequency peaks in both the southern Balkans and northern-central Italy [56] and is associated with expansion from the Near East to the Balkans during Neolithic period [57].

Haplogroup E, mainly represented by E1b1b1a1b1a-V13, displayed intermediate frequencies in Corsica compared to Tuscany and Provence. E1b1b1a1b1a-V13 was thought to have initiated a pan-Mediterranean expansion 7,000 years ago starting from the Balkans [52] and its dispersal to the northern shore of the Mediterranean basin is consistent with the Greek Anatolian expansion to the western Mediterranean [22], characteristic of the region surrounding Alaria, and consistent with the TMRCA estimated in Corsica for this haplogroup. A few E1b1a-V38 chromosomes are also observed in the same regions as V13.

Related:

Haplogroup J spread in the Mediterranean due to Phoenician and Greek colonizations

iron_age_europe_mediterranean

Open access A finely resolved phylogeny of Y chromosome Hg J illuminates the processes of Phoenician and Greek colonizations in the Mediterranean, by Finocchio et al. Scientific Reports (2018) Nº 7465.

Abstract (emphasis mine):

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.

greek-phoenician
J2-L397. The star indicates the centroid of derived alleles. The solid square indicates the centroid of ancestral alleles, with its 95% C.I. (ellipse). In the insets: distributions of the pairwise sampling distances (in Km) for the carriers of the ancestral (black) and derived (white) allele, with solid and dashed lines indicating the respective averages. At right: median joining network of 7-STR haplotypes and SNPs in the same groups, with sectors coloured according to sampling location. Haplotype structure is detailed for some nodes, in the order YCA2a-YCA2b-DYS19-DYS390-DYS391-DYS392-DYS393 (in italics).

Interesting excerpts:

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.

greek-colonization
Supplemental Figure 7. Maps of sampling locations for the carriers of the derived allele (white triangle point down) at the indicated SNP vs carriers of the ancestral allele (black triangle point-up), conditioned on identical genotype at the same most terminal marker. Coastlines were drawn with the R packages18 “map” and “mapproj” v. 3.1.3 (https://cran.r-project.org/web/packages/mapproj/index.html), and additional features added with default functions. The star triangle indicates the centroid of derived alleles. The solid square indicates the centroid of ancestral alleles, with its 95% C.I. (ellipse). In the insets: distributions of the pairwise sampling distances (in Km) for the carriers of the ancestral (black) and derived (white) allele, with solid and dashed lines indicating the respective averages. At right: median joining network of 7-STR haplotypes and SNPs in the same groups, with sectors coloured according to sampling location. Haplotype structure is detailed for some nodes, in the order YCA2a-YCA2b-DYS19-DYS390-DYS391-DYS392-DYS393 (in italics).

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.

Related:

The fast spread of Neolithic farmers in the western Mediterranean

Recent open access Symbols in motion: Flexible cultural boundaries and the fast spread of the Neolithic in the western Mediterranean, by Rigaud, Manen, García-Martínez de Lagrán, PLOS One (2018).

Abstract (emphasis mine):

The rapid diffusion of farming technologies in the western Mediterranean raises questions about the mechanisms that drove the development of intensive contact networks and circulation routes between incoming Neolithic communities. Using a statistical method to analyze a brand-new set of cultural and chronological data, we document the large-scale processes that led to variations between Mediterranean archaeological cultures, and micro-scale processes responsible for the transmission of cultural practices within farming communities. The analysis of two symbolic productions, pottery decorations and personal ornaments, shed light on the complex interactions developed by Early Neolithic farmers in the western Mediterranean area. Pottery decoration diversity correlates with local processes of circulation and exchange, resulting in the emergence and the persistence of stylistic and symbolic boundaries between groups, while personal ornaments reflect extensive networks and the high level of mobility of Early Neolithic farmers. The two symbolic productions express different degrees of cultural interaction that may have facilitated the successful and rapid expansion of early farming societies in the western Mediterranean.

neolithisation-mediterranean
Mean Inverse Distance Weighting (IDW) interpolation of the first two axes of the Principal Coordinates Analysis (Figure D in S1 File). Diversity of the pottery attributes (A) and bead-type associations (B) express two different cultural geographies. Maps were made by S. R. using the software QGIS 2.6.1 and Etopo1 Digital Elevation Model [110]. https://doi.org/10.1371/journal.pone.0196488.g002.
The maps of interpolated pottery decorative techniques and bead-type diversities throughout the western Mediterranean show the highest interpolated values in southern Italy (Fig B). Hotspots restricted to the east of the Rhône Valley in southern France and eastern Iberia are also visible on the map of bead-type association diversity. Conversely, southern France and eastern Iberia are characterized by lower interpolated values on the map of pottery decorative techniques diversity (Fig A).

Conclusions:

Our results shed light on the cultural mechanisms responsible for the complex cultural geography of the western Mediterranean during the transition to farming. Pottery decorations participated in restrained networks in which geographical proximity and local processes of transmission played an influential role. Bead-type associations were used to tell multiple stories about social identities, were especially resistant to change and are characterized by a greater stability through time and space. The high level of cultural connection between the early farming communities favored movement, interaction and exploration and likely represented a successful strategy for their rapid expansion in the western Mediterranean. Cultural boundaries persisted despite a flow of individuals and symbolic transfer across them.

Genetic studies indicate that the last foragers and the first farmers developed social and cultural relationships more closely tied than previously indicated through components of the material culture [139]. Biological data and chronological models support a pattern of diffusion implying geographically discontinuous contacts between local foragers and incoming farmers, but repeated in time [9,140,141]. This process of diffusion conjointly occurred with changes in material culture, including pottery decorations and personal ornaments. Pottery production represents a technological innovation mostly associated with the Neolithic way of life in the western Mediterranean. Pottery decorations were likely particularly sensitive to interactions, leading to their high variability in time and space in order to reinforce group membership. Conversely, personal ornaments were less inclined to change in space and time. Their production by both local foragers and incoming farmers implies different cultural readjustments that led to a completely different pattern of variation in time and space. The preservation of the foragers’ personal ornament styles (and likely also meanings) within emerging farming communities [20,58] has probably contributed to the maintenance of their stability through time and space.

The two symbolic productions appear as a polythetic set of cultural behaviors dedicated to mediating early farmer identities in many ways, and personal ornaments likely reflected the most entrenched and lasting facets of farmers’ ethnicity.

This research is similar to the recent one by Kılınç et al. (2018) studying the same processes initially in Anatolia and the Aegean. With this one it may also be concluded that Archaeology is necessary to assess meaningful cultural (and thus potential ethnolinguistic) change, beyond gross genetic inflows, even in the case of the Near Eastern farmer expansion waves.

Related:

Distribution of Southern Iberian haplogroup H indicates exchanges in the western Mediterranean

Recent open access paper The distribution of mitochondrial DNA haplogroup H in southern Iberia indicates ancient human genetic exchanges along the western edge of the Mediterranean, by Hernández, Dugoujon, Novelletto, Rodríguez, Cuesta and Calderón, BMC Genetics (2017).

Abstract (emphasis mine):

Background
The structure of haplogroup H reveals significant differences between the western and eastern edges of the Mediterranean, as well as between the northern and southern regions. Human populations along the westernmost Mediterranean coasts, which were settled by individuals from two continents separated by a relatively narrow body of water, show the highest frequencies of mitochondrial haplogroup H. These characteristics permit the analysis of ancient migrations between both shores, which may have occurred via primitive sea crafts and early seafaring. We collected a sample of 750 autochthonous people from the southern Iberian Peninsula (Andalusians from Huelva and Granada provinces). We performed a high-resolution analysis of haplogroup H by control region sequencing and coding SNP screening of the 337 individuals harboring this maternal marker. Our results were compared with those of a wide panel of populations, including individuals from Iberia, the Maghreb, and other regions around the Mediterranean, collected from the literature.

Results
Both Andalusian subpopulations showed a typical western European profile for the internal composition of clade H, but eastern Andalusians from Granada also revealed interesting traces from the eastern Mediterranean. The basal nodes of the most frequent H sub-haplogroups, H1 and H3, harbored many individuals of Iberian and Maghrebian origins. Derived haplotypes were found in both regions; haplotypes were shared far more frequently between Andalusia and Morocco than between Andalusia and the rest of the Maghreb. These and previous results indicate intense, ancient and sustained contact among populations on both sides of the Mediterranean.

Conclusions
Our genetic data on mtDNA diversity, combined with corresponding archaeological similarities, provide support for arguments favoring prehistoric bonds with a genetic legacy traceable in extant populations. Furthermore, the results presented here indicate that the Strait of Gibraltar and the adjacent Alboran Sea, which have often been assumed to be an insurmountable geographic barrier in prehistory, served as a frequently traveled route between continents.

mtdna-h1-h3-europe-frequency
a, b, c. Interpolated frequency surfaces of clade H and its main sub-clades (H1 and H3). Frequencies (%) are showed in a colour scale. See information about the populations used in Additional files 4 and 5. Map templates were taken from Natural Earth free map repository (http://www.naturalearthdata.com/)

I usually find mtDNA data, especially studies like this one based on modern populations, very difficult to interpret for anthropological purposes. It is well-known that there are important differences in the pattern of Y-DNA and mtDNA expansion and distribution.

A paragraph in this respect caught my attention:

The patterns of variation in the Y-chromosome between western and eastern Andalusians, based on 416 males, have also been investigated for a set of Y-Short Tandem Repeats (Y-STRs) and Y-SNPs [53, 54, 55], Calderón et al., unpublished data] in combination to mtDNA analyses ([18, 19] and present study). In general, for both uniparental makers, Andalusians exhibit a typical western European genetic background, with peak frequencies of mtDNA Hg H and Y-chromosome Hg R1b1b2-M269 (45% and 60%, respectively). Interestingly, our results have further revealed that the influence of African female input is far more significant when compared to male influence in contemporary Andalusians. The lack of correspondence between the maternal and paternal genetic profiles of human populations reflects intrinsic differences in migratory behavior related to sex-biased processes and admixture, as well as differences in male and female effective population sizes related to the variance in reproductive success affected, for example, by polygyny [56, 57].

I think that the greater reduction in patrilineal lineages compared to maternal lineages we usually see during and after prehistoric or historic migrations have more to do with the renown Uí Néill family case and with war-related casualties (since combatants were usually men) than with other more popular explanations, such as enslavement of women or polygyny.

The most successful paternal lines (anywhere in the world) were probably those who remained in power for a long time (be it a patriarchal society based on families, clans, or more complex organizational units), who were richer and thus more capable of having healthy offspring, who in turn were able to survive longer and have more children who inherited power, etc.

In case of recent migrations or population movements that disrupt the previously established organization, after a certain number of generations, successful patrilocal families (usually from incoming lineages) might slowly dominate over a whole region, with poorer families (usually of ‘indigenous’ lineages) suffering a greater – especially perinatal and child – mortality, without any obvious (pre)historic event associated to these gradual changes.

This gradual replacement of paternal lineages is compatible with the adoption of the native language by newcomers. If the number of migrants is greater that the native population, and especially if their technology is more advanced, then a more radical change including ethnolinguistic identification is more likely.

I don’t deny the (pre)historic existence of radical replacement of male populations with continuity of female lineages due to massacres of men, female slavery, or polygyny, but they are probably not the main explanation for most regional differences seen in paternal lineages, and should thus be used with caution.

Gradual replacement and founder effects are also the most logical explanation for why autochthonous continuity myths (that the modern regional prevalence of few successful lineages tended to create in the 2000s) haven’t been corroborated by ancient DNA; e.g. R1b-DF27 in Basques, N1c-M178 in Finnic populations, R1a-Z283 in Slavs, etc. There is nothing different in those areas from other recent founder effects and internal migratory flows seen everywhere in Europe in the past millennia.

Paper discovered via a link by Alberto Gonzalez on Facebook group Iberia ADN

Related:

Iberian prehistoric migrations in Genomics from Neolithic, Chalcolithic, and Bronze Age

iberia-neolithic-bronze-age

New open access paper Four millennia of Iberian biomolecular prehistory illustrate the impact of prehistoric migrations at the far end of Eurasia, by Valdiosera, Günther, Vera-Rodríguez, et al. PNAS (2018) published ahead of print.

Abstract (emphasis mine)

Population genomic studies of ancient human remains have shown how modern-day European population structure has been shaped by a number of prehistoric migrations. The Neolithization of Europe has been associated with large-scale migrations from Anatolia, which was followed by migrations of herders from the Pontic steppe at the onset of the Bronze Age. Southwestern Europe was one of the last parts of the continent reached by these migrations, and modern-day populations from this region show intriguing similarities to the initial Neolithic migrants. Partly due to climatic conditions that are unfavorable for DNA preservation, regional studies on the Mediterranean remain challenging. Here, we present genome-wide sequence data from 13 individuals combined with stable isotope analysis from the north and south of Iberia covering a four-millennial temporal transect (7,500–3,500 BP). Early Iberian farmers and Early Central European farmers exhibit significant genetic differences, suggesting two independent fronts of the Neolithic expansion. The first Neolithic migrants that arrived in Iberia had low levels of genetic diversity, potentially reflecting a small number of individuals; this diversity gradually increased over time from mixing with local hunter-gatherers and potential population expansion. The impact of post-Neolithic migrations on Iberia was much smaller than for the rest of the continent, showing little external influence from the Neolithic to the Bronze Age. Paleodietary reconstruction shows that these populations have a remarkable degree of dietary homogeneity across space and time, suggesting a strong reliance on terrestrial food resources despite changing culture and genetic make-up.

iberia-admixture
(A) f4 statistics testing affinities of prehistoric European farmers to either early Neolithic Iberians or central Europeans, restricting these reference populations to SNP-captured individuals to avoid technical artifacts driving the affinities. The boxplots in A show the distributions of all individual f4 statistics belonging to the respective groups. The signal is not sensitive to the choice of reference populations and is not driven by hunter-gatherer–related admixture (Datasets S4 and S5). (B) Estimates of ancestry proportions in different prehistoric Europeans as well as modern southwestern Europeans. Individuals from regions of Iberia were grouped together for the analysis in A and B to increase sample sizes per group and reduce noise

Conclusion:

We present a comprehensive biomolecular dataset spanning four millennia of prehistory across the whole Iberian Peninsula. Our results highlight the power of archaeogenomic studies focusing on specific regions and covering a temporal transect. The 4,000 y of prehistory in Iberia were shaped by major chronological changes but with little geographic substructure within the Peninsula. The subtle but clear genetic differences between early Neolithic Iberian farmers and early Neolithic central European farmers point toward two independent migrations, potentially originating from two slightly different source populations. These populations followed different routes, one along the Mediterranean coast, giving rise to early Neolithic Iberian farmers, and one via mainland Europe forming early Neolithic central European farmers. This directly links all Neolithic Iberians with the first migrants that arrived with the initial Mediterranean Neolithic wave of expansion. These Iberians mixed with local hunter-gatherers (but maintained farming/pastoral subsistence strategies, i.e., diet), leading to a recovery from the loss of genetic diversity emerging from the initial migration founder bottleneck. Only after the spread of Bell Beaker pottery did steppe-related ancestry arrive in Iberia, where it had smaller contributions to the population compared with the impact that it had in central Europe. This implies that the two prehistoric migrations causing major population turnovers in central Europe had differential effects at the southwestern edge of their distribution: The Neolithic migrations caused substantial changes in the Iberian gene pool (the introduction of agriculture by farmers) (6, 9, 11, 13, 24), whereas the impact of Bronze Age migrations (Yamnaya) was significantly smaller in Iberia than in north-central Europe (24). The post-Neolithic prehistory of Iberia is generally characterized by interactions between residents rather than by migrations from other parts of Europe, resulting in relative genetic continuity, while most other regions were subject to major genetic turnovers after the Neolithic (4, 6, 7, 9, 25, 48). Although Iberian populations represent the furthest wave of Neolithic expansion in the westernmost Mediterranean, the subsequent populations maintain a surprisingly high genetic legacy of the original pioneer farming migrants from the east compared with their central European counterparts. This counterintuitive result emphasizes the importance of in-depth diachronic studies in all parts of the continent.

Related:

Y-DNA relevant in the postgenomic era, mtDNA study of Iron Age Italic population, and reconstructing the genetic history of Italians

iron_age_europe_mediterranean

Open Access Annals of Human Biology (2018), Volume 45, Issue 1, with the title Human population genetics of the Mediterranean.

Among the most interesting articles (emphasis mine):

Iron Age Italic population genetics: the Piceni from Novilara (8th–7th century BC), by Serventi, Panicucci, Bodega, et al.

Background: Archaeological data provide evidence that Italy, during the Iron Age, witnessed the appearance of the first communities with well defined cultural identities. To date, only a few studies report genetic data about these populations and, in particular, the Piceni have never been analysed.

Aims: To provide new data about mitochondrial DNA (mtDNA) variability of an Iron Age Italic population, to understand the contribution of the Piceni in shaping the modern Italian gene pool and to ascertain the kinship between some individuals buried in the same grave within the Novilara necropolis.

Subjects and methods: In a first set of 10 individuals from Novilara, we performed deep sequencing of the HVS-I region of the mtDNA, combined with the genotyping of 22 SNPs in the coding region and the analysis of several autosomal markers.

Results: The results show a low nucleotide diversity for the inhabitants of Novilara and highlight a genetic affinity of this ancient population with the current inhabitants of central Italy. No family relationship was observed between the individuals analysed here.

Conclusions: This study provides a preliminary characterisation of the mtDNA variability of the Piceni of Novilara, as well as a kinship assessment of two peculiar burials.


Reconstructing the genetic history of Italians: new insights from a male (Y-chromosome) perspective, by Grugni, Raveani, Mattioli, et al.

Background: Due to its central and strategic position in Europe and in the Mediterranean Basin, the Italian Peninsula played a pivotal role in the first peopling of the European continent and has been a crossroad of peoples and cultures since then.

Aim: This study aims to gain more information on the genetic structure of modern Italian populations and to shed light on the migration/expansion events that led to their formation.

Subjects and methods: High resolution Y-chromosome variation analysis in 817 unrelated males from 10 informative areas of Italy was performed. Haplogroup frequencies and microsatellite haplotypes were used, together with available data from the literature, to evaluate Mediterranean and European inputs and date their arrivals.

Results: Fifty-three distinct Y-chromosome lineages were identified. Their distribution is in general agreement with geography, southern populations being more differentiated than northern ones.

Conclusions: A complex genetic structure reflecting the multifaceted peopling pattern of the Peninsula emerged: southern populations show high similarity with those from the Middle East and Southern Balkans, while those from Northern Italy are close to populations of North-Western Europe and the Northern Balkans. Interestingly, the population of Volterra, an ancient town of Etruscan origin in Tuscany, displays a unique Y-chromosomal genetic structure.

italy-y-dna
Frequencies of the main Y-chromosome haplogroups E1b, J2 and R1b and their sub-clades in the 10 analysed Italian population samples. Black sectors in the primary pies are proportional to the frequency of the main haplogroup in each population. Coloured sectors in the secondary pies are proportional to the frequencies of sub-haplogroups within the relative main haplogroup.

Mitochondrial variability in the Mediterranean area: a complex stage for human migrations, by De Angelis, Scorrano, Martínez-Labarga, et al.

Context: The Mediterranean area has always played a significant role in human dispersal due to the large number of migratory events contributing to shape the cultural features and the genetic pool of its populations.

Objective: This paper aims to review and diachronically describe the mitogenome variability in the Mediterranean population and the main demic diffusions that occurred in this area over time.

Methods: Frequency distributions of the leading mitochondrial haplogroups have been geographically and chronologically evaluated. The variability of U5b and K lineages has been focussed to broaden the knowledge of their genetic histories.

Results: The mitochondrial genetic makeup of Palaeolithic hunter-gatherers is poorly defined within the extant Mediterranean populations, since only a few traces of their genetic contribution are still detectable. The Neolithic lineages are more represented, suggesting that the Neolithic revolution had a marked effect on the peopling of the Mediterranean area. The largest effect, however, was provided by historical migrations.

Conclusion: Although the mitogenome variability has been widely used to try and clarify the evolution of the Mediterranean genetic makeup throughout almost 50 000 years, it is necessary to collect whole genome data on both extinct and extant populations from this area to fully reconstruct and interpret the impact of multiple migratory waves and their cultural and genetic consequences on the structure of the Mediterranean populations.

mtdna-mediterranean
Major migratory routes with the associated mtDNA haplogroups for the Upper Palaeolithic (solid lines) and the Neolithic (dashed lines) chronologies. Other hypothetical migratory routes are presented with dotted lines (see text for more details).

Mediterranean Y-chromosome 2.0—why the Y in the Mediterranean is still relevant in the postgenomic era, by Larmuseau & Ottoni.

Context: Due to its unique paternal inheritance, the Y-chromosome has been a highly popular marker among population geneticists for over two decades. Recently, the advent of cost-effective genome-wide methods has unlocked information-rich autosomal genomic data, paving the way to the postgenomic era. This seems to have announced the decreasing popularity of investigating Y-chromosome variation, which provides only the paternal perspective of human ancestries and is strongly influenced by genetic drift and social behaviour.

Objective: For this special issue on population genetics of the Mediterranean, the aim was to demonstrate that the Y-chromosome still provides important insights in the postgenomic era and in a time when ancient genomes are becoming exponentially available.

Methods: A systematic literature search on Y-chromosomal studies in the Mediterranean was performed.

Results: Several applications of Y-chromosomal analysis with future opportunities are formulated and illustrated with studies on Mediterranean populations.

Conclusions: There will be no reduced interest in Y-chromosomal studies going from reconstruction of male-specific demographic events to ancient DNA applications, surname history and population-wide estimations of extra-pair paternity rates. Moreover, more initiatives are required to collect population genetic data of Y-chromosomal markers for forensic research, and to include Y-chromosomal data in GWAS investigations and studies on male infertility.

y-dna-plot
Two-dimensional plot of the PCA of Y-chromosomal haplogroup frequencies of modern populations from Europe, the Near and Middle East and North Africa. Symbols are as in the legend. The inset shows the plot of factor coordinates of the variables used.

We are clearly seeing in the latest genomic papers that Y-DNA was indeed extremely important to assess ancient population movements.

See also: