Etruscan Genetics

Mixed bag for the Nordicists.

See this.

Abstract:

The origin, development, and legacy of the enigmatic Etruscan civilization from the central region of the Italian peninsula known as Etruria have been debated for centuries. Here we report a genomic time transect of 82 individuals spanning almost two millennia (800 BCE to 1000 CE) across Etruria and southern Italy. During the Iron Age, we detect a component of Indo-European–associated steppe ancestry and the lack of recent Anatolian-related admixture among the putative non–Indo-European–speaking Etruscans. Despite comprising diverse individuals of central European, northern African, and Near Eastern ancestry, the local gene pool is largely maintained across the first millennium BCE. This drastically changes during the Roman Imperial period where we report an abrupt population-wide shift to ~50% admixture with eastern Mediterranean ancestry. Last, we identify northern European components appearing in central Italy during the Early Middle Ages, which thus formed the genetic landscape of present-day Italian populations.

Let’s get into some details, and distinguish facts from the author’s spin.

Ancient genomes from Italy are very limited, with only sparse data available from the Neolithic to the Roman Republic period across the entire Italian mainland (fig. S1) (14–18). Individuals from the ancient city of Rome and its surroundings during the Iron Age and Roman Republic (900 to 27 BCE) harbored the predominant genomic components that characterize most Europeans from the Bronze Age onward (15, 17, 19, 20). In addition, three individuals were found to carry recent genetic influences from Africa and the Near East, a further demonstration of Rome’s wide connections across the Mediterranean as far back as the Iron Age. 

OK. Thus, such “exotic” ancestries, to the extent they exist in the modern Italian genepool, can date to ancient times, and are part of the ethnogenesis of Italy, just as Asian/Siberian admixture was part of the ethnogenesis in areas of Northern Europe.

Unexpectedly, almost all individuals from the later, Imperial period in the vicinity of the Empire’s capital carried large proportions of eastern Mediterranean ancestry, which was later reduced during the Late Antique and Early Medieval periods (17). 

“Almost all” is a matter of interpretation, and the “eastern Mediterranean” ancestry in many cases actually overlaps with modern Southeastern European populations.

However, the extent to which these changes are representative of the processes that occurred across the rest of the Italian peninsula remains to be clarified from individuals outside the megacity of Rome and its ancient metropolitan area.

Yes, but in this paper the authors look at an area of Central Italy relatively close to Rome. First, the extent to which this can be extended to all of modern day Italy is open to question. Second, if we are to adopt a “far and wide” attitude – then why doesn’t this possibly extend to other areas of the Roman Empire, such as France and England?  Further, given that Spain was long a part of the Roman Empire, and likely subject, to some extent, to similar population events, and later had the Moorish period, the Spain-like PCA placement of the mass of Etruscans becomes open to a variety of interesting interpretations.

Of individuals associated with the first time interval, the vast majority (40 of 48) form a genetic cluster here named “C.Italy_Etruscan” that overlaps with present-day Spanish individuals in a principal components analysis (PCA) built with West Eurasian populations from the Human Origins dataset (Fig. 2A) (21). 

See what I wrote above. Another major point is that overlapping with “present-day Spanish individuals” clearly shows that the original Etruscans, just like the original Romans, were not “Nordic” or “Northern European.”

Across this temporal interval (800 to 1 BCE), three groups of PCA outliers are identified, i.e., four individuals shifted toward northern African populations (C.Italy_Etruscan.Afr), three individuals shifted toward central European populations (C.Italy_Etruscan.Ceu), and one individual shifted toward Near Eastern populations (C.Italy_Etruscan_MAS001) (table S1A). To further inspect the genetic clustering of the central and southern Italian populations studied, we performed unsupervised ADMIXTURE on 71 individuals (Fig. 2, B and C) after the exclusion of genetically related individuals (table S1B and fig. S2). C.Italy_Etruscan individuals harbor the three genetic ancestries associated with Anatolian Neolithic farmers, European hunter-gatherers, and Bronze Age pastoralists from the Pontic-Caspian Steppe. C.Italy_Etruscan.Ceu carries a higher proportion of “steppe-related ancestry,” while C.Italy_MAS001 shows a genetic component maximized in Iranian Neolithic farmers. The latter is also present in C.Italy_Etruscan.Afr individuals alongside an ancestry component identified in an Early Neolithic Moroccan group.

These ancestries were all present in ancient times.

This suggests that the genetic history of Sicilians and Sardinians during the Bronze and Iron Ages was substantially different from that of populations on the Italian mainland, as confirmed by the distinctive spheres of interaction observed in the archeological record.

Differences inherent from ancient times, part of the ethnogenesis of these European peoples.

During the first half of the first millennium CE, we observe a marked shift in PCA space of all studied individuals toward the Near Eastern cline (Fig. 4A), distributed across the genetic space occupied by present-day southeastern European populations.

Note: “distributed across the genetic space occupied by present-day southeastern European populations.” Shifted toward the “Near Eastern cline” in relation to the original Western Mediterranean population, but still to a large extent within the European genetic spectrum. Greeks, perhaps?

C.Italy_Imperial was modeled as a mixture of the sources C.Italy_Etruscan and 158 published European and Near Eastern genomes from the Bronze and Iron Ages. As a result, the models that were found to fit the data best are those with a 38 to 59% contribution from Levantine or Anatolian populations into the local/preexisting C.Italy_Etruscan gene pool (Fig. 4B and table S4D). Substantial gene flow from the eastern Mediterranean was also reported in ancient individuals from Rome dated to the Imperial period (17). Despite our limited number of data points from the first five centuries CE, the new results suggest that the contribution of nonlocal ancestry in Rome was larger than in Etruria (Fig. 4A). However, this large-scale genetic impact of incoming groups during the Imperial period was not only limited to the metropolitan area around Rome but also extended into the neighboring and more distant regions considered here.

Here is the part of the paper most congenial to Nordicist narratives. But there are some difficulties here.  As outlined in my criticism of commercialized ancestry testing, admixture modeling is limited based on what reference populations are used.  The authors write:

The software qpAdm v810 was used on the 1240K dataset to test two populations being consistent (P value above 0.05) to be equally related to a set of reference groups or to model one population resulting from the admixture of two source populations (one-way and two-way admixture, respectively).

One can “model” any population as mixtures of other populations if one wishes do so (e.g., can Germans be modeled as Sardinian-Asian mixes?); that does not necessarily imply that the “modeling” reflects the actual population history of the peoples involved. For example – can Southeastern Europeans be “modeled” as admixture between Spaniards and Anatolians?  If so, does that imply that, say, Greeks originated from Iberian-Anatolian panmixia? The genetic modeling at most suggests a possibility.

The most that one can say here is that, yes, there was a south-east genetic shift compared to the original population – that was already clear from the previous Roman data – and that the people involved were for the most part similar to modern Southeastern Europeans, and if you choose as parental reference samples the original population and Near Easterners, then the Imperial samples could be so modeled, but they are still Southeast Europe-like. Thus, the “Central Italy Imperial” samples actually overlap with modern Southern Europeans (and some Jews) for the most part, not modern Near Easterners.

Regarding the last temporal interval of our ancient genomic transect (500 to 1000 CE), we observe that individuals grouped in the “C.Italy_Early.Medieval” cluster are generally shifted toward central European groups compared to C.Italy_Imperial and largely overlap with present-day populations from central Italy (TSI.SG)…This finding is consistent with a genetic input of northern European ancestry in central Italy during the Longobard period. However, the influence of other Germanic tribes in Italy like the Ostrogoths could also have enhanced the observed genomic shift.

So, the Dark Ages are associated with a north-west genetic shift.  No cause and effect can be discerned here. And the same goes for earlier shifts and historical narratives.  Nordicists don’t have much grist for the mill here.

Since modern-day central Italians largely overlap in PCA space with C.Italy_Early.Medieval individuals (Fig. 5A), we tested the consistency of the former group deriving from the latter. To enhance resolution, qpAdm was implemented with present-day worldwide populations in the reference set. No present-day Italian populations are consistent with deriving from the C.Italy_Early.Medieval cluster (P values below 0.05), although high-coverage genomes from Tuscany (Tuscan.DG) (32) yielded no grounds for strong rejection of genetic continuity (P = 0.02) (Fig. 5C and tables S2E and S4G). This suggests that the genetic makeup of present-day central Italian populations was largely formed at least by 1000 CE. To investigate whether an analogous picture is observed in contemporaneous individuals from southern Italy, data from the Early Medieval archeological site of Venosa in Basilicata were similarly analyzed. With the exception of VEN002, all Venosa individuals (S.Italy_Venosa) broadly overlap modern-day southern Italian populations in PC space and can be jointly modeled in qpAdm as deriving from the same stream of ancestry (P = 0.42) (Fig. 5, A and C). In PCA space, most Medieval and Early Modern individuals from Rome fall in an intermediate position between Early Medieval groups from Tuscany and Basilicata (Fig. 5A).

Thus, modern Italians are relatively similar to that resulting from all of this ethnogenesis.  We have a Central Mediterranean European population resulting from all of this.

This distribution is thus consistent with the current north-south genetic cline that mirrors geography (33, 34) (fig. S4), with Italy bridging the genetic gap between Europe and the eastern Mediterranean.

Err, excuse me, Italy is part of Europe. Modern Italians, in PCA, fall exactly where one would expect to find them, with the “genes mirror geography” paradigm, so the net result of all this racial population history is a European population that fits in with the various axes of European genetic variation. That sentence is better written as:

“…with Italy bridging the genetic gap between Northern Europe and the eastern Mediterranean.” 

Keeping in mind Asian/Siberian influences in Northern Europe.

The genetic replacement of ~50% of the preceding Etruscan-related gene pool was likely influenced by the movement of slaves and possibly soldiers, along with a larger pattern of human mobility from the eastern Mediterranean toward Italy (45–49).

This speculation is based to a large extent on their questionable modeling, unless by “eastern Mediterranean” they mean Southeastern Europe.

Continuing our genomic transect into the Early Middle Ages (500 to 1000 CE), we observe an additional genetic transition in some of the former Etruria territories through the spread of northern European–related ancestries…our analyses identify broad population continuity between the Early Medieval times and today in the regions of Tuscany, Lazio, and Basilicata, suggesting that the main gene pool of present-day people from central and southern Italy was largely formed at least 1000 years ago.

Again, modern Italians are as they are, fitting into the European spectrum of genetic variation, mostly fixed as of “at least 1000 years ago.”

Essentially, the findings here mirror that of the paper on ancient Roman genetics that I previously reviewed. A founding population of Western Mediterranean racial provenance (*), with Eastern Mediterranean,  Near Eastern influx, centered on Southeastern Europe, followed by a Northwest European influx - the stories in both cases are relatively similar.

The Nordicists celebrate the population changes (and the Imperial “modeling”), but weep at the fact that the original population was (Western) Mediterranean and not "Nordic," that the “newcomers” overlap within present day Southeastern Europeans for the most part, and that the north-west influx was not associated with any great historical resurgence (to say the least).  Further, contra what the authors may wish, the data are restricted to the data at hand, and cannot be broadly interpreted geographically beyond that.