The Senate, People, and Genes of Rome

Der Movement is right about the existence of change over time, but is wrong about mostly everything else.

See here. Abstract, emphasis added:

Ancient Rome was the capital of an empire of ~70 million inhabitants, but little is known about the genetics of ancient Romans. Here we present 127 genomes from 29 archaeological sites in and around Rome, spanning the past 12,000 years. We observe two major prehistoric ancestry transitions: one with the introduction of farming and another prior to the Iron Age. By the founding of Rome, the genetic composition of the region approximated that of modern Mediterranean populations. During the Imperial period, Rome's population received net immigration from the Near East, followed by an increase in genetic contributions from Europe. These ancestry shifts mirrored the geopolitical affiliations of Rome and were accompanied by marked interindividual diversity, reflecting gene flow from across the Mediterranean, Europe, and North Africa.

Note: By the founding of Rome, the genetic composition of the region approximated that of modern Mediterranean populations.

That's a key finding, and at odds with "movement" dogma.

Overall, the findings are somewhat similar to what I previously reported.  Some highlights (emphasis added):

We generated whole-genome data for 127 ancient individuals from 29 archaeological sites in Rome and central Italy (Fig. 1 and table S1). 

The oldest genomes in our dataset are from three Mesolithic hunter-gatherers (10,000 to 7,000 BCE) from Grotta Continenza, a cave in the Apennine Mountains. In PCA, these individuals project close to Western hunter-gatherers (WHG) from elsewhere in Europe, including those from the Villabruna cave in northern Italy and from Grotta d’Oriente in Sicily (12–15) (fig. S17). 

As reported previously for WHG groups (12, 14), these individuals show particularly low heterozygosity, ~30% lower than that of early modern central Italians (7). After this period, we see a sharp increase in heterozygosity in the Neolithic Age and smaller increases afterwards, reaching modern levels by around 2000 years before present (fig. S6).

The first major ancestry shift in the time series occurred between 7000 and 6000 BCE, coinciding with the transition to farming and introduction of domesticates including wheat, barley, pulses, sheep, and cattle into Italy (Fig. 2) (6, 16).

Similar to early farmers from other parts of Europe, Neolithic individuals from central Italy project near Anatolian farmers in PCA (13, 14, 17–19) (Fig. 2A). However, ADMIXTURE reveals that, in addition to ancestry from northwestern Anatolia farmers, all of the Neolithic individuals that we studied carry a small amount of another component that is found at high levels in Neolithic Iranian farmers and Caucasus hunter-gatherers (CHG) (Fig. 2B and fig. S9). This contrasts with contemporaneous central European and Iberian populations who carry farmer ancestry predominantly from northwestern Anatolia (fig. S12). Furthermore, qpAdm modeling suggests that Neolithic Italian farmers can be modeled as a two-way mixture of ~5% local hunter-gatherer ancestry and ~95% ancestry of Neolithic farmers from central Anatolia or northern Greece (table S7), who also carry additional CHG (or Neolithic Iranian) ancestry (fig. S12) (14). These findings point to different or additional source populations involved in the Neolithic transition in Italy compared to central and western Europe.

Note: Different or additional source populations. Genetic differences in Europe were established at least as far back as the Neolithic.

During the late Neolithic and Copper Age, there is a small, gradual rebound of WHG ancestry (Fig. 2B and fig. S24), mirroring findings from ancient DNA studies of other European populations from these periods (10, 13, 18, 20). This may reflect admixture with communities that had high levels of WHG ancestry persisting into the Neolithic, locally or in neighboring regions (tables S9 to S11).

The Iron Age and the origins of Rome

The second major ancestry shift occurred in the Bronze Age, between ~2900 and 900 BCE (Figs. 2 and 3, A and B, and tables S13 and S14). We cannot pinpoint the exact time of this shift because of a gap in our time series.

We collected data from 11 Iron Age individuals dating from 900 to 200 BCE (including the Republican period). This group shows a clear ancestry shift from the Copper Age, interpreted by ADMIXTURE as the addition of a Steppe-related ancestry component and an increase in the Neolithic Iranian component (Figs. 2B and 3B). Using qpAdm, we modeled the genetic shift by an introduction of ~30 to 40% ancestry from Bronze and Iron Age nomadic populations from the Pontic-Caspian Steppe (table S15), similar to many Bronze Age populations in Europe (10, 13, 14, 19, 22). The presence of Steppe-related ancestry in Iron Age Italy could have happened through genetic exchange with intermediary populations (5, 23). Additionally, multiple source populations could have contributed, simultaneously or subsequently, to the ancestry transition before Iron Age. By 900 BCE at the latest, the inhabitants of central Italy had begun to approximate the genetics of modern Mediterranean populations.

That last part is the authors' broad conclusion from their data.

The Iron Age individuals exhibit highly variable ancestries, hinting at multiple sources of migration into the region during this period (Figs. 2A and 3B). Although we were able to model eight of the 11 individuals as two-way mixtures of Copper Age central Italians and a Steppe-related population (~24 to 38%) using qpAdm, this model was rejected for the other three individuals (p &lt; 0.001; table S16). Instead, two individuals from Latin sites (R437 and R850) can be modeled as a mixture between local people and an ancient Near Eastern population (best approximated by Bronze Age Armenian or Iron Age Anatolian; tables S17 and S18). An Etruscan individual (R475) carries significant African ancestry identified by f-statistics (|Z-score|>3; fig. S23) and can be modeled with ~53% ancestry from Late Neolithic Moroccan (table S19). Together these results suggest substantial genetic heterogeneity within the Etruscan (n = 3 individuals) and Latin (n = 6) groups. However, using f-statistics, we did not find significant genetic differentiation between the Etruscans and Latins in allele sharing with any preceding or contemporaneous population (|Z-score|<2 although="" by="" detect="" differentiation="" font="" genetic="" is="" limited="" power="" sample="" size.="" small="" subtle="" the="" to="">

In contrast to prehistoric individuals, the Iron Age individuals genetically resemble modern European and Mediterranean individuals, and display diverse ancestries as central Italy becomes increasingly connected to distant communities through new networks of trade, colonization, and conflict (3, 6).

Imperial Rome and the expanding empire

During the Imperial period (n = 48 individuals), the most prominent trend is an ancestry shift toward the eastern Mediterranean and with very few individuals of primarily western European ancestry (Fig. 3C). The distribution of Imperial Romans in PCA largely overlaps with modern Mediterranean and Near Eastern populations, such as Greek, Maltese, Cypriot, and Syrian (Figs. 2A and 3C). This shift is accompanied by a further increase in the Neolithic Iranian component in ADMIXTURE (Fig. 2B) and is supported by f-statistics (tables S20 and S21): compared to Iron Age individuals, the Imperial population shares more alleles with early Bronze Age Jordanians (f4 statistics Z-score = 4.2) and shows significant introgression signals in admixture f3 for this population, as well as for Bronze Age Lebanese and Iron Age Iranians (Z-score &lt; −3.4).

…two-thirds of Imperial individuals (31 out of 48) belong to two major clusters (C5 and C6) that overlap in PCA with central and eastern Mediterranean populations, such as those from southern and central Italy, Greece, Cyprus, and Malta (Fig. 4B). An additional quarter (13 out of 48) of the sampled Imperial Romans form a cluster (C4) defined by high amounts of haplotype sharing with Levantine and Near Eastern populations, whereas no pre-Imperial individuals appear in this cluster (Fig. 4AC). 

Notice that these are two separate groups – a majority of European Mediterranean genetics and a significant Near Eastern minority.

…some of the individuals in this cluster also project close to four contemporaneous individuals from Lebanon (240 to 630 CE) (fig. S18) (28). In addition, two individuals (R80 and R132) belong to a cluster featuring high haplotype sharing with North African populations (C4) and can be modeled with 30 to 50% North African ancestry in explicit modeling with qpAdm (table S28).

Different individuals.

The average ancestry of the Late Antique individuals (n = 24) shifts away from the Near East and toward modern central European populations in PCA (Fig. 3D). Formally, they can be modeled as a two-way mixture of the preceding Imperial individuals and 38 to 41% ancestry from a late Imperial period individual from Bavaria or modern Basque individuals (table S24). The precise identity of the source populations and the admixture fractions should not be interpreted literally, given the simplified admixture model assumed and the lack of data for most contemporaneous ancient populations (7). This ancestry shift is also reflected in ChromoPainter results by the drastic shrinkage of the Near Eastern cluster (C4), maintenance of the two Mediterranean clusters (C5 and C6), and marked expansion of the European cluster (C7) (Fig. 4C).

The high interindividual heterogeneity observed in Imperial Rome continues into Late Antiquity (Figs. 3D and 4). Late Antique individuals are distributed across the eastern Mediterranean (C5), Mediterranean (C6), and European (C7) clusters in roughly equal proportions. Using f-statistics, we identified three outliers who are genetically distinct from others in the same period, including R104, who genetically resembles Sardinians, and R106 and R31, who overlap with modern Europeans in PCA (Fig. 3D). 

In the Medieval and early modern periods (n = 28 individuals), we observe an ancestry shift toward central and northern Europe in PCA (Fig. 3E), as well as a further increase in the European cluster (C7) and loss of the Near Eastern and eastern Mediterranean clusters (C4 and C5) in ChromoPainter (Fig. 4C). The Medieval population is roughly centered on modern-day central Italians…The Normans expanded from northern France to a number of regions, including Sicily and the southern portion of the Italian Peninsula (and even sacked the city of Rome in 1084), where they established the Kingdom of Sicily (3, 36). 

Sallis Summary

Of course, we would like to have more samples, particularly for the Iron Age/Republic period, but the data are (for now) what they are, with the samples available, and we can, for the time being, make an assumption (that may be valid or invalid) that these samples are representative of the wider population. Also, how class differences in that period (e.g., patricians vs. plebeians) can be genetically modeled is unknown. Perhaps more samples will be found, and assayed, in the future.

The only part of the narrative that fits “movement” dogma is the genetic shift to the "east and south" (Eastern Mediterranean and Near East) during the Imperial period. However, it is interesting that the Fall of the Western Empire coincided with the later genetic shift to the "western and northern" directions. That is wholly opposite of “movement” dogma, which suggests Rome fell because of the influence of the “eastern and southern” influx (I suppose they’ll spin it that the “eastern rot” could not be reversed). The major anti-“movement” finding is that the original Romans (as per the study's limited samples) were not Nordic, they were not Dolph Lundgren walking around in a toga. Similarities of the old Roman stock to modern “Mediterranean” populations suggest that the genetics of later Roman populations were roughly returned part-way to the original genetic “centroid” (see Figure 3) by the later "western and northern" influences that counter-acted the "eastern and southern" Imperial influx, resulting in the more modern Roman populations – although this of course only partly approximated the original genetic position, and did not recapitulate the original stock. 

Note that the study is about Rome and surrounding regions (and not all of the areas that constitute the modern Italian nation state). Rome was obviously a very cosmopolitan city as the center of a vast empire, and therefore genetic heterogeneity there over time would be expected to be significantly higher than in other parts of Italy and in the empire as a whole. Thus, likely, genetic heterogeneity in the Roman Empire was at its maximum in Rome and surrounding regions..

So, the “movement” is "one for three."

1. The "movement" is correct about “eastern” (and "southern") influences in the Imperial period, and a genetic shift from the Republic to Imperial periods. Likely, Der Movement will be happiest about Figure 4C (as well as the changes shown in Figure 3), and concentrate on that to the exclusion of all else, as it demonstrates these shifts in a dramatic visual fashion. However, keep in mind that - similar to population genetics in general - the labels for genetic components (e.g., in Figure 4C) are descriptive and not meant to be taken literally, and that by "European" the authors are talking about samples whose PCA position is mostly in the area of Northern Italy-Tuscany, extending to Spain/France/Croatia at the far edges (not Northwest Europe proper and certainly not Scandinavia). 

One thing that people have a hard time understanding, and what I harp on about here frequently, is that labels given to things are not equivalent to the things themselves. For example, some of the populations included as “Mediterranean” (or even "Eastern Mediterranean" if that includes Greeks) are European populations; the distinction between that and “European” is arbitrary.  With specific respect to the PCA placement of the Ancient Roman (Iron Age/Republic) samples "European" is more South-Central  European.

The somewhat subjective labeling of Figure 4C can be interpreted in light of some of the fundamental "raw" data. Figures 4A and S26 show haplotype sharing between the Roman samples and modern populations. To be fair to the “movement,” some (not all) of the Iron Age/Republic samples have significant haplotype sharing with “Central and Northern Europe.” However, most of the Roman samples with significant haplotype sharing with “Central and Northern Europe” are actually those from the Late Antiquity and Medieval and Early Modern periods.  Moreover, looking at Roman samples with significant haplotype sharing with “Southern Italy” and “Greek” (as well with the general “Southern Europe and Mediterranean" category), some of these are Iron Age/Republic. In fact, some of the same Iron Age/Republic Roman samples have relatively high haplotype sharing with both sets of modern populations (Europeans in general tending to share many genetics) – sample R1 is a prime example of this phenomenon.  Note that “Basque” is included in the “Central and Northern Europe” category and some Iron Age/Republic samples (R473, R105) with relatively high “Central and Northern Europe” actually have relatively higher haplotype sharing with Basques and French.  

Figure S27 is a PCA of the Figure S26 haplotype data and clarifies some issues. Of the Roman samples that are outside the range of modern (North-Central-South) Italy, those that are shifted in the direction of populations of actual Northern and Central European origin (e.g., Roman samples R1219,106, 62, 1286, 1288, 1224, 116, 31) are all from the Late Antiquity and Medieval and Early Modern periods (decline, fall, post-fall).  Several of the Iron Age/Republic samples that seem to show relatively high haplotype sharing with “Central and Northern Europe” in Figure S26 are actually shifted in the direction of “Spanish” and “Basque” (and to some degree “French”) in Figure S27 – these include the aforementioned R473 and R1015. The aforementioned R1 sample clusters near “Northern Italy.” Another Iron Age/Republic sample (R850) is in between “Southern Italy” and “Cypriot” in Figure S27. Other Iron Age/Republic samples are close to “Spanish.” Thus, the Iron Age/Republic samples are mostly “West Mediterranean” with some being “Central Mediterranean” (and one or two are outliers), with the former "West Mediterranean" group tending to have more of the relatively high haplotype sharing with “Central and Northern Europe” (likely due to the Basque or Basque/French similarities). I do not observe any of the Iron Age/Republic samples overlapping Northern European populations in the PCA of Figure S27.

Thus, the fraction of Iron Age/Republic samples that exhibit significant haplotype sharing with “Central and Northern Europe” tend to either (1) also exhibit significant haplotype sharing with “Southern Italy/Greek” as well as “Northern Italy” and “Central Italy” and hence end up overlapping with Northern Italy; or (2) be shifted in the direction of Basques/Spain, exhibiting a West Mediterranean genotype more Western Hunter Gatherer (WHG)-enriched than other “Mediterranean” populations, thus resulting in enhanced haplotype sharing with other WHG-enriched populations. On the other hand, a smaller fraction of the Iron Age/Republic samples are of a Central/East Mediterranean type (along with an unusual Etruscan sample that may or may not be an outlier for the general Etruscan population), with less haplotype sharing with WHG-enriched populations and, in general, modest haplotype sharing with several of the other population groupings used for comparisons.  

The Iron Age/Republic samples therefore crudely cluster in two groups – the larger group centered on Northern Italy, Central Italy, Basques, Spain, and to some extent France; and a smaller group centered on Central Italy, Southern Italy, general Southern Europe/Central Mediterranean, with some associations with East Mediterranean, as well as that Etruscan sample previously mentioned. This interpretation is broadly consistent with the authors’ comments on their overall findings in the main text, and is also consistent with the right side of Figure S25, which summarizes data of haplotype sharing, identifying “recipient clusters containing ancient individuals.”  Most of the Iron Age/Republic Roman samples are in cluster C12 - "Northern Italy, Central Italy, Spanish, French." The remainder of the Iron Age/Republic Roman samples are in cluster C22 - "Southern Italy/Greek, " and cluster C21 - "Spanish."  The Roman samples shown in cluster C10 - essentially Northern Europeans - are Medieval and Early Modern.

Further, and importantly, Figures S10-12 show admixture analyses for different Roman samples and population groups, along with timelines. To my eyes, the Iron Age/Republic Roman samples exhibit an admixture profile relatively similar to present-day Italy as well as to the various of Roman history in between Iron Age/Republic and modern Italy (including the Imperial period), contrasting to the admixture profile of Northern Europe, which is clearly more different.

Figure S29 gives functional allele frequency data, which mirrors the general genetic data. For example, throughout most of Roman history, lactase persistence is low, and increases only toward the end periods, starting with Late Antiquity, precisely those periods that have samples exhibiting the most haplotype sharing with “Central and Northern Europe.”  Blue eye color was highest in the earliest (Mesolithic) and latest (Late Antiquity and Medieval and Early Modern) Roman periods; Iron Age/Republic and the Imperial periods look similar.  Hair color was not studied.

All of these data suggest a predominantly West Mediterranean character of the Iron Age/Republic (responsible for the haplotype sharing patterns discussed above), with some Central and Eastern Mediterranean influences. That is consistent with the overall PCA of Figure 2, as well as with the authors’ general conclusion that the area approximated modern "Mediterranean" genetics by the time of the founding of Rome. Thus, the general PCA positions (Figure 2) of the Iron Age/Republic samples show that a majority of these fall in the area of Northern Italy/Tuscany ("European") with a minority (keeping in mind the low number of samples from this period) in the area of Central and Southern Italy ("Mediterranean"). These are different parts of Italy, in Southern Europe; hence, again, the authors overall conclusion is that "By the founding of Rome, the genetic composition of the region approximated that of modern Mediterranean populations." 

Two other points. First, the authors make clear that genetic modeling of the Imperial population was a problem due to a poor data fit, suggesting that “this was a complex mixture event, potentially including source populations that have not  yet been identified or studied.” That sounds a lot like the parental population problem exhibited by commercially available ancestry testing.  Second, for those interested in single locus data (I am not), mitochondrial DNA (Figure S4) and Y chromosome (Figure S5) show changes over time similar to that of the autosomal genome.

One critique of the paper is that they could have, in the main text, discussed the haplotype sharing data in more detail. Needless to say, genetic kinship analyses would have been helpful, but as I have noted at my blog many times, population geneticists typically eschew performing such determinations.

Now, I have already observed signs that the dishonest "movement" is retconning their dogma, making believe that they never said that the original Romans were Celto-Germanic Nordics. No, now, with 20-20 hindsight, they make believe that they asserted that the original Romans were akin to Northern Italians/Tuscans - that is a complete fabrication of the dogma as well as not fully reporting the full spectrum of the ancient individuals' genetics. 

Essentially, very crudely speaking, Iron Age/Republic was shifting in the direction of Benito Mussolini, Imperial was shifting toward – and past – Julius Evola, and then Late Antiquity and Medieval was shifting toward Il Duce again, but not getting back to the original position. These are just very crude approximations; the peoples of that period were not literally exactly the same as similar modern peoples. Further, even though genetic heterogeneity in Rome obviously significantly increased after the establishment of Empire, the samples assayed exhibit genetic heterogeneity even before Empire - "The Iron Age individuals exhibit highly variable ancestries, hinting at multiple sources of migration into the region." If we assume these samples represent the general population (obviously an important assumption for this study), then the founding of Rome was due to a somewhat diverse population base. Whether that correlates to patricians vs. plebeians is an interesting question. Regardless, the existence of genetic heterogeneity from the beginning of the Roman state is not consistent with much of "movement" dogma.

Another point, as alluded to above, is that while we can determine which extant groups seem most similar to Roman samples from different time periods, with Iron Age/Republic being of particular interest, that doesn't mean that the Romans of any particular period were actually the same as any extant group or groups. Populations change over periods of centuries and millennia and this is particular true of an area with the history of Rome, with various population movements and important historical events over time. Similarity is not the same as exact identity.  Ancient peoples no longer exist as they did at their time, but we can determine which extant groups are most similar, and when the extant groups occupy similar territory as the ancients, then the extant groups are likely to be in part descended from those ancients. The Roman stock as such no longer exists, but we can determine what a small subset of them were like genetically (and get some phenotypic characteristics from functional genes), and make possible associations with modern populations. A careful study of busts and statues from, e.g., the Roman Republic shows facial phenotypes that are not really precisely the same as any extant group. One can look for phenotypic similarity, as with the genes, but not exact identity, when comparing ancients and moderns. The same goes for other groups. There are no Gauls anymore, as they were back then, but there are extant groups similar, with likely a linkage of descent between them.

2. The "movement" is wrong about the Fall of the Western Empire being associated with an increasing "eastern" and "southern" component. It is the other way around. The Fall occurred as the population of Rome was, genetically speaking, moving "west" and "north."  Unlike Der Movement, I do not postulate (a crudely deterministic) cause and effect between these genetic changes and the sociopolitical situation in Rome (as far as I understand, corruption was maximal in Late Antiquity). Der Movement would of course, I presume, make distinctions between "decline" and "fall" and assert that the "fall" was due to the "decline" caused by the "eastern (and "southern") influx." Indeed, one can expect the most "interesting" interpretations of these findings by the "movement." Nevertheless, the Roman state was founded by a Southern European population likely most akin (but not identical) to modern Northern Italians, but with Central and Southern Italian influence as well, and at the height of Imperial power, the city of Rome was more "Mediterranean" in character, albeit with some unfortunate significant influences from regions outside of what is today Italy (or Europe as a whole). 

3. Most of all the "movement" is wrong – 100% wrong – with the idea that the original Romans were Nordics akin to modern Northwest Europeans.  See my comments for points 1 and 2 above; also as regards point 3, I once again cite from the paper:

After two major prehistoric population turnovers—one with the introduction of farming and another prior to the Iron Age—individuals in central Italy began to genetically approximate modern Mediterranean populations…The Iron Age individuals exhibit highly variable ancestries, hinting at multiple sources of migration into the region during this period …An Etruscan individual (R475) carries significant African ancestry identified by f-statistics (|Z-score|>3; fig. S23) and can be modeled with ~53% ancestry from Late Neolithic Moroccan (table S19). Together these results suggest substantial genetic heterogeneity within the Etruscan (n = 3 individuals) and Latin (n = 6) groups….In contrast to prehistoric individuals, the Iron Age individuals genetically resemble modern European and Mediterranean individuals, and display diverse ancestries as central Italy becomes increasingly connected to distant communities through new networks of trade, colonization, and conflict (3, 6).

From a historical-sociopolitical narrative, pride of place first of all does of course has to go with the founders of Rome, who established the city and its traditions, as well as conquered the bulk of what was to become the Empire – the Iron/Age Republic group.  However, from the same narrative perspective, second place has to go to the extenders, maintainers, and rulers of the Empire, who established the Pax Romana.  Now, one cannot conflate all of the urban rabble of any period (Iron Age/Republic as well as Imperial, or later) with the ruling strata. Thus, from a biopolitical perspective, the ruling strata of the Imperial period would likely be those of European Mediterranean stock; that Imperial population would likely be similar to the smaller “group 2” fraction of the Iron/Age Republic era described above. 

An important take-away point on all of this is that the political situation of a polity can affect its genetic composition (which we know intuitively, but it is demonstrated here). The division of the Roman Empire between West and East shifted the genetics of Rome in a more "western and northern" direction. Indeed, these data support a trend opposite of "movement" dogma - it is more that political changes drive genetic changes than vice versa (although, in theory, there can be feedback in both directions; the point here is that the Roman data - from the "movements" own assumptions about population character - support the politics affecting genes' direction and not the reverse).

Similar to Ancient Rome, a European Imperium that deports non-Europeans and cuts off population movements with non-Europe will decrease kinship overlap between Europe and non-Europe and increase kinship overlap between European peoples, given enough time (and the latter will occur without any panmixia). 

In any case, with respect to the paper, we can expect the most outrageous lies, distortions, and misinterpretations about it from the fundamentally dishonest "movement."  They've done it  before.  I urge the reader to take a look at the paper itself (and much of the text is reproduced here, above), including the supplementary data section, and come to your own conclusions. Hopefully, you'll see that my summary is essentially correct and that whatever nonsense Der Movement comes up with is just that - nonsense.