Could Sarmatians have Spread the G-M406 Signature?

Researchers from the Ancient Genomics Laboratory in London, have completed a study which concludes that a 2nd century CE skeleton found in Cambridgeshire, England had Sarmatian-like ancestry.  The intact Roman era skeleton of an 18-25 year-old man was originally found near the village of Offord Cluny, as a result of road development in Cambridgeshire.  The article An Individual with Sarmatian-related Ancestry in Roman Britain was published on December 19, 2023 by a team of researchers led by Dr. Marina Silva.  In addition to examining the ancient remains for autosomal & uniparental DNA, the team also conducted carbon (C), nitrogen (N), oxygen (O), and strontium (Sr) isotope analyses in an effort to determine the ancient populations most closely related to the skeleton and where he may have lived.  According to the paper, the isotopic analysis indicated a history of mobility during the man's brief life, particularly in his childhood.

The individual was not found in a formal Roman cemetery of the time period.  Instead, the man was found in a rural location in "...an isolated burial that had been placed...toward the fringes of [a] farmstead".  This farmstead would eventually grow into a Roman villa, the study claimed.  Despite the rather simplistic burial and lack of grave goods, the authors note that the internment of the man does distinguish him from the rural population of the time which often left little trace at all.

Principal-component analysis (PCA) of the sample by the authors showed that the sample is completely different from any other Roman era DNA found in Britain.  Instead, the paper claimed that the sample "...is most similar to present-day individuals from Anatolia and the Caucasus... [with] affinities to Late Bronze Age individuals from Armenia and individuals recovered from Alan-associated contexts in the North Caucasus, but not with individuals from Armenia who post-date the Bronze Age."

YDNA analysis of the sample found it positive for R-Y13369.  R1b-Y13369 is a sub-branch of R1b1a1b1b/R1b-Z2103.  The study claimed this Y signature "...has been previously identified in skeletal remains ranging from the Late Bronze Age to the Urartian period recovered from present-day Armenia."  The study also noted that present-day bearers of this haplogroup show a diverse spread over the Caucasus, Anatolia, and the Near East (see Y-Full or FTDNA Discover).

According to the stable isotope analysis, researchers believed the individual may have experienced two relocations during his lifetime.  One shift in diet seemed to have happened around the age of 5-years-old, and another again after the age of 15-years-old.  This shift, they argued could represent this individual's treck westward across Europe to Britain. 

How and why the man ended up in Britain is purely speculative.  

The author's list several historical connections between Roman Britain and Sarmatia:

1. "Contributions of Caucasus or Pontic-Caspian-associated ancestry, usually admixed with local populations, have been identified in Roman cemeteries in other parts of the empire, such as in Italy or the Balkans." 

2. Greater Armenia's brief stint as a Roman Province.  

3. Sarmatian-Alan incursions into the Roman-controlled South Caucasus.

4. The Marcomannic Wars (166–180 CE) between Rome and Germanic and Sarmatian peoples.

The author's put forward a strong claim that the man was connected to the Roman Military:  

1. "The age at death (18–25 years old) and history of migration...could be consistent with this individual having come to Britain as part of a military movement, either as part of a soldier’s family or as a soldier himself. One possibility, given the radiocarbon date obtained (126–228 cal. CE; median 176 cal. CE), would be the historically attested deployment of Sarmatian cavalry in 175 CE, following Roman emperor Marcus Aurelius’s victory in the Marcomannic Wars, as described by the Roman historian Cassius Dio. In this scenario, the dietary shifts we see...would be explicable if he was associated with groups of Sarmatians who moved into central Europe before or during the Marcomannic wars...the plausibility of this interpretation depends on whether children were likely to have been part of movements of Sarmatians across Europe. Little is known about where the 5,500 Sarmatians were stationed in Britain. There are suggestions of Sarmatian horse equipment from Chesters on Hadrian’s Wall and epigraphic evidence for them from Ribchester, Bremetennacum Veteranorum in northwest England and Catterick, Cataractonium in northeast England, all a considerable distance from the A14 sites in Cambridgeshire."

2. "Other interpretations that could plausibly account for long-distance movement across the Roman Empire include, although are not limited to, governance of the empire, economic migration, or slavery."

3. "The absence of grave goods and the generally unremarkable nature of his grave prevents assessment of which scenario is most likely. A plausible explanation is that he died while en route somewhere, although this scenario may be weakened by the location of his burial one kilometer to the west of a major Roman road connecting Sandy and Godmanchester, Durovigutum (Figure 1A). An alternative hypothesis is that Offord Cluny 203645 was associated with the farmstead, possibly integrated within a rural civilian community."

What does this mean for G-M3302, G-FGC5089 and G-M406?

Clearly the sample itself is not a member of Haplogroup G.  It does however, illustrate the broad spectrum of possibility when it comes to the movement of people in ancient times.  Just one man planting the seed of a YDNA lineage could result in thousands of direct male descendants 2,000 years later. 

The study found that the closest single source match of the sample in question is Armenia_LBA.  However, being that Armenia_LBA dates to about 1200-850 BCE, the study discards this as a source population for the sample 1,000 years later.  The study finds some consistency in contemporary populations such as Armenia_Antiquity, Russia_Sarmatian_PonticSteppe, Russia_Sarmatian_SouthernUrals, and Russia_Sarmatian_Alan, "Overall, our results suggest that there may have been substantial diversity among groups identified as Sarmatians, some of which could have had ancestry that in our data is most closely represented by Armenia_Antiquity."

Central Anatolia, a core region for the G-M3302,G-FGC5089, and G-M406 YDNA signature, suffered great upheavel during the Bronze Age Collapse.  Based on current understandings, Late Bronze Age Armenia was a part of, or at the very least, intersected this core region during the LBA.  The post-collapse period of drought, famine, and instability in the region is a impetus for population movement and spread of the genetic signatures into secondary regions.  One of these secondary regions may be the Caucuses and the Pontic Caspian Steppe.

Based on modern-day testers, we see a sizable presence of G-M406 YDNA in the Pontic Steppe, specifically north of the Caucuses, and west along the northern Black Sea.  The findings of Dr. Silva's study, where  Armenian_LBA ancestry is present as a principal component in a supposed Sarmatian individual coincides with the idea that the Pontic Steppe geographical region may have become a secondary zone for G-M406 following the Late Bronze Age.  It also suggests that part of G-M406's spread into Eastern Europe may have been through assimilation of these individuals into cultures such as the Sarmatians, Alans, and Scythians on the eastern periphery of the Roman Empire.

Historical Overview: The Pontic-Caspian Stepp Late Bronze Age to Iron Age:

The Srubnaya Culture was an Iranic horse culture of the Bronze Age, in s successors of the Indo-European Yamnaya and Catacomb cultures.  They occupied the region north of the Black Sea and Caucuses.  They were contemporaneous with the Andronovo culture which stretched east of the Caspian Sea to the southern Ural Mountains.  The Sauromatian Culture is said to be a blend of these cultures that occupied the steppe north of the Caucuses and Caspain Sea from around 600 - 400 BC.

The Sarmatians are 

According to Wikipedia, "The ethnogenesis of the Sarmatians occurred during the 4th to 3rd centuries BC, when nomads from Central Asia migrated into the territory of the Sauromatians in the southern Ural mountains.  These nomads conquered the Sauromatians, resulting in an increased incidence of eastern Asiatic features in the Early Sarmatians, similar to those of the Sakas.

The name "Sarmatians" eventually came to be applied to the whole of the new people formed out of these migrations, whose constituent tribes were the Aorsi, Roxolani, Alans, and the Lazyges. Despite the similarity between the names Sarmatian and Sauromatian, modern authors distinguish between the two, since Sarmatian culture did not directly develop from the Sauromatian culture and the core of the Sarmatian culture was composed of these newly arrived migrants."

Ancient Sample Details

Sample: Offord Cluny 203645
ADatege: 126 CE – 228 CE
YDNA: R-Y13369
https://www.yfull.com/tree/R-Y13369/
MTDNA: K1A
ENS Study Accession: PRJEB67353
G25: England_Roman_Empire_Offord_Cluny_AD_177:C10271,0.094473,0.129988,-0.046386,-0.023579,-0.029852,-0.008367,0.006345,-0.006692,-0.051131,-0.022962,-0.00065,0.009292,-0.013825,0.000413,0.009636,-0.005967,0.001565,0.002027,0.001257,0.013256,0.004118,-0.004451,0.002835,-0.006386,-0.003233