I-Y33765 and ancient DNA - Lakenheath 6 (ERL104 G294, LAK006)

The first two published, ancient DNA, I-L233 specimens were each excavated from archaeological sites bordering the Baltic region in north eastern Europe, one in Lithuania (Spiginas 1) and the other in the north-west of the Russian Federation (5680-13 aka VK22).  Recently, Gretzinger et al., (2022) published the genetics for two additional ancient I-L233+ males whose remains have been recovered from burials in Holland and England (Figures 1 and 2).  In their Supplementary Information the authors identify these specimens as GRO002, from Groningen, Netherlands and LAK006 from, Lakenheath, England, and they report both men are derived for the I-Y4231 mutation which is downstream from I-L233. They further refined their result for the LAK006 Y-haplogroup to I-Y4252 and theirs is the first report of this clade in an ancient DNA sample.  This clade is particularly noteworthy because its formation precedes a period of extremely rapid genetic expansion with nineteen branches forming immediately downstream (FTDNA, 2023a).  Subsequent to the publication of the Nature article (Gretzinger et al., 2022) the Y-haplogroup of LAK006 was again refined and has now been assigned to one of these downstream clades, I-A19485 (FTDNA, 2023b).  At the present time, this I-A19485 haplogroup has been reported in FTDNA customer samples from men with paternal ancestry in England, the Netherlands and Poland (FTDNA 2023c). 

Depending on the source reference consulted, the LAK006 specimen is referred to by several designations.  Its original excavation number is G294, but, as already stated, in the recent genetic study it is called LAK006, and in online sources, notably FamilyTreeDNA, this has been expanded to "Lakenheath 6". In what follows I will to use this latter form because it seems to me it has a descriptive clarity that is helpful.

So, to be clear, this article will review the published reports that relate to the Lakenheath 6 skeleton and to the context in which it was found. I will also briefly consider how the identification of this individuals Y-DNA haplogroup may help our understanding of the rapid genetic and geographic expansion which seems to have occurred soon after the I-Y4252 mutation was formed.   

Figure 1 : The phylogenetic relationship between Lakenheath 6 (aka ERL104 G294 or LAK006) and other ancient DNA samples close to the I-Y33765 clade. In April 2023 the FTDNA phylogenetic Y-tree shows nineteen clades, including I-Y33765 and I-A19485, immediately downstream of I-Y4252.

To begin, let's consider what is known about the archaeological context of the Lakenheath 6 skeleton.  The bones are those of a young adult male and they were recovered from one of several early Anglo-Saxon cemeteries excavated in the parish of Eriswell, Suffolk. This part of Suffolk borders the Fens and, like much of East Anglia, is rich in early Anglo-Saxon archaeology since it was in this part of England that Germanic migrant communities from north-western Europe established themselves during the early 5th century. A characteristic of these first "English Settlements" are cemeteries that demonstrate a variety of mortuary practices associated with cremation and inhumation burials. Between 1997 and 2008, a group of three such cemeteries, containing in total 427 inhumation graves and at least 8 cremation burials, were excavated by Suffolk Archaeology on ground owned by the UK Ministry of Defence at RAF Lakenheath (Caruth & Hines, 2018). The excavation team particularly noted that the small number of cremations were only a fraction of those that may have originally occurred judging by the significant amounts of dispersed cremated human bone in the vicinity.  

Figure 2: Lakenheath 6 and other ancient DNA samples in relation to the putative origin of I-Y33765 in Tjust, Sweden.

These Anglo-Saxon burials have been dated to between the latter half of the 5th and the late 7th century and are distributed between the three, very closely separated, cemeteries which have been designated ERL104 (West), ERL046 (Central) and ERL114 (East).  The earliest burials are in ERL104, starting with the cremations after which inhumations begin at that site and at ERL046 and ERL114 and continue until about the third quarter of the 6th century.  After this date further inhumations occurred, but only at ERL104, for another hundred years until finally that cemetery too was abandoned in favour of a new site about 300m to the south. This new site was then utilised during the middle Anglo-Saxon period.  It has been estimated (Caruth & Hines, 2018) that the total burying population during the first phase, when all three cemeteries were in use, was 90-115 individuals but, in the second phase, when inhumations happened only at ERL104, the population had declined significantly to just 15-20 people. 

The Lakenheath 6 individual was interred during the first phase of burials in the West cemetery and his grave is identified in the archaeological reports as, ERL104 G294. This West cemetery is the largest of the three and, as already mentioned, the only one used throughout the early Anglo-Saxon period. It held 261 graves which were typically aligned east to west with a minority showing evidence of log coffin burial.  In their report (Cruth & Anderson, 2005) the archaeological team observed that "there is a general trend that suggests that the earlier burials are in the southern half of the site and that the area of burial extended northwards during the period of the cemetery’s use".  From published images of the grave plans I have not been able to identify the position of G294 with any confidence but, in the numbered plan of the ERL104 cemetery area (Figure 6, Cruth & Anderson, 2005), some twenty graves are identified within the G200-299 numbering sequence and all are grouped together in the north-eastern corner of the site so this perhaps is the area where Lakenheath 6 was buried (see Figure 3). 

Figure 3:  Plan of the West (ERL104) early Anglo-Saxon cemetery at RAF Lakenheath, Eriswell, Suffolk.  The red dashed circle indicates the area of the cemetery containing graves within the range G200-G299.  It seems to me possible that Lakenheath 6 may have been excavated from this area. (Plan illustration after that published in Caruth, J & Anderson, S., 2005) 

Remains of men, women and children were present in roughly equal proportions (Cruth & Anderson, 2005). The cemetery contained a variety of interesting mortuary practices including a warrior buried with his horse, several examples of young children buried with spears, several multiple inhumations and one grave in which a man was buried with a quiver of seven arrows. In three graves, G255, G221 & G313, putative musicians were buried each with a lyre (Caruth & Hines, 2018). Other grave goods included annular and cruciform brooches, glass and amber beads, wrist clasps, girdle hangers, shield bosses, knives and vessels. 

The burial of Lakenheath 6 (G294) is particularly noteworthy in that it is one of three graves of young adult males at Lakenheath that contain groupings of animal bone (Rainsford, 2017). The inclusion of animal remains was a routine aspect of Anglo-Saxon cremation rites and it sometimes also happened with inhumations during the early Anglo-Saxon period.  In both instances it is seen as an indication of probable pagan identity.  In burials G117, G294 and G443 animal bones of differing species are included; G117 includes cattle ribs, G294 contains a complete chicken and G443 contains sheep ribs.  In the G294 grave the chicken bones were placed above the mans' right shoulder beside his head.  So we can perhaps consider that, based on these burial rites Lakenheath 6 believed in a pre-Christian, pagan cosmology.  Another interesting characteristic of the Lakenheath 6 individual that is reported in the supplementary data published by Gretzinger et al.,(2022) is that he has an additional X chromosome and demonstrates the XXY kareotype associated with Klinefelter's syndrome.  Two other ancient DNA examples of Klinefelter's syndrome have recently been reported (Roca-Rada et al., 2022; Moilanen,et al.,2022). In modern populations the syndrome is reported at a frequency of around one in a thousand and is associated with above average height, learning difficulties and reduced fertility but the genotype may go unnoticed in perhaps a quarter of those effected (Anon, 2021). It is interesting to consider how Lakenheath 6 would have experienced his gender and how, if at all, this influenced his life and role in the Anglo-Saxon community at Eriswell.

Radio carbon dates from the grave of the warrior buried with his horse (G323), indicate that he was born circa 470CE and stable isotope analysis shows he grew up in the Lakenheath area.  This finding is typical for strontium and oxygen isotope results obtained from the Lakenheath skeletons where "the overwhelming majority of individuals had never moved more than 30 miles from where they were buried" (Caruth & Hines, 2018).  Hence we can conjecture that the Lakenheath 6 individual would have spent his life entirely within the locality surrounding the Lakenheath settlement and its cemeteries.  No radio carbon analysis has been performed on his skeleton but based on the position and cultural context in which he was excavated, his burial date estimate is 400-600CE (Gretzinger et al.,2022).  

So,"the material culture of the communities using the burial grounds [at Lakenheath] is entirely characteristic of Anglian England" (Hines, 2022) and stable isotope analysis confirms that most of those buried there were undoubtedly born and lived their lives in eastern England. Remains of the migrant founders of the community may have been among the earliest burials, possibly in some of the earliest cremations whose remnants are dispersed across the ERL104 site although, from the published reports, there is no evidence that any founder graves have been identified with certainty.  However, "both isotopic and genetic data yield a clear case for a substantial new population having settled here from across the North Sea from around the mid-5th century" (Hines, 2022). 

Table 1: Summary of fifteen samples from the three early Anglo-Saxon cemeteries at Lakenheath, Suffolk, England that were used in the study by Gretzinger et al.,2022.

Our understanding of the Anglo-Saxon migration into Suffolk, and its contribution to the early English gene pool, has been significantly expanded by NGS genome sequencing of 460 medieval skeletons excavated from across northwestern European (Gretzinger et al.,2022).  Fifteen of these samples came from the three Lakenheath cemeteries (seeTable 1). One individual came from each of the two smaller east and central cemeteries and thirteen were from the major west cemetery, ERL104.  In total the genomes of ten males from Eriswell were analysed and Lakenheath 6 was one of this group. In selecting the Lakenheath skeletons to be used "the principal criterion.....has been observable evidence suggesting close genetic relationship; eg. collocation in what look like family plots".    Based on their ancient DNA genome sequences the ancestry of all the individuals analysed from the Lakenheath cemeteries was primarily from the population that Gretzinger et al. have called Central Northern European (CNE).  They state that the emmigration source for this CNE population is that area we now refer to as Freisland, northern Germany, Denmark and southern Sweden (see Figure 4). From this, it seems to me reasonable to infer that the Y-chromosome lineages of the males buried at Lakenheath were also likely to have been present in this CNE geographic area at some time prior to the second half of the 5th century.  That is perhaps a generation or so before the earliest settlers were buried at Lakenheath.

Figure 4: Map showing the emmigration source (shaded red) for the Central Northern European (CNE) population in relation to the district of Tjust, Sweden (yellow circle), which is the seventeenth century ancestral origin of modern I-Y33765+,Swedish men. (Map after that published in Joscha Gretzinger,Twitter post dated, 21 September 2022)

At the present time, Lakenheath 6 is the earliest occurrence of any branch of the I-Y4252 clade whose mean formation date estimate is 13CE (95%CI, 325BCE-323CE).  In modern populations the I-Y4252 haplogroup has been reported throughout north western Europe, southern Scandinavia and the British Isles (see Figure 5).   So, it is possible that, within less than 500y of the formation of the I-Y4252 mutation, a male lineage of at least one of that clades branches, the ancestral line of Lakenheath 6, who we know to be derived for I-A19486, had enjoyed some proliferation within southern Scandinavia and then become part of a settler group that emmigrated and flourished in eastern England at the beginning of the Anglo-Saxon period.

 Figure 5: Distribution of I-Y4252 in modern Europe (source: Phylogeographer)

It seems to me that this straightfoward but dynamic narrative provides a helpful illustration of, and possible explanation for, the rapid expansion we see in the downstream phylogeny of I-Y4252.  In my previous post, I-Y33765 and other Baltic Sea branches of I-Y4252 , I speculated about changes and developments in Scandinavian society that may have contributed to a period of enhanced reproductive success for the earliest groups of men who were derived for the I-Y4252 mutation.  The glimpse we catch in our story of Lakenheath 6 and his direct-line male ancestors, is of a group of I-Y4252 men who were likely involved in some of those cultural developments. Certainly they must have been familiar with the dangers and advantages of travel by sea and the opportunities and hazards offered for their interactions with strangers and new places.  Two published studies have demonstrated that innovations in transport technology associated with migration and colonisation of new environments can produce fast expansion in dominant and priveledged male lineages that are seen as bursts of phylogenetic expansion in the Y-chromosome (Poznik et al., 2016; Balaresque et al., 2015).  I would argue that this is perhaps the case we observe with the quick development of so many branches below I-Y4252, where the development of the shallow draft, clinker built, iron rivet technology coincides with the migration of Germanic peoples outwards from southern Scandinavia.  Archaeological evidence for the origins of this revolutionary shipbuilding technique are found particularly in southern Sweden (Scania) and around the shores of the Danish archipelago.  In this south west corner of the Baltic these developments have been dated to the first half of the fourth century (Wolf, 2015).  Within a couple of centuries burials containing examples of complete ships or parts of such vessels are found from the province of Uppland in Sweden to the counties of Suffolk and Kent on the south-eastern corner of the British Isles (Brookes, 2007).  The archaeological context of these sites demonstrate how innovative Scandinavian ship design allowed communities bordering the Baltic and North Sea to interact with the early Anglo-Saxon settlements in eastern England including the community at Lakenheath.  

At the present time, the Lakenheath 6 individual is the closest ancient Y-DNA to our I-Y33765 clade with a TMRCA of around 1BCE according to the FTDNA Discover algorithm.  We know that he lived circa 500CE so that the founder of his migrant line likely arrived in Suffolk perhaps a generation or two before that date.  For the English arm of I-Y33765, I have speculated that our founder was a man from south eastern Sweden who arrived in England at about the time Cnut became king, so maybe circa 1020CE.  The proximity of the seventeenth century locus for the ancestry of modern Swedish I-Y33765 men in Tjust, Smaland, Sweden, (see Figure 4) would seem to imply our patriarchs community had some genetic affinity with the CNE population.  The migration from Scandinavia of both these men, although separated by half a millenium, was dependent on the seafaring culture and shipbuilding innovations that had developed in the south-western Baltic, particularly during the early iron age. My guess is that this unusually dynamic period would have given many opportunities for male reproductive success which fostered the genetic proliferation we see within the I-Y4252 haplogroup coincident with the Migration Period of the Germanic tribes.   

While writing this review, I have been very concious of the way in which our hobby has been transformed thanks to Next Generation Sequencing (NGS) technology. It will soon be the tenth anniversary of NGS becoming available as a direct-to-consumer, mass-market product.   This happened on 9th November 2013, when FamilyTreeDNA announced their BigY NGS test. I remember that then there was quite a flurry of speculation about how this new technology might benefit and increase the scope of "Citizen Science" genetic genealogy research.  The introductory offer price through to 31st November 2013 was $499 (£311) and  I was one of a group of five I-L233 "early adopters", all members of the I2a Y-haplogroup Project, who purchased the BigY test during that initial launch offer.  The four other chaps were Recker 246886, Lambert N20745, Fleming N10316 and Brown 4020. Our results eventually became available for us to download on 1st April 2014.  To any rational soul April Fools Day might seem quite an appropriate date on which to start puzzling about variants in vcf and BAM files. During the next few months, I am sure few of us hobbyists thought that within less than a decade we would be able to identify our Dark Age cousins and make TMRCA estimates with the precision now possible for Lakenheath 6 and his "brother" branches downstream of I-Y4252.  But this enormous benefit has only become possible because NGS produced great savings in the cost and time needed for whole genome academic research and because this revolution was so quickly then applied to many ancient genomes preserved in archaeological repositories and museams worldwide. It seems to me that the rate at which these studies of ancient population genetics have increased the number of archaeological samples for which we now have Y-haplogroup data is quite astonishing.  Even for our small "twigs" on the spreading Y-phylogenetic tree, the 2022 publication of the I-A19486 haplogroup assignment for Lakenheath 6 seems to open the possibility that perhaps, within the next ten years or maybe sooner, by some happy and whimsical chance, an archaeological sample with an I-Y33765 Y-haplogroup will been sequenced. Now that will be news worth writing about.

References

Anon (2021), Klinefelter Syndrome (XXY), Saint Mary's Hospital, Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, TIG 44/08, 5pp. 

Balaresque, P. et al. (2015) Y-chromosome descent clusters and male differential reproductive success: Young lineage expansions dominate Asian pastoral nomadic populations. European Journal of Human Genetics 23, 1413-1422

Brookes, S. (2007) Boat-rivets in Graves in pre-Viking Kent: Reassessing Anglo-Saxon Boat-burial Traditions. Medieval Archaeology 51, 1-18

Caruth, J & Anderson, S.(2005)  An assessment of the potential for analysis and publication for archaeological work carried out ar RAF Lakenheath between 1987 and June 2005. Vol1,
The Anglo-Saxon cemeteries ERL 104, ERL 046 and ERL 114. Suffolk C.C. Archaeological Service.

Caruth,J. & Hines, J. (2018), Excavations in the Anglo-Saxon Burial Grounds at RAF Lakenheath, Eriswell,Suffolk. A lecture given at the Society of Antiquaries of London, Burlington House, Piccadilly, 15 March,2018.https://www.youtube.com/watch?v=R9Q9yXir1gg

FTDNA (2023a), FamilyTreeDNA Y-DNA Haplotree https://www.familytreedna.com/public/y-dna-haplotree/I;name=I-Y4252 Retrieved, 1 May 2023

FTDNA (2023b), FamilyTreeDNA Discover Haplogroup Reports  https://discover.familytreedna.com/ Retrieved, 1 May 2023.

FTDNA (2023c), FamilyTreeDNA I2a Y-Haplogroup Project, DNA Results, Classic Chart https://www.familytreedna.com/public/I2aHapGroup?iframe=yresults Retrieved, 1 May 2023.

Gretzinger, J., Sayer, D., Justeau, P. et al., (2022) The Anglo-Saxon migration and the formation of the early English gene pool. Nature 610, 112–119. https://doi.org/10.103/s41586-022-05247-2

Hines, J (2022), A new Anglian community on the Suffolk Fen Edge: the sites at RAF Lakenheath.  Presentation given at the Society for Medieval Archaeology Annual Conference, "Current Perspectives on Early Medieval Migration, Mobility and material Culture", Oxford, 24-26 June 2022. 

Moilanen, U., Kirkinen, T., Saari, N-J. et al., (2022) A Woman with a Sword? - Weapon Grave at Suontaka Vestitorninmaki, Finland. European Journal of Archaeology 25, 42-60

Poznik, G.D. et al.  (2016) Punctuated bursts in human male demography inferred from 1244 worldwide Y-chromosome sequences. Nat. Genet. 48(6), 593-599

Rainsford, C.E (2017), Animals, Identity and Cosmology: Mortuary Practice in Early Medieval Eastern England.  PhD Thesis, School of Archaeological and Forensic Sciences, Faculty of Life Sciences, University of Bradford, UK

Rocca-Rada, X, Tereso, S, Rohrlach, A.B.et al., (2022) A 1000-year-old case of Klinefelter's sydrome diagnosed by integrating morphology, osteology, and genetics. The Lancet, 400, 691-692. 

Woolf, A. (2015) Sutton Hoo and Sweden Revisited In: The Long Seventh Century, Continuity and discontinuity in an age of transition. Ed.G.Alessandro. Peter Lang AG.

FamilyTreeDNA "Discover" and TMRCA estimates for I-Y33765

In previous articles I have discussed Time to Most Recent Common Ancestor (TMRCA) estimates for the phylogenetically important mutations in our I-Y33765 clade and how we can calculate these time intervals using the mutation rate of SNP and STR Y-DNA genetic markers. Being able to calculate approximate TMRCA is obviously a great benefit when we are researching the supposed historical context of events involved in our genealogy. 

One characteristic of the types of calculations we have used for obtaining TMRCA intervals is that these have relied upon either SNP-only or STR-only methods. It has been reported (Balanovsky, 2017) that while experimentally obtained SNP marker mutation rates largely overlap and produce usable TMRCA estimates for both genealogy and evolutionary studies, STR markers are more useful when constructing fine-scale phylogenies that are typically associated with genealogical pedigrees. However both types of marker have their own inherent problems. when they are used as the basis for TMRCA estimations. 

First, when using SNP markers to estimate periods within the genealogical timescale it is important to take care to select only the very high confidence mutations. Unfortunately these may not always be available or easy to identify with confidence.  Because genealogical timescales are relatively short, the omission or addition of just a single SNP can significantly alter estimates. Next, when using STR markers the major difficulty is presented by convergent and/or multiple mutations which can introduce error that again can be hard to identify with confidence, especially when a small number of individuals are being compared.  

For these reasons, the confidence intervals provided for our estimates are poor and there is a consequent need for an alternative method to estimate TMRCA that would give improved accuracy.  In 2021, a paper was published in Genes by Iain McDonald (McDonald, 2021) in which he presented a novel mathematical approach that combines probability calculations based on using SNP and STR markers with other probabilities derived from historical data and from ancient DNA to achieve more precise and accurate TMRCA intervals for genealogy.  

Earlier this month (July 2022) FamilyTreeDNA announced the release of an online feature they call "Discover" that provides "information about the haplogroup from your Y-DNA test".  The application is available to FTDNA customers and to others who simply need to register with that company. The tool allows users to input a Y-DNA haplogroup designation from which the application generates report pages which give a summary of relevant information, including geographic frequency, notable related individuals, migration routes and ancient DNA examples.  In addition, a section called "scientific details" gives options that list the base variants associated with that haplogroup, show its position within the Y-DNA haplotree and, most importantly for our interests, provide an estimation of the TMRCA at various confidence levels.  In presenting this latter feature (see Figure 1) the page rubric explains that it "is calculated based on SNP and STR test results from many present-day DNA testers" and "the state-of-the-art FamilyTreeDNA algorithm for inferring age estimates for the Y-DNA Haplotree. [was] Developed together with Iain McDonald."   

It seems to me this description and the helpful credit provide an indirect but clear reference to the combined probability model Iain McDonald describes in detail in his paper mentioned above.  As a result I think it worth briefly mentioning the significant advantages shown in McDonald's work now that we can all make use of the user-friendly version of his algorithm as it is provided by the FTDNA application.

In his paper McDonald describes the mathematical basis for a method which merges "the Y-SNP and Y-STR molecular clocks, and takes into account other available evidence (eg:, ancient DNA, proven paper genealogies, relatedness through autosomal DNA, etc)."  He demonstrates his revised algorithm using four examples.  In three scenarios he generates data which illustrate DNA ancestry either in colonial America, or in historical Scotland and Ireland, or medieval or prehistoric Europe and for the fourth model he uses real data from royal Stuart lineages.  With each of these example data sets he illustrates how his combined method gives improvements in the precision and accuracy of the TMRCAs compared to either STR-only or SNP-only methods.  

McDonald writes that "the most significant improvements in the precision of the TMRCAs come from the ability to combine both STR and SNP mutations into a single calculation" and he notes that in the future, improving the definition of STR and SNP mutation rates, offers the greatest likelihood for getting further benefits from his combined method over either STR-only or SNP-only TMRCA calculations.

Figure1: FamilyTreeDNA Discover presentation of TMRCA probability for I-Y33765

 

So it seems these advantages and possibilities are very encouraging, especially now that we all have easy access to an online tool that produces TMRCA periods based on this McDonald combined probability model.  

 

Now let us turn to how these developments may help our I-Y33765 research. When we compare the previously calculated SNP-only TMRCA estimates for the haplogroups within our clade with those produced using the FamilyTreeDNA "Discover" app. (Table 1) we can see it has provided some useful improvement.

Table 1: Comparison of TMRCA estimates for haplogroups within the I-Y33765 clade

At present within our clade we only have two haplogroups, I-Y33761 and I-BY198548, for which the dates are known from documentary sources. When we compare the "Discover" TMRCA estimates for both of these haplogroups with those obtained using our normal SNP-only methodologies (Table 1) there are improvements in the precision and accuracy achieved for both.  It seems to me that this is the most obvious practical method by which to judge the new FTDNA algorithm and based on this result I consider the new methodolgy is definitely helpful.  

In addition, the 95% confidence interval for the "Discover" estimates is significantly more constrained compared with the YFull SNP-only method.  Lastly, the mean dates given by the "Discover" application are broadly similar to those we have obtained using our clade-specific SNP mutation rate that we calculated directly from the nineteen generation Nils Swensson (1631-1713) pedigree. Because of these several positive indicators I have updated our draft I-Y33765 chart (Figure 2) using the TMRCA dates highlighted in Table 1.  As you can see the majority of these are taken from the FTDNA "Discover" application.

 Figure 2: I-Y33765 draft chart, July 2022 

(Click on images and table to enlarge)

References

Balanovsky, O (2017) Toward a consensus on SNP and STR mutation rates on the human Y-chromosome, Human Genetics, 136, 575-590

McDonald, I. (2021) Improved models of Coalescence Ages of Y-DNA Haplogroups, Genes, 12, 862 

I-Y33765 and ancient DNA - 5680-13 (VK22)

Only two ancient DNA samples with Y-DNA identified as haplogroup I-L233 or one of it's downstream clades have been published.  Both these samples were found in areas that border the Baltic Sea which makes them especially interesting for us given the apparent modern locus of I-Y33765 in south eastern Sweden.  In the previous article I considered the older of these specimens, an I-L233, late mesolithic adult male known as "Spiginas 1" that was excavated in Lithuania in 1985.  In the present notes I want to concentrate on the much younger specimen, originally catalogued as "5860-13" but more recently designated "VK22", an I-A8462 12th century adult male that was excavated in 1938-40 in north-western Russia.

The archaeological context of "5680-13" (Figure 1) is particularly interesting and has been extensively reviewed by Evgeniy L.Nosov and his colleagues (2018).  Although their book is written in Russian each chapter contains a helpful and comprehensive summary in English. In Chapter 3, Nadezhda Platonova and Serafina Sankina report and discuss excavations of an elite Christian cemetery adjacent to the Church of St Clement at Zemlyanoye Gorodishche  (Earthen Hillfort), Staraya Ladoga, Russian Federation.  In the late 1930's, the individual "5680-13" was one of 65 skeletons recorded from this cemetery when it was first excavated by a team led by Vladislav I Ravdonikas and Grigoriy P Grozdilov.  In 1941, the physical anthropologist Alexander N Yuzefovich was the first to observe "The strikingly Norse features of the 11th century skeletons sharply differentiate the Staraya Ladoga series from the Slavonic ones". The significance of his observations concerning a possible Scandinavian origin for the individuals buried at St Clement's church has, during the past decade, been internationally investigated (Magaryan et al.,2020; Douglas Price et al., 2019). All the skeletons recovered from the cemetery are now part of the collection of the Peter the Great Museum of Anthropology and Ethnography (Kunstkamera), St Petersburg, Russian Federation.   

Figure 1: Location of skeleton "5680-13" (VK22) in the southern half of the medieval cemetery of St Clement church at Zemlyanoye Gorodishche, Staraya Ladoga, Russian Federation. (a) Relationship of Staraya Ladoga settlement (red icon) to Lake Ladoga and to the Baltic Sea (b) The Kremlin and earth hillfort. Red rectangles represent the approximate position of the 11th century St Clement church and its cemetery.  Cross symbol indicates approximate burial location of individual "5680-13" (VK22).   (c) Map of excavation sites at Zemlyanoye Gorodishche. (Source of site plan Fig.B7, Nosov et al., 2018). [Click on image to enlarge]

The pre-World War II excavations by the team of Ravdonika and Grozdilov indicated that the cemetery had been used over many decades and that, at least in part, those interred there represent a quite distinct population. The earliest graves were in the southern part of the cemetery and had been dug in rows.  These graves contained men aged under thirty years together with some children and infants but adult female burials were notably absent.  In contrast the layout of the more recent graves in the northern part of the cemetery was irregular and in this part of the cemetery the skeletal remains included both sexes. Throughout the St Clement cemetery all graves suggested a Christian burial rite with almost no grave goods.  Typically individuals lay on their backs with heads to the west.  Radio carbon dating of bone samples indicates burials began in the eleventh century. 

During the medieval period, in the Ladoga region adjacent to the River Volkhov, a significant Viking age trade emporium developed. This was because the river was part of one of the major routes linking Scandinavia with the Black Sea and eastern Roman Empire.  From historical sources we are told that in 1019, when Yaroslav the Wise, Grand Prince of Kiev married the daughter of King Olav of Sweden their alliance resulted in the "Ladoga Jarlsdom" passing to Ragnvald Ulfsson who was the grandson of Skagel Toste (909-975).  Skagel Toste has been linked by some writers with the Toste or Tusti mentioned as taking Danegeld in England on the U344 runestone at Orkesta in Vallentuna near Stockholm. Although this appears an interesting idea it seems to me this connection is unlikely as the period from 954-980 saw little Viking raiding in England and no large payments of tribute are recorded.  However, returning to our main narrative, documentary evidence shows that Jarl Ragnvald was in fact permanently exiled from the Swedish court to Staraya Ladoga with his entire household and retinue.  It is conjectured (Nosov et al., 2018) that some male members of the Jarl's comitatus may be represented among the burials at St Clement.  Certainly men who came with Jarl Ragnvald may have had  Christian beliefs and it is possible that the cemetery was the place where such warriors were buried.  Snorri Sturlusson recounts in the Heimskringla that Ragnvald and his guards were involved in conflict with endogenous pagan tribes.   

Whatever his true background, the "5860-13" individual was buried among the distinctive population of young male skeletons from the southern half of the cemetery (see Figure 1b & c). Based on his long bones his body length has been estimated at between 166 and 169.3cm and this compares with an average for the cemetery "warrior" group of 170.6-172.6cm. It has been observed that this is appreciably taller than the height of the modern Russian population in the Ladoga region (Nosov et al., 2018). 

In a recent molecular genetics study (Magaryan et al.,2020), individual "5680-13" was one of seventeen burials from the St Clement cemetery that were used to characterize Viking age population genomics. In this investigation skeleton "5680-13" was given the sample ID, "VK22".  Ancient DNA extracted from the "VK22" skeleton confirmed his Y-DNA haplogroup as I-A8462.  In the modern European male population this haplogroup has so far only been identified in the British Isles and more particularly in Scotland and the northern half of Ireland (Figure 2).  In view of earlier comments about the putative origins of men buried at Zemlyanoye Gorodishche it seems possible that his Y-DNA haplogroup could imply "VK22" grew up in the northern British Isles and subsequently traveled, possibly via Sweden, to Staraya Ladoga where he served in the guard of a prince of the Rus.  Such a biography would demonstrate the potential mobility of Y-DNA during the Viking age and it would also emphasize that the find location of a marker obtained using ancient DNA may differ significantly both from its historical origin and from the region of its prevalence in modern populations.

Figure 2: Distribution of I-A8462 in modern male populations in Europe and the British Isles (Source: https://phylogeographer.com, June 2022)

In a further recent paper (Douglas Price et al., 2019) the authors used strontium isotope analysis to show that about one third of the individuals (n=5) from the southern part of the St Clement cemetery who they tested (n=15) are first-generation migrants likely from central Scandinavia or another area with very high 87Sr/86Sr values (Figure 3).  All this "Scandinavian" group had strontium ratios well above 0.7150. In contrast, individual "5860-13" showed 87Sr/86Sr values that were almost the lowest of any in the sample examined.  Douglas Price et al.,(2019) suggest the burials with values below 0.7150 may either indicate local individuals or individuals from Gotland both of whom may have grown up eating terrestrial and marine food from the Baltic.  Although the authors say "at present, we are unable to resolve this question" they conclude that "all (or many) of these individuals are non local [to Staraya Ladoga] and all (or many) of the individuals in this study would be from Sweden or Gotland".  Given the prevalence of I-A8462 in the British Isles and particularly in Scotland, it seems to me, it can be argued that individual "5680-13" more likely grew up in the British Isles since his strontium values are also consistent with those for that area which range between 0.07078 and 0.7165 (Evans, Chenery & Montgomery, 2012).  Hence it seems to me the combination of Y-DNA haplogroup and strontium isotope estimates make it likely the "5680-13" man was a first-generation migrant from the northern British Isles.  

Figure 3: Strontium isotope value for individual "5680-13" (second blue bar from left) compared with fourteen other burials at St Clement cemetery (blue bars). (Source: Figure 9 from Douglas Price et al., 2019). The estimate shown for the I-A8462 individual "5680-13" falls within the range of strontium isotope values recorded in the British Isles, i.e: 0.07078 - 0.07165, when using samples of tooth enamel from archaeological sites.

So, in the context of our interest in ancient DNA samples that are phylogenetically close to the I-Y33765 clade, the recent studies on the "5680-13" skeleton from Staraya Ladoga have illustrated the potential during the Viking period for male movement from the British Isles into the eastern Baltic Sea. Hence, it is as if "5680-13" had used a "return ticket" for the journey we conjecture must have been taken by the patriarch of the English arm of I-Y33765, from Sweden to Somerset, at about the same time.

In addition, it seems to me, the proximity of the "5680-13" burial to a church dedicated to St Clement is yet another, somewhat whimsical, coincidence.  As I have discussed several times already the cult of St Clement has been shown to have particular significance for the Scandinavian ruling elites of the Viking Age (Crawford, 2008). To illustrate this point from the perspective of the "5680-13" burial in the cemetery at Zemlyanoye Gorodishche I think it well worth quoting from the English summary to Chapter 3 of the review of those excavations (Nosov et al., 2018), written by Platonova and Sankina in which they observe: -  

"The consecration to the name of Pope St Clement also confirms that the first church was built as early as the 11th century. In the times of Vladamir and Yaroslav, St Clement still was considered as the main heavenly protector of the Rus'.  However, already as early as the 12th century, the cult of St Clement as the first saint associated with the Rus' is ousted by the cult of St Andrew the First-Called. In Rus' of the 12th-13th century, practically no stone temples dedicated to St Clement are known. Ladoga is nearly [the] single exception".   

References

Crawford, B.,(2008)., The Churches Dedicated to St. Clement in Medieval England. A Hagio-geography of the Seafarer´s Saint in 11th Century North Europe. St. Petersburg: Axioma, 237 pp.

Douglas Price,T, Moiseyev,V, & Grigoreva, N., (2019)., Vikings in Russia: origins of the medieval inhabitants of Staraya Ladoga,  Archaeological and Anthropological Sciences, https://doi.org/10.1007/s12520-019-00897-2 

Evans,JA, Chenery, CA, & Montgomery, J., (2012), A summary of strontium and oxygen isotope variation in archaeological human tooth enamel excavated from Britain, Journal of Analytical Atomic Spectrometry, 27, 754-764

Margaryan, A., et al., (2020)., Population genomics of the Viking world, Nature, 585, 390–396. https://doi.org/10.1038/s41586-020-2688-8

Nosov,EN, Platonova,NI, Beletsky,SV, Kirpichnikov,AN, Kurbatov,AV, Lapshin,VA, Milyaey,PA, & Sankina,SL (2018)., Advance in Archaeology of Staraya Ladoga: materials and studies, Proceedings of the Russian Academy of Sciences, Institute for the History of Material Culture, Vol. LIII, Neva Book Publishing House, St Petersburg, Russian Federation, 536pp

 

I-Y33765 and ancient DNA - Spiginas 1

Most of what we know about the I-Y33765 clade is based on interpretation of results from Y-DNA samples taken from ten men. Four of these men live in England, and another four in Sweden.  The two remaining DNA donors both have family origins in England but their nineteenth century ancestors migrated either to the United States or to New Zealand.  An obvious, but very important, characteristic of all these men is that, when their DNA samples were collected they were all living.  In other words their Y-DNA is modern.  

In previous articles I have used results of their Y-DNA analysis and details of their documented genealogies to speculate on the geographic origins of the I-Y33765 clade.  In particular, I have used the genealogies of the four modern Swedish men to support a narrative in which I have linked the Viking age patriarch of our clade to the south eastern part of present-day Sweden and more specifically to the area of Tjust.  While it seems to me such speculation is helpful and productive it's credibility rests on the unproven assumption that the places of residence of the ancestors of modern Swedish Y-DNA donors during the seventeenth century will be approximately localised in the area inhabited, 1000 years earlier, by their shared Viking age patriarch.  Without some additional evidence that seems a large leap of faith.

Obviously, it would be very nice to have an ancient DNA sample from Sweden that is derived for Y33765, but the expense and difficulties of finding, extracting and sequencing ancient DNA make the existence of such optimal evidence rather improbable.  At present only two ancient DNA samples with Y-DNA identified as haplogroup I-L233 or one of it's downstream clades have been published; "Spiginas 1", an I-L233 late mesolithic adult male excavated in Lithuania in 1985 and "5860-13" (also known as VK22) an I-A8462 12th century adult male excavated in north-western Russia in 1938-40.  At first glance, a feature common to these specimens, and especially interesting in the context of the apparent modern locus of I-Y33765 in Sweden, is that both were found in regions that border the Baltic Sea. 

Figure 1: Geographic and phylogenetic relationship between Spiginas1, 5680-13 (VK22) and I-Y33765  

In this and the next article I intend to examine the published archaeology of both these I-L233+ men and see how this may help us test our present hypothesis that I-Y33765 originated in south-eastern Sweden.  

First, it seems appropriate to consider the older ancient DNA sample Spiginas 1.  This is the designation given to a 6000y old Mesolithic or Sub-Neolithic I-L233+ male hunter-gatherer excavated from a small cemetery in Western Lithuania in 1985-86.  His grave was closely grouped with three others (Spiginas 2, 3 & 4) on the former island of Spiginas in the marshy southern part of Lake Birzulis.  In the southeastern Baltic region there are no large stone-age burial sites and human remains are instead found singly or in small cemeteries, as at Spiginas and another island cemetery in Lake Birzulis, Duonkalnis, where 14 graves were excavated in 1985.  At Spiginas the four burials were on the summit of a glacial kame formation at an elevation of 163m above sea level and their radiocarbon date estimates span more than 4000 years (7780ybp, Kunda culture, Spiginas 4 to 3580ybp, Neolithic corded ware culture, Spiginas 2).  Two papers (Butrimas, 1992; Balcione, Cesnys & Jankauskas, 1992) describing the original archaeological investigations are written in Lithuanian and each has an English and Russian summary.

Figure 2: Mesolithic sites in the area of Birzulis Lake (from original paper by Butrimas,1992).

1, the sites of Swiderian culture; 2, early Mesolithic sites of Pulli type of the Kunda culture; 3, sites of the Middle and the Late Mesolithic; 4, sites of the early Mesolithic sites of Pulli type and of the Late Mesolithic; 5, sites of undetermined chronological determination; 6, Mesolithic graves; 7. Stray find location of bone point of Kunda type.  Sites: 1. Kulnikas   2. mesolithic graves of Spiginas island   3. Spigino sala   4. Spigino Ragas   5. Oznagaris1   6. Oznagaris2   7. Oznagaris3   8. Birzulio Sasmauka   9. Birzulio Sasmauka2   10. Dreniai   11. Lingenai   12. Duonkalnis   13.

According to the excavation report English abstract (Butrimas, 1992) the grave of Spiginas 1 "was destroyed during World War II, and only fragments of long bones and a skull have preserved. Two flint arrow heads of early Kungemosen microlith type were found among these bone fragments".  Translation of the Lithuanian text of Butrimas, 1992, dealing with the Spiginas 1 grave confirm that as a result of the war-time disturbance "fragments from this grave were dispersed over a fairly large area - 4 x 4m, but mainly within the presumed grave site. Blurred contours of the grave pit is exposed at a depth of 45-48cm.  In the pit two romboid flint (cross) arrowheads [see Figure 4]. At the north-east boundary of the grave was a small pebble covered in brownish ochre. Three more small ochre patches were observed in various areas of the grave [see Figure 3]. North of the grave there was a recent shell hole and disturbed ground.  Material from the grave pit was given to the Moscow Institute of Geological and Geochemistry Isotope Geochronology Laboratory (USSR).  The grave dated from 5020 +/ -200 ybp, 3070 +/- 200BC.  This radiocarbon date suggests that the grave is early Neolithic.  However, arrowheads and grave No4 date suggests this date underestimates the true age. Anthropologists believe that a 35-45y old man is buried."

Figure 3: Spiginas 1 grave situation plan (from original paper by Butrimas,1992). 1 - bone fragments  2 - flint  3 - ochre covered pebble  4 - ochre  5- disturbed ground  6 -  grave outline  (after Figure 3 from Butrimas, 1992.  Although no scale is specified in the original paper it seems possible that the plan represents the 4 metre by 4 metre area over which “fragments from this grave were dispersed”)

Figure 4: The two early Kungemosen microlith type rhomboid flint arrowheads from Spiginas 1 grave pit (Figure 5 from Butrimas, 1992).  These appear to have been “grave goods” but could possibly be the cause of injury or death of Spiginas 1?  The only source of flint in the Eastern Baltic is in Estonia and this is very poor in quality (Tringham, 1971, page 60)

Figure 5: Drawings of the two flint points from the Spiginas 1 grave pit. (Figure 10 from Ostrauskas, 1996)

The second original paper (Balcioniene, Cesnys & Jankauskas, 1992) gives more detail on the skeletal remains of Spiginas 1.  From the English summary,“In Grave 1 a male,35-45 years old, was buried.  Craniometric analysis was impossible; teeth were abrased to the 3^rd – 4^th degree.  M¹  had four tubereles and was quite massive.  Oesteometrical data are presented in Tabes 3 – 7.  No pathological changes were identified”.  Transaltion of the Lithuanian text indicates that “of the skeleton there remained a left maxillery fragment, right radial shaft, the right ulna, without the distal end of the femoral shaft, the distal end of the left tibia shaft, right and left fragment of the fifth metatarsal. …… tooth wear is consistent with a 35-45 year old".

Mittnik, A et al. (2018) use Spiginas 1 as one of ten samples representative of the Narva culture that occupied the eastern Baltic region from the late Mesolithic to the Middle Neolithic (Baltic EMN Narva).  They report his Y chromosomal haplogroup is I which they further refine to I2a1a2a1a based on L233:G→A (2x) (see their Supplementary Information, Supplementary Note 3. They also report he has one upstream mutation for haplogroup I2a1a2a (L1286: G→A at 1x) and one mutation for I2a1 (PF4004: T→C at 1x) and I2a (L460: A→C at 1x).  In addition they determined his mitochondrial DNA haplogroup was H11a (see their Table 1) and they note that while this haplogroup is “normally associated with the Neolithic expansion into Europe, but (he) shows no evidence of Neolithic farmer ancestry on the nuclear level suggesting that this haplogroup might have been present already in foraging groups”.  The woman who founded the H11a mitrochondrial haplogroup lived between 8000 and 4200 ybp (Behar et al., 2012).

Figure 6: Frequencies of four selected Y haplogroups in ancient DNA samples from Europe (from original paper by Jobling & Tyler-Smith, 2017).  The dark blue line shows the decline in haplogroup I2 from its significant proportion of the male population during the Mesolithic to a possible nadir approximating to the late Bronze age.

So, based on radiocarbon dating and the flint grave goods we can infer that Spiginas 1 lived in a late Mesolithic or early Neolithic hunter-gatherer society centered on Lake Birzulis.  Butrimas (2017) has speculated on the basis of archaeological, linguistic and historical evidence that the northern part of this lake represents a ritual complex of cemeteries, sacrificial hearths and funerary feast sites which date from the middle Mesolithic period to historical times.  He considers the four graves at Spiginas to be part of this ritualistic landscape.

At the time Spiginas 1 was buried at lake Birzulis the I2 Y-DNA haplogroup constituted a significant proportion of the European male population (see Figure 6).  The decline in haplogroup I2 from about 3000BC has been linked with the migration of populations from the Eurasian steppe which introduced significant cultural and genetic replacement, including R haplogroup Y-DNA (principally R1b) into central and western Europe and eventually the British Isles (Olalde et al., 2018).  In Scandinavia these migrations are characterized by the Corded Ware Culture (CWC) (also termed Battle-Axe Culture within Scandinavia) which in this region notably introduced R1a Y-DNA (Mittnik et al., 2018; Gunther et al., 2018) 

However, for the ancestral narrative of our I-Y33765 clade in SE Sweden, the significant neolithic culture is associated with the indigenous Scandinavian Hunter Gatherers (SHG).  These SHG peoples are derived from a mixture of Western (WHG) and Eastern Hunter Gatherer (EHG) populations (Gunther et al., 2018) in which the dominant male haplogroups are G and I2.  The Narva culture, of which Spiginas 1 is a member are genetically closer to WHG than EHG and hence Spiginas 1 can be considered genetically related to SHG men.

Within south eastern Sweden, Denmark and Estonia CWC sites are more usually associated with inland locations and with herding and farming while the SHG sites are typically coastal and involve a mobile maritime lifestyle that is called the Pitted Ware Culture (PWC).  The nomenclature "corded" or "pitted" refers to decorative characteristics of the pottery produced by the respective cultural groups.  The principle food source for PWC populations were seals and fish, giving them a nickname as "Inuit of the Baltic".  A recent study (Coutinho et al., 2020) of twelve male skeletons from three PWC sites on the island of Gotland was able to characterize the Y-DNA for eight of the individuals and each belonged to haplogroup I2.  Fifty percent of the total sample (n=6) were confirmed as haplogroup I2a (I-CTS595).  The radiocarbon dates for these individuals are estimated within the range 3000-2500 yBCE and so are not dissimilar to that quoted for Spiginas 1.  Also like the Spiginas grave PWC burial rituals involve single individual graves and include the use of red ochre.

Gotland is about 100km from the Swedish mainland but slate arrow points, found in some PWC graves on the island, seem to substantiate contact with mainland sources to obtain this material.  During the past century PWC sites have been recorded at many coastal locations bordering the Baltic (see Figure 7).  In Tjust, Smaland, Sweden, (see Figure 8) PWC sites have been excavated, at Hellero and Gardsholmens, north of Vastervik.  Finds from Vivastemala, which is just to the south of Vastervik have been important in interpreting Pitted Ware pottery in south-east Sweden because the styles found there in the late 1930's were very similar to those found at PWC sites in east central Sweden (Papmehl-Dufay, 2006).  Clearly, because of their maritime lifestyle, PWC populations would have appreciated the opportunities offered by the Tjust archipelago.   

Figure 7: Pitted Ware Culture (PWC) sites in Southern Scandinavia (after Douglas Price, 2015)

After about 2800yBCE there is archeological evidence for cultural contacts between CWC and PWC so that from about 2400yBCE, the PWC becomes absorbed into the late CWC or Battle Axe Culture (BAC). Further sources have suggested that the resulting Nordic Bronze Age population was the progenitor for the Germanic tribes which dispersed throughout Europe during the Migration Period.  

 

Figure 8: Pitted Ware sites in the Tjust archipelago

In summary, the Spiginas 1 individual is a representative of hunter-gatherer societies of the Baltic region.  His genomic DNA seems closer to WHG rather than EHG populations and his I2 Y-DNA haplogroup is found at high frequencies in pre-Neolithic samples from Europe but becomes progressively less common from the early Neolithic onward.  The coastline of south east Sweden was home to the last humans to adopt a hunter-gather lifestyle in Europe, the PWC, who had a mobile maritime lifestyle.  Genetic analysis of male PWC graves on Gotland shows a high frequency of the I2a Y-DNA haplogroup throughout the Neolithic. Several PWC sites have been excavated in the Tjust archipelago. 

References

Balcioniene, I.,Cesnys, G & Jankauskas, R.,(1992) Craniometry, Odontology, Osteometry and Paleopathology of the Mesolithic graves from Spiginas, Lietuvas Archeologia, v8,  p10-16

Behar, D.M. et al (2012) A “Copernican” reassessment of the human mitochondrial DNA tree from its root.  American J of Human Genetics, 90(4), 675-684

Butrimas, A (1992) Mesolithic Graves from Spiginas, Lietuvos Archeologia, v8,  p4-9

Butrimas, A (2017) From Mesolithic to Early Christianity: The development of the ritual Complex in the northern part of Lake Birzulis (Lithuania) according to archaeological, linguistic and historical research. Sociology and Anthropology, 5, 204-219

Cesnys, G.,Butrimas, A., (2009) Reinventing Mesolithic skulls in Lithuania: Donkalis and Spiginas sites.  Acta Medica Lituanica, 16, 1-8

Coutinho, A.,Gunther,T.,Munters,A.R.,Svensson,E.M.,Gotherstrom,A.,Stora,J.,Mailmstrom,H., & Jakobsson, M. (2020) The Neolithic Pitted Ware culture foragers were culturally but not genetically influenced by the Battle Axe culture herders. American Journal of Physical Anthropology, 172, 638-649

Douglas Price, T (2015) Ancient Scandinavia, OUP, Oxford, 494pp

Gunther, T et al. (2018) Population genomics of Mesolithic Scandinavia: Investigating early post-glacial migration routes and high-latitude adaption.  PLOS Biology, 16, e2003703, https://doi.org/10.1371/journal.pbio.2003703

Jobling, M.A & Tyler Smith, C (2017) Human Y-chromosome variation in the genome sequencing era. Nature Reviews Genetics, 18, 485-497

Mittnik, A et al. (2018) The Genetic Prehistory of the Baltic Sea region, Nature Communications

Ostrauskas, T. (1996) The Mesolithic in Western Lithuania, Lietuvos Archeologia, v14,  p192-212

Papmehl-Dufay, L. (2006) Shaping an Identity. Pitted Ware pottery and potters in southeast Sweden. Theses and Papers in Scientific Archaeology 7, Stockholm University, Sweden, 329pp

Trinham, R.(1971) Hunters, Fishers and Farmers of Eastern Europe 6000-3000 BC, Hutchinson University Library, Hutchinson & Co, London