The Beaker phenomenon and genetic transformation of Northwest Europe 2017. A layman's take.

They say that you cannot write prehistory, but here in Britain, prehistory is currently being rewritten, and it's thanks to DNA.  A new study , "The Beaker Phenomenon, And The Genomic Transformation Of Northwest Europe" has been published on BioRxyv.  A new study that recently analysed the DNA of 170 ancient human remains in Europe.

A little background...

1. British Archaeology and the Bell Beaker

British archaeologists have long been aware of a late prehistoric artifact culture found across the British Isles, and across large areas of Western Europe.  It bridged the Late Neolithic and Early Bronze Age periods around 4,400 to 3,800 years ago.  It was characterised by the use of fine bell-shaped beaker pots, usually red ceramic fabric, heavily decorated with simple motifs.  These motifs were characteristically impressed with a fine toothed comb or dentated spatula.  Many Bell beaker burial rituals have been excavated and studied.  The inhumed body would usually be crouched on the side, roughly on a north to south alignment.  A bell beaker would often be stood near to the body, at the feet, or near the head.  Other grave goods often included barbed and tanged flint arrowheads, flint flakes and blades, antler picks, sometimes one or two more beakers, amber beads, copper awls, and gold earrings / hair rings.  64% of British Beaker burials were flat graves, but sometimes a barrow or cist would be erected above it (Beaker Pottery of Great Britain & Ireland. DL Clarke.  CUP 1970).

Above, a flint barbed & tanged arrowhead of the Beaker Culture, that I found and recorded during a surface collection survey some years ago.

Archaeologists studying the artifact culture in Britain, compared the British finds to those on the Continent in order to try to find an origin for these people.  They suggested either Brittany in North West France, or the Lower Rhine Valley, in the Netherlands and Northern Germany.  Some alternatively promoted Iberia as the origin.

Then British Archaeology entered an intellectual phase where it became fashionable to dismiss migration or invasions of people, in favour of cultural exchange.  Pots not People.  Rather like today, we British wear denim, t-shirts, listen to R&B, and drink coke.  However, we have not been displaced by North Americans - we just absorbed the artifacts of another culture.  From the 1970s on, many late prehistoric migrations were dismissed by British archaeologists as cultural exchanges rather than representing population displacement.

2. The New Population Genetics and the Steppe Pastoralists.

A new field of study has been gathering pace with the arrival of the 21st Century, that uses genetic evidence, to explore past migrations, movements, admixtures, and origins of peoples.  The earliest pioneers used blood types, then mitochondrial DNA mutations, followed by STR of Y-DNA.  Some of the early conclusions supported the new orthodoxy of British Archaeology.  Stephen Oppenheimer's infamous publication "The Origins of the British" championed that there had been little change in British populations since the Ice Age.  They were to be proven wrong.  Early conclusions, based on little evidence, misunderstandings that were later corrected with more data, seriously damaged the reputation of population genetics in British prehistoric studies.

The most common Y-DNA haplogroup of Western Europe, particularly of Ireland and Britain was R1b.  Early mistakes gave this male haplogroup an Ice Age origin of the Basque Region in Southwest Europe.  As more data gathered, and debate developed, it became apparent that the origin was not the Basque region, but the Pontic and Caspian Steppes of Eurasia!  It became associated with an archaeological culture in Southern Russia called the Yamna.  The R1b and R1a haplogroups appeared to have spilled off the Steppes into Europe during the Copper Age during a significant migration event around 4,900 - 4,600 years ago.  In Eastern and Central Europe, this migration of pastoralists appears to be responsible for the fused artifact culture known as the Corded Ware (again, after a prehistoric pottery style).

A few lectures on Youtube to watch:

Havard lecture by David Reich 2015.

CARTA lecture by Johannes Krause 2016

That brings us up to date.  In summary, population geneticists have discovered a movement of people, not just pots, from the Steppes into Europe.  Modern Europeans descend from an admixture of three major founder populations: 1) the Western Eurasian hunter-gatherers, then a layer of 2) Early Neolithic farmers (that originated in Anatolia and the Middle East), and finally, 3) the Steppe Pastoralists.  The actual mix varies not only from person to person, but also regionally across Europe.

So how does the Bell Beaker Culture of Britain and Western Europe fit into all of this?  The strong assumption over the past couple of years was that the diffusion of R1b Y-DNA haplogroups occurred then, so therefore, it was a simple extension of this westward drift across Europe that originated on the Pontic and Caspian Steppes.  It first spawned the Corded Ware Culture in Central Europe, but then when it met Western Europe, spawned the Bell Beaker Culture.  However, until now, this hypothesis hadn't been tested.

The Beaker phenomenon and genetic transformation of Northwest Europe 2017

Has now examined some of these questions, through the examination of an unprecedented scale of ancient DNA sampling. The link to their published document (which is still awaiting peer review) is at the top of this post, and I'd invite others to read it for themselves.  An article covering the document can also be read on the Scientific American.  However, I personally with my layman head take five suggestions from the study.

  1. They found that the DNA of human remains on Continental Europe did not suggest one cohesive or homogeneous population.  There was in this case, evidence of cultural diffusion.  Different peoples were taking on the Bell Beaker artifact assemblage in Western Europe.  Pots rather more than people.  This was a great surprise, as we still know from the earlier study, that much of our DNA and Y-DNA in particular, originated around 400 years earlier from the Eurasian Steppes.  However, although the Central European Corded Ware Culture does still appear to have been a response to that great influx of new people from the Steppes, the picture with the Western European Bell Beaker is more complex.
  2. An exception was Britain.  Here, the remains associated with Bell Beaker Culture were all one population, and they were very different to the earlier Neolithic population of Britain.  It appears to have been a case of population displacement.  They suggest at least 90% displacement!  It means that very few or none of our Neolithic ancestors built the amazing monuments of Neolithic Britain.  They were built by earlier peoples, that our ancestors displaced.
  3. They confirm a Lower Rhine origin as most likely for the British Beaker People.  The ancient DNA that most closely matched British Beaker DNA, came from Beaker human remains in the Netherlands and Northern Germany.  This correlates nicely with the 1970 archaeological study mentioned above.
  4. It's confirmed.  Previous to their entry into the British Isles, there is no evidence of any Steppe ancestry, no Steppe autosomal DNA, no Steppe Y haplogroups such as R1b-L21 here.  (Nor any mtDNA haplogroup H6a1).  The Beaker people from the Lower Rhine, brought the initial layers of this DNA to Britain.  The founder population were admixed, but with significant percentages of Steppe ancestry, particularly on Y lines.
  5. The previous Neolithic Farmer population were mainly Y haplogroup I2, and appear to have descended mainly from populations in the South, from Iberia, rather than from the Danube, although before that from Anatolia.  The modern population that is closest to them today are Sardinians.

Also as a layman, I guess that this suggests that most, or even any "Neolithic Farmer" DNA suggested by our ancient ancestry calculators, was most likely picked up elsewhere than Britain, and brought here by later migrants (descended through that mixture of cultural diffusion and admixture), rather than directly from the British Neolithic population.

I also notice a correlation with an Irish study last year ("Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome" Cassidy etal.  Queens University Belfast 2016), that again, suggested major displacement of earlier peoples in Ireland, at the end of the Neolithic, by a population with largely Steppes origins.

How not to use online genealogy

I recently decided to invest in an annual subscription to Ancestry.co.uk.  I therefore intend to use it extensively over the next year in order to bolster my tree and to add leafs through their very fat database of resources.

A little background.  I've researched my family tree since at least 1988, but not continuously.  Back in the day, there were no online resources.  the most modern thing were census on microfilm and the Mormon IGI (International Genealogical Index - the ancestor of FamilySearch.org) available in the Local Studies Library.  My tree started, as it should, through interviewing elderly relatives, looking through their photos, the few birth and marriage certificates, and any other artifacts.  Those elderly relatives have all passed on now.  if you are just starting with genealogy - do it now.  I then moved on to the English & Welsh County record offices.  White gloves and pencils, in order to peruse through the original parish registers and other documents - no digitalisation, or even microfilming of them then.  Very little indexing as well.

Then I was ordering GRO certificates from London, paying professional researchers to collect them for me, as it worked out cheaper than having them mailed to me by the GRO!  Then rather than looking for DNA matches, it was searching through surname interests or through the annually published GRD (Genealogical Research Directory) for shared ancestry.  The good old days.

I said it wasn't continuously.  Interests changed, I lived out life recklessly, and moved on a few times, leaving all behind.  I lost pretty much all of my genealogy.  Meanwhile, digitalisation was coming in fast, indexing increasing, and the Internet was giving birth to online genealogy.  During this birth, I had used an early version of Broderbund Family Tree Maker (it installed on several floppy disks) on a personal computer, and even managed to upload data and a GEDCOM file to a few places.

Then maybe 16 months ago, after ordering a 23andMe test, I picked it up again.  I found my old GEDCOM file on a web archive.  Downloaded it, opened it with open source Gramps software.  It worked!  Since then, I've gathered surviving notes (so many lost), photos, and certificates.  I then discovered a remarkable resource.  Online Genealogy.

Online Genealogy

There are many online resources.  The big providers include Ancestry.com (Ancestry.co.uk), FindMyPast.co.uk, MyHeritage.com, and FamilySearch.org.  All but the latter website are subscription fee based.  Asides from these providers, there are many other services for genealogy online.  Of the above, I have heavily used FindMyPast, FamilySearch, and Ancestry.

Online Genealogy using Ancestry.com

The big advantage of Online Genealogy is indexing and the database.  Over the past 25 years or so, armies of volunteers and paid researchers, have been reading through microfilmed, microfisches, or digitalised images of masses of parish registers, parish records, wills, criminal registers, state records, military records, Bishop's transcripts, Headstone surveys, and more - from not only England & Wales but from all over the World, where they are available.  They read the names of those recorded, and add them to computer files with references.  Businesses such as Ancestry.com, buy access to these indexes, and often to the original digitalised images if they exist.  These are all added to their own database.  Their customers search, and find ancestors.

A Few Problems

  1. I can report this for English records, for which I have a lot of experience. The record is still very incomplete.  You might see a Joe Bloggs, but is it your ancestor Joe Bloggs?  Many of the parish records were missing, or damaged.  Parish chests in cold churches can be damp places, the registers pulled out for every baptism, marriage, or burial, thumbed through by all.  Paper was valuable in older records, and the priests and clerks cram their little scribbled lines in them.  There were stories of vicar's wife's using old registers to kindle the fire in the vicarage.  In addition, not ALL parish registers are online at any one depository.  I've noticed that Ancestry.com is very good for Norfolk registers, but abysmal for Suffolk.  FindMyPast is good for Berkshire records.  They are far from complete records.  In addition, some ancestors were not in any parish records.  They were rogues on the run, vagabonds, or even more often ... non-conformists.  Some priests were lazy.  All of this on top of those many missing or damaged records.
  2. The indexers were human beings.  Sometimes volunteers, sometimes more recently I suspect, poorly paid human beings outside of Europe (is this the case?)  They vary in skill at reading 18th century, 17th, even 16th century hand writing that has been scribbled down in often damaged records.  The database searches for names that sound similar (to a computer program), but they miss so many that are incorrectly transcribed.  Try to read through the original images if you can.

So the record is far from complete.  The online record less so.  A brilliant tool, but it's not going to hand you your family tree all perfect and true.  If you understand this problem, and you are more concerned about truth and quality, than about quickly producing a family tree back to Queen Boadicea (I have seen people claim such things!), then you are already aware of this.  The problem is, that you know that an ancestor was called Joe Bloggs.  Online, you find a Joe Bloggs, living 100 miles away, born about the right time.  With a click, you "add" him to the tree, then resume climbing up from him.  What you may not realise, is that there were maybe 20 Joe Bloggs born at about the right time within a 100 mile radius of the next generation.  You just picked the one that your online ancestry service flashed up to you.  He is quite probably not close family, never mind your ancestor.  All above him are not your ancestors.

Truth and quality in a family tree

Do you care?  Is it possible to trace back more than several generations, and to preserve that quality? The 20th and 19th centuries in England & Wales are great.  We have records from a national census every 10 years between 1841 and 1911.  They can be searched with your online service.  We have them as correlations for parish records.  We also have state records to correlate with from 1837!  Before that though, it gets a bit scratchy.  Particularly if your ancestors were not titled - as most of them were not!  Then we are down to scribbles in parish registers, a few tax books, tithes, military rolls.  Great stuff, but increasingly - we lose correlations.  We lose certainty.

When we lose certainty, we have to start to make judgments.  Do we add an ancestor based on little record?  We have to make that judgement ourselves.  We should add the resource, name it, perhaps publish our uncertainty.  We should be ready to remove if doubt grows rather than certainty.

I've not mentioned biological certainty here.  Haplogroup DNA can challenge some very old trees.  Things happen in biology.  We call them NPE (Non Parental Event).  Spouses cheat, lie, prostitute, are raped, commit bigamy, incest, confused.  People secretly adopt, particularly during a crisis.  I have seen a claim of the average NPE happening once in every ten generations on average.  I don't think that we can truly measure this.  Anyway, I'm of the school that although DNA genealogy is interesting in the pursuit of the past, that family is not always just about biology.  Who reared them?  Who gave them their name?  If that is family, it's also ancestry.


But the ultimate mistake with using online genealogy

This one is easy.  It is that companies such as Ancestry.com and MyHeritage.com, allow, sometimes encourage the resourcing of other members family trees.  It has nothing to do with rights or property.  It has to do with the reproduction of mistakes, and bad quality research.  It indeed gives genealogy at online sites like these, a pretty bad name.

Many users of these sites are casual.  They have only used the online resources available through the quick click and collect ancestry of these services.  They are only trying to pursue as far back, as possible, within as short time as possible.  Truth and quality is of very much secondary value.  It's the consume society.  They leave their disjointed trees of fiction all over these web services.  Then Ancestry / MyHeritage, invites you to add them to your own.  Very much internet viral in form - the errors replicate like mutations in a strand of DNA, only with lightening speed.  It's so easy to add new layers of ancestry.  But they are fiction.  I've seen people marrying before they are born, dying before they give birth.  I've seen people marry their parents or uncles.   I myself, recently tried it en mass as an experiment to a tree.  It was incredible.  The discrepancies and errors.  Ugly.

So, if you have to, look at other trees. I strongly recommend that you avoid that temptation to simply click and collect ancestry.  Most of the genuine ancestry on these trees is available to be quickly found with your own use of the services on that site.  Do that, but make your own judgments.  Don't add to the virus trees.  Genealogy is for the long haul.

K36 Timeline - Ancient Ancestry

This new DNA tool can be found here.  It's just a little bit of fun.  It requires results from your DNA test results run through the Eurogene K36 calculator (available on GEDmatch).



15,000 years ago (Upper Palaeolithic - LGM):


Total Europe 81%
including:
Hunter-gatherer North & East 71%
Hunter-gatherer South 10%

Anatolia 19%

I've previously explored my Ancient Ancestry from this period in the post Celebrating my Ice Age ancestors.





4,500 years ago (Late Neolithic / Copper Age):

Indo-European Expansion 70%
European Farmer 28%
Local European HG 1%

Anatolian Copper Age 1%

I've previously explored my Ancient Ancestry in the two posts Celebrating my Neolithic Ancestors and Celebrating my Steppe and Beaker ancestors.

Review

As with any ancient DNA calculators, this shouldn't be taken as a serious result, but as a fun approach, to compare results with others.  It's great that as enthusiasts, we can now start to explore our ancient admixtures for ourselves.  Compared to CARTA:

From CARTA 2016.

The results look a little weighted towards the "Indo-European" (Copper Age Steppe Expansion), and this repeats when compared with my other ancient calculators.  I suspect that my actual European Neolithic (Early Farmer) percentage is a little higher than 28%, and my IE rather lower - but it's all just fun.

In addition, I'd still stay clear of labelling the Steppe Expansion as "Indo-European" or entering the linguistic debate.  Finally, the 15,000 year old map.  I think that it plays down some of our ancestry from Asia north of the Caucasus, or at least Eurasia, and would be better labelled Western Eurasia than as Total Europe.  My Y line proves that I have some Ice Age ancestry from SW Asia, from the area of Iran.  Of course, this is the issue with any test on autosomal DNA, it's going to rock around, even between siblings, due to each random recombination.

However, an excellent tool, thank you to the creator.


Total Genealogy

I'm certainly not descended from the bonobos in the above photograph (Credit: W. H. Calvin Ape Bonobo San Diego Zoo.  Creative Commons Attribution 4.0).  However, at some point, perhaps around seven million years ago, we do share common ancestry.  That is a link in the inter-connectivity of Life on Earth.  Also an excuse to post a photo of those wonderful beings.

I recently attended a lecture on Total Genealogy, but I was disappointed that the subject was surname study.  I had hoped that it would relate more to my own concept of the term.  A genealogy that doesn't just embrace documentary research of recorded ancestors over the past 500 years or so, but a more general interest in heritage, that overlaps with DNA, genetics, population genetics, anthropology, physical anthropology, archaeology, local history, national and regional history, cultural and social history, prehistory, linguistics, human evolution, and yes, even our shared ancestry with those bonobo cousins.  Everything ancestral, how we came to be how we are, and above all, time travel in our imaginations.  That is what I mean by Total Genealogy.

Researching the written record, following names is great fun.  Why should the fun stop there though?  Where were my ancestors 12,000 years ago?  Actually, DNA and population studies gives my imagination some good answers to that question.  What did my ancestors 500,000 years look like?  How did they live?  If I could time travel, what would I see?

Total genealogy leads you to bridges, the concept of genetic folding, and of bottlenecks.  You start to relate closer to all humans, and see everyone as a distant cousin.  It embraces a love of heritage, of people, and of the Natural World.  It leaves me in awe.

FT-DNA Family Finder My Origins 2.0 - April 2017 update

If there is anyone out there reading this blog, you know my recorded ancestry - all SE English, mainly East Anglian. No recorded evidence of anything but English over the past two or three centuries. This is not to say that I don't think any actually happened.




51% British might seem low for an Englishman - but I'm aware that my personal DNA flavour is a bit atypical for a Brit, more Continental. My Origins 1.0 gave me 36% British. 23andMe un-phased gives me 32% British / Irish. I do however suspect that my flavour isn't so atypical for an East Anglian of local rural ancestry. Living DNA gave me the most, a whopping 74% British. Therefore on that score, you could say that for myself, My Origins 2.0 actually comes in at 2nd place - better than 23andMe, DNA.land, or WeGene. I'm currently waiting for Ancestry.com results, but I'm not expecting better.

46% West and Central European where I have no record of any such ancestry - but East Anglian has been noted as close to North German, and certainly, SE England has plenty of early medieval admixture from that part of the world during the Anglo-Saxon event. In addition, we've continued to have immigration from the Continent over the past several hundred years, particularly but not exclusively, from the Netherlands and Northern France. I recently noticed that a 5xgreat grandparent had the surname Moll that is often found in Germany. However, it is also found in East Anglia, but are they connected? One day I'll find a recorded non-English ancestor! So as an East Anglian, I forgive autosomal DNA for ancestry algorythms that suggest that I have Dutch, German, French, or Danish ancestry. 23andMe (un-phased) gave me 27% French & German". Even Living DNA gave me 4.6% Scandinavian and 2% Germanic.

Now the Traces. I find these really interesting. Because they could fit in with other evidence. The My Origins 2.0 "Southeast European" designation appears to include Italy. My Origins 1.0 gave me a very silly 32% Southern European. 23andMe gave me 2% Southern European (although I have noted that the majority of English testers get a small percentage of this). Living DNA gave me a whopping 9.6% Tuscany. A friendly discussion with one of the LDNA techs, suggested that it looked to them, to be genuine. There was a family story on my father's side, that there was a "foreigner" - but I've never found any recorded evidence. I've scanned and scanned the tree for any sign, but nada. Not in great gp to 3 x great gp range. I'm open to a possible NPE, but I need more evidence than one auDNA test result.

The trace West Middle East and Ashkenazi are interesting, because although I have no recorded West Middle East or Ashkenazi ancestry, my Y-DNA does originate in SW Asia, possibly the area of Iran or Iraq. However, no auDNA test or GEDmatch calculator so far has provided any surviving evidence in the autosomes of any Asian, above that of average for a Brit. It all appeared washed out by genetic recombination. I share my Y with another family (different surname) from England, and we trace our lines back to the 1740's in Southern England (32 miles apart). That to me suggests that our immigrant Y ancestor most likely arrived in Southern England at least 400-500 years ago. I suspect earlier, maybe Medieval or even Roman. However, has the new algorithm picked something up? Maybe just a coincidence. The nearest non-English STR tester to us hailed from South Khorasan, Iran

A better prediction for myself than the My Origins 1.0 (below).

Thoughts in understanding ancestry DNA

Above image.  My Global 10 Genetic Map coordinates:  PC1,PC2,PC3,PC4,PC5,PC6,PC7,PC8,PC9,PC10 ,0.019,0.0272,0.0002,-0.0275,-0.0055,0.0242,0.0241,-0.0033,-0.0029,0.0015.  The cross marks my position on a genetic map by David Wesolowski, of the Eurogenes Blog

The above map shows genetic distances between different human populations around the planet.  Look how tightly the Europeans cluster.  Razib Kahn recently blogged on just this subject.  The fact of the matter is that the greatest diversity exists between populations outside of Europe, particularly within Africa, and between African and non-African populations.  However, we obsess over tiny differences within European populations, when in truth, most Western Eurasians are very closely related.  We share ancient ancestry from slightly varied mixes of only three base ancestral groups, with the last layer arriving only 4,300 years ago.  This obsession in the Market drives DNA to the consumer businesses to largely ignore non-European diversity, and to focus too closely on differences that blur into each other.

The above image is from CARTA lecture. 2016. Johannes Krause of the Max Planck Institute. It shows the currently three known founder populations of Europeans and their average percentages.

However, at the same time the new Living DNA service seeks to zoom in closer on British populations, attempting to detect ancestry percentages from such tiny zones as "East Anglia".  They appear to be having a level of success with it as well, although that blurriness, that overlap and closeness of populations in Europe gives problems.  Germans are given false percentages of British, Some Scottish appear as Northern Irish, and the Irish dilute into false British areas.  However, I've seen enough results now to suggest that it is far from genetic astrology.  They get it correct to a certain level, particularly for us with English ancestry.  Ancestry DNA customers expect perfection.  I don't think that we will ever get that from such closely related populations at this resolution, but it does provide a new genealogical tool that can point us into some revealing directions.

Above image.  My Living DNA Map.  Based on my recorded genealogy, I estimate 77% to 85% East Anglian ancestry over the past 250 years or so.  Living DNA at Standard Mode gave me 39%.  I'm impressed by that.  That a DNA test can recognise even at a 50% success, my recent ancestry in such a tiny zone of the planet.  I have doubts though that this sort of test will ever be free of errors, and mistakes.  The safest DNA test for ancestry is still one that is based on more distinct populations, and outside of Africa, that can be as wide as "European".  23andMe for example in their "Standard Mode" (75% confidence), assign me 97.3% European, and 0.3% Unassigned.  That is a pretty safe result.

Autosomal DNA tests for ancestry, particularly for West Eurasian (European and Western Asia) descendants, are not reliable at high resolution.  If you want to get really local, then sure - do it.  However, only use the results as an indication, not as a truth.  Populations in Western Eurasia are closely related, and share recent common descent.  There has been a high degree of mobility and admixture ever since.  Some modern populations tested do not have a high level of deep rooted local ancestry in that region.  They overlap with each other.  Keep researching and meander through different perspectives of what your older pre-recorded ancestry could have been.

Above image by Anthrogenica board member Tolan.  Based on 23andMe AC results.  My results skew away from British, and towards North French.  He generated this map, plotting myself (marked as Norfolk in red), and my Normand Ancestral DNA twin Helge in yellow.  My results fall in the overlap with French.  Helge is Normand but in AC appears more British than myself.  I am East Anglian yet in this test appear more French than he does.



What have the Romans done for us?

I can feel Spring in the air.  So, day off from work, I decided to take a field trip.  Wasn't sure where to when I hit the road, but I ended up at Burgh Castle, the ruin of a Roman Fort of the Saxon Shore.

Information board at Burgh Castle.

Traditionally, the Roman Shore Forts of South-East Britain were seen as Late Roman defensive structures, to protect Roman Britain from attack from barbarians from the other side of the North Sea, outside of the Empire.  This remains a valid view, although I remember attending a lecture by a local archaeologist many years ago, that argued that these shore forts, were a little odd.  With civilian activity inside the forts, and not particularly very defensive.  He was arguing that rather than protect Roman Britain from invasion by Anglo Saxon pirates, they were intended to control and tax heavy commerce across the North Sea.  No I'm not going to take sides, perhaps there was an element of both intentions.

I personally also like to see this fort as a sort of 4th Century AD immigration control.  My mother's 18th and 19th Century ancestors are so strongly clustered nearby at the Reedham area, that I can't help but imagine that at least some of her ancestors lived in East Norfolk way back into the medieval, and perhaps some of them rowed passed this recently decommissioned shore fort during the early 5th century AD.  I imagine them jeering at the now abandoned post of the Empire, as they rowed past.  Arriving into Britain, with fealty free land just for the grabbing, a land of opportunity for rural self sustaining farmers from the Continent.

The view down on the Yare and Breydon Water from Burgh Castle.  Much of this would have been flooded during the 4th Century by higher sea levels and the absence of drainage.

From a population genetics point of view, we are usually told that the 360 year long period of Roman Britain contributed little to our present day DNA.  More important was the contribution of the Early Bronze Age, that carried DNA from the Eurasian Steppes, followed perhaps by the Anglo-Saxon / Danish / Norman Medieval immigration events that followed the collapse of shore forts such as this one.  It is usually suggested that because actual migration from Rome was sparse, and troops were scattered from all over the Empire, that there was little impact on the late prehistoric British genome.

However, whenever an odd haplotype turns up in an old British family, including for example, my own Y-DNA that appears to have originated from the area of present day Iran or Iraq, someone will suggest that it could have arrived during the Roman Empire.  Indeed, in some cases they may well have made their way into North west Europe, even to the British Isles during that time.  Trade and exchange across Western Eurasia was thriving.

I give you Burgh Castle, Norfolk.  They may have built it in order to keep some of my ancestors out.