Saturday, April 29, 2023

Modern-day Scottish, Welsh and Northern Irish people have Pictish ancestry

PLOS

The Picts of Scotland who have long intrigued and have been ascribed exotic origins in fact descended from indigenous Iron Age society and were genetically most similar to people living today in Scotland, Wales, North Ireland and Northumbria. Adeline Morez of Liverpool John Moores University and Linus Girdland-Flink of the University of Aberdeen report these findings in a new study published April 27 in the journal PLOS Genetics.

The Picts, who inhabited early medieval Scotland from about 300-900 AD, formed the first documented kingdoms of eastern Scotland, but have often been a subject of mystery due to the lack of historical and archaeological evidence and due to their enigmatic symbol tradition inscribed on stone. In their new study, Morez and Girdland-Flink sampled Pictish burials to extract genomes to explore how the Picts are related to other cultural groups in Britain. They sequenced DNA from two individuals from central and northern Scotland that dated from the fifth to the seventh century AD. They compared the resulting high-quality genomes to more than 8,300 previously published ancient and modern genomes.

The analysis revealed that Picts descended from local Iron Age populations, who lived across Britain before the arrival of mainland Europeans. Additionally, the researchers found genetic similarities between the Picts and present-day people living in western Scotland, Wales, Northern Ireland and Northumbria. Medieval traditions, including from the time of the Picts themselves, had ascribed exotic origins to the Picts including them coming from Thrace (north of the Aegean Sea), Scythia (eastern Europe), or isles north of Britain, but the new research suggests much less sensational origins.

A further analysis of DNA sequenced from seven individuals interred in a Pictish cemetary showed that the individuals did not share a common ancestor on their mother’s side. This finding suggests that females may have married outside their own social group and runs counter to older speculation, such as that mentioned by the great English scholar Bede, that the Picts were matrilineal; that they had had a society based on kinship through the mother’s lineage.

The new findings support current archaeological theories that Picts descended from Iron Age people in Britain. The study also provides novel insights into the genetic relationships that existed amongst Pictish individuals buried in cemeteries together and between ancient Picts and present-day groups in the United Kingdom.

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Author Interview:

PLOS: What first drew you to study paleogenetics?

Dr. Morez: I always have been fascinated by human evolution overall: where are we from? How did we manage to settle worldwide and adapt to the wide diversity of environments? I chose to focus on paleogenetics, the study of ancient DNA, as it is a formidable opportunity to gain direct knowledge of an individual ancestry or a population's genetic diversity, free from inference based on modern genomes. And now, we actually see that the migrations and population mixtures are more numerous and complex than previously hypothesised.

PLOS: What did you choose to investigate in this study, and why?

Dr. Morez: In this study, I chose to investigate the genetic ancestry of the Picts - people living in Scotland during the early medieval period (here from individuals buried in eastern and northern Scotland). It has never been done and many historical-based hypotheses stated that they were biologically diverse from their neighbours, with possible ties from the Eurasian steppes. Once we realised they were actually genetically very similar to their contemporaries living in the UK, we decided to push the limit in terms of analytical resolution using imputation of genotypes and analyses based on the autosomal haplotype information (chunks of DNA shared from parents to offspring, modify by mutation and recombination). It allows us to study the fine-scale genetic structure between the Picts and ancient and modern individuals from the UK and Europe.

PLOS: What are the key findings from your research on ancient Pictish genetics?

Dr. Morez: The two Picts studied here showed a greater affinity (by haplotype sharing) with present-day populations from western Scotland, Wales, Northern Ireland and Northumbria compared to the populations from southern England, which is important for understanding how present-day diversity formed in the UK.

Thanks to comparison with previously published genomes from Pictish people living in the Orkney islands, we could also show that individuals living in the Orkney and in mainland Scotland, likely gathered under the same cultural unit, were slightly divergent likely because of limited gene flow between the two regions and small population size in Orkney, which is known to speed up genetic divergence.

PLOS: What most surprised or interested you about your findings?

Dr. Morez: I was surprised to find that the two Pictish genomes from eastern and northern Scotland show a slightly higher but noticeable haplotype sharing with present-day people living in western Scotland, rather than with those from the East where Pictish culture is believed to thrive. This was unexpected and may be caused by several reasons; either we are detecting a population movement from the west of Scotland toward the east but which did not leave a long-lasting genetic signature, or later population movements in the East replaced some of the Pictish ancestry. We still don’t know which one is correct.

PLOS: What do you hope your findings might lead to, and what are the next steps for your research?

Dr. Morez: I hope the fascination for the Iron Age and medieval period in the UK will increase and lead to more genomes being discovered and analysed, to get a better understanding of the genetic structure across Scotland. Thanks to these genomes, those already published and the many more yet to come, the UK will soon become the first country where we understand in detail how genetic diversity has formed.

Future research will provide new information on the Pictish lifestyle, thanks to archaeologists from the University of Aberdeen and co-authors of the study. Gordon Noble who is reassessing and excavating new Pictish sites, and Kate Britton who investigates dietary habits and mobility using stable isotopes. Linus Girdland Flink (senior author, University of Aberdeen) is coordinating further research on Pictish DNA. This ongoing project will provide an excellent tool to facilitate interdisciplinary research to connect archaeology, archaeological science, history, and human population genetics.

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In your coverage, please use this URL to provide access to the freely available article in PLOS Genetics:

http://journals.plos.org/plosgenetics/article?id=10.1371/journal. pgen.1010360

Citation: Morez A, Britton K, Noble G, Günther T, Götherström A, Rodríguez-Varela R, et al. (2023) Imputed genomes and haplotype-based analyses of the Picts of early medieval Scotland reveal fine-scale relatedness between Iron Age, early medieval and the modern people of the UK. PLoS Genet 19(4): e1010360. https://doi.org/10.1371/journal.pgen.1010360

Author Countries: Germany, Sweden, UK

Funding: AM was supported by ECR strategic support of early career researchers in the faculty of science at LJMU, awarded to LGF. LGF was supported by the School of Geoscience, University of Aberdeen. KB was supported by the Leverhulme Trust (PLP-2019-284) during production of this manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

JOURNAL

PLoS Genetics

DOI

10.1371/journal.pgen.1010360

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE PUBLICATION DATE

27-Apr-2023

Robert Louis Stevenson

Heather Ale

A GALLOWAY LEGEND

From the bonny bells of heather
  They brewed a drink long-syne,
Was sweeter far then honey,
  Was stronger far than wine.
They brewed it and they drank it,
  And lay in a blessed swound
For days and days together
  In their dwellings underground.

There rose a king in Scotland,
  A fell man to his foes,
He smote the Picts in battle,
  He hunted them like roes.
Over miles of the red mountain
  He hunted as they fled,
And strewed the dwarfish bodies
  Of the dying and the dead.

Summer came in the country,
  Red was the heather bell;
But the manner of the brewing
  Was none alive to tell.
In graves that were like children's
  On many a mountain head,
The Brewsters of the Heather
  Lay numbered with the dead.

The king in the red moorland
  Rode on a summer's day;
And the bees hummed, and the curlews
  Cried beside the way.
The king rode, and was angry,
  Black was his brow and pale,
To rule in a land of heather
  And lack the Heather Ale.

It fortuned that his vassals,
  Riding free on the heath,
Came on a stone that was fallen
  And vermin hid beneath.
Rudely plucked from their hiding,
  Never a word they spoke;
A son and his aged father --
  Last of the dwarfish folk.

The king sat high on his charger,
  He looked on the little men;
And the dwarfish and swarthy couple
  Looked at the king again.
Down by the shore he had them;
  And there on the giddy brink --
"I will give you life, ye vermin,
  For the secret of the drink."

There stood the son and father,
  And they looked high and low;
The heather was red around them,
  The sea rumbled below.
And up and spoke the father,
  Shrill was his voice to hear:
"I have a word in private,
  A word for the royal ear.

"Life is dear to the aged,
  And honour a little thing;
I would gladly sell the secret,"
  Quoth the Pict to the king.
His voice was small as a sparrow's,
  And shrill and wonderful clear:
"I would gladly sell my secret,
  Only my son I fear.

"For life is a little matter,
  And death is nought to the young;
And I dare not sell my honour
  Under the eye of my son.
Take him, O king, and bind him,
  And cast him far in the deep;
And it's I will tell the secret
  That I have sworn to keep."

They took the son and bound him,
  Neck and heels in a thong,
And a lad took him and swung him,
  And flung him far and strong,
And the sea swallowed his body,
  Like that of a child of ten; --
And there on the cliff stood the father,
  Last of the dwarfish men.

"True was the word I told you:
  Only my son I feared;
For I doubt the sapling courage
  That goes without the beard.
But now in vain is the torture,
  Fire shall never avail:
Here dies in my bosom
  The secret of Heather Ale."

NOTE TO HEATHER ALE

Among the curiosities of human nature this legend claims a high place. It is needless to remind the reader that the Picts were never exterminated, and form to this day a large proportion of the folk of Scotland, occupying the eastern and the central parts, from the Firth of Forth, or perhaps the Lammermoors, upon the south, to the Ord of Caithness on the north. That the blundering guess of a dull chronicler should have inspired men with imaginary loathing for their own ancestors is already strange; that it should have begotten this wild legend seems incredible. Is it possible the chronicler's error was merely nominal? that what he told, and what the people proved themselves so ready to receive, about the Picts, was true or partly true of some anterior and perhaps Lappish savages, small of stature, black of hue, dwelling underground -- possibly also the distillers of some forgotten spirit? See Mr. Campbell's Tales of the West Highlands.

Novel biomarker score could help measure adherence to Mediterranean diet

New evidence suggests Mediterranean diet may reduce type 2 diabetes risk more than previously thought

Peer-Reviewed Publication

PLOS

Novel biomarker score could help measure adherence to Mediterranean diet — IMAGE: RESEARCHERS DEVELOPED A NEW WAY TO DETECT WHETHER SOMEONE FOLLOWS A MEDITERRANEAN DIET USING A BLOOD TEST AND SHOWED THAT A MEDITERRANEAN DIET IS ASSOCIATED WITH LOWER RISK OF TYPE 2 DIABETES. view more
CREDIT: GALYAFANASEVA, PIXABAY (CC0, HTTPS://CREATIVECOMMONS.ORG/PUBLICDOMAIN/ZERO/1.0/)

Researchers have developed a novel way to detect whether a person follows a Mediterranean diet using a blood test and, applying this method, have shown that a Mediterranean diet is associated with lower risk of type 2 diabetes. Jakub Sobiecki of the University of Cambridge, UK and colleagues present these findings April 27th in the open access journal PLOS Medicine.

Prior research has shown that people who self-report that they follow a Mediterranean diet have a modestly lower risk of type 2 diabetes. However, the subjectivity of self-reports makes that link uncertain. Until now, the potential link between a Mediterranean diet and type 2 diabetes risk has not been evaluated using objective biological indicators—biomarkers—of adherence to the diet.

Sobiecki and colleagues developed a novel biomarker-based indicator of a Mediterranean diet that incorporates levels of certain molecules in the blood. First, the researchers identified that blood levels of 24 fatty acids and 5 carotenoids could be applied to predict whether participants from a clinical trial of 128 people were assigned to following a Mediterranean diet. Levels of these molecules in a person’s blood were used to calculate a biomarker score, which the researchers used as a measure of the extent to which they followed a Mediterranean diet.

Next, the researchers applied the biomarker score in a study of 340,234 people living in eight European countries, of whom 9,453 developed type 2 diabetes during follow-up and had relevant biomarkers measured. Comparing them with 12,749 participants who remained free of type 2 diabetes, the researchers found that people whose biomarker score indicated greater adherence to a Mediterranean diet were less likely to develop type 2 diabetes.

For comparison, the researchers also asked participants to self-report their diet. They found that using the biomarker score identified a stronger link between the Mediterranean diet and reduced risk of type 2 diabetes than when self-report was used. This finding suggests that previous self-report-based studies may have underestimated the association.

Based on these findings, the researchers argue that even a modest improvement in people’s adherence to a Mediterranean diet could meaningfully reduce the incidence of type 2 diabetes. However, they also point out that additional research will be needed to confirm and extend these new findings since it is currently unknown to what extent the biomarker score is specific for the Mediterranean diet.

Senior author Professor Nita Forouhi said, “Our research combining information from a dietary clinical trial and a large cohort study to identify and apply blood biomarkers for a dietary pattern is exciting and should stimulate development of improved methods to study diet-disease associations which are typically limited by reliance on subjective recall of eating.”

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In your coverage, please use this URL to provide access to the freely available paper in PLOS Medicine: http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1004221

Citation: Sobiecki JG, Imamura F, Davis CR, Sharp SJ, Koulman A, Hodgson JM, et al. (2023) A nutritional biomarker score of the Mediterranean diet and incident type 2 diabetes: Integrated analysis of data from the MedLey randomised controlled trial and the EPIC-InterAct case-cohort study. PLoS Med 20(4): e1004221. https://doi.org/10.1371/journal.pmed.1004221

Author Countries: United Kingdom, Australia, Spain, Germany, China, Italy, Colombia, France, Sweden, Norway, Denmark, and the Netherlands

Funding: see manuscript