From genes to latrines—Vikings and their worms provide clues to emphysema

In a paper published today in Scientific Reports a group of researchers led by LSTM have found that the key to an inherited deficiency, predisposing people to emphysema and other lung conditions, could lie in their Viking roots.

Archaeological excavations of Viking latrine pits in Denmark have revealed that these populations suffered massive worm infestations http://sciencenordic.com/dna-study-vikings-were-plagued-intestinal-parasites. The way that their genes developed to protect their vital organs from disease caused by worms has become the inherited trait which can now lead to lung disease in smokers.

Chronic obstructive pulmonary disease (COPD) and emphysema affect over 300 million people, or nearly 5% of the global population. The only inherited risk factor is alpha-1-antitrypsin (A1AT) deficiency, and this risk is compounded if individuals smoke tobacco.

A1AT protects the lungs and liver from enzymes called proteases that are produced by cells of the immune system, but also by parasitic worms. In the absence of A1AT these proteases can break down lung tissue leading to COPD and emphysema. Deficiency of A1AT is genetically determined and is due to deviants of A1AT that are surprisingly common, particularly in Scandinavia, where they evolved in Viking populations more than two thousand years ago. Why these disease-causing deviants of A1AT are so common in human populations today has long been a mystery.

LSTM's Professor Richard Pleass is senior author on the paper. He said: "Vikings would have eaten contaminated food and parasites would have migrated to various organs, including lungs and liver, where the proteases they released would cause disease."

In this latest paper the authors show that these deviant forms of A1AT bind an antibody called immunoglobulin E (IgE) that evolved to protect people from worms. The binding of A1AT to IgE prevents the antibody molecule from being broken down by such proteases.

"Thus these deviant forms of A1AT would have protected Viking populations, who neither smoked tobacco nor lived long lives, from worms." Continued Professor Pleass, "it is only in the last century that modern medicine has allowed human populations to be treated for disease causing worms. Consequently these deviant forms of A1AT, that once protected people from parasites, are now at liberty to cause emphysema and COPD."
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Reference:

Phys.org. 2016. “From genes to latrines—Vikings and their worms provide clues to emphysema”. Phys.org. Posted: February 4, 2016. Available online: http://phys.org/news/2016-02-genes-latrinesvikings-worms-clues-emphysema.html

Greenland Vikings outlived climate change for centuries

In the middle of the 13th century the Vikings who had settled in Greenland encountered no less than ten years of harsh and cold winters and summers. The Norsemen, who were living as farmers, bid farewell to many of their cattle during that period.

The Greenland Vikings were also prevented from setting sail to fetch supplies from their homelands in Europe because they didn't have enough timber to build trading ships. So when Scandinavian traders didn't happen to pass by they were left entirely on their own.

But this didn't knock them out; on the contrary they lived with the worsening climate for almost 200 years during what we later would call the Little Ice Age. This is the conclusion of a new Ph.D. Thesis.

"The stories we have heard so far about the climate getting worse and the Norsemen disappearing simply don't hold water. They actually survived for a long time and were far better at adapting than we previously thought," says the author of the new study, Christian Koch Madsen, Ph.D. student at the National Museum of Denmark.

Study a "breakthrough" for archaeologists

It has always been a mystery why the Greenland Vikings disappeared so suddenly from the cold territory up north, and according to Andrew Dugmore, a professor of archaeology at the University of Edinburgh, the study's results have made us a good deal wiser about what actually happened to the Greenland Vikings.

"The study makes us realise that the Norsemen were really good at making use of the landscape around them and at adapting, contrary to what the usual myths would have us believe. The entire dissertation is a breakthrough for us archaeologists and a distinguished piece of work," says Dugmore.

Myth of 'conservative' Vikings mistaken

So why did the Greenland Vikings disappear so quickly? For starters, Madsen tells us in his thesis that they didn't disappear as quickly as we used to believe. The ten years of exceptionally cold winters and summers were only the beginning of an ice age lasting hundreds of years which the Norsemen survived for a very long time.

Moreover, previous estimates of how many Norsemen lived in Greenland have been far too high. In his more comprehensive studies of the landscape, Madsen has ascertained that no more than 2,500 people lived in all Greenland during the time, and they were spread over a huge area. Previous estimates have been as hihg as 6,000.

According to Madsen, the myth of the conservative Vikings who had no clue as to what the word 'adapt' meant, is mistaken. The "saeter" -- small farms -- were, for instance, in reality the key to their impressive, seasonal exploitation of the landscape.

"When the harsh climatic changes began to set in, we can see that the outermost farms were gradually abandoned. This indicates a centralisation of both power and resources, which are clear countermeasures against climate deteriorations -- even though they were highly involuntary.

Huge disparities between rich and poor, big and small

When the climate began to show its teeth in the mid-13th century, the society began to shrink. Until this time, the Norsemen had spread their resources over huge areas of the country which became increasingly barren and less and less suitable for cattle farming.

As a result, the smaller farms in remote area were abandoned and the Norsemen began to gather in large settlements.

"With centralisation came greater disparity between the big and rich and the small and poor. The society was structured as a natural economy, paid in the form of products and manpower, and when less agricultural produce becomes available it is the small farmers’ manpower that the large farmers began to draw on," says Madsen.

"This impacts the small farmers, who at the same time get less for themselves. This actually results in a built-in fragility in the society," he says.

The Norsemen became trappers, trade collapsed, and the Innuit moved in

As the climate became harsher and farming became more difficult, the Norsemen became more reliant on seafood. Previous analyses of the late Norsemen have shown that they lived on up to 80 per cent seal. They became trappers instead of farmers.

There is also good reason to believe that some of the young Norsemen eyed the opportunity to jump aboard the rare trading ships headed for Iceland or Norway.

Whether the Norsemen meeting their end was due the centralisation of a surprisingly small and shrinking number of people which broke down on its own accord or due to the collapse of trade with Europe or whether it was actually their encounter with the Inuit, we still don't know. According to Madsen it was probably a convergence of “a whole lot of unfortunate circumstances."

We do know, on the other hand, the the Norsement lived with climate change for much longer than previously thought.

"With these results we can certainly remove some of the focus on the climate mechanism to which we have previously attached too much importance," says Madsen.
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Reference:

Persson, Charlotte Price. 2015. “Greenland Vikings outlived climate change for centuries”. Science Nordic. Posted: April 5, 2015. Available online: http://sciencenordic.com/greenland-vikings-outlived-climate-change-centuries

Vikings May Have Been More Social Than Savage

Academics at Coventry University have uncovered complex social networks within age-old Icelandic sagas, which challenge the stereotypical image of Vikings as unworldly, violent savages.

Pádraig Mac Carron and Ralph Kenna from the University's Applied Mathematics Research Centre have carried out a detailed analysis of the relationships described in ancient Icelandic manuscripts to shed new light on Viking society.

In a study published in the European Physical Journal, Mac Carron and Kenna have asked whether remnants of reality could lurk within the pages of the documents in which Viking sagas were preserved.

They applied methods from statistical physics to social networks -- in which nodes (connection points) represent individuals and links represent interactions between them -- to home in on the relationships between the characters and societies depicted therein.

The academics used the Sagas of Icelanders -- a unique corpus of medieval literature from the period around the settlement of Iceland a thousand years ago -- as the basis for their investigation.

Although the historicity of these tales is often questioned, some believe they may contain fictionalised distortions of real societies, and Mac Carron's and Kenna's research bolsters this hypothesis.

They mapped out the interactions between over 1,500 characters that appear in 18 sagas including five particularly famous epic tales. Their analyses show, for example, that although an 'outlaw tale' has similar properties to other European heroic epics, and the 'family sagas' of Icelandic literature are quite distinct, the overall network of saga society is consistent with real social networks.

Moreover, although it is acknowledged that J. R. R. Tolkien was strongly influenced by Nordic literature, the Viking sagas have a different network structure to the Lord of the Rings and other works of fiction.

Professor Ralph Kenna from Coventry University's Applied Mathematics Research Centre said: "This quantitative investigation is very different to traditional approaches to comparative studies of ancient texts, which focus on qualitative aspects. Rather than individuals and events, the new approach looks at interactions and reveals new insights -- that the Icelandic sagas have similar properties to those of real-world social networks.
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References:

2013. “Vikings May Have Been More Social Than Savage”. Science Daily. Posted: October 1, 2013. Available online: http://www.sciencedaily.com/releases/2013/10/131001091338.htm