Showing posts with label Black Death. Show all posts
Showing posts with label Black Death. Show all posts

Dec 4, 2023

'Bone biographies' reveal lives of medieval England's common people -- and illuminate early benefits system

A series of 'bone biographies' created by a major research project tell the stories of medieval Cambridge residents as recorded on their skeletons, illuminating everyday lives during the era of Black Death and its aftermath.

The work is published alongside a new study investigating medieval poverty by examining remains from the cemetery of a former hospital that housed the poor and infirm.

University of Cambridge archaeologists analysed close to 500 skeletal remains excavated from burial grounds across the city, dating between the 11th and 15th centuries. Samples came from a range of digs dating back to the 1970s.

The latest techniques were used to investigate diets, DNA, activities, and bodily traumas of townsfolk, scholars, friars and merchants. Researchers focused on sixteen of the most revealing remains that are representative of various "social types."

The full "osteobiographies" are available on a new website launched by the After the Plague project at Cambridge University.

"An osteobiography uses all available evidence to reconstruct an ancient person's life," said lead researcher Prof John Robb from Cambridge's Department of Archaeology. "Our team used techniques familiar from studies such as Richard III's skeleton, but this time to reveal details of unknown lives -- people we would never learn about in any other way."

"The importance of using osteobiography on ordinary folk rather than elites, who are documented in historical sources, is that they represent the majority of the population but are those that we know least about," said After the Plague researcher Dr Sarah Inskip (now at University of Leicester).

The project used a statistical analysis of likely names drawn from written records of the period to give pseudonyms to the people studied.

"Journalists report anonymous sources using fictitious names. Death and time ensure anonymity for our sources, but we wanted to them to feel relatable," said Robb.

Meet 92 ('Wat'), who survived the plague, eventually dying as an older man with cancer in the city's charitable hospital, and 335 ('Anne'), whose life was beset by repeated injuries, leaving her to hobble on a shortened right leg.

Meet 730 ('Edmund'), who suffered from leprosy but -- contrary to stereotypes -- lived among ordinary people, and was buried in a rare wooden coffin. And 522 ('Eudes'), the poor boy who grew into a square-jawed friar with a hearty diet, living long despite painful gout.

Inside the medieval benefits system

The website coincides with a study from the team published in the journal Antiquity, which investigates the inhabitants of the hospital of St. John the Evangelist.

Founded around 1195, this institution helped the "poor and infirm," housing a dozen or so inmates at any one time. It lasted for some 300 years before being replaced by St. John's College in 1511. The site was excavated in 2010.

"Like all medieval towns, Cambridge was a sea of need," said Robb. "A few of the luckier poor people got bed and board in the hospital for life. Selection criteria would have been a mix of material want, local politics, and spiritual merit."

The study gives an inside look at how a "medieval benefits system" operated. "We know that lepers, pregnant women and the insane were prohibited, while piety was a must," said Robb. Inmates were required to pray for the souls of hospital benefactors, to speed them through purgatory. "A hospital was a prayer factory."

Molecular, bone and DNA data from over 400 remains in the hospital's main cemetery shows inmates to be an inch shorter on average than townsfolk. They were more likely to die younger, and show signs of tuberculosis.

Inmates were more likely to bear traces on their bones of childhoods blighted by hunger and disease. However, they also had lower rates of bodily trauma, suggesting life in the hospital reduced physical hardship or risk.

Children buried in the hospital were small for their age by up to five years' worth of growth. "Hospital children were probably orphans," said Robb. Signs of anaemia and injury were common, and about a third had rib lesions denoting respiratory diseases such as TB.

As well as the long-term poor, up to eight hospital residents had isotope levels indicating a lower-quality diet in older age, and may be examples of the "shame-faced poor": those fallen from comfort into destitution, perhaps after they became unable to work.

"Theological doctrines encouraged aid for the shame-faced poor, who threatened the moral order by showing that you could live virtuously and prosperously but still fall victim to twists of fortune," said Robb.

The researchers suggest that the variety of people within the hospital -- from orphans and pious scholars to the formerly prosperous -- may have helped appeal to a range of donors.

Finding the university scholars

The researchers were also able to identify some skeletons as probably those of early university scholars. The clue was in the arm bones.

Almost all townsmen had asymmetric arm bones, with their right humerus (upper arm bone) built more strongly than their left one, reflecting tough working regimes, particularly in early adulthood.

However, about ten men from the hospital had symmetrical humeri, yet they had no signs of a poor upbringing, limited growth, or chronic illness. Most dated from the later 14th and 15th century.

"These men did not habitually do manual labour or craft, and they lived in good health with decent nutrition, normally to an older age. It seems likely they were early scholars of the University of Cambridge," said Robb.

"University clerics did not have the novice-to-grave support of clergy in religious orders. Most scholars were supported by family money, earnings from teaching, or charitable patronage.

"Less well-off scholars risked poverty once illness or infirmity took hold. As the university grew, more scholars would have ended up in hospital cemeteries."

Isotope work suggests the first Cambridge students came mainly from eastern England, with some from the dioceses of Lincoln and York.

Cambridge and the Black Death

Most remains for this study came from three sites. In addition to the Hospital, an overhaul of the University's New Museums Site in 2015 yielded remains from a former Augustinian Friary, and the project also used skeletons excavated in the 1970s from the grounds of a medieval parish church: 'All Saints by the Castle'.

The team laid out each skeleton to do an inventory, then took samples for radiocarbon dating and DNA analysis. "We had to keep track of hundreds of bone samples zooming all over the place," said Robb

In 1348-9 the bubonic plague -- Black Death -- hit Cambridge, killing between 40-60% of the population. Most of the dead were buried in town cemeteries or plague pits such as one on Bene't Street next to the former friary.

However, the team have used the World Health Organization's methods of calculating "Disease Adjusted Life Years" -- the years of human life and life quality a disease costs a population -- to show that bubonic plague may have only come in tenth or twelfth on the risk rundown of serious health problems facing medieval Europeans.

"Everyday diseases, such as measles, whooping cough and gastrointestinal infections, ultimately took a far greater toll on medieval populations," said Robb.

Read more at Science Daily

Jan 20, 2023

Plague trackers: Researchers cover thousands of years in a quest to understand the elusive origins of the Black Death

Seeking to better understand more about the origins and movement of bubonic plague, in ancient and contemporary times, researchers at McMaster University, University of Sydney and the University of Melbourne, have completed a painstaking granular examination of hundreds of modern and ancient genome sequences, creating the largest analysis of its kind.

Despite massive advances in DNA technology and analysis, the origin, evolution and dissemination of the plague remain notoriously difficult to pinpoint.

The plague is responsible for the two largest and most deadly pandemics in human history. However, the ebb and flow of these, why some die out and others persist for years has confounded scientists.

In a paper published today in the journal Communications Biology, McMaster researchers use comprehensive data and analysis to chart what they can about the highly complex history of Y. pestis, the bacterium that causes plague.

The research features an analysis of more than 600 genome sequences from around the globe, spanning the plague's first emergence in humans 5,000 years ago, the plague of Justinian, the medieval Black Death and the current (or third) Pandemic, which began in the early 20th century.

"The plague was the largest pandemic and biggest mortality event in human history. When it emerged and from what host may shed light on where it came from, why it continually erupted over hundreds of years and died out in some locales but persisted in others. And ultimately, why it killed so many people," explains evolutionary geneticist Hendrik Poinar, director of McMaster's Ancient DNA Centre.

Poinar is a principal investigator with the Michael G. DeGroote Institute for Infectious Disease Research and McMaster's Global Nexus for Pandemics & Biological Threats.

The team studied genomes from strains with a worldwide distribution and of different ages and determined that Y. pestis has an unstable molecular clock. This makes it particularly difficult to measure the rate at which mutations accumulate in its genome over time, which are then used to calculate dates of emergence.

Because Y. pestis evolves at a very slow pace, it is almost impossible to determine exactly where it originated.

Humans and rodents have carried the pathogen around the globe through travel and trade, allowing it to spread faster than its genome evolved. Genomic sequences found in Russia, Spain, England, Italy and Turkey, despite being separated by years are all identical, for example, creating enormous challenges to determining the route of transmission.

To address the problem, researchers developed a new method for distinguishing specific populations of Y. pestis, enabling them to identify and date five populations throughout history, including the most famous ancient pandemic lineages which they now estimate had emerged decades or even centuries before the pandemic was historically documented in Europe.

"You can't think of the plague as just a single bacterium," explains Poinar. "Context is hugely important, which is shown by our data and analysis."

To properly reconstruct pandemics of our past, present, and future, historical, ecological, environmental, social and cultural contexts are equally significant.

Read more at Science Daily

Oct 20, 2022

The Black Death shaped the evolution of immunity genes, setting the course for how we respond to disease today

An international team of scientists who analyzed centuries-old DNA from victims and survivors of the Black Death pandemic has identified key genetic differences that determined who lived and who died, and how those aspects of our immune systems have continued to evolve since that time.

Researchers from McMaster University, the University of Chicago, the Pasteur Institute and other organizations analyzed and identified genes that protected some against the devastating bubonic plague pandemic that swept through Europe, Asia and Africa nearly 700 years ago. Their study has been published today in the journal Nature.

The same genes that once conferred protection against the Black Death are today associated with an increased susceptibility to autoimmune diseases such as Crohn's and rheumatoid arthritis, the researchers report.

The team focused on a 100-year window before, during and after the Black Death, which reached London in the mid-1300s. It remains the single greatest human mortality event in recorded history, killing upwards of 50 per cent of the people in what were then some of the most densely populated parts of the world.

More than 500 ancient DNA samples were extracted and screened from the remains of individuals who had died before the plague, died from it or survived the Black Death in London, including individuals buried in the East Smithfield plague pits used for mass burials in 1348-9. Additional samples were taken from remains buried in five other locations across Denmark.

Scientists searched for signs of genetic adaptation related to the plague, which is caused by the bacterium Yersinia pestis.

They identified four genes that were under selection, all of which are involved in the production of proteins that defend our systems from invading pathogens and found that versions of those genes, called alleles, either protected or rendered one susceptible to plague.

Individuals with two identical copies of a particular gene, known as ERAP2, survived the pandemic at a much higher rates than those with the opposing set of copies, because the 'good' copies allowed for more efficient neutralization of Y. pestis by immune cells.

"When a pandemic of this nature -- killing 30 to 50 per cent of the population -- occurs, there is bound to be selection for protective alleles in humans, which is to say people susceptible to the circulating pathogen will succumb. Even a slight advantage means the difference between surviving or passing. Of course, those survivors who are of breeding age will pass on their genes," explains evolutionary geneticist Hendrik Poinar, an author of the Nature paper, director of McMaster's Ancient DNA Centre, and a principal investigator with the Michael G. DeGroote Institute for Infectious Disease Research and McMaster's Global Nexus for Pandemics & Biological Threats.

Europeans living at the time of the Black Death were initially very vulnerable because they had had no recent exposure to Yersinia pestis. As waves of the pandemic occurred again and again over the following centuries, mortality rates decreased.

Researchers estimate that people with the ERAP2 protective allele (the good copy of the gene, or trait), were 40 to 50 per cent more likely to survive than those who did not.

"The selective advantage associated with the selected loci are among the strongest ever reported in humans showing how a single pathogen can have such a strong impact to the evolution of the immune system," says human geneticist Luis Barreiro, an author on the paper, and professor in Genetic Medicine at the University of Chicago.

The team reports that over time our immune systems have evolved to respond in different ways to pathogens, to the point that what had once been a protective gene against plague in the Middle Ages is today associated with increased susceptibility to autoimmune diseases. This is the balancing act upon which evolution plays with our genome.

"This highly original work has been possible only through a successful collaboration between very complementary teams working on ancient DNA, on human population genetics and the interaction between live virulent Yersinia pestis and immune cells," says Javier Pizarro-Cerda, head of the Yersinia Research Unit and director of the World Health Organization Collaborating Centre for Plague at the Pasteur Institute.

"Understanding the dynamics that have shaped the human immune system is key to understanding how past pandemics, like the plague, contribute to our susceptibility to disease in modern times," says Poinar.

Read more at Science Daily

Jun 16, 2022

Origins of the Black Death identified

The Black Death, the biggest pandemic of our history, was caused by the bacterium Yersinia pestis and lasted in Europe between the years 1346 and 1353. Despite the pandemic's immense demographic and societal impacts, its origins have long been elusive. Now, a multidisciplinary team of scientists, including researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, the University of Tübingen, in Germany, and the University of Stirling, in the United Kingdom, have obtained and studied ancient Y. pestis genomes that trace the pandemic's origins to Central Asia.

In 1347, plague first entered the Mediterranean via trade ships transporting goods from the territories of the Golden Horde in the Black Sea. The disease then disseminated across Europe, the Middle East and northern Africa claiming up to 60 percent of the population in a large-scale outbreak known as the Black Death. This first wave further extended into a 500-year-long pandemic, the so-called Second Plague Pandemic, which lasted until the early 19th century.

The origins of the Second Plague Pandemic have long been debated. One of the most popular theories has supported its source in East Asia, specifically in China. To the contrary, the only so-far available archaeological findings come from Central Asia, close to Lake Issyk Kul, in what is now Kyrgyzstan. These findings show that an epidemic devastated a local trading community in the years 1338 and 1339. Specifically, excavations that took place almost 140 years ago revealed tombstones indicating that individuals died in those years of an unknown epidemic or "pestilence." Since their first discovery, the tombstones inscribed in Syriac language, have been a cornerstone of controversy among scholars regarding their relevance to the Black Death of Europe.

In this study, an international team of researchers analysed ancient DNA from human remains as well as historical and archaeological data from two sites that were found to contain "pestilence" inscriptions. The team's first results were very encouraging, as DNA from the plague bacterium, Yersinia pestis, was identified in individuals with the year 1338 inscribed on their tombstones. "We could finally show that the epidemic mentioned on the tombstones was indeed caused by plague," says Phil Slavin, one of the senior authors of the study and historian at the University of Sterling, UK.

Researchers found the Black Death's source strain


But could this have been the origin of the Black Death? Researchers have previously associated the Black Death's initiation with a massive diversification of plague strains, a so-called Big Bang event of plague diversity. But the exact date of this event could not be precisely estimated, and was thought to have happened sometime between the 10th and 14th centuries. The team now pieced together complete ancient plague genomes from the sites in Kyrgyzstan and investigated how they might relate with this Big Bang event. "We found that the ancient strains from Kyrgyzstan are positioned exactly at the node of this massive diversification event. In other words, we found the Black Death's source strain and we even know its exact date [meaning the year 1338]," says Maria Spyrou, lead author and researcher at the University of Tübingen.

But where did this strain come from? Did it evolve locally or did it spread in this region from elsewhere? Plague is not a disease of humans; the bacterium survives within wild rodent populations across the world, in so-called plague reservoirs. Hence, the ancient Central Asian strain that caused the 1338-1339 epidemic around Lake Issyk Kul must have come from one such reservoir. "We found that modern strains most closely related to the ancient strain are today found in plague reservoirs around the Tian Shan mountains, so very close to where the ancient strain was found. This points to an origin of Black Death's ancestor in Central Asia," explains Johannes Krause, senior author of the study and director at the Max Planck Institute for Evolutionary Anthropology.

Read more at Science Daily