A medieval manuscript may seem unassuming under glass, its painted letters fixed in place for centuries. But the skin beneath the ink can tell another story — one involving ancient sheep, long-forgotten farms, and a livestock virus that remains a threat today.
Researchers have recovered sheeppox virus DNA from parchment used in some of Europe’s best-known manuscripts, including the 1,000-year-old York Gospels. The parchment samples, combined with evidence from Bronze Age sheep teeth, trace the virus back at least 3,500 years.
The findings, published in Science Advances, turn precious books into unexpected biological archives, preserving evidence of the animals whose hides became parchment.
“Parchment making has been considered a vanishing craft, but we are beginning to understand just how much of the past it has retained. This project shows that parchments not only preserve our cultural history for hundreds of years, but also the landscape of disease in our livestock in the medieval period,” said supervising author Kevin G. Daly in a press release.
Medieval Manuscripts Preserve Ancient Sheeppox Virus DNA
Close-up of the eighth-century copy of St. Paul’s Epistles.
(Image Credit: Reproduced with kind permission of the Master and Fellows of Trinity College, Cambridge)
Sheeppox is highly contagious and can sweep quickly through a flock. It can be especially deadly for young animals and reduce wool, meat, and milk yields.
The researchers detected viral DNA in manuscripts from Britain and continental Europe. The collection included the Corpus Glossary at Corpus Christi College, Cambridge, one of the earliest English dictionaries. Several books carried the virus across multiple pages, suggesting parchment makers used hides from infected livestock.
Explore All OptionsSheeppox DNA also appeared on calfskin and goatskin. This could represent unusual cross-species infections or contamination during parchment production.
“The recording of ancient DNA of pathogens has completely changed our understanding of infectious disease in the past, and here we show that parchment can also preserve animal pathogen DNA. It is possible that archives and libraries around the world also contain the genetic traces of disease outbreaks in animals in the past,” explained lead author Louis L’Hôte.
Read More: Ancient Smallpox DNA Hidden in Two Chilean Mummies Traces the Disease’s Colonial Arrival
How Parchment Pages Became Biological Time Capsules
Parchment was made from prepared sheep, goat, and cattle hides. Although craftspeople transformed the skins into writing surfaces, fragments of animal and pathogen DNA remained trapped within them.
Researchers sequenced the viral DNA and compared the ancient sequences with modern sheeppox genomes and viral DNA recovered from sheep teeth found at pastoral settlements on the Eurasian steppe.
The evidence suggests the major capripoxvirus lineages — sheeppox, goatpox, and lumpy skin disease viruses — separated between 11,500 and 3,700 years ago. That window overlaps with livestock domestication and sheep’s movement into Europe.
Why Ancient Virus DNA Matters Today
This history is not confined to medieval farms. Greece continues to battle a large sheep and goat pox epidemic, damaging rural livelihoods and prompting animal culls. The viruses responsible do not infect humans, but they can disrupt food production and cause severe economic loss.
“Ancient genomes can help us understand how these pathogens affecting us today evolved. We find that unlike the smallpox virus, the sheeppox virus genome was very stable over the last few millennia. This might mean that genetic changes before this point were very important to how the sheeppox virus evolved to infect its host, which may help us fight the pathogen in the future,” concluded L’Hôte.
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Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from a study published in Science Advances: Three thousand five hundred years of sheeppox virus evolution inferred from archaeological and codicological genomes
