Researchers have teased out ancient DNA from the animal skin-based parchment on which medieval scribes wrote records, New Scientist reports.
"We realized all these dead cows have a date written on them," Matthew Collins from the University of Copenhagen tells New Scientist. "We thought, 'This is crazy, why aren't we exploiting this?'"
As Collins and his colleagues report in a preprint posted to bioRxiv, they recovered DNA and protein from pages of the York Gospels, which are thought to be about 1,000 years old. Rather than use the same techniques to recover DNA from ancient bones — they would have damaged the pages — Collins and his team analyzed the rubber erasers conservators use to clean the book.
From this, they learned that the book's pages were largely made from calfskin, though a small portion was made from sheepskin. Most pages were made from female animals, giving insight into how medieval peoples made parchment.
Additionally, they uncovered Saccharopolyspora, a bacterium that causes spotting on old manuscripts, on some of the pages, which could help conservators protect the book.
"It is the type of collaboration between arts and humanities and science which one wishes to see more often," the University of Glasgow's MA Michael tells New Scientist.