28 JULY 2017 • VOL 357 ISSUE 6349 349 SCIENCE sciencemag.org
eye color, ailments, and ancestry.
By sampling roughly dated parchment
documents, researchers could also trace
changes in the ethnic identity of people
who made and used books over time, and
perhaps identify some of their diseases.
Bradley is seeking samples from books that
have identifiable contrasts between early
and later users, such as books that have
been moved from one continent to another.
With funding from the European Union
and book owners, Collins is now traveling
the world, from the J. Paul Getty Museum in
Los Angeles, California, to the Royal Library
in Copenhagen, gathering eraser debris
from all manner of illustrious books. Other
scholars are sending samples and entering
the field as well: Researchers studying the
Dead Sea Scrolls in Israel are reportedly getting ancient DNA from those parchments.
And Stinson has tried to extract DNA from a
medieval poem. “We want to build a parch-
ment DNA library,” he says.
Collins is seeking advice on what to do
with any DNA his team finds and sequences.
What hypotheses should they address?
“We’re fishing for proteins and DNA and
catching a lot of stuff,” Collins says. “But we
scientists come up with questions humanities scholars think are dumb,” such as the
cause of a death already described in mortuary records. And scientists and humanities
scholars have different approaches: Given
the concerns about DNA contamination,
scientists prefer to touch books only with
gloves. But among humanities scholars, the
tradition is to use bare hands to ensure that
people handle the pages gently; those wearing gloves are thought be rougher.
Some scholars at the Bodleian meeting
had lofty ideas—would it be possible to
get DNA of famous people such as Isaac
Newton, who left behind many diaries and
documents? Others were more interested
in the bookworms. Hedges announced that
the wormholes he measured in the Gospel of
Luke were 1.3 millimeters in diameter, sug-
gesting that they were made by Anobium
punctatum, a northern European beetle.
That would confirm that the book was made
in the United Kingdom or northern Europe,
rather than in southern Europe. The DNA
of bookworms “can provide clues as to when
and where objects such as books originated
and were transported,” Hedges says.
Some medievalists are enthused about
the idea that biologists might be able to aid
their studies, filling in the blanks left by
written records. “I look at handwriting and
dialect analysis to figure out a manuscript’s
age—ridiculous!” laments Stinson, given the
Herculean effort required to do so. Now, he
says, “I could go ask a biologist.” j
Front fyleaf Back fyleaf
3 1 10
Estimated number of skins used
II III IV V VI VII VIII IX X XI XII XIII XIV XVI XV XVII XVIII XIX
Calf Sheep Goat Roe deer Fallow deer
or red deer
Mining the molecules of an ancient book
Researchers applied new methods to probe the history of a single
12th century book, the Gospel of Luke, treating the parchment as
a biological sample. They uncovered a pattern of interleaved calfskin
and sheepskin, with goatskin used as a last resort.
Making a manuscript
The Gospel of Luke is made of
19 quires, each consisting of
four skins laid with flesh sides
facing each other and folded
together to make 16 pages.
How scientists “read” ancient books
Cutting-edge methods provide information beyond textual content and style.
collected by rubbing
pages with an eraser
can reveal the kinds of
animals used to
Beetle larvae tunnel
in wooden covers
and emerge as adults,
leaving exit holes
that can be used to
identify their species.
DNA left on books
by bacteria, beetles,
humans, and other
organisms can be
sequenced to learn
about their identity.
Pigments and dyes
Researchers can shine
on ink to identify the
source of components,
such as blue lapis lazuli