Scientists Devise Clever Way to Test Old Manuscripts’ DNA

Jim Forest, Flickr Creative Commons // CC BY-NC-ND 2.0
Jim Forest, Flickr Creative Commons // CC BY-NC-ND 2.0

When encountering an obstacle, some people stop and give up, some force their way through, and others find another way around. That's what scientists in the United Kingdom have done with a delicate manuscript from the Dark Ages. Barred from taking parchment samples, the resourceful researchers instead analyzed the eraser crumbs left behind after archivists cleaned the paper. They describe their findings in an article on the prepress server bioRxiv.

Co-author and archaeologist Matthew Collins of the University of York did not start out a manuscript man. Collins had been trying to extract DNA from animal bones unearthed at a Viking settlement to learn more about the culture's use of livestock. But the bones had decayed too far to offer much in the way of genetic material. "You can imagine the frustration," Collins said in an interview with The Atlantic.

Then he realized that animal remains can be more than just bones. There are skins, too—and those, at least, we've taken some pains to preserve. At least the ones we've written on.

"You look at [archive] shelves," Collins said, "and every one of them has a skin of an animal with a date written on it."

Collins's excitement at discovering this untapped bounty of data was soon tempered when he and his collaborator, biochemist Sarah Fiddyment, learned that sampling the manuscripts was completely off-limits.

But they weren't about to give up that easily. Fiddyment spent weeks following the conservators as they worked with the fragile animal-skin paper, learning their process and watching for possible openings. Finally, she saw it: eraser crumbs.

Conservators routinely use PVC erasers to lift stains, grime, and damage from historic documents. The friction created by gently rubbing the eraser against the paper creates an electric charge that pulls in molecules of dirt and oil. And probably other things, too, Fiddyment thought.

Fiddyment, Collins, and their colleagues began collecting eraser crumbs from manuscript conservators around the world. They analyzed each document's chemical makeup and were even able to compare proteins to identify the livestock species responsible for the skin.

The next step was to look at the DNA itself. The researchers turned to the York Gospels, a leatherbound Bible with pages dating back to the year 990. By collecting another tiny pile of eraser crumbs from cleanup of eight pages, they were able to collect enough of a sample to run thorough DNA tests.

Those pages had quite a lot to say about their creation and history. The tests revealed 1000-year-old genetic material from the cows and sheep that gave the book its parchment pages. Remarkably, the DNA was so intact that the scientists could identify the cows' ancestry (something close to our modern-day Norwegian reds and Holsteins) and sex (mostly female).

The pages also contained human DNA and even bacteria, most likely from the hands and saliva of the people who made, wrote, and used the book.

Speaking to The Atlantic, parchment expert Bruce Holsinger of the University of Virginia called the findings "an exciting breakthrough."

[h/t The Atlantic]

Shocker: This Electric Eel Delivers More Voltage Than Any Creature on Earth

stacey_newman/iStock via Getty Images
stacey_newman/iStock via Getty Images

Eels are proving to be more slippery than previously believed. A newly identified species of these skinny fish (yes, eels are really fish) delivers more electric voltage than any other creature on the planet.

All species in their taxonomic order (Gymnotiformes) are capable of producing a modest electrical field to help them navigate, a perk that compensates for their poor vision. But electric eels (in the genus Electrophorus) pack a far more potent punch. They bear three organs full of cells that can produce electricity on demand. The cells act as a defense mechanism and can effectively taser prey into submission.

In a study published in Nature Communications, researchers collected more than 100 electric eels in the Amazon region and analyzed their DNA, voltage, and habitat. To their surprise, they found that the single known species of electric eel, Electrophorus electricus, was actually three distinct species. They gave the two new ones the very heavy metal names of E. varii and E. voltai. The latter (named for Alessandro Volta, who invented the electric battery) produced the strongest shock: 860 volts, topping the previous record of 650 volts.

Why the varying strength? The researchers suggested that some eels occupy water with low salt content, and therefore reduced conductivity. A stronger charge may be needed to deliver an effective jolt.

While those numbers sound formidable, their low current means a shock wouldn’t necessarily be harmful to a human. Voltage is the measure of pressure of the flow of electrons; current, or amperage, is the volume of electrons. Eels have high voltage but low current; household power outlets have lower voltage but more current and can be deadly. Eels might startle you with a shock, but it won't be fatal.

If you should find yourself in a school of electric eels bent on subduing you, however, the shocks could result in brief incapacitation that could lead to drowning or an aggravation of an existing heart condition. The study authors hope to eventually film a coordinated eel attack on (non-human) prey.

The discovery of two new species was “quite literally shocking,” lead author Carlos David de Santana told The New York Times.

[h/t Phys.org]

Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn
iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception: in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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