Did Your Ancestors Eat Shrew? Consult the Poo

Eating a parboiled insectivore whole for the sake of science is dedication. It won scientists Brian D. Crandall and Peter W. Stahl the Ig Nobel prize for Archaeology.

'Tis the season of red leaves in the north, spring in the south and of the Ig Nobel prizes everywhere. And an intrepid member of one group of scientists ate a shrew, thereby teaching mankind a lesson in dedication to the job and winning an award for it, too.

Professors Brian D. Crandall and Peter W. Stahl of the Binghamton University Department of Anthropology were awarded the 2013 Ig Nobel in Archaeology by the Annals of Improbable Science, for going way beyond the call of duty in providing researchers with a means of testing whether our ancestors ate micro-mammals.

What our ancestors ate has been a subject of fascination, not to mention revulsion, for years. Even diets going back a mere few centuries are viewed askance. The neighbors would think you were worse than peculiar if you dined on delicacies acceptable in ancient Rome, such as newborn rabbits or peacock tongue pastry. And it is assumed that our ancestors supped, among other things, on rodents.

But how can we know for sure? By analyzing remains in places of human habitation, from piles of bones, to the manner of how the humans' teeth were worn down, to their tools, to their coprolites – in other words, fossilized feces.

Now, just finding rodent skeletons in a human habitat means nothing. A rodent could have been living there peacefully, stealing food from the humans, and died of a heart attack. Or, it could have been eaten and its remains dropped by a cat or owl.

"I excavate archaeological sites which are the products of both human and natural activity," Stahl elaborates. "The problem with micro-vertebrates is that they can accumulate in archaeological sites in many different ways. They live locally. They could just die and their skeletons are intruded into archaeological deposits. Very often perhaps they're meals of different animals and entered the archaeological deposits from regurgitated pellets and scats from animals. You can get vertebrate bones entering deposits through water action."

In each such case, the bones look a bit different.

But if one finds digested rodent remnants, how can one tell they were emitted by our forefathers, rather than by a fox, say?

Who ate that shrew?

Enquiring minds want to know. But proving human provenance of shrew skeletons proved elusive. Until Stahl and Crandall heroically decided to emulate the postulated diet and analyze the results. Or have somebody do it. They're not saying.

So they set a trap, which caught a shrew – a Blarina brevicauda, to be precise. They then killed it, boiled it for two minutes, cut it into big pieces and had one of their members swallow the chunks whole.

Now, if they were proto-men, they'd probably have just torn the shrieking micro-beast into pieces with their nails and swallowed the pieces raw while beating their hairy chests, then wiped off the guts hanging from their lips with their blood-matted forearms. But, being western and squeamish, they skinned the shrew first and gutted it too, probably to the relief of readers the world over. Then they cooked it and somebody ate it. The head, too, by the way.

Frankly, it's not a million miles away from eating a very small rabbit (that head aside). Combing through the feces for three days following ingestion – lest they miss any bone fragments – also demonstrated great dedication. But let us not cast cheap arrows at their heroic achievement in the name of science.

The group refuses to disclose who the hero was, possibly out of consideration for his family – "You kiss your mother with that mouth" would gain a whole new meaning. "This is irrelevant. What is relevant is what was consumed? How was it consumed? By what was it consumed? The world could care less who ate it," Stahl insists.

He also modestly disclaims the suggestion of valor: food is a case of different strokes for different folks. "I've lived in different contexts throughout the world where people eat rodents," he says. In the West, people might shrink from the shrew, but, statistically, they're the strange ones. "I lived and worked in areas where people consider cheese to be revolting."

Point taken. Why a shrew? Because it got caught in the trap. And has humankind been bettered by its fatal blunder?

There was a wealth of scatological studies by everybody from archaeologists to park rangers to paleontologists, Stahl says. Science had demonstrated through controlled experiments what certain bones look like when subjected to different kinds of environmental and cultural variables – think, wind and rain damage versus getting eaten. "We had evidence for owls, hawks, eagles," but there was practically no study of the effects of human digestion of micro-mammals. Enter Stahl et Crandall.

"I didn't know what to expect," he says. "I did know that humans tend to have comparatively higher acidic environments in their digestive systems. I think we were surprised with some of the things that were preserved and some that weren't."

For instance, they had expected density-dependent preservation. Fangs for instance are supposed to be sturdy. "But if you look at what was preserved, it was fairly fragile bones, like mandibula," Stahl says. "Yet many teeth, which are coated in enamel and are extremely durable, disintegrated."

Like the Nobel itself, the Ig Nobel takes its sweet time. The landmark paper, "Human Digestive Effects on a Micromammalian Skeleton", was published in the Journal of Archaeological Science in 1995. "At the time, there were many people like you who asked me about it for the same reason," Stahl laughs. "If there's any surprise, it's that 18 years later somebody would dredge this up again."

No, he didn't attend the Ig Nobel ceremony, but Crandall did. Acknowledging the satirical prize is a point in their favor. So is their first acknowledgement in that rather ancient paper: "We give belated thanks to an anonymous Blarina brevicaudu whose ultimate sacrifice in the name of science is appreciated."

Gilles Gonthier, WIkipedia Commons