By Heather Pringle | August 9, 2012 | 13 Comments
I shouldn’t say this. In fact, as someone who covers the field of archaeology for a living, I probably shouldn’t even be thinking this. But I find myself wondering increasingly whether it’s time for some dirt archaeologists to relinquish one of their great pleasures, namely the beloved rite of summer: field season.
I say this as someone who loves the field, albeit in the hit-and-run way that journalists favor. Each summer I look forward to stuffing faded jeans, t-shirts and a couple of pounds of steno pads into an old canvas duffle bag—the bag my husband bought at an army surplus store in Edmonton for $3 in the 1970s—and catching a plane somewhere, nervous, expectant, thrilled to be heading off. At the other end, usually a long way from civilization, I plunk my bag down in some sprawling tent city or field-camp house and then hustle off to meet the team. Invariably, they are young, much younger than me—grad students mostly on a great adventure in a place that’s often heartbreakingly beautiful, like the cactus lands of the lower Pecos or the lavender fields of southern France. Very little in life, I’ve found, beats the strange joy of living with strangers in a kind of hippie commune atmosphere, in a place completely divorced from its time, a place before Facebook and Twitter.
Often, like my archaeologist-friends, I dream about the field in the off-season. And yet, I think those days are numbered for many researchers. Digging is an expensive proposition, and archaeologists as a whole have excavated far more sites than they really know what to do with. Museum shelves sag under the tonnage of brown cardboard boxes filled with untouched, unanalyzed, unreported finds—sherds, projectile points, textiles, shells, butchered animal bones, fire-broken rock, soil columns, bags of fossilized feces, and human skeletal remains. Most archaeologists have decades of work ahead of them, just studying collections they made in previous years.
This lab work isn’t half as much fun as field life in Tonga or Ecuador, but there’s a lot to be learned, a lot to be seen and understood for the first time. At the Centre for Evolutionary Medicine at the University of Zurich, for example, Christina Warinner, an evolutionary geneticist has been sampling and analyzing the dental calculus that coats teeth in fossil skull collections. It turns out that ancient humans accumulated as much as 600 milligrams of calculus—a mineralized biofilm peppered with food remnants and oral bacteria—on their teeth. (We collect much less today, thanks to the zeal of dental hygenists: in a typical appointment, a hygienist pries loose just 10 to 30 milligrams from our teeth.)
But back to the fossil plaque. Warinner has discovered an astounding amount of DNA embedded in the calculus coating medieval German teeth—about 1000 times more by weight than researchers customarily find in fossil bones. This is very good news for geneticists, who often struggle to extract enough ancient DNA for their work. Moreover, the DNA is very diverse. Not only did Warinner find human DNA: she also identified that belonging to some 2,000 to 4000 species of bacteria. While some species are harmless, others are known pathogens, and as Warinner explained recently in a published interview in The Guardian, “that should allow us to investigate the long-term evolutionary history of human health and disease, right down to the genetic code of individual pathogens, and it should allow us to reconstruct a detailed picture of the dynamic interplay between diet, infection and immunity that occurred thousands of years ago.”
Not too shabby, I’d say. It looks to me as if archaeologists could be rolling in data if they just spent a bit more time looking at old collections, old satellite images, old human remains, and thinking about new ways of extracting information from them. Life in the field is oh so seductive. But those rows of identical cardboard boxes on museum shelves beg to be studied, and they just may be the future of the discipline.
Photos: Illustration of skull by bwrahbwrah jonguh; photo of skulls by Pieter Cornelissen; photo of peridontal bacteria by Darren Ready, courtesy Welcome Images.