Peru’s Buena Vista archaeological site has already offered up a number of important finds for the MU archaeologists, led by Robert Benfer, who have spent years working the dig. Most notable, perhaps, was evidence that the site contained a 4,000-year-old ceremonial center housing what may be the Western Hemisphere’s oldest celestial calendar.
That discovery, detailed in the Fall 2006 edition of Illumination, led Benfer and his colleagues to surmise that Buena Vista’s ancient agronomists were using the temple calendar to predict the onset of the region’s rainy and dry periods. Such a system would have been a boon to farmers, as well as to those dependent on their crops.
Figuring out just what thirsty crops those farmers were growing, however, demanded further investigation. Finding answers, says MU doctoral student Neil Duncan, could provide key insights into more than just ancient diets—in itself an important anthropological goal—but could also shed light on the role food may have played in the religion and culture of Pre-Columbian South America.
Unfortunately, early Peruvians left no menus. Yet the Buena Vista site did yield up artifacts that could be almost as revealing, among them traces of foods consumed in well-preserved squash and gourds that were likely used during ceremonial repasts.
“Squash and bottle gourds had a variety of uses 4,000 years ago,” Duncan says, “including being used as dishes, [fishing] net floats and symbolic containers. Residue analysis can help determine the specific use.”
Archaeological “residue analysis” most often involves recovering molecular evidence of proteins or starches from trace residues left on the surfaces of cooking or serving vessels. Writing in the July 24 edition of the Proceedings of the National Academy of Sciences, Duncan described how he and his team put the Buena Vista squashes and gourds to the test.
First, the artifacts were given a special water bath to loosen and remove adhering residue. Next the researchers lightly brushed the surface to remove any remaining material. These sediments were chemically dispersed using a disodium salt solution, and then lightly oxidized with hydrogen peroxide. Finally, the starch was floated out from sediment using a heavy liquid solution of cesium chloride.
When viewed under the microscope, a modest cornucopia emerged. The researchers confirmed that manioc, potato, and chili pepper had been served in the vessels, as had, surprisingly, arrowroot and algarrobo. These final two finds—algarrobo is a form of carob, arrowroot a digestible tuber—represent the earliest evidence of the consumption of these foodstuffs in Peru. Because the squash and gourd vessels were found in a ceremonial complex, Duncan says, they may have served a purpose beyond simple sustenance: “The starch residues of edible plants found on the artifacts and the special archaeological context from which these artifacts were recovered suggest that the artifacts were used in a ritual setting for the serving and production of food.”
The study, Gourd and Squash Artifacts Yield Starch Grains of Feasting Foods From Preceramic Peru, included MU co-authors Deborah Pearsall, professor of anthropology, and Robert Benfer, emeritus professor of anthropology. The researchers are also indebted, says Duncan, to the scores of MU students who worked at Buena Vista during 2003 and 2004. “None of what we’re doing now would be possible without the work they did excavating the site,” he says.