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One Hot Archaeological Find
Chili Peppers Spiced Up Life 6,100 Years Ago

By David Brown
Washington Post Staff Writer
Friday, February 16, 2007

Inhabitants of the New World had chili peppers and the makings of taco chips 6,100 years ago, according to new research that examined the bowl-scrapings of people sprinkled throughout Central America and the Amazon basin.

Upcoming questions on the research agenda -- and this is not a joke -- include: Did they have salsa? When did they get beer?

The findings described today in a 15-author report in the journal Science make the chili pepper the oldest spice in use in the Americas, and one of the oldest in the world.

The researchers believe further study may show that the fiery pod was used 1,000 years earlier than their current oldest specimen, as it shows evidence of having been domesticated, a process that would have taken time. If so, that would put chili peppers in the same league (although probably not the same millennium) as hoarier spices such as coriander, capers and fenugreek.

The chili pepper, however, makes up for its junior status with rapid spread and wild popularity. Within decades of European contact, the New World plant was carried across Europe and into Africa and Asia, adopted widely, and further altered through selective breeding.

Today, the chili pepper is an essential cooking ingredient in places as different as Hungary (where paprika is a national symbol), Ethiopia (where signature spice, berbere, is a mixture of chili powder and half a dozen other substances), and China (where entire cuisines are built around its heat).

In all seven New World sites where chili pepper residue was found, the researchers also detected remnants of corn. That suggests the domestication of the two foods -- still intimately paired in Latin American cuisine -- may have gone hand in hand.

The study, led by Linda Perry of the Smithsonian Institution, does more than illuminate one aspect of early cooking. It provides details about early plant cultivation in South America, where agriculture emerged independent of its "discovery" in the Fertile Crescent of Mesopotamia.

Chili residue was found in both the Amazon basin and on the coast of Ecuador. Because the plants don't grow in the high, arid regions where advanced Andean cultures evolved, the domestication probably occurred in more primitive, tropical cultures, which then traded domesticated plants across the mountains.

"The usual idea is that the tropical lowlands were mostly on the receiving end, that they were not areas of innovation. Now our findings are beginning to cast doubt on that," said J. Scott Raymond, an archaeologist at the University of Calgary and co-author of the paper. Artifacts he excavated in western Ecuador contained chili residue.

The research also advances techniques in "archaeobiology," a discipline that fuses archaeology and, in this case, botany. Specifically, it shows that the study of microscopic starch granules stuck in the crevices of cooking implements can reveal foods that weren't thought to have enough starch in them to be traceable.

Peppers are in the botanical family Solanaceae, which includes tomatoes, another popular New World plant. A high priority now, Perry said, is to see if there are overlooked and still preserved starches from tomatoes in ancient implements.

Many plants have distinctive starch granules visible when dissolved in water and viewed under a microscope. A scientist recognized in 1913 that they could be used to identify the presence of different species. But only recently have researchers discovered that starch could survive for thousands of years in the "microclimate" of tiny pits in ancient implements dug up from warm and wet environments, where other plant material had long ago rotted away.

"They are really tough little guys," Perry said.

She went to work in 2005 trying to identify a starch granule she saw in material provided by Raymond, who had been excavating a 6,100-year-old site in western Ecuador for many years. It clearly wasn't from any of the usual sources such as yams, potatoes or cassava.

Perry recalled hearing that chilies can cause gas and diarrhea in some people, and those are problems often blamed on undigested starches. This seemed odd, because peppers weren't thought to have starches.

"And that is when the light bulb went on. What if they do?" she said.

She went to the Smithsonian's storehouse of plant material in Suitland, Md., and retrieved a sample of wild chili. It included a small fruit -- a pepper. She rubbed it on a slide, added water and looked through the microscope. She saw tiny starch granules.

Next, she looked at samples of modern, domesticated chili peppers. Their granules were much larger and had a characteristic central depression. The mystery granule looked just like them.

Ultimately, she found traces of at least three different kinds of peppers, already domesticated, from seven sites.

It's impossible to identify with certainty the first spice ever sprinkled on a roasting haunch or thrown into a stew pot. But Wendy L. Applequist, an ethnobotanist at the Missouri Botanical Garden, said capers have been found at 10,000-year-old sites in Iran and Iraq; coriander at an 8,500-year-old site in Israel; and fenugreek in Syria's Tell Aswad, which is 9,000 years old. Whether these were domesticated or wild is not known.

As for the beer, David John Goldstein, an anthropologist at Northeastern Illinois University in Chicago, said the New World's oldest dedicated brewery is at a 2,600-year-old site in southern Peru. There, people from the Wari empire made a drink called chicha from the sugary seeds of a tree and used it for ceremonial purposes.

Goldstein, who has brewed his own, says it has "a sort of dirty-sock taste, deep, very sour, acrid." But the alcohol works, and he is sure some version of it was made much earlier and in many other places.

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