One Hot Archaeological Find

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.