Paleoethnobiology is the study of how prehistoric people used plants. It includes determining which plants were collected and managed, and how they were used, whether for food, fibers, fuel or medicine. How did people process the plants? How did they detoxify other wise poisonous plants for food? When did they learn to cultivate various plants? What were the effects of consuming specific plants?

Addressing these and other questions requires collecting, studying and organizing huge amounts of data not only from archaeological sites, but from laboratory work and research projects from several disciplines as well, including anthropology, history, biology, botany, biochemistry, ecology, nutrition, public health and wildlife sciences.

To help his graduate seminar students develop expertise in this challenging field, Richard I. Ford, Arthur F Thurneau Professor of Anthropology and Biology, and chair of the department, worked with Todd Fadoir of the Information Technology Division's Office of Instructional Technology, who designed a group software database especially for the class.

"It's a shared database," Fadoir said, "which allows students to work and communicate with another simultaneously from their individual terminals. This permits them to share data among themselves, compare and contrast them and discuss their findings and ideas." The database also contains data from research projects throughout the world.

"Now we can sit in that class and collect and examine data from around the globe," Ford said. "I might tell the students that a certain edible grass was deficient in the amino acid lysine, and then ask them if any other food in the prehistoric menu might compensate for the deficiency. They can pull up all of the data on the grass, on other foods the people ate, on the nutritional value and composition of each, and look for a pattern in the food use that might suggest a source of lysine.

"Or," Ford continued, "I might ask whether domesticated plants have greater yield than their ancestors. The students can use the database to study the fluctuations of the yield of the wild ancestor, and see how domestication of the plant stabilized the annual yield. They can derive these generalizations themselves rather than have me telling them what happened. We can share information from one to another and learn from each other. The computer aids in the democratization of education and promotes collegial sharing.

Each student becomes an expert on a single plant, placing in the database and exploring all the literature about it-its origin, history, geography, use, nutritional value, effect on ecology and so on. This mastery of information about a single plant leads to deeper discussion of paleobiological issues.

Liz Sobel, a doctoral candidate in archaeology, focused on a member of the family Chenopodiaceae that is commonly known as gooseweed, lamb's quarter or pigweed. Its domestic relatives are still eaten, but there is no known record of Chenopodiaceae in the historic era.

"The plant's earliest archaeological record is about 3,500 years ago," Sobel said. "It appears to have been domesticated in what is now Tennessee." The plant's seeds have been discovered in storage pits, old woven bags and "middens"-the archaeologists' term for garbage dumps. The seeds differ in shape from the seeds of wild varieties and also are thinner."

Gooseweed's origin is important to specialists in prehistoric North America, Sobel explained, because previously all of the plants domesticated in this hemisphere came from Central or South America, giving rise to the opinion that North American cultures "lacked the mental faculties to domesticate plants, or at least hadn't evolved a complex enough society to do so."

Another issue with gooseweed, as with other prehistoric plants, is "what led people to go from eating its seeds to planting them?" That is one of the big questions for paleoethnobotanists, and it is closely tied to the question of how cultures solved the biochemical problems posed by potential plant foods, especially the problem of poisons.

Both manioc and the sweet potato, for example, contain many toxins that people had to devise a way to defuse. One student in Ford's seminar, Renato Kipnis, is studying sweet and bitter varieties of manioc.

Bitter manioc is "loaded with toxins," Kipnis said, and yet as early as 4,000 to 3,000 years ago, Amerindians living near the Amazon developed a process that rendered it healthful. "First they soaked it in water for a week," Kipnis said, "then they peeled it, grated it, resoaked it and dried it before grinding it into flour Amazonian villagers still use similar techniques to prepare bitter manioc."

Paleoethnobotanists now believe that plants in the Americas were domesticated independently from plants in other continents. The Old World societies, however, became more populous and accumulated more wealth "probably because they had the advantage of having many more animal species that could be domesticated," Ford said. "In the Americas, aside from the dog, only the alpaca and Ilama were available, and they lived only in the high Andes of Peru and Bolivia."--MT