The development and spread of agriculture in America changed peoples' lives. By sifting through archaeological plant remains, Associate Professor Gayle Fritz gleans answers to the many questions surrounding agriculture's initial effects on society.

By Terri McClain

Gayle Fritz is interested in the past lives of people and plants—how ancient Americans interacted with plants, particularly when and how they developed agriculture. Her studies are broad, ranging from the domestication of squash in the eastern United States to early agricultural outcomes from Spanish-Indian interaction in the Southwest and Mexico.

"I primarily identify myself as an archaeologist," says Fritz. "My specialty is paleoethnobotany, analyzing archaeological plant remains, and I'm especially interested in plant domestication and the adoption and spread of agriculture."

She seeks answers to many tantalizing historical questions: Did early peoples take up agriculture before or after settling into fixed dwelling sites? How did the availability of natural resources affect the development of agriculture? How and when did the cultivation of crops like corn or squash spread throughout the Americas? Does the appearance of new agricultural techniques and crops in the archaeological record reflect changes within an indigenous culture, a cultural exchange with a neighboring group, or the migration of a new cultural group into the region? What is the cultural significance of specific plants, such as tobacco? How is cultivation reflected in the morphology of the plants themselves?

By sifting through the charred remains of seeds or the contents of food storage sites, Fritz is able to glean answers to many of these questions. Small details, and small plant samples studied under a microscope, yield large results.

Sometimes the trick is simply finding the samples.

"First we separate things from the soil, because most of the things that are important to us are black and too small to see as we dig," Fritz says. "We get flotation samples either in the field or in a lab with a flotation machine—basically a 55-gallon drum with a water source and an overflow spout. The soil will sink through a small mesh in the main tank, and the plant remains hopefully will float and overflow into an even smaller meshed sieve attached to the overflow spout."

Fritz's lab is equipped with microscopes and computers for detailed analysis of organic materials, as well as numerous reference books and indexed cabinets filled with plant samples for comparison.

"We look at anatomical and morphological features," she says. "Most of our samples are very, very small. Answers aren't easy to come by."

For example, Fritz is an expert on amaranth, a grain often found in archaeological sites in the Southwest. Domesticated amaranth seeds are lighter in color and have a thinner seed coat than the wild variety, plus there are intermediate variations. It takes training to recognize the significance of the variations, and to determine whether the charred remains under the microscope are indeed amaranth.

"I came to Washington University to study under Gayle, to learn how to identify plant remains from archaeological sites," says Kevin Hanselka, a second-year Ph.D. student in anthropology. "I met Gayle on a project in northern New Mexico while I was working on my master's thesis. She invited me to apply here, to study with her. Right now I'm working on samples for a Ph.D. student in New Mexico, for his dissertation project.

"Working in Gayle's lab has been very rewarding," he adds. "It is much more intensive than I'm used to, but Gayle is very well-respected in the field, so I'm lucky to be studying under her."

"Gayle teaches," says Patty Jo Watson, the Edward Mallinckrodt Distinguished University Professor and professor of anthropology in Arts & Sciences. "You can enter her lab as an undergraduate or a graduate student, and she will teach you how to identify the plants that turn up most frequently in the archaeological record here in the East or in the Southwest or in parts of Mexico, which is tough enough, because they're usually burned and often somewhat mangled when they appear in an archaeological context. But then she's also very, very good at the other end of the scholarly spectrum, which is interpreting what those things mean. She understands a great deal about relationships between people and plants in many parts of the Americas and in many different time periods."

Karla Hansen-Speer is another Ph.D. candidate who came to the University specifically to study with Fritz in the ethnobotany lab. "Gayle has certain interests, but her students are not confined to those areas when working with her. She has been very good about allowing me to follow my own interests," says Hansen-Speer. "Gayle really encourages her students to go into areas that appeal to them."

Fritz's own interest in plants began at an early age.

"My father is a naturalist," she says. "He was the president of the Audubon Society, and everywhere we went in the woods or camping we had to learn all the plants. And I loved it. I have three sisters, but I liked it the best. They always thought that I should be a botanist, but I really didn't want to be a botanist.

"When I entered graduate school, environmental and ecological approaches to archaeology were just becoming very big, and that was perfect. It's the interaction between plants and people that is compelling to me. That's endlessly fascinating. There's no way ever to know enough about that."

Fritz graduated from the University of Michigan with a degree in classical archaeology and then, after working in Yugoslavia, realized that she would prefer to do North American archaeology. She returned to school and earned a master's degree in anthropology from the University of Texas at Austin.

"My husband got a job at the University of Arkansas, in Fayetteville, which has a wonderful archaeological survey. So I went to work as survey registrar, where I got to know the records and the site files. And then I was asked to become the assistant to the survey archaeologist at the Fayetteville station. I became interested, both as registrar and as assistant archaeologist, in the dry rock shelters and the incredible plant remains that had come from them—and they had not yet received modern, state-of-the-art kinds of analysis. So it just all came together. I went back to graduate school at the University of North Carolina at Chapel Hill, got a Ph.D., and learned paleoethnobotany [the study of direct interrelations between ancient peoples and plants]. The Ozark rock shelter materials were my dissertation."

Fritz came to Washington University in 1990 after a three-year appointment as a visiting professor at the University of Michigan.

"From the day I got here there were opportunities for interdisciplinary research and team teaching with faculty from other departments. This is a wonderful institution for that kind of communication and collaboration," she says. "I was delighted at having the opportunity to build a new lab and be a part of this program. And then being able to work with John Kelly on excavations at Cahokia—it was just a fabulous opportunity."

The Cahokia Indian Mounds in Illinois have yielded many intriguing clues about prehistoric Native Americans. Mound 51 was particularly abundant, having been filled so rapidly that some uncarbonized plant remains had not even rotted away when the mound was excavated. Fritz's analysis of the samples revealed that maygrass was the most common plant in the mix, which included tobacco and relatively little corn.

"I don't want to be the person who denigrates the significance of corn," she says wryly. "The scarcity of corn was a big surprise. But paying attention to these other crops, some of them very important, some of them minor, sort of defines a lot of my work. In the past there's been an overemphasis on corn. I try to look beyond the assumptions."

Fritz initially built her reputation on her research in eastern North America, beginning with those Ozark rock shelters. Now known also as an expert on Southwestern plants like amaranth, she is driven by her innate curiosity to continue to expand the scope of her studies.

"I want to do more research in the Southwest without totally giving up some projects in eastern North America," she says. "I'm hoping to do more historic period paleoethnobotany. I have questions about how early Hispanic land grantees made a living. How much of the agriculture did they bring with them, and how much did they learn from the local Pueblo peoples?

"Some of the questions that we have about the spread of agriculture—the dynamics of the adoption of agriculture—aren't being answered to my satisfaction," she continues. "There are just so many fascinating questions—I want to try to answer them."

Terri McClain is a free-lance writer based in St. Charles, Missouri.