Science and humanities wed to explore origins and consequences of domesticated rice

Susan McCouch speaks at the Rice and Language Across Asia: Crops, Movement and Social Change International Symposium on Cornell’s campus on Sept. 23.

At Cornell, studying the origins and spread of domesticated rice doesn’t just involve plant geneticists; but a new course also includes insights from archaeology, geography, plant genetics, anthropology and linguistics.

The upper level undergraduate course, Rice and Language: Geography, Movement and Exchange, offered for the first time this fall, covers such parallel socio-cultural and linguistic developments as migration and language diversification.

And a Sept. 22-25 symposium that brought an international cadre of researchers to campus to share multidisciplinary findings on the topic helped enrich the dialogues.

"In the course, we are trying to be explicit about how there could be links between findings in these different disciplines," said Magnus Fiskesjö, associate professor of anthropology and co-instructor for the course. "Archaeologists can find terraces and villages and the remains of plants, while geneticists are building family trees of relationships of rice from samples in the present, and linguists speak of words associated with these plants that are shared across linguistic groups, from which they can begin to tease out the history of rice."

The course also addresses the pros and cons of comparing data and insights from different disciplines. For example, interdisciplinary work can build a broader understanding of a subject. Specialists, on the other hand, learn new ways of looking at a topic and may question ideas that are taken for granted in their field. They also may adopt techniques across disciplines, such as the family tree model, which originated in linguistics with language trees but are now used by biologists, said linguist John Whitman, a co-instructor of the course.

But interdisciplinary work also has challenges, as "people may talk past each other," and the units that specialists analyze, such as language, population or culture, may not be clearly or uniformly defined, said Fiskesjö.

The 15 students in the class this semester also learned from experts presenting at the September event, "Rice and Language Across Asia: Crops, Movement and Social Change International Symposium," which offered the latest findings from linguists, anthropologists and plant geneticists.

At the symposium, archaeologists dated the earliest evidence of domesticated rice grains, when humans imposed artificial selection on wild rice populations to select larger, fatter seeds that no longer "shattered" (natural shedding of mature grains). They reported that the selection was a gradual process that came to fruition around 6,500 years ago, based on archaeological discoveries of charred remains of non-shattering rice grains in the Lower Yangtze region of China.

Rice geneticists supported the theory that rice was first domesticated around this time in the same general region by tracing the origins of alleles for such traits as non-shattering and white grain color that are associated with ease of harvest, loss of grain dormancy and aesthetic appeal.

Meanwhile, historical linguists added to the debate about the origins of rice domestication by identifying the first known words for rice in ancient languages in and around China.

Researchers also debated about whether parallel domestication events occurred, for example, in India, and how and when rice spread to the rest of the world. Susan McCouch, a Cornell rice geneticist and course co-instructor, presented her rice genetics research findings, which identify a mutation for white rice color that originates in japonica rice and was then moved into indica rice, suggesting that domesticated rice dispersed from China to India and elsewhere.

The symposium was sponsored by various Cornell programs and departments, the Lehman Fund for Scholarly Exchange with China and the Wenner-Gren Foundation for Anthropological Research.