From Plant Press, Vol. 13, No. 4 from October 2010.
By Gary Krupnick
The ninth annual Smithsonian Botanical Symposium was held on 24-25 September at the National Museum of Natural History in Washington, DC, bringing together botanists, anthropologists, archaeobiologists, and other scientists to examine “Food for Thought: 21st Century Perspectives on Ethnobotany.” The event, hosted by the Departments of Botany and Anthropology, was held in collaboration with the United States Botanic Garden.
The symposium began with opening remarks by Warren L. Wagner, Chair of the Botany Department, and Cristián Samper, Director on the National Museum of Natural History. As Wagner introduced Samper, a slide of the Encyclopedia of Life webpage for “Sampera V. Funk & H. Rob, 2009” was displayed. The webpage <http://www.eol.org/pages/17860196> recently went live in honor of Samper’s birthday. Vicki Funk and Harold Robinson named the genus Sampera (Asteraceae) in honor of Samper’s research and service.
Before the seven invited speakers gave their talks, Laurence Dorr presented the ninth José Cuatrecasas Medal for Excellence in Tropical Botany to Beryl B. Simpson, C.L. Lundell Professor of Systematic Botany, University of Texas at Austin. Simpson is an expert in the phylogeny and biogeography of various angiosperm groups, with particular emphasis on plants from the American Southwest, Mexico, and Central and South America. While accepting her award, Simpson spoke of her long relationship with the Smithsonian Institution, a place “dear to [her] heart.” She was honored to have been in the same department with Cuatrecasas for several years, and even noted that she had named a species (Polylepis pepei) in his honor, using for the species epithet a form of his nickname “Don Pepe.”
Bruce D. Smith, Curator of North American Archaeology, Smithsonian Institution, who chaired the morning session, introduced the first set of speakers. Kenneth Olsen of Washington University in St. Louis first spoke of “Genetic Signatures and Consequences of Dual Crop Domestication Events in the Old World Tropics.” Olsen discussed evidence as to whether or not certain species under domestication were brought into cultivation once or multiple times. He presented two cases studies, coconut (Cocos nucifera)and rice (Oryza sativa), which both show evidence of more than one domestication event. Using microsatellite markers and a worldwide germplasm collection, Olsen showed differentiation between coconut populations in the Pacific and Indian Oceans. These patterns reveal that cultivated coconuts are derived from two distinct ancestral gene pools, with independent cultivation origins in the Pacific and Indian Oceans. There is also evidence of Pacific coconut admixture in the southwestern Indian Ocean, specifically along ancient Austronesian trade routes.
Olsen also spoke of the two independent origins of rice domestication. Two monophyletic groups (Japonica, Aromatic and Indica, Aus) are nested within Oryza rufipogon. A weedy rice (red rice, Oryza sativa) has lead to major loss in rice crop yields in the southern United States. Using molecular neutral markers, Olsen examined the origin of US weedy rice: US crop varieties (de-domestication), other Asian domesticated rice, wild Oryza populations, or multiple origins. He argued that the weed is likely derived from domesticated rice, but not directly derived from extant crop varieties, which suggests a long-term presence of current weed populations.
Next, Allison Miller of Saint Louis University spoke about the “Evolution of Clonally Propagated Plants under Domestication.” Miller presented two case studies, horseradish (Armoracia rusticana) and pecan (Carya illinoinensis), to explain the evolutionary dynamics of clonally-propagated crop perennials. One of the evolutionary consequences of clonal reproduction for plant mating systems is reduced fertility. Miller explored the possible mechanisms underlying reduced fertility by testing the hybrid origin of horseradish. A phylogenetic and Bayesian approach suggests a progenitor-descendant relationship between A. macrocarpa and A. rusticana, and that A. rusticana may have been domesticated from A. macrocarpa in Hungary or the Ukraine. The next step in future research is to ask whether horseradish is mate-limited and self-incompatible.
Miller’s second case study explored how domestication bottlenecks reduce genetic variation in cultivated populations. Her data suggest that three factors have shaped the variation in domesticated pecan trees: (1) native pecans exhibit geographic patterns of genetic variation; (2) domesticated populations were derived from geographically and genetically distinct native populations; and (3) local environmental control of flowering time suggests a mechanism for ongoing gene flow with wild progenitors. Her results support the role of perennial crops in sustainable agriculture and food security.
Following Miller was Eve Emshwiller from the University of Wisconsin at Madison who examined the role of human and plant interactions in crop evolution. Emshwiller presented her 17 years of ethnobotanical research on the origins and the continuing evolution of the tuber crop oca (Oxalis tuberosa) in the Central Andes. In discussing the origins of oca, an octopolyploid species, she spoke of the “Oxalis tuberosa alliance,” a clade of diploid species from the Andes. Emshwiller hypothesized that Oxalis tuberosa is the result of autoallopolyploidy, the hybridization of three diploid species.
Emshwiller continued with a discussion of the enthnotaxonomy of oca in three communities in southern Peru. Her research integrates anthropological survey data with molecular data. Through surveys, Emshwiller found different modes of exchange of the crops at different scales. Patterns of distribution of clonal genotypes of oca are correlated with distributions of different human languages and dialects. Some genotypes have very restricted distributions while others are widespread, leading to implications on how to conserve the oca varieties. Emshwiller expressed concern about the status of oca in the villages, as many farmers are switching to either an introduced potato or growing feed for dairy cattle.
After lunch, Dolores R. Piperno, Curator of Archaeobotany and South American Archaeology, Smithsonian Institution, chaired the session and introduced the afternoon speakers. Chocolate was the topic on everyone’s mind as Cameron L. McNeil of Lehman College, The City University of New York, discussed the ritual associations of Theobroma cacao in ancient and modern Mesoamerica. An archaeologist, McNeil presented results from her 9-year research program from Copan, which is on the southeastern Maya periphery. Evidence shows that cacao was used both culturally and economically in Mesoamerica nearly 4,000 years ago. Seeds were used as money, and the cacao beverage was a sign of wealth in paintings on vessels. Two plant species were commonly used: cacao (Theobroma cacao) and pataxte (T. bicolor). Pataxte, a more expensive form of cacao, contains high levels of ethylene, which can be used to ripen other fruit such as bananas. Because of the ripening process, pataxte was associated with the “male” in artwork, while cacao was associated with the “female.” Chemical residue analysis of vessels from 1900 B.C. shows evidence of cacao. Most believe cacao was only consumed as a beverage, but other vessels show possible use of cacao as a sauce. Today, the traditional uses of cacao in Mesoamerica are fading away as fields once devoted to cacao are being turned over to cattle and sugar. Additionally, soda is being used as a substitute for home-grown cacao in many rituals.
Cultural anthropologist Julie Velásquez Runk from the University of Georgia in Athens followed McNeil’s talk by “Exploring Connections in Culturally Oriented Ethnobotany: Examples from Panama and the U.S.” Focusing her research on the Wounaan people of the Darién in eastern Panama, Velásquez Runk explored the endangered traditions in agriculture, medicine, art, and decoration while living with the Wounaan for over two years. The lunar cycle has a strong influence on their traditions, as the high and low tide affect the harvesting time of plants. Velásquez Runk explained how the development of the Pan-American Highway has impacted the livelihoods of the Wounaan, once a nomadic people who are now sedentary. She described how the Wounaan perceive their land as a relationship and network between the plant, rivers, and spirits, as opposed to conservationists who focus on trees and forests with a bias on the physical rather than the spiritual.
Next, Torben Rick of the National Museum of Natural History spoke about “Archaeology, Marine Paleoethnobotany, and California Coastal Ecosystems.” As a zooarchaeologist, Rick was able to provide a unique perspective on the intersection of botany, biological sciences, and anthropology. Most marine plants have not come under domestication, but Native Americans have a history of interacting with kelp forest ecosystems around the Northern Channel Islands of California. Rick described how kelp forests sustained hunter-gatherers on the Channel Islands for 10,000 years. There is evidence that the Chumash people used kelp as a fuel source, boat anchors, and protection against magic. It is difficult, however, to ascertain whether or not kelp was harvested, mainly because fronds preserve poorly in the archaeological record. In the Channel Islands, there is an abundant sea grass archaeological record, but none for kelp. Rick explained that there is an archaeological record for three invertebrate animal species that live on kelp (Calliostoma annulatum, C. ligatum, and Tegula brunnea), and thus Native Americans may have used the kelp to harvest these animal species. He argued that an increase in the integration of ethnobotany and ethnozoology—especially in archaeological research—can provide new insights into anthropology.
The final speaker of the day was Ruth Defries from Columbia University who spoke about “Food, Landscapes and the Planet’s Life Support System.” Defries, a geographer, discussed how the Earth’s metabolism cycles carbon and nitrogen among the atmosphere, land, and ocean, which makes our planet uniquely suited to produce food for the 6.7 billion-strong human population. She explained that an increase in food production triggers population growth, and that when ecological parameters limit further increases in food production, population density will decrease (starvation, migration). She showed how the discovery of an industrial way to synthesize nitrogen allowed for a tremendous increase in food production, which lead to an increase in the global population size. Defries then contemplated doomsday scenarios where drought and increasing food prices lead to riots and instability. She pointed out trends such as when the size of urban areas increases, income and the consumption of animal products also increase. The challenge for the future, she explained, is how to intensify food production while maintaining biodiversity. She pointed out that there are no clear answers on the horizon.
From Olsen’s morning talk focusing at the genome level to Defries’ final presentation at the global level, the 2010 Smithsonian Botanical Symposium provide a unique perspective on the interactions between humans and plants.
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