Transcript Document
Ethnobotany and Domesticated Plants Wheat First ethnobotanical rule of food production • In indigenous agriculture where the crops are consumed and not sold, there evolves and is maintained a reasonable level of nutritional adequacy Second ethnobotanical rule of food production • In indigenous agriculture where the crops are grown mainly or only for sale, there develops an expanding surplus of food. The overall objective of such agricultural systems is to replace a pre-existing (natural) plant community with a cultivator-made community It then follows that: If the potentially unstable increase in food production and human population is to be maintained, it must be consistent with three aims: 1. To operate at a maximum profit (labor/yield). 2. To minimize year-to-year instability in production. 3. To operate so as to prevent long-term degradation of the production capacity of the agricultural system. Mexican Corn Varieties Darwin on Artificial Selection “Although man did not cause variability and cannot even prevent it, he can select, preserve, and accumulate the variations given to him by the hand of nature almost in any way which he chooses; and thus can certainly produce a great result… Selection by man may be followed either methodically and intentionally, or unconsciously and unintentionally… We can further understand how it is that domestic races of plants often exhibit an abnormal character, as compared to natural species, for they have been modified not for their own benefit, but for that of man.” Street in Cuzco, Peru with advertisement for California seeds Plant Germ Plasm • The first category of germ plasm includes the native or indigenous varieties of cultivated crop plants used elsewhere in commercial agricultural production. • At present many of the major crop plants have a limited genetic base, as these have been developed through a series of selections that emphasize yield often at the expense of insect or disease resistance, environmental tolerance, multiple use, etc. Spread of Southern Corn Leaf Blight Southern Corn Leaf Blight Close up of Southern Corn Leaf Blight Southern Corn Leaf Blight – damage to ear Sweet Potato Healthy Sweet Potatoes – Ipomoea batatas Sweet potatoes with black rot Sweet potatoes with soft rot Sweet potatoes with russet crack Sweet potato attacked by nematodes Sweet potato with stem rot Healthy sweet potato Plant Germ Plasm • The second category of germ plasm material includes the identification and collection of wild relatives of the more commonly cultivated plants. Wild Tomato Species Domestic High Altitude Another S. sisymbrifolium Plant Germ Plasm • The third category includes plants not yet in the economic system and not related to domesticated plants. These may have properties of great value to us, but these can be very difficult to identify. Seed and germplasm storage facility – Kew Seed Bank Breadfruit Diane Ragone Checking Breadfruit Collection in Hawaii Ethnobotanical Methods William Withering and foxglove as a modern medicine Basic Working Method in Ethnobotany 1) Folk knowledge of a plant’s possible benefit to humans accumulates. 2) Indigenous people use that plant to benefit themselves 3) The folk knowledge is then related to a scientist 4) The scientist collects and identifies the plant 5) The scientist tests the plant to determine if it really is beneficial to humans. The form of the scientific test can vary significantly depending upon the potential use of the plant – whether as food, fiber, a dye, medicine, etc. 6) The scientist will attempt to determine what exactly makes the plant beneficial - what substance or aspect of the plant is beneficial. 7) The scientist determines the structure of the pure substance Rhubarb – Rheum x. cultorum Edible stems, deadly toxic leaves Study of the on-going process of domestication 1. Informant interviews – especially about desired traits, planting methods, methods of selection for breeding or seed stock. 2. Participation observation 3. Collection of native texts 4. Field observations – grain, fruit, or vegetable measurements; altitude, temperature, varietal flowering and maturation rates; mapping locations and distances to fields from farm or village; soil and vegetative analysis of sample fields at various stages of crop-fallow cycle. Phytoanthropology • Phytoanthropology examines the extent of similarities and differences in the responses of various human communities to their plant neighbors, and the reasons for these human responses. Bo Tree – Ficus religiosa Silk Cotton Tree – Bombax ceiba Arrowhead – Sagittaria sagittifolia