Dynamics of Andean potato agriculture

Abstract

The invention and development of agriculture created tremendous diversity among the species selected for domestication. This diversity is still evident in cradle areas of domestication, maintained as ancestral varieties or landraces by traditional farmers. These centers of diversity have been recognized as imporant since N. I. Vavilov's work 50 yr ago. Archaeologically, they are significant because of their association with the origins of agriculture and the resulting new way of life for human populations. Genetically, they are important to geneticists and plant breeders as sources of germ plasm for the improvement of our modern crop varieties and for backup crop genetic resources (Harlan, 1976; Oldfield, 1979). Moreover, they are areas where ongoing crop evolution occurs in and around fields. They can thus provide information as to the ancestry of modern crop cultivars and enable us to understand better the genetic architecture of our modern domesticates. Although extensive germ plasm collecting and archaeological and botanical research have been undertaken in these areas of crop evolution and crop genetic diversity, our knowledge of the dynamics and systematics of traditional agriculture that supports this diversity remains rudimentary. Little anthropological or ethnobotanical investigation has concerned itself directly with how farmers in these areas identify, select, maintain and distribute the diverse genetic material of their crops. This lack of research contrasts sharply with recent advances in understanding the overall patterns of folk plant classification (Berlin et al., 1974; Conklin, 1972; Witkowski and Brown, 1978) and the wealth of material on the socioeconomic dimensions of traditional agriculture (e.g., Halperin and Dow, 1977; Wharton, 1969). The lack of detailed historical studies of genetic resources and agriculture in areas of crop diversity hampers our ability to model the dynamics of primitive selection, but it does not preclude attempts to extrapolate from synchronic analysis. There is mounting evidence from virtually every center of crop genetic diversity of the vulnerability and loss of primitive germ plasm, a problem popularly known as "genetic erosion," the replacement of complex assemblages of ancestral genetic material by more uniform hybrid and high yielding varieties (e.g., Eckholm, 1978; Harlan, 1975a; Frankel and Hawkes, 1975; Myers, 1979; Oldfield, 1979). By understanding the dynamics of the agricultural systems being affected by genetic erosion, we might gain a better idea of how to cope with these endangered resources (Brush, 1980). Human cultural diversity plays an essential role in the continuing evolution of these valuable primitive crop genetic resources (Harlan, 1975a), and the crop system of agricultural people maintaining these resources