Beyond adaptation: locating social processes in crop evolution

The dominant Darwinian framework for understanding crop evolution includes both natural and human (“artificial”) selection acting on variation in crop populations. Crop research has emphasized adaptation and geographic dispersal in determining macro-level patterns of diversity, but understanding diversity at smaller geographic levels remains challenging. At micro- and meso-regional levels, social research has emphasized methodical selection expressed by folk taxonomies and rational choice among crop varieties. Unconscious selection, while noted in the Darwinian model, has received less attention and has been mainly associated with phenomena such as migration and diffusion that operate at larger geographic levels. We ask how societies introduce discontinuity into the continuum of individual variations and what guides selection. Our paper argues that crop diversity cannot be seen solely as a technical product of adaptation to environmental and economic conditions but also a product of the cultural context. Factors such as the seed exchange across production environments and the fact that the number of crop varieties often exceeds the number of different uses for the crop, lead us to look beyond adaptation and conscious selection as the only mechanisms operating to produce crop diversity. Previous efforts to model unconscious selection have been limited by failure to utilize observable patterns in social factors and processes at the group level, such as ethnolinguistic diversity. Recent research has demonstrated the usefulness of social organization for investigating crop diversity. We develop a framework for explaining crop differentiation: GxExS, where genetic variation (G) is determined not only by environmental variations (E), but also by social differentiation (S). The paper reviews the background of this framework and discusses operational mechanisms of S, such as perceptual distinctiveness, food preferences, and seed circulation networks. We conclude with a call for considering crop diversity as a “total social fact” inserting symbolic and cultural perspectives into the picture