Ecological and social overviews of ethnobotanical research

Abstract

I was kindly invited by the organizers of this Symposium to comment on the papers presented by the contributors, particularly from an ecological point of view. In attempting to do so, I did not restrict my commentaries to the purely ecological aspects, but tried also to express my viewpoints, as a scientist working in a country like Mexico, on the social and economic issues that form an indivisible part of the subject of the Symposium. All papers in the Symposium have pointed directly or indirectly to both the cultural and biological diversities that go hand in hand in all examples of plant utilization by human societies, across space and time. Such diversities are the result of the interplay among a given physical and biotic environment, a given set of genotypes that man recognizes as belonging to a species of useful or potentially useful plant, and man, a fundamentally energy-economic organism, surrounded by an intricate mesh of cultural attributes. This interplay is basically ecological in its nature, so much so that throughout human historyand currently for certain societies -one should consider culture to be an ecologically determined trait. When we speak of the interactions by which early societies developed domesticated plants, it is easy for us to think in terms of selection of the plant populations through domestication, and we implicitly accept many underlying ecological interactions in that process. What does not come so readily to mind is the fact that man also has been under the selective pressure of ecological-energetic efficiency. Decisions, such as the seed selection, the right planting times, and the appropriate field management of his crop, had to focus on the prospect of a positive balance between his energy inputs and his crop's energy yields. Red figures in this balance usually meant famine, propensity for disease, reduced life expectancy, and reduced birth rates; in a word, the risk of his genotype being left out of the evolutionary game. What better school than this for man to learn his trade well and teach it to his progeny well! The long process of plant evolution under domestication and the resulting cultural evolution of human societies are the roots of the cultural and biological diversity that constitute the riches of the field of ethnobotany and for which examples were given in the Symposium by Efraim Hemrnandez, Robert Bye, Anson Thompson, and Gary Nabhan. However, the impact of man upon his plants is not restricted to the relatively reduced number of present-day crops that constitute the bulk of human food sources, but may have had a very important expression