Alors que le débat sur le caractère scientifique ou pseudo-scientifique de l’agriculture biodynamique occupe régulièrement le débat public, l’histoire et la philosophie des sciences ne semblent que très peu s’être emparées de ce sujet. La thèse défendue ici est double : tout d’abord, si l’agriculture biodynamique rencontre un relatif succès aujourd’hui, cela tient sans doute au fait que son théoricien, R. Steiner, a été un des premiers à critiquer le paradigme qui domine l’agronomie, ou en tout cas l’agriculture, depuis (...) plus d’un siècle. Cette critique semble d’ailleurs se maintenir dans ses motifs tout au long du XXe siècle, jusqu’à une certaine critique contemporaine de l’agro-industrie et de ses conséquences désastreuses sur l’environnement. Or, et c’est la seconde thèse défendue ici, cette critique semble méconnaître voire occulter la réalité des débats internes qui ont traversé l’agronomie au cours du XXe siècle et qui continuent de l’agiter aujourd’hui : l’agronomie système a ainsi par exemple intégré dans ses objets des éléments de l’agriculture biodynamique. Selon nous, le problème principal est que l’agronomie est souvent abordée selon une approche externaliste, qui doit impérativement être complétée par une approche internaliste afin tout d’abord de distinguer ce qui relève de la science et ce qui relève du mysticisme, et ensuite de saisir toute la richesse historique et épistémologique de l’agronomie. (shrink)

In a very general sense, hybrid can be understood to be any organism that is the product of two (or more) organisms where each parent belongs to a different kind. For example; the offspring from two or more parent organisms, each belonging to a separate species (or genera), is called a “hybrid”. “Hybridity” refers to the phenomenal character of being a hybrid. And “hybridization ” refers to both natural and artificial processes of generating hybrids. These processes include mechanisms of selective (...) cross-breeding and cross-fertilization of parents of different species for the purpose of producing hybrid offspring. In addition to these processes, “hybridization ” also refers to natural and artificial processes of whole genome duplication that result in the doubling or trebling of the sets of chromosomes of the organism. This entry provides an overview of the impact of hybridity on agriculture. It begins with an historical sketch that traces the early horticulturalists’ and naturalists’ investigations of hybrids. This starts with the observations of Thomas Fairchild and Georges-Louis Leclerc, Comte de Buffon; and leads to the explanation of its mechanism by Gregor Mendel, James Watson and Francis Crick, and Ernst Mayr; and the eventual manipulation of hybrids and hybridization by Barbara McClintock. Following this, the reader is introduced to a number of key terms and concepts in use within current research as well as highlighting diverse ethical concerns that center on hybridization. Recent research that attempts to ascertain the role of hybridization in adaptive change will be introduced. This will include research on the evolution of crop species, increased biodiversity, and the use of hybrids to manipulate phenotypically desirable traits in agricultural crops. The focus of the discussion is on a particularly significant type of naturally occurring hybridization, polyploidy hybridization. Polyploids are organisms which have more than two complete genomes in each cell. This kind of hybridization is ubiquitous among crop plants. The role of polyploidy in plant evolution and the affects of polyploidy on plants and animals will be reviewed. A critical discussion of its agricultural value in the production of fertile polyploid hybrids highlights key epistemological, ontological, and ethical issues. These are illuminated with reference to the distinct processes of artificial and natural hybridization. A survey of these different kinds of hybridization includes the ethical and economic impacts of hybridity on global nutrition, the environment, and considerations of some practical implications for the agricultural industry. Tracking the role of hybrids, the process of hybridization, and the current impacts of it for agriculture requires knowledge of the history of its early conceptualization, understanding, and use. This is the topic of the following section. (shrink)