“Evolutionary origin and persistence of mutualism: A formal model for the Rhizobium-legume interaction

DIANA MARCO; JUAN SANJUÁN

Toulouse, Francia

Congreso; 6th European Nitrogen Fixation Conference; 2004

Mutualistic interactions pose challenging ecological and evolutive problems. Complex questions concerned with the evolutionary origin of the mutualism, like the existence of conflict of interests between mutualistic partners, or with the persistence of mutualism in spite of cheating partners can be approximated using formal models. In particular, mutualism (symbiosis) between Rhizobium and legumes constitutes an ideal system for using this approach.     We are exploring some of the main theoretical questions involved in mutualism by developing a formal model for Rhizobium-legume interaction, using the adaptive dynamics framework. Specifically, we address the following factors: -Ecological dynamics of partners -Altruism -Evolutive rates -Cheating from non-fixing rhizobia and possible sanctions from the plant -Evolutive dynamics given by genetic transfer between rhizobial strains.