Exploring selection mosaics and coevolution in multiespesific generalized systems

Jose Gomez (April 5, 2011)

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Abstract

The geographic mosaic theory of coevolution (GMTC) considers that populations differ in evolutionary dynamics due to spatial variation in selective regimes. According to GMTC, three components of geographic structure drive the overall coevolutionary dynamics of such interactions: selection mosaics, coevolutionary hotspots, and trait remixing. Furthermore, the GMTC suggests the occurrence of a spatial pattern of interaction-mediated local adaptation and maladaptation. Empirical support to these theoretical predictions has come mostly from specialist antagonistic interactions. Contrasting with specialist interactions, free-living generalist interactions are formed by multispecies networks of interacting organisms that vary spatially in composition. Extreme reciprocal specialization between pairs of species is rare in these interactions. Consequently, multispecific selection and diffuse coevolution are prevalent in generalist interactions. Here I explore the possibilities of selection mosaic and interaction-mediated local adaptation in multiespecific generalized systems. To overcome the inherent difficulties of studying the interactions occurring among many species, I propose the combined use of structural equation modeling and individual-based network tools. This approach has allowed to detect that geographic mosaic of selections occur in generalist systems as well, and may be even a driver of the evolution of generalization in these types of multispecific systems.