Format: ORAL

Pablo R. Stevenson1, Diana C. Acosta-Rojas1, Sasha Crdenas1, L. Francisco Henao-Daz1,2

1 Centro de Investigaciones Ecológicas La Macarena, Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá, Colombia 2 Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA

Variation in fruit and seed traits could originate from selection pressures exerted by frugivores or other ecological factors (adaptive hypotheses) and developmental constraints (by-product hypotheses) or chance. We evaluated fruit and leaf traits for nearly 850 plant species from a rainforest in Tinigua Park, Colombia. Through a series of linear regressions controlling for the phylogenetic signal of the traits (minimum N = 542), we tested (1) whether the allometry between seed width and length depends on seed dispersal system (Mazer and Wheelwrights adaptive hypothesis of allometry for species dispersed in the guts of animals = endozoochory) and (2) whether fruit length is associated with leaf length (i.e., Herreras by-product hypothesis derived from the assumption that both organs develop from homologous structures). First, we discovered a robust negative allometric relationship between seed width and length in endozoochorous species, aligning with our expectations. Surprisingly, this association also held true for anemochorous species. In addition, we found a positive relationship between fruit and leaf length, but this relationship was not evident for zoochorous species. Our findings lead us to the conclusion that the allometric relationship between seed length and width exhibits variability among dispersal systems. This supports the notion that fruit and seed morphology has undergone modifications due to interactions with frugivores and the unique adaptability to rotate, particularly evident in certain wind-dispersed species.