title: Spatial interactions within modular organisms: genetic heterogeneity and organism fitness.
abstract: Modular organisms are composed of iterated units of construction that vary in their spatial arrangement. This variation is expected to affect the fitness of modular organisms due to interactions among neighboring modules and the potential for such organisms to be genetically heterogeneous. We devise a spatially explicit model to investigate how spatial interactions among neighboring modules affect organism fitness. We show that fitness is strongly dependent on the spatial arrangement of modules in both genetically homogeneous and heterogeneous organisms, and that the magnitude of the variation is dependent on the strength of interactions among modules. Organism fitness is more variable with interactions among modules that are symmetrical (each affects each other in the same directions) than with asymmetrical interactions (neighbors affect each other in different directions). We conclude by discussing potential extension of the present framework to a general dynamic model of spatially structured organism development.
authors.affiliation: Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver BC, Canada V6J IV9. pineda@zoology.ubc.ca
authors.forename: Mario
authors.initials: M
authors.lastname: Pineda-Krch
authors.forename: Alistair G B
authors.initials: AG
authors.lastname: Poore
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000465:Algorithms; D000818:Animals; D017753:Ecosystem; D018740:Genetic Heterogeneity; D006801:Humans; D008962:Models, Theoretical; D063245:Plant Development; D010944:Plants / Q000235:genetics; D013037:Spatial Behavior / Q000502:physiology*