A spatially-explicit model of genetic tradeoff

Spatially-explicit, individual based models are used to explore the consequences of introducing two simple genetic tradeoff mechanisms to the gradient response of monoecious diploid individuals. A simple linear gradient is used to produce a structured environment. One tradeoff relates the plasticity of an individual to its overall fitness, where individuals that can tolerate a wide range of environmental values are less fit than individuals with a narrow tolerance range. The second tradeoff assumes that individuals that can live at greater environmental values are placed under stress and therefore reach maturity later in their life cycle. Here all individuals have the same fitness, but the penalty for tradeoff is less time for breeding after reaching maturity. In both cases the resulting population distributions produced clear genetic differentiation, showing that simple tradeoff mechanisms are one route towards genetic isolation and, ultimately, speciation.PublishedPeer ReviewedBall, M. C. (1988). Ecophysiology of mangroves. Trees 2, 129-142. Dieckmann, U., and M. Doebeli. (1999). On the origin of species by sympatric speciation. Nature 400, 354-357. Doebeli, M., and U. Dieckmann. (2003). Speciation along environmental gradients. Nature 421, 259-264. Durrett, R., L. Buttel, and R. Harrison. (2000). Spatial models for hybrid zones. Heredity 84, 9-19. Epperson, B. (1995). Spatial distributions of genotypes under isolation by distance. Genetics 140, 1431-1440. Ermentrout, G. B., and L. Edelstein-Keshet. (1993). Cellular automata approaches to biological modeling. J. Theor. Biol. 160, 19-133. Green, D. G., D. Newth, and M. Kirley. (2000). Connectivity and catastrophe - towards a general theory of evolution. Pages 153-161 in M. A. Bedau, editor. Artificial Life VII: Proceedings of the Seventh International Conference. MIT Press. Hoffmann, A., C. Sgro, and S. Lawler. (1995). Ecological Population-Genetics: The interface between genes and the environment. Annual Rev. of Genetics 29, 349-370. Hogeweg, P. (1988). Cellular automata as a paradigm for ecological modeling. Applied Math. Comput. 27, 81-100. Holland, J. H. (1992). Adaptation in natural and artificial systems. MIT Press, second edition. Kondrashov, A., and F. Kondrashov. (1999). Interactions among quantitative traits in the course of sympatric speciation. Nature 400, 351-354. Leroi, A. (2001). Moelcular signals versus the Loi de Balancement. TRENDS in Ecology and Evolution 16, 24-29. Mayr, E. O. (1942). Systematics and the Origin of Species. Columbia University Press, New York. Sadedin, S., and M. Littlejohn. (2003). A spatially explicit Individual-based model of reinforcement in hydrid zones. Evolution 57, 962-970. Sokal, R., G. Jacquez, and M. Wooten. (1989). Spatial autocorrelation analysis of migration and selection. Genetics 121, 845-855. von Neumann, J. (1966). Theory of self-reproducing automata. University of Illinois Press