A spatially-explicit model of genetic tradeoff

Abstract

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.