Towards the theory of pollinator–mediated gene flow

Abstract

I present a new exposition of a model of gene flow by animal–mediated pollination between a source population and a sink population. The model's parameters describe two elements: (i) the expected portion of the source's paternity that extends to the sink population; and (ii) the dilution of this portion by within–sink pollinations. The model is termed the portion–dilution model (PDM). The PDM is a parametric restatement of the conventional view of animal–mediated pollination. In principle, it can be applied to plant species in general. I formulate a theoretical value of the portion parameter that maximizes gene flow and prescribe this as a benchmark against which to judge the performance of real systems. Existing foraging theory can be used in solving part of the PDM, but a theory for source–to–sink transitions by pollinators is currently elusive.