Genes in Streams: The Role of Life-History, Habitat Specialisation and River Architecture

Understanding the patterns of connectivity among natural populations is critical for making predictions concerning impacts of anthropogenic influences that cause local extinctions. Based on genetic studies, four main models of connectivity have been proposed for animals that inhabit stream systems. These are the death valley model, the stream hierarchy model, the headwater model and panmixia. Each of these models has specific predictions as to the spatial structuring of genetic variation and the subsequent effects of local extinctions. We will present predictions from each of the models. Then we will present analysis of molecular data from our lab and recently published studies to test the idea that a knowledge of a species' life-history, its habitat requirements and the architecture of the rivers in which it lives can be used to predict the model of connectivity it will best fit.  We will present analysis on fish, insects crustaceans and molluscs.