Abstract :

Patterns of connectivity and propagule exchange are typically very variable between populations, since they are often determined by highly stochastic vection or transport processes. As a result, exchanges of genes among populations can be very episodic, with periods (or pulses) of relatively intense exchange followed by periods with little or no connectivity. In such conditions, the average connectivity level (or rate of migration) between any two populations may not be a sufficient descriptor to predict the amounts of geneflow or patterns of allele fixation. I will present mathematical and simulation results regarding the expected consequences of migration variaibility for observable patterns of genetic differentation. I will discuss ecological and evolutionary implications of migration variaibility and suggest ways to infer the mode of population coupling from population genomics patterns.