Genetic differentiation in populations with different classes of individuals

I formulate and analyse a model of population structure with different clas ses of individuals. These different classes may be age classes, other demog raphic classes, or different types of habitats homogeneously distributed ov er a geographical area. The value of population differentiation under an is land model of dispersal and the increase of differentiation with geographic al distance in one- and two-dimensional "isolation by distance" models are then obtained for a generalization of the F-ST measure of population struct ure, as a function of "effective" mutation, migration, and population size parameters. The relevant effective subpopulation size is related to the "mu tation effective population size" of a single isolated subpopulation and, i n models of age-structured populations, to the inbreeding effective populat ion size, (C) 1999 Academic Press.