Document: JUL-3-92-7

When can genetic differentiation be used as a quantitative measure of inter-population movement?

BRENNAN, J.M.* and L.FAHRIG

Carleton University, Ottawa, ON, K1S 5B6, CANADA ¹

Abstract:
Movement of organisms between populations is linked to population survival and conservation. Recent reviews suggest potential for using genetic information to quantify inter-population movement. The theoretical basis for this approach is that genetic differentiation between populations is inversely related to inter-population movement. However, in practice the approach may be limited because the models are based on assumptions often either violated or not testable. The usefulness of genetic methodologies in the field hinges on assessing how well these measures perform when these assumptions are violated. One assumption often not met in conservation studies is that of genetic equilibrium. To determine the effects of violating this assumption we developed an individual-based object-oriented simulation model in which both the ecology and the genetics of the populations are known. In experimental simulations we manipulated the amount of movement of individuals between two populations and calculated F_ST (genetic differentiation) values. We performed this for a set of two small (n=50) and two larger populations (n=5000). We quantified the relationship between actual movement and that derived from the F_ST values, with changes in population size and approach to equilibrium. As expected, this relationship improved with approach to equilibrium and decreased for smaller population sizes. These results will be used to establish guidelines for the appropriate use of population genetic information to measure inter-population movement.

Keywords: movement; F_ST; genetic differentiation; object-oriented and/or individual-based models; population conservation

This abstract is being presented at: 10:30 AM in session:
STATISTICAL ECOLOGY