GENE FLOW IN GROUND BEETLES (COLEOPTERA: CARABIDAE) OF DIFFERING HABITAT PREFERENCE AND FLIGHT-WING DEVELOPMENT.

Estimates of gene flow vary 100-fold among five carabid species, ranging from the winged lowland subtropical Agonum elongatulum to the flightless montane temperate Platynus angustatus. Results based on Wright's (1943) F method, and Slatkin's (1981) graphical and (1985a) private-allele methods are concordant. Genetic heterogeneity, measured by Wright's F , is not correlated with degree of flight-wing development; one fully winged species exhibits heterogeneity of the same order as a vestigially winged species. Genetic heterogeneity is positively correlated with the average elevation of collection sites for these species. Lower levels of gene flow associated with greater genetic subdivision may occur in upland areas because of habitat fragmentation (due to topographic diversity) and habitat persistence (leading to a lower extinction rate for populations). In at least one species, the distribution of stable infraspecific polymorphisms indicates that the high estimate of present-day gene flow is likely to be due to historical gene flow and not to present-day conditions.