PARENT SESSION

Genetics/Evolution 1 -- Session Chair: Hopi Hoekstra-- University Center, Kate Buchanan Room

DOES HABITAT HETEROGENEITY RESTRICT GENE-FLOW? FINE SCALE GENETIC STRUCTURE IN THE PACIFIC JUMPING MOUSE (ZAPUS TRINOTATUS). Sacha N. Vignieri^1,2 and G J. Kenagy^1,2. ¹ Department of Biology, University of Washington, Seattle, WA, USA; ² Burke Museum, University of Washington, Seattle, WA.

ABSTRACT- Anthropogenic fragmentation of a species' habitat is predicted to restrict gene flow, perhaps to such a degree as to affect the persistence of the species within remnant habitat patches and subsequently the species as a whole. Species living in naturally heterogeneous habitat persist, but are subject to similar restrictions of individual movement within and between patches. Clearly, connectivity is maintained between natural habitat patches, but we might expect it to be limited by the availability and location of suitable habitat. We used microsatellite markers to investigate this prediction in a species naturally affiliated with patchily distributed habitat, the Pacific jumping mouse (Zapus trinotatus). In order to test for restricted gene-flow at the level of the individual, we used spatial autocorrelation analysis to reveal the presence of a correlation between individual genotypes and space. We found a significant correlation at multiple scales, from 25 meters up to a remarkably large distance of >5000 meters. Males and females showed similar patterns but to a different degree indicating potential differences in dispersal. In addition, significant sub-population structure was found between relatively short distances indicating that restriction of gene flow at the local or individual level also has an effect on the population structure within the region. These results indicate that despite the maintenance of connectivity between habitat patches, the heterogeneous distribution of habitat can have a structuring effect on affiliated species.

KEY WORDS: habitat heterogeneity, sub-population structure, spatial autocorrelation, Dipodidae