An investigation of finescale genetic structure of wood frog (Rana sylvatica) breeding sites in a fragmented habitat
Habitat fragmentation is often assumed to lead to the genetic subdivision of populations. Using eight neutral microsatellite DNA markers, I tested whether recent anthropogenic habitat fragmentation in Wellington County and the Greater Toronto Area (GTA), Ontario, Canada correlated with genetic subdivision of wood frog ('Rana sylvatica') populations. Geographic distance, road density, canopy cover, and watershed discontinuity were chosen as relevant geographic features affecting the wood frog. Of the chosen geographic features, geographic distance accounted for most of the observed variance in neutral allele frequencies; however, there was also significance for road density. Overall, there was very little genetic differentiation between the breeding sites, with the exception of one site in the GTA. This suggests that large effective population sizes, compounded with sufficient migration between sites, and little divergence time have contributed to the observed genetic homogeneity.