Genetic structure in a montane mayfly Baetis bicaudatus (Ephemeroptera: Baetidae), from the Rocky Mountains, Colorado

摘要: SUMMARY 1. Populations of a number sub-tropical stream insect species have been found to show unexpected patterns genetic variation, with more differences between samples from the same than whole streams or subcatchments. Many also showed deviations Hardy–Weinberg proportions. It has proposed that these result limited numbers matings contributing given reach, because adults emerge throughout year, and low levels larval drift reaches. These may be less likely in northern hemisphere montane synchronous emergence high drift. We tested hypothesis variation mayfly Rocky Mountains, Colorado, would reflect pattern ‘isolation by distance’ creek being similar different creeks proportions minimal. 2. Based on allozyme minimal Hardy– Weinberg was not supported there no evidence isolation distance. Nevertheless differentiation among within were those reported for most subtropical species. 3. Results analysis fragment cytochrome oxidase gene (subunit 1) revealed contrasting patterns. The an order magnitude higher streams. In addition, although significant distance effect overall, nested clade provided restricted flow some clades. 4. suggest results male female dispersal While at nuclear markers (allozymes) give information about both dispersal, mitochondrial DNA only dispersal. this species, restricted, perhaps mostly along channels, whereas is