title: Indirect estimates of natal dispersal distance from genetic data in a stream-dwelling fish (Mogurnda adspersa).
abstract: Recent work has highlighted the need to account for hierarchical patterns of genetic structure when estimating evolutionary and ecological parameters of interest. This caution is particularly relevant to studies of riverine organisms, where hierarchical structure appears to be commonplace. Here, we indirectly estimate dispersal distance in a hierarchically structured freshwater fish, Mogurnda adspersa. Microsatellite and mitochondrial DNA (mtDNA) data were obtained for 443 individuals across 27 sites separated by an average of 1.3 km within creeks of southeastern Queensland, Australia. Significant genetic structure was found among sites (mtDNA Φ(ST) = 0.508; microsatellite F(ST) = 0.225, F'(ST) = 0.340). Various clustering methods produced congruent patterns of hierarchical structure reflecting stream architecture. Partial mantel tests identified contiguous sets of sample sites where isolation by distance (IBD) explained F(ST) variation without significant contribution of hierarchical structure. Analysis of mean natal dispersal distance (σ) within sets of IBD-linked sample sites suggested most dispersal occurs over less than 1 km, and the average effective density (D(e)) was estimated at 11.5 individuals km(-1); indicating sedentary behavior and small effective population size are responsible for the remarkable patterns of genetic structure observed. Our results demonstrate that Rousset's regression-based method is applicable to estimating the scale of dispersal in riverine organisms and that identifying contiguous populations that satisfy the assumptions of this model is achievable with genetic clustering methods and partial correlations.
authors.affiliation: the Australian Rivers Institute and Griffith School of Environment, Griffith University, Brisbane, Queensland 4111, Australia.
authors.forename: Ashlee
authors.initials: A
authors.lastname: Shipham
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Schmidt
authors.forename: Jane M
authors.initials: JM
authors.lastname: Hughes
mesh_terms: D000818:Animals; D001315:Australia; D016000:Cluster Analysis; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics*; D014644:Genetic Variation; D005828:Genetics, Population; D018895:Microsatellite Repeats / Q000235:genetics; D008969:Molecular Sequence Data; D011156:Population Density; D011157:Population Dynamics
chemical_list: D004272:DNA, Mitochondrial
keywords: BAPS; Mogurnda adspersa; SAMOVA; effective density; isolation by distance; kMeans; natal dispersal