Factors and processes shaping the population structure and distribution of genetic variation across the species range of the freshwater snail radix balthica(Pulmonata, Basommatophora)

BMC Evolutionary Biology

Research Article

Timm Haun¹  Moritz Salinger¹  Markus Pfenninger¹  Barbara Feldmeyer¹ 

[1] Molecular Ecology Group, Biodiversity and Climate Research Centre, Biocampus Siesmayerstraße, Goethe-University, 60323, Frankfurt am Main, Germany;

关键词: Genetic Variability;    Minimum Span Tree;    Species Range;    Akaike Weight;    Mitochondrial Haplotype;   

DOI  :  10.1186/1471-2148-11-135

 received in 2010-12-20, accepted in 2011-05-20,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundFactors and processes shaping the population structure and spatial distribution of genetic diversity across a species' distribution range are important in determining the range limits. We comprehensively analysed the influence of recurrent and historic factors and processes on the population genetic structure, mating system and the distribution of genetic variability of the pulmonate freshwater snail Radix balthica. This analysis was based on microsatellite variation and mitochondrial haplotypes using Generalised Linear Statistical Modelling in a Model Selection framework.ResultsPopulations of R. balthica were found throughout North-Western Europe with range margins marked either by dispersal barriers or the presence of other Radix taxa. Overall, the population structure was characterised by distance independent passive dispersal mainly along a Southwest-Northeast axis, the absence of isolation-by-distance together with rather isolated and genetically depauperated populations compared to the variation present in the entire species due to strong local drift. A recent, climate driven range expansion explained most of the variance in genetic variation, reducing at least temporarily the genetic variability in this area. Other factors such as geographic marginality and dispersal barriers play only a minor role.ConclusionsTo our knowledge, such a population structure has rarely been reported before. It might nevertheless be typical for passively dispersed, patchily distributed taxa (e.g. freshwater invertebrates). The strong local drift implied in such a structure is expected to erode genetic variation at both neutral and coding loci and thus probably diminish evolutionary potential. This study shows that the analysis of multiple factors is crucial for the inference of the processes shaping the distribution of genetic variation throughout species ranges.

【 授权许可】

CC BY   
© Pfenninger et al; licensee BioMed Central Ltd. 2011