title: Factors and processes shaping the population structure and distribution of genetic variation across the species range of the freshwater snail radix balthica (Pulmonata, Basommatophora).
abstract: BACKGROUND
  Factors 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.
  
  
  RESULTS
  Populations 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.
  
  
  CONCLUSIONS
  To 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.
authors: Molecular Ecology Group, Biodiversity and Climate Research Centre, Biocampus Siesmayerstraße, Goethe-University, 60323 Frankfurt am Main, Germany. Pfenninger@bio.uni-frankfurt.de
authors: Markus
authors: M
authors: Pfenninger
authors: Moritz
authors: M
authors: Salinger
authors: Timm
authors: T
authors: Haun
authors: Barbara
authors: B
authors: Feldmeyer
references: Bioinformatics. 2009 Jun 1;25(11):1451-2
references: 19346325
references: Mol Ecol. 2007 Jun;16(12):2474-87
references: 17561907
references: Heredity (Edinb). 2005 Dec;95(6):428-36
references: 16175196
references: Cold Spring Harb Symp Quant Biol. 1959;24:87-105
references: 13807991
references: Am Nat. 2002 Dec;160(6):741-55
references: 18707462
references: Genetics. 1996 Dec;144(4):2001-14
references: 8978083
references: Mol Ecol Resour. 2009 Jul;9(4):1152-5
references: 21564859
references: Theor Appl Genet. 1996 May;92(7):832-9
references: 24166548
references: Evolution. 1997 Oct;51(5):1518-1528
references: 28568614
references: Oecologia. 2007 Feb;151(1):93-103
references: 16964502
references: Mol Ecol Notes. 2007 Jul 1;7(4):574-578
references: 18784791
references: Bioinformatics. 2012 Oct 1;28(19):2537-9
references: 22820204
references: Am J Bot. 2006 Sep;93(9):1289-94
references: 21642193
references: Trends Ecol Evol. 1993 Nov;8(11):409-13
references: 21236213
references: Evolution. 1997 Feb;51(1):21-28
references: 28568782
references: Nature. 2000 Jun 22;405(6789):907-13
references: 10879524
references: Nature. 1989 Oct 12;341(6242):497-503
references: 2677747
references: Am Nat. 2006 Dec;168(6):769-83
references: 17109319
references: Evolution. 2002 Sep;56(9):1776-88
references: 12389722
references: Mol Ecol. 2009 Mar;18(6):1137-44
references: 19226317
references: Am Nat. 1997 Jul;150(1):1-23
references: 18811273
references: Evolution. 1998 Jun;52(3):657-668
references: 28565251
references: Front Biol. 1975;40:I-288
references: 1228006
references: Monogr Popul Biol. 1971;4:1-219
references: 5162676
references: BMC Evol Biol. 2006 Nov 23;6:100
references: 17123437
references: Evol Bioinform Online. 2007 Feb 23;1:47-50
references: 19325852
references: Science. 2003 Jun 6;300(5625):1563-5
references: 12791991
references: Am Nat. 2003 Oct;162(4):474-88
references: 14582009
references: Mol Ecol. 2007 Apr;16(8):1649-60
references: 17402980
references: J Evol Biol. 2006 Jul;19(4):1071-82
references: 16780508
references: Mol Ecol. 2006 Aug;15(9):2643-51
references: 16842433
references: Trends Ecol Evol. 2008 Jul;23(7):347-51
references: 18502536
references: Trends Ecol Evol. 2007 Mar;22(3):140-7
references: 17113679
references: Mol Ecol. 2009 Feb;18(3):534-44
references: 19161472
references: Genetics. 2000 Jun;155(2):945-59
references: 10835412
references: Mol Mar Biol Biotechnol. 1994 Oct;3(5):294-9
references: 7881515
references: BMC Evol Biol. 2007 Jul 19;7:121
references: 17640383
references: Mol Ecol. 2001 May;10(5):1333-40
references: 11380888
references: Mol Ecol. 2008 Mar;17(5):1170-88
references: 18302683
references: J Hered. 1998 May-Jun;89(3):238-47
references: 9656466
references: Evolution. 1995 Oct;49(5):911-920
references: 28564864
references: Genetics. 1987 Oct;117(2):353-60
references: 3666446