title: Ongoing Speciation and Gene Flow between Taxonomically Challenging Trochulus Species Complex (Gastropoda: Hygromiidae).
abstract: Geographical isolation, selection and genetic drift can cause the geographical diversification of populations and lead to speciation. Land snail species in the genus Trochulus show overlaps in geographical ranges as well as in morphology, but genetic data do not always support the species-level taxonomy based on morphological characters. Such a group offers an excellent opportunity to explore the processes involved. We have addressed the problem by determining the status of the restricted endemic T. graminicola within the larger context of Trochulus taxonomy. We used an integrated approach based on morphological features, ecological preferences and two molecular markers: mitochondrial COI sequences and microsatellites. Comparison of these results demonstrated: (i) conchological distinction of T. striolatus and T. sericeus; (ii) anatomical, ecological and genetic differentiation of T. graminicola and (iii) concordance between morphological characters and mtDNA markers in T. striolatus. Moreover, our data showed an intricate evolutionary history within the genus Trochulus, which can be best explained by: (i) recent or ongoing gene flow between taxa or (ii) their large ancestral polymorphism. Both of these hypotheses suggest that diversification within this group of snails has occurred relatively recently. The mismatches between species defined on morphology and on molecular genetics indicate the complexity of the processes involved in the diversification of this genus.
authors.affiliation: Museum of Natural History, University of Wrocław, Wrocław, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Proćków
authors.affiliation: Department of Genetics, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Strzała
authors.affiliation: Department of Invertebrate Systematics and Ecology, Institute of Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Kuźnik-Kowalska
authors.affiliation: Department of Plant Biology, Institute of Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
authors.forename: Jarosław
authors.initials: J
authors.lastname: Proćków
authors.affiliation: Department of Genomics, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Mackiewicz
mesh_terms: D000818:Animals; D049851:Gastropoda / Q000145:classification / Q000235:genetics*; D051456:Gene Flow