title: Speciation Progress: A Case Study on the Bushcricket Poecilimon veluchianus.
abstract: Different mechanisms such as selection or genetic drift permitted e.g. by geographical isolation can lead to differentiation of populations and could cause subsequent speciation. The two subspecies of Poecilimon veluchianus, a bushcricket endemic to central Greece, show a parapatric distribution and are partially reproductively isolated. Therefore, P. veluchianus is suitable to investigate an ongoing speciation process. We based our analysis on sequences of the internal transcribed spacer (ITS) and the mitochondrial control region (CR). The population genetic analysis based on the nuclear marker ITS revealed a barrier to gene flow within the range of Poecilimon veluchianus, which corresponds well to the described subspecies. In contrast to the results based on the nuclear ITS marker, the mitochondrial CR marker does not clearly support the separation into two subspecies with restricted gene flow and a clear contact zone. Furthermore, we could identify isolation by distance (IBD) as one important mechanism responsible for the observed genetic structure (based on the ITS marker). The population genetic analysis based on the nuclear marker ITS also suggests the existence of hybrids in the wild. Furthermore, the simultaneous lack of strong prezygotic barriers and the presence of postzygotic mating barriers, observed in previous laboratory experiments, suggest that a secondary contact after an allopatric phase is more likely than parapatric speciation.
authors.affiliation: Department of Evolutionary Biology, Bielefeld University, Bielefeld, Germany.
authors.forename: Lucienne
authors.initials: L
authors.lastname: Eweleit
authors.affiliation: Department of Evolutionary Biology, Bielefeld University, Bielefeld, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Reinhold
authors.affiliation: Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Sauer
mesh_terms: D063147:Animal Distribution; D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics; D021903:DNA, Ribosomal Spacer; D066264:Datasets as Topic; D019143:Evolution, Molecular; D005260:Female; D051456:Gene Flow; D005819:Genetic Markers; D049810:Genetic Speciation; D014644:Genetic Variation; D006115:Greece; D006135:Gryllidae / Q000145:classification / Q000235:genetics*; D006702:Homing Behavior; D019901:Locus Control Region; D008297:Male; D008957:Models, Genetic; D060047:Reproductive Isolation; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial; D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers