title: Phylogeographic patterns of Merodon hoverflies in the Eastern Mediterranean region: revealing connections and barriers.
abstract: We investigated the phylogeographic patterns of Merodon species (Diptera, Syrphidae) in the Eastern Mediterranean. Ten species were sampled on five different islands and mainland sites as a minimum. All samples were screened for their mtDNA COI barcode haplotype diversity, and for some samples, we additionally generated genomic fingerprints. The recently established zoogeographic distribution categories classify these species as having (1) Balkan distribution; (2) Anatolian distribution; (3) continental areas and large islands distribution; and (4) with wide distribution. The ancestral haplotypes and their geographical localities were estimated with statistical parsimony (TCS). TCS networks identified as the ancestral haplotype samples that originated from localities situated within the distributional category of the species in question. Strong geographical haplotype structuring was detected for many Merodon species. We were particularly interested to test the relative importance of current (Aegean Sea) and past Mid-Aegean Trench) barriers to dispersal for Merodon flies in the Aegean. We employed phylogenetic β-diversity (Pβ total) and its partition in replacement (Pβ repl) and richness difference (Pβ rich) to test the importance of each explanatory variable (interisland distance, MAT, and island area) in interisland differences using partial Mantel tests and hierarchical partitioning of variation. β-Analyses confirmed the importance of both current and past barriers to dispersal on the evolution of group. Current interisland distance was particularly important to explain the replacement of haplotypes, while the MAT was driving differences in richness of haplotypes, revealing the MAT as a strong past barrier whose effects are still visible today in the phylogenetic history of the clade in the Aegean. These results support the hypothesis of a highly restricted dispersal and gene flow among Merodon populations between islands since late Pleistocene. Additionally, patterns of phylogeographic structure deduced from haplotype connections and ISSR genome fingerprinting data revealed a few putative cases of human-mediated transfers of Merodon spp.
authors.affiliation: Zoology Unit Finnish Museum of Natural History University of Helsinki PO Box 17 00014 Helsinki Finland.
authors.forename: Gunilla
authors.initials: G
authors.lastname: Ståhls
authors.affiliation: Department of Biology and Ecology University of Novi Sad Trg Dositeja Obradovića 2 21000 Novi Sad Serbia.
authors.forename: Ante
authors.initials: A
authors.lastname: Vujić
authors.affiliation: Department of Geography Laboratory of Biogeography & Ecology University of the Aegean 81100 Mytilene Greece.
authors.forename: Theodora
authors.initials: T
authors.lastname: Petanidou
authors.affiliation: Zoology Unit Finnish Museum of Natural History University of Helsinki PO Box 17 00014 Helsinki Finland.
authors.forename: Pedro
authors.initials: P
authors.lastname: Cardoso
authors.affiliation: Department of Biology and Ecology University of Novi Sad Trg Dositeja Obradovića 2 21000 Novi Sad Serbia.
authors.forename: Snezana
authors.initials: S
authors.lastname: Radenković
authors.affiliation: BioSense Institute University of Novi Sad Dr Zorana Đinđića 1 21000 Novi Sad Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Ačanski
authors.affiliation: Department of Environmental Sciences & Natural Resources/Research Institute CIBIO University of Alicante Apdo 99 E-03080 Alicante Spain.
authors.forename: Celeste
authors.initials: C
authors.lastname: Pérez Bañón
authors.affiliation: Department of Environmental Sciences & Natural Resources/Research Institute CIBIO University of Alicante Apdo 99 E-03080 Alicante Spain.
authors.forename: Santos
authors.initials: S
authors.lastname: Rojo
keywords: Aegean archipelago; Merodon; haplotype diversity; mtDNA COI; phylogeography