Phylogenetic analysis of the genus Euscorpius (Scorpiones: Euscorpiidae) across the Mediterranean region (86 specimens, 77 localities, four DNA markers: 16S rDNA, COI, COII, and ITS1), focusing on Greek fauna, revealed high variation, deep clade divergences, many cryptic lineages, paraphyly at subgenus level, and sympatry of several new and formerly known lineages. Numerous specimens from mainland and insular Greece, undoubtedly the least studied region of the genus' distribution, have been included. The reconstructed phylogeny covers representative taxa and populations across the entire genus of Euscorpius. The deepest clades detected within Euscorpius correspond (partially) to its current subgeneric division, outlining subgenera Tetratrichobothrius and Alpiscorpius. The rest of the genus falls into several clades, including subgenus Polytrichobothrius and a paraphyletic subgenus Euscorpius s.s. Several cryptic lineages are recovered, especially on the islands. The inadequacy of the morphological characters used in the taxonomy of the genus to delineate species is discussed. Finally, the time frame of differentiation of Euscorpius in the study region is estimated and the distributional patterns of the lineages are contrasted with those of other highly diversified invertebrate genera occurring in the study region.
Background Glossina fuscipes fuscipes is the major vector of human African trypanosomiasis, commonly referred to as sleeping sickness, in Uganda. In western and eastern Africa, the disease has distinct clinical manifestations and is caused by two different parasites: Trypanosoma brucei rhodesiense and T. b. gambiense. Uganda is exceptional in that it harbors both parasites, which are separated by a narrow 160-km belt. This separation is puzzling considering there are no restrictions on the movement of people and animals across this region.Methodology and ResultsWe investigated whether genetic heterogeneity of G. f. fuscipes vector populations can provide an explanation for this disjunct distribution of the Trypanosoma parasites. Therefore, we examined genetic structuring of G. f. fuscipes populations across Uganda using newly developed microsatellite markers, as well as mtDNA. Our data show that G. f. fuscipes populations are highly structured, with two clearly defined clusters that are separated by Lake Kyoga, located in central Uganda. Interestingly, we did not find a correlation between genetic heterogeneity and the type of Trypanosoma parasite transmitted.ConclusionsThe lack of a correlation between genetic structuring of G. f. fuscipes populations and the distribution of T. b. gambiense and T. b. rhodesiense indicates that it is unlikely that genetic heterogeneity of G. f. fuscipes populations explains the disjunct distribution of the parasites. These results have important epidemiological implications, suggesting that a fusion of the two disease distributions is unlikely to be prevented by an incompatibility between vector populations and parasite.
Sequence data derived from two mitochondrial markers, 16S rRNA and COI genes, were used to infer the evolutionary history of 47 insular and mainland populations covering most of the distributional range of the northeastern Mediterranean scorpion species Mesobuthus gibbosus. Based on the estimated divergence times of Mesobuthus lineages, the temporal frame of the genus differentiation in the northeastern Mediterranean region is placed in middle Miocene (15 million years ago). The biogeographic affinities of M. gibbosus populations point towards a mainly vicariant pattern of differentiation of the species which is consistent with the geological events that transformed the Aegean region during the period from 12 to 5 million years ago. M. gibbosus is an old northeastern Mediterranean species that has retained valuable bits of genetic information, reflecting some of the oldest vicariant events that have occurred in the area. Most importantly, the history witnessed by M. gibbosus has not been obscured by more recent palaeoevents of the region. Therefore, the case of M. gibbosus is in favour of a taxon-oriented 'perception' of the natural history of a given area.
Three endemic Cretan land snail species of the genus Mastus (Beck, 1837) from the island group of Koufonisi (southeast Crete) and the eastern part of Crete, were studied by multivariate analysis of shell morphology and analysis of mtDNA sequences. The phylogeny of the populations studied and the processes effecting the genetic and morphological diversity of the species were investigated. Extremely high mtDNA sequence divergence was observed both within and between populations. The Cretan populations could not be distinguished morphologically, while the populations of the islets were more distinct. We argue that the active geological past of the area (including sea level changes) and the longterm presence of humans has produced a mixing up of Mastus populations leading to the accumulation of high divergence of mtDNA sequences on a small spatial scale. The limited morphological diversity and the distinct shell 'identity' of the islets' populations can be attributed to the selective pressures of the island group.
Aim This study uses molecular data in conjunction with palaeogeography to infer the most plausible biogeographical scenario accounting for the current distributional pattern of Iurus dufoureius. Location North‐eastern Mediterranean region. Methods Sequencing of a 441‐bp segment of the mitochondrial 16S rRNA gene in seven populations covering the whole distributional range of the species. Phylogenetic analyses performed included neighbour joining, maximum parsimony and Bayesian inference. Results The molecular phylogeny showed that two Iurus clades are strongly supported. These clades correspond to the two subspecies Iurus dufoureius dufoureius and Iurus dufoureius asiaticus, currently recognized within the genus. The assumption of a clock‐like evolution could not be rejected, and this enabled us to estimate an approximation of the local rate of evolution for the I. dufoureius lineages. Based on the estimated evolutionary rate (0.79 ± 0.17 Myr−1), the split between the two Iurus clades occurred c. 8 Ma. Main conclusions Contrary to what was believed in the past, the genus Iurus is an old north‐eastern Mediterranean genus that has been differentiating in southern Greece and south‐west Turkey at least from the middle Miocene. According to the phylogenetic trees obtained and the dating of the divergence times of lineages, the genus dispersed into the Aegean Archipelago when the Aegean was still a uniform land mass. Although the phylogenetic relationships of I. d. dufoureius populations have been shaped by the most recent vicariant events, the phylogenetic relationships of I. d. asiaticus populations are mostly attributable to older palaeoevents occurring in the area.
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