Moysis Mylonas

Molecular phylogeny and biogeography of the wall-lizard Podarcis erhardii (Squamata: Lacertidae).

Erhards wall lizard, Podarcis erhardii (Sauria: Lacertidae), is highly diversified in Greece and especially in the southern Aegean region. Out of the 28 recognized subspecies, 27 are found in Greece from the North Sporades island-complex in the North Aegean (grossly south of the 39th parallel) to the island of Crete in the South. The species exhibits great morphological and ecological plasticity and inhabits many different habitats from rocky islets and sandy shores to mountaintops as high as 2000m. By examining intraspecific variability at a segment of the mitochondrial gene cytochrome b we have found that that extant populations of P. erhardii are paraphyletic. Furthermore, we have found that subspecies previously defined on the basis of morphological characteristics do not correspond to different molecular phylogenetic clades, so that their status should be reconsidered. The DNA based biogeographical and phylogenetic history of Podarcis in Southern Greece is congruent with available paleogeographic data of the region, which supports the view that DNA sequences may be a useful tool for the study of palaeogeography.

Phylogeography of Balkan wall lizard (Podarcis taurica) and its relatives inferred from mitochondrial DNA sequences

Wall lizards of the genus Podarcis (Sauria, Lacertidae) comprise 17 currently recognized species in southern Europe, where they are the predominant reptile group. The taxonomy of Podarcis is complex and unstable. Based on DNA sequence data the species of Podarcis falls into four main groups that have substantial geographical conherence (western island group, southwestern group, Italian group and Balkan group). The Balkan species are divided in two subgroups: the subgroup of Podarcis taurica (P. taurica, P. milensis, P. gaigeae and perhaps P. melisellensis), and the subgroup of Podarcis erhardii (P. erhardii and P. peloponnesiaca). We addressed the question of phylogenetic relations among the species of the P. taurica subgroup encountered in Greece, as they can be inferred from partial mtDNA (cyt b and 16S) sequences. Our data support the monophyly of P. taurica subgroup and suggest that P. gaigeae, P. milensis and P. melisellensis form a clade, which thereinafter connects to P. taurica. Within the previous clade, P. gaigeae is more closely related to P. milensis than to P. melisellensis. However, the specimens of P. taurica were subdivided in two different groups. The first one includes the specimens from northeastern Greece, and the other group includes the specimens from the rest of continental Greece and Ionian islands. Because the molecular clock of the cyt b and 16 rRNA genes was not rejected in our model test, it is possible to estimate times of speciation events. Based on the splitting of the island of Crete from Peloponnisos [c. 5 million years ago (Ma)], the evolutionary rate for the cyt b is 1.55% per million years (Myr) and for the 16S rRNA is 0.46% per Myr. These results suggest that the evolutionary history of P. taurica in Greece is more complex than a single evolutionary invasion. The data analysed, stress the need for a reconsideration of the evolutionary history of Greek Podarcis species and help overcome difficulties that classical taxonomy has encountered at both the species level.

Evolution of Mesobuthus gibbosus (Brullé, 1832) (Scorpiones: Buthidae) in the northeastern Mediterranean region

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.

Phylogenetic analysis and biogeography of Aegean taxa of the genus Dendarus (Coleoptera: Tenebrionidae)

The genus Dendarus Latr. is distributed throughout the Mediterranean basin with numerous species in the Aegean islands. This paper presents a phylogenetic analysis and the biogeography of most taxa present in the area. Phylogenetic analysis of two outgroup and 25 ingroup taxa based on adult morphology, including 50 characters and 119 character states, produced two equally parsimonious trees (tree length = 148, C.I. = 0.42, R.I. = 0.70, R.C. = 0.294). These trees provide strong support for the monophyly of Dendarus and also define four species groups: the foraminosus group, present mainly on the island of Crete; the rhodius group, present in Dodecanese islands, the sinuatus group present in the central Aegean islands, and another group consisting of taxa from mainland Greece (D. messenius, D. caelatus, D. tenellus, and D. plicatulus paganettii). All area cladograms produced by Compatibility Component Analysis, Brooks Parsimony Analysis, and especially by Component Analysis, correspond quite closely to the hypothesized palaeogeographic history of the studied area and therefore partly support the idea of a vicariant evolution of Dendarus taxa in this region. We distinguished certain monophyletic groups distributed (with some exceptions) within well-defined geographical and palaeogeographical regions of the Aegean. However, we found certain inconsistencies (with Reconciled Tree Analysis) that are probably the result of dispersal, extinction, or duplication events that are independent of the sequence of vicariance events.

Phylogeography of the ocellated skink Chalcides ocellatus (Squamata, Scincidae), with the use of mtDNA sequences: a hitch-hiker's guide to the Mediterranean.

We analyze geographic genetic variation in C. ocellatus to evaluate the influences of major climatic, paleogeographic and anthropogenic factors in its biogeographic history. Ninety four specimens from 61 populations were collected across all of its geographical range and analyzed based on partial mitochondrial sequences (cyt b, 12S, and ND1). Our results demonstrate that an ancestral form of C. ocellatus, which expanded in northwestern Africa at the end of Miocene, diverged in at least three separate evolutionary lineages approximately 4.57Ma: C. humilis spread south of the Sahara, while the other two (C. ocellatus sensu stricto) were restricted in the coastal North African region. The complicated history of the ocellated skink is a result of multiple vicariant phenomena followed by multiple active or passive dispersals. The Messinian salinity crisis and the re-flooding of the Mediterranean basin, the climatic transition from Middle to Upper Pliocene, and the hyperarid phase of the Sahara, affected the distribution and diversification of C. ocellatus, while in historical times it was introduced in the central Mediterranean islands and eastern Mediterranean region from Tunisia and Cyrenaica, respectively.

Mitochondrial DNA reveals the genealogical history of the snake-eyed lizards (Ophisops elegans and O. occidentalis) (Sauria: Lacertidae)

The snake-eyed lizards of the genus Ophisops (Lacertidae) have been through a series of taxonomical revisions, but still their phylogenetic relationships remain uncertain. In the present study we estimate the phylogeographic structure of O. elegans across its distributional range and we evaluate the relationships between O. elegans and the sympatric, in North Africa, species O. occidentalis, using partial mtDNA sequences (16S rRNA, COI, and cyt b). All phylogenetic analyses produced topologically identical trees where extant populations of O. elegans and O. occidentalis were found polyphyletic. Taking into account all the potential causes of polyphyly (introgressive hybridization, incomplete lineage sorting, and imperfect taxonomy) we suggest the inaccurate taxonomy as the most likely explanation for the observed pattern. Our results stress the need for re-evaluation of the current taxonomical status of these species and their subspecies. Furthermore, our biogeographic analyses and the estimated time of divergences suggest a late Miocene diversification within these species, where the present distribution of O. elegans and O. occidentalis was the result of several dispersal and vicariant events, which are associated with climatic oscillations (the late Miocene aridification of Asia and northern Africa) and paleogeographic barriers of late Miocene and Pliocene period.

Molecular phylogeny of three Mesalina (Reptilia: Lacertidae) species (M. guttulata, M. brevirostris and M. bahaeldini) from North Africa and the Middle East: Another case of paraphyly?

Mesalina is a widespread lacertid genus occurring throughout the Saharo-Sindian region from North Africa to Pakistan. It has been through a series of taxonomic revisions, but the phylogenetic relationships among the species remain unclear. In this study we estimate the phylogeographic structure of M. guttulata across most of its distributional range and we evaluate the relationships between M. guttulata and the sympatric species M. brevirostris and M. bahaeldini using partial mitochondrial DNA (mtDNA) sequences (cyt b and 16S). M. guttulata and M. brevirostris represent species complexes, whereas M. bahaeldini considered before as M. guttulata is a recently described species with very restricted distribution. Here we present the first evidence that M. guttulata is a paraphyletic taxon with respect to M. bahaeldini, while M. brevirostris proves to be a polytypic species or even a species complex, confirming previous studies. Although mtDNA markers have several properties that make them suitable for phylogeographic studies, they are not free of difficulties. Phylogeographic inferences within and between closely related species can be mislead by introgression and retention of ancestral polymorphism (incomplete lineage sorting). However, the present distribution pattern, the estimated times of divergence and the significant variation in morphology within M. guttulata led us to accept that the paraphyletic pattern observed, is most likely due to inaccurate taxonomy. Our hypothesis is that what has hitherto been considered as intraspecific variation, actually reflects species-level variation. Furthermore, our biogeographic analyses and the estimated time of divergences suggest that the present distribution of M. guttulata was the result of several dispersal and vicariant events, which are associated with historical changes (climatic oscillations and paleogeographic barriers) of late Miocene and Pliocene period.

Origin and taxonomy of the fossil elephants of the island of Crete (Greece): problems and perspectives

Abstract Despite the fact that during the last century more than 30 studies have been published referring to the fossil elephants of the island of Crete (Greece), there are still many questions that remain unanswered. These questions concern their geographic and phylogenetic origin, how and when they reached the island, the number of valid species, how, when and why each species became extinct and, finally, the possible effect of the phenomenon of dwarfism on each species. (Dwarfism is characteristic of large mammals in insular faunas.) In addition to the available data, which we have reviewed, cross-checked and updated, we describe new fossil elephant material found in the interior of the island, at an altitude of 1000 m above sea level. Using this revised data set, we propose to (1) retain the separate taxonomic status of the dwarf elephant Mammuthus creticus; and (2) join all the described specimens of larger size under the new subspecies name Elephas antiquus creutzburgi. Moreover, in the light of the new approaches that have been attempted for the fossil elephants in other localities of the Mediterranean region, we try to solve and at least explore the mentioned problems and identify the remaining gaps in our knowledge which need to be filled in order to obtain a complete picture of the natural history of the elephants on Crete.

Two new species of Podarcis (Squamata; Lacertidae) from Greece

Abstract Recently, several works have focused on the lacertid lizards of the genus Podarcis, revealing cases of hidden diversity and paraphyly, and offering evidence that suggests the revision of the extant taxonomical arrangements within the genus. Hidden diversity and paraphyly have been shown to exist in the relationships between the Balkan species P. peloponnesiaca and P. erhardii as well. Here we couple a molecular (mtDNA) dataset with a corresponding morphological one, consisting of morphometric and pholidotic characters, to check for concordance between the two. Phylogenetic analyses reinforced previous suggestions for paraphyly of P. erhardii with respect to P. peloponnesiaca. We found the variation of certain pholidotic characters concordant with the relationships inferred from partial mtDNA sequences, whereas morphometric characters were not. The latter is possibly due to greater influence of morphometric characters by environmental factors. To avoid the observed paraphyly we proceed with the description of the populations from Crete and the islet of Pori, until now designated as P. erhardii, as separate taxa at the species level.

Breeding behaviour and parental care in the Griffon Vulture Gyps fulvus on the island of Crete (Greece)

A field study of the breeding behaviour of griffon vultures (Gyps fulvus) was conducted in Crete (Greece) during 1997–2000. The main behavioural patterns examined were aerial displays, nest defence, copulation, nest building, brooding and food provisioning to the chicks. The nesting territory consisted of a semicircle ca 5 m radius around the nest that was defended against conspecifics. Copulation attempts mainly occurred in the nesting ledge with a success rate of 77%. On average every pair accomplished 0.16 ± 0.34 copulations per day (range = 0–4) while 3.3% of the total attempts accounted for extra–pair copulations. Supplying material to the nest started 32 ± 9 days prior to egg laying (range = 17–44) at a rate of 5 ± 3.52 bouts/pair/day (range = 1–14).The mean number of items added to the eyrie was 2 ± 1.3/bout/pair (range = 1–8) with 63.5% of these being soft greenery.The mean frequency of relief at the nest relieves was 0.5 ± 0.64 bouts/pair/day (range = 0–2) while an incubation shift lasted on average 37.4 ± 0.5 hr (range = 25.6–50.2 hr). Nest attendance by breeding birds was continuous during the first 2 months after the hatching of the egg, dropping to 35% of daytime hours before fledging. Adult griffons foraged on average every other day while food delivery rate to the chick was calculated at 1.9±1.09 bouts/pair/day (range = 1–4). The most critical period of the reproductive cycle was May when chicks (6–10 weeks old) grew at their fastest rate and parent birds foraged on alternate days. Differences in behavioural patterns among this insular population and continental ones were minimal.