首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Aim To investigate the molecular phylogenetic divergence and historical biogeography of cave crickets belonging to the genus Dolichopoda (Orthoptera, Rhaphidophoridae). Location Caves in continental and insular Greece. Methods We sequenced 1967 bp of mitochondrial DNA, corresponding to three fragments of the small and large subunit of the ribosomal RNA (16S and 12S rRNA, respectively) and to the subunit I of cytochrome oxidase (COI), to reconstruct phylogenetic relationships among all 30 known Greek species of Dolichopoda. Alternative hypotheses about the colonization of the Hellenic Peninsula by Dolichopoda species were tested by comparing the degree of discordance between species trees and gene trees under four plausible biogeographical scenarios. Results The present study revealed a rather well resolved phylogeny at species level, identifying a number of clades that represent long‐separated lineages and diverse evolutionary histories within the genus Dolichopoda. Two main clades were revealed within Hellenic–Aegean species, identifying a north‐western and a south‐eastern species group. Based on Bayesian analysis, we applied a relaxed molecular clock to estimate the divergence times between the lineages. The results revealed that the origins of eastern Mediterranean lineages are much older than those of previously studied western Mediterranean Dolichopoda. Tests of alternative biogeographical hypotheses showed that a double colonization of the Hellenic Peninsula, following separate continental and trans‐Aegean routes during the Messinian stage, best accounts for the present distribution of Greek Dolichopoda species. Main conclusions Reconstruction and biogeographical hypothesis testing indicated that the colonization of Greece by Dolichopoda species comprised two episodes and two different routes. The southern lineage probably arose from a trans‐Aegean colonization during the Messinian salinity crisis (5.96–5.33 Ma). The northern lineage could be the result of dispersal from the north through the Balkan Peninsula. The opening of the Mid‐Aegean Trench could have promoted an initial diversification within the uprising Anatolian Plateau, while the Messinian marine regression offered the conditions for a rapid dispersal through the whole Aegean–Hellenic region. In addition, climatic events during the Plio‐Pleistocene may have been responsible for the speciation within each of the two different phylogeographical units, principally attributable to vicariance events.  相似文献   

2.
The urodelan genus Lyciasalamandra, which inhabits a relatively small area along the southern Turkish coast and some Aegean islands, provides an outstanding example of a diverse but phylogenetically unresolved taxon. Molecular trees contain a single basal polytomy that could be either soft or hard. We here use the information of nuclear (allozymes) and mitochondrial (fractions of the 16S rRNA and ATPase genes) datasets in combination with area relationships of lineages to resolve the phylogenetic relationships among Lyciasalamandra species in the absence of sufficient node support. We can show that neither random processes nor introgressive hybridization can be invoked to explain that the majority of pairs of sister taxa form geographically adjacent units and interpret that this pattern has been shaped by vicariant events. Topology discordance between mitochondrial and nuclear trees mainly refers to an affiliation of L. helverseni, a taxon restricted to the Karpathos archipelago, to the western-most and geographically proximate mainland taxon in the nuclear tree, while in the organelle tree it turns out to be the sister lineage to the geographically most distant eastern clade. As this discordance cannot be explained by long-branch attraction in either dataset we suppose that oversea dispersal may have accounted for a second colonization of the Karpathos archipelago. It may have initiated introgression and selection driven manifestation of alien eastern mitochondrial genomes on a western nuclear background. Our approach of testing for area relationships of sister taxa against the null hypothesis of random distribution of these taxa seems to be especially helpful in phylogenetic studies where traditional measures of phylogenetic branch support fail to reject the null hypothesis of a hard polytomy.  相似文献   

3.
The vast diversity of land snail forms is insufficiently understood even in seemingly familiar taxa. This holds for Helix Linnaeus, 1758, a genus with several common edible species which comprises the largest Western Palearctic snails. The taxonomy of this genus, which has a centre of diversity in the eastern Mediterranean, has recently undergone significant changes, in both the delimitation of the genus itself and its species‐level systematics. Here, we compare the lineage diversity of Helix, as revealed by two mitochondrial markers, with the conclusions of the recently published morphology‐based taxonomic revision. For the molecular analysis, we assembled a representative data set covering almost all species of the genus as recognized by the mentioned revision. We obtained sequences not only from fresh and preserved soft tissues but also from dried tissue remains (some of them decades old) from shell collections. Our results show that the genus Helix, in the narrow sense proposed by recent studies, is paraphyletic because the genus Tacheopsis was unambiguously revealed as one of the tip branches of Helix. The monophyly of several species, as presently recognized, was not supported; partly, this may be attributed to a lineage diversity overlooked so far. This holds also for the type species of the genus, H. pomatia, which comprises at least one additional lineage. Greece, the Aegean and western Turkey is the core area for the diversity of Helix and its relatives, and the region is probably a major long‐term refuge for large Helicidae. The highest species diversity is found along the Alpide belt from the western Balkans to southern Turkey. The diversity of Helix in Europe, north of Greece and the Apennines, is a result of a single European radiation. Our data also suggest that past human activities likely influenced the present‐day distributions of some species.  相似文献   

4.
Turtle remains are common in the Miocene-Holocene deposits of Greece, and are a key focus of the growing research interest in Neogene herpetofaunas from the Aegean region. Some of the most important finds include one of Europe's stratigraphically youngest pleurodiran taxa, Nostimochelone lampra, from the Early Miocene of Macedonia, together with arguably the richest record of fossil tortoises from the Eastern Mediterranean. This incorporates the presently oldest definitive representatives of the quintessential genus Testudo sensu stricto from the Late Miocene of Attica and Macedonia, and numerous specimens of the colossal (carapace ∼2 m-length) testudinid Cheirogaster from Late Miocene-Late Pliocene sediments in southern and northern Greece, as well as on the eastern Aegean islands of Samos and Lesvos. Tantalising, but as yet unconfirmed Miocene accounts of the geoemydid Mauremys in Macedonia, and indeterminate emydid-like remains from Euboea, also provide potentially significant range extensions. Although hampered by a historically sparse documentation, the fossil turtles of Greece are a significant resource that record both assemblage changes and the origin of modern lineages.  相似文献   

5.
6.
The extensive human-mediated modifications of shallow coastal habitats drastically alter selection regimes and may assist alien invasions. The preferential presence of a non-indigenous scleractinian coral (Oculina patagonica) on anthropogenic hard substrata was investigated in a highly disturbed coastal area, along the eastern Saronikos Gulf (Aegean Sea, Eastern Mediterranean). Although the species occurred on both natural and anthropogenic substrata at similar frequencies, its abundance was substantially higher on the latter. The species was present all along the shallow (0.5–5 m) infralittoral zone of the studied coastline, and its percent cover even exceeded 50 % at a site of anthropogenic hard substratum. The occupancy of the species declined with distance from a highly disturbed industrialized/urbanized area (Athens metropolitan coastal front and the port of Piraeus). Space availability as a result of habitat modification appears to have been an important factor enhancing the coral’s abundance in this area. The ongoing degradation of the coastal zone, as a combined effect of coastal pollution, proliferation of artificial substrata and overgrazing seems to be paving the way to this new invasion in the Aegean Sea.  相似文献   

7.
Background: The South Aegean Volcanic Arc (SAVA), one of the most notable geological structures of the Mediterranean Sea, is floristically well known. Nevertheless, the factors that contribute to shaping the plant species richness of the SAVA remain unclear.

Aims: To investigate the factors that affect plant species richness and identify plant diversity hotspots in the SAVA and other central Aegean islands.

Methods: We used stepwise multiple regression to test the relationship between a number of environmental factors and plant species richness in the SAVA, as well as the residuals from the species–area linear regressions of native, Greek and Cycladian endemic taxa as indicators of relative species richness.

Results: The area was confirmed to be the most powerful single explanatory variable of island species richness, while geodiversity, maximum elevation and mean annual precipitation explained a large proportion of variance for almost all the species richness measures. Anafi, Amorgos and Folegandros were found to be endemic plant diversity hotspots.

Conclusions: We have demonstrated that geodiversity is an important factor in shaping plant species diversity in the Cyclades, while mean annual precipitation, human population density and maximum elevation were significant predictors of the Greek endemics present in the Cyclades. Finally, Anafi was found to be a plant diversity hotspot in the South Aegean Sea.  相似文献   

8.
The phylogeny of Greek populations of the terrestrial isopod genus Ligidium is reconstructed based on three mtDNA gene segments: 12S rRNA, 16S rRNA and COI. Two widely distributed European species, as well as three outgroups belonging to different isopod genera, were also included in the analyses. The samples used represent almost all Ligidium species known to occur in Greece, as well as several populations of unknown specific status plus some new records. Phylogenetic analyses of the combined data set were performed using Bayesian inference and maximum parsimony. The two main sister clades with good support indicate the sympatric differentiation of two lineages in southern continental Greece (Peloponnisos), where Ligidium populations exhibit a mosaic distribution of sibling species. The insular populations of the Aegean Islands show increased genetic divergence and form separate clades. The presence of a third lineage of Asiatic origin is strongly suggested by both the molecular phylogeny and morphology. The only presumably valid diagnostic morphological character exhibits only partial correspondence to well supported clades of the molecular phylogeny. Genetic differentiation between populations is very high, a fact that can be attributed to the strict ecological specialization of these animals that leads to increased levels of isolation even between populations that are in close proximity. As a consequence, Greek Ligidium populations, especially those present on islands, are unique genetic pools and extremely vulnerable to extinction.  相似文献   

9.
《Flora》2005,200(4):376-397
World distribution of 488 out of 619 vascular plant species known from an area of 500 km2 within the western Khentey Mountains, northern Mongolia is analyzed. Most species belong to Eastern Asian (29%) or Asian, Eurasian, or circumpolar temperate species (24%) supporting the classification of the Khentey Mountains as part of the temperate zone of Eurasia. Seventeen percent of species are boreal plants. Circumpolar temperate-boreal (9%), Central (-Eastern) Asian (9%), Continental mountain species (5%), Middle-Central Asian (3%), arctic-alpine (3%) as well as Western Eurasian and western Siberian species are of lower significance for the flora of the western Khentey Mountains. Eastern Asian species occur in all types of habitats, whereas plants of other distribution types are focused on certain habitats. Boreal species preferably grow in the dark taiga, which prevails in the upper montane belt and on northern and eastern slopes of the most humid parts of the lower montane belt. Temperate and temperate-boreal species prefer subtaiga forests, which are found on northern and eastern slopes in drier parts of the lower montane belt as well as in upper parts of sun-exposed, southern and western slopes of the lower montane belt. Central (-Eastern) Asian and Middle-Central Asian species primarily inhabit forest steppe habitats, such as meadow and mountain steppes, Ulmus pumila open woodlands and dry Pinus sylvestris forests on steep, southern slopes.  相似文献   

10.
Contact zones occur at the crossroad between specific dispersal routes and are facilitated by biogeographic discontinuities. Here, we focused on two Lepidoptera sister species that come in contact near the Turkish Straits System (TSS). We aimed to infer their phylogeographic histories in the Eastern Mediterranean and finely analyze their co‐occurrence and hybridization patterns in this biogeographic context. We used molecular mitochondrial and nuclear markers to study 224 individuals from 42 localities. We used discordances between markers and complementary assignment methods to identify and map hybrids and parental individuals. We confirmed the parapatric distribution of Thaumetopoea pityocampa (Lepidoptera: Notodontidae) in the west and Thaumetopoea wilkinsoni in the east and identified a narrow contact zone. We identified several glacial refugia of T. wilkinsoni in southern Turkey with a strong east–west differentiation in this species. Unexpectedly, T. pityocampa crossed the TSS and occur in northern Aegean Turkey and some eastern Greek islands. We found robust evidence of introgression between the two species in a restricted zone in northwestern Turkey, but we did not identify any F1 individuals. The identified hybrid zone was mostly bimodal. The distributions and genetic patterns of the studied species were strongly influenced both by the Quaternary climatic oscillations and the complex geological history of the Aegean region. T. pityocampa and T. wilkinsoni survived the last glacial maximum in disjoint refugia and met in western Turkey at the edge of the recolonization routes. Expanding population of T. wilkinsoni constrained T. pityocampa to the western Turkish shore. Additionally, we found evidence of recurrent introgression by T. wilkinsoni males in several T. pityocampa populations. Our results suggest that some prezygotic isolation mechanisms, such as differences in timing of the adult emergences, might be a driver of the isolation between the sister species.  相似文献   

11.
12.
Aphanius almiriensis is the first time reported from Italy, where it occurs in the Palude del Capitano. The newly found population agree with Greek A. almiriensis in molecular (COI) and morphological characters. Aphanius almiriensis might be native to the the Palude del Capitano, which is outside from the species known range in the Aegean Sea basin. It might also have been imported with goods from the eastern Aegean in the late Republican age and the late Imperial period. The diagnostic morphological characters as well as the distribution and conservation status of A. almiriensis is discussed. A distribution map and associated, georeferenced database of A. almiriensis as well as of A. fasciatus are presented.  相似文献   

13.
Deep-sea smelts (Argentiniformes: Microstomatidae, Bathylaginae) from the Miocene of Far East Russia (Sakhalin and Urup islands) are described. The specimens described belong to four taxa, one of which is assigned to a new species of the genus Leuroglossus. Like Recent smoothtongues, the new species has thickened medial rays in the caudal fin. The small number of abdominal vertebrae makes the new species similar to the extant southern smoothtongue L. stilbius, which occurs along the eastern coasts of the Pacific Ocean. The new species differs from extant smoothtongues in the short snout, which is not longer than the orbit. Phylogenetic analysis of morphological features of the new species, using a matrix of characters of living deepsea smelts, shows that it occupies a basal position in the genus Leuroglossus. Three other extinct taxa cannot be reliably classified below the level of the subfamily Bathylaginae or tribe Bathylagini because of insufficient preservation of available specimens. The new records of deep-sea smelts in Far East Russia show that this fish subfamily was widespread and highly morphologically differentiated in the Neogene.  相似文献   

14.
The aim of this study was to estimate the influence of the palaeogeographic and climatic history of the Aegean region on the diversity of freshwater crabs of the genus Potamon and to test whether this area served as source or reservoir in species diversity. Necessary species delimitation was accomplished by phylogenetic analyses of the mitochondrial markers COX1 and ND1, partial 16S rRNA gene and the tRNALeu gene. We found 14 genetic lineages of which nine could be assigned to previously recognised species. Temporal estimates of the splitting pattern in the phylogeny of Potamon indicated that a combination of geological and climatic events influenced their diversification. Within Potamon, the lineages separated into a western group and an eastern group. This first split in the genus occurred approximately 8.3-5.5 Mya, thus possibly correlated with the Messinian salinity crisis. A likelihood approach to geographic range evolution suggested for most species, occurring in the Aegean area, an origin in the Middle East. Moreover, there were no insular endemics in the central Aegean archipelago, therefore low sea-levels during the Pleistocene glacial periods possibly enabled dispersal to these islands, but subsequent rise in sea-level did not cause speciation. Nevertheless, the diversification of most lineages occurred during the Pleistocene epoch thus coinciding with Quaternary fluctuations of the climate.  相似文献   

15.
The taxonomy of Megaloptera from the Nearctic region is fairly well known and their faunal diversity has been largely surveyed, even in relatively remote regions. However, the evolutionary history of Nearctic Megaloptera is still poorly known with phylogenetic and biogeographic studies lacking. In this paper, we report a new fishfly species of the endemic North American genus Neohermes Banks, 1908, increasing the total number known of species to six. This new species (Neohermes inexpectatus sp. nov.) is currently known to occur only in California (USA) and is apparently confined to the Northern Coastal Range. The new species resembles the three Neohermes species from eastern North America based on the relatively small body size and the presence of female gonostyli 9. However, our phylogenetic analysis using adult morphological data recovered the new species as the sister species to the remaining Neohermes, which includes two species from western North America and three from eastern North America. According to the present interspecific phylogeny of Neohermes, with reconstructed ancestral areas, the initial divergence within the genus was found to take place in western North America, with a subsequent eastward dispersal. This likely lead to the modern distribution of Neohermes in eastern North America with the closure of the Mid-Continental Seaway, which separated western and eastern North America in the Mid-Late Cretaceous (100–80 MYA) and finally disappeared at the end of the Cretaceous (70 MYA). The uplift of the Cordilleran System probably accounted for the divergence between the eastern and two western Neohermes species.  相似文献   

16.
The present study deals with the presence of Diopatra marocensis in the eastern Mediterranean. This species is small-sized and inhabited muddy bottom near the opening of rivers or lagoons [salinity range: 33−39‰] in the Aegean and Levantine Seas, and reached a maximum density of 90 ind.m-2 in Mersin Bay. This species might be an alien species that was introduced from the East Atlantic (near Gibraltar) to the eastern Mediterranean via ballast water of ships, as it has never been reported from the western Mediterranean Sea.  相似文献   

17.
Recently, the systematics and biogeography of the Mediterranean biota have received much attention. This paper deals with Eupholidoptera Ma?an, a Mediterranean lineage of Tettigoniidae. The genus is restricted to the northern and eastern basin of the Mediterranean, with a significant number of species found on the Aegean islands. To produce a phylogeny and use it to make assumptions about the historical biogeography of Eupholidoptera, material of 46 species from several collections was studied. A phylogenetic analysis based mainly on morphological characters suggested two lineages in the genus: the E. chabrieri and the E. prasina groups. Based on the consistency between historical geographical events and branching events on the phylogenetic tree, Eupholidoptera is assumed to have evolved from an ancestor present in the Aegeid plate in the Mid‐Miocene. The division of the Aegeid plate into Anatolia and Greece in the Tortonian, the reoccurrence of terrestrial corridors between these mainlands in the Messinian, the regression of the Aegean area in the Pliocene and sea level changes in the Pleistocene are assumed to have been the main palaeogeographical events directing speciation in Eupholidoptera. As most of the species are allopatric, vicariance is suggested to be the main pattern. By combining the nature of the characters used in the phylogenetic analysis, the phylogenetic tree produced and the biogeographical assumptions, four tentative conclusions can be made: (i) radiation in the genus is a result of divergence in morphology; (ii) because the main character source is male genitalia, there has possibly been intensive sexual selection, which leads to morphological speciation; (iii) as the difference in temporal parameters of the song is prominent in sympatric/parapatric species pairs only, co‐occurrence is suggested to be the main reason driving divergence in the song; (iv) there seems to be a negative correlation between the size of the distribution range and the evolutionary rate in speciation; this may be the reason why the E. prasina group (restricted to a small part of the range of the genus) is more diverse than the E. chabrieri group, which is distributed over the entire range.  相似文献   

18.
A statistical analysis of morphological variation and a Chromatographic analysis of flavonoid variation were performed to determine taxonomic relationships among the species ofTilia of eastern North America. No apparent morphological discontinuities were seen between populations within the sample area although two characters (involving leaf pubescence and gland length) showed definite patterns of geographical variation. Flavonoid patterns showed definite differences between northern and southern populations with an intermediate zone in the Smoky Mountain region. The continuous nature of the morphological and flavonoid variation suggested that the genus as represented in eastern North America should be regarded as one species,Tilia americana L.  相似文献   

19.
Aim Vireya rhododendrons are distinctive and easily recognizable by their general form; however, they are virtually circumscribed geographically, predominantly distributed throughout the biogeographically intriguing Malesian Archipelago. Hypotheses of the evolutionary relationships of the group have been proposed but the biogeography of vireyas has not been analysed based on molecular phylogeny. Recently, the first detailed molecular phylogenetic investigation of section Vireya was completed based on cp‐ and nrDNA sequence data, therefore making this cladistic biogeographic study of vireya rhododendrons possible. Location Malesia, Australia, Solomon Islands, Taiwan, Himalayas, north Vietnam and south China. Methods Based on distribution maps, areas of endemism were determined for the biogeographic region of Malesia. Area relationships were analysed based on a recent molecular phylogeny of species in section Vireya. The method of paralogy‐free subtree analysis was applied. Results Individual distribution maps were produced for 74 species of Rhododendron section Vireya. Species clades with bootstrap support proved to be biogeographically informative. Major clades correspond to three regions: eastern Malesia, western/middle Malesia and Taiwan/north Vietnam/south China. Within eastern Malesia, Australia, New Guinea, the Bismarck Archipelago and Solomon Islands are related. In western Malesia, northern Philippines, Borneo, southern Moluccas and north and west Sulawesi are related. These areas are more distantly related to Sumatra, the Malay peninsula, Java, Bali, Palawan, Lesser Sunda islands and the southern Philippines. The position of the Himalayas is equivocal and part of a basal polytomy in the summary area cladogram. Main conclusions Two alternative hypotheses are proposed for the evolution of vireya rhododendrons based on the pattern of area relationships. The first hypothesis is that the vireyas are an old group, with ancestors present on Gondwana, rifting north in the Cretaceous. The second alternative hypothesis is that vireyas are a young group that has dispersed eastwards from India to Australia and the Solomon Islands since the current Malesian islands formed.  相似文献   

20.
Subterranean rodents of the genus Ctenomys usually present an allopatric or parapatric distribution. Currently, two cases of sympatry have been recognized for the genus in the coastal dunes of southern Argentina and southern Brazil. In this context, they are ideal models to test hypotheses about the factors that delimit the patterns of space use and to understand interspecific interactions in small mammals. We investigated the vegetation structure, plant biomass and soil hardness selected by two species of subterranean rodents (Ctenomys flamarioni and C. minutus) when distributed in sympatry and allopatry from nine different areas along the line of coastal dunes in southern Brazil. In addition, our work presents a new record of a third area of sympatry for the genus Ctenomys. Ctenomys flamarioni and C. minutus show habitat segregation in the area where they occur in sympatry. These species show segregation in their selection of microhabitats, differing in relation to soil hardness, plant biomass, and plant cover. Ctenomys flamarioni showed a distinction in habitat selection when occurring in allopatry and sympatry, whereas C. minutus selected the same habitat characteristics under both conditions. A possible explanation to the observed pattern is that these species have acquired different adaptations over time which allows them the ability to exploit different resources and thus avoid competitive interactions all together.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号