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1.
Phylogeographic studies are useful in reconstructing the history of species invasions, and in some instances can elucidate cryptic diversity of invading taxa. This can help in predicting or managing the spread of invasive species. Among terrestrial invasive species in North America, earthworms can have profound ecological effects. We are familiar with the centuries‐old invasions of European earthworms (Lumbricidae) and their impacts on nutrient cycling in soils. More recent invasions by Asian earthworms of the family Megascolecidae are less fully understood. We used data for two mitochondrial gene fragments, cytochrome oxidase I (COI) and 16S rRNA, to examine the relationships among populations of Asian earthworms in the megascolecid genus Amynthas in the northeast United States. Recent reports have indicated that one species in particular, Amynthas agrestis, is having detrimental effects in mixed forest ecosystems, and we were interested in understanding the invasion history for this species. We were surprised to discover three divergent mitochondrial lineages of Amynthas occurring sympatrically in upstate New York. Given the gap between intra‐ and inter‐lineage sequence divergences, we propose that these three lineages represent cryptic species of Amynthas, one of which is A. agrestis. For each of the three lineages of Amynthas, we observed shared haplotypes across broad geographic distances. This may reflect common origins for populations in each lineage, either by direct routes from native ranges or through post‐introduction spread by natural dispersal or human‐mediated transport within North America. Management efforts focused on horticultural imports from Asia, commercial nurseries within the USA, and on prohibition of bait disposal may help to reduce the further invasion success of Amynthas.  相似文献   

2.
Pleistocene glaciations had a determining role for shaping the current distribution and diversity of organisms, especially in the Palearctic region. In this work, we carry out a phylogeographic analysis of Iberian and two Eastern European populations of the tiger beetle Calomera littoralis (Fabricius, 1787) in order to infer the processes that may have affected their evolutionary history. According to our results, the genetic diversity of central Iberian C. littoralis populations is very low. The haplotype networks also suggest that these populations experienced a genetic bottleneck in the past, possibly related to the last glacial maxima, similar to that observed in other cicindelid taxa. These results highlight the remarkable dispersal capacity of this species, being able to move freely from one locality to another, despite the relatively long distances of sub-optimal habitat that separates them. The genetic data of central Iberian populations contrast with those of the Eastern European populations, with higher genetic diversity and no hints of any past bottleneck. This can be explained by the different characteristics of both (Iberian and Pontic) glacial refuges. The high degree of genetic differentiation between the three C. littoralis clades, and the inclusion of C. lunulata between them, suggests that the three analysed populations could be considered as different cryptic species. In that case, C. littoralis may correspond to a species complex that is still undergoing a process of speciation, similar to that observed in Cicindela campestris.  相似文献   

3.
To examine the diverse colonization histories in eight tiger beetle species of the genus Cylindera (Coleoptera: Cicindelidae) on the East Asian islands, we conducted phylogenetic analyses and divergence time estimation using mitochondrial cytochome oxidase subunit I (COI) and nuclear 28S rDNA sequences. The island fauna consisted of four subgenera: Apterodela, Cicindina, Ifasina, and Cylindera. Apterodela is a flightless group with large bodies, whereas the others are fliers with small bodies. In Apterodela, the divergence among endemic species in Taiwan, Japan, and the mainland was ancient (2.1–4.7 Mya), as expected from their flightlessness. Their dispersal might have occurred across the extended landmass in East Asia during the Pliocene. In the subgenus Cicindina, Cylindera elisae has spread throughout East Asia, from which an endemic species, Cylindera bonina, was derived on the oceanic Bonin Islands during the early Pleistocene (0.9 Mya). This indicates the significance of Cylindera bonina, which is currently confined to a single island, for conservation. In the subgenus Ifasina, Cylindera kaleea is widely distributed in East Asia, and its sister species Cylindera humerula, endemic to Okinawa Island, diverged 1.0 Mya, whereas Cylindera psilica on Taiwan and the Yaeyama Islands diverged approximately 0.8 Mya. In the subgenus Cylindera, the colonization of Cylindera gracilis in Japan from the mainland occurred during the last glacial period. With the exception of C. bonina, which likely colonized new territories by flight or drifting, other dispersal events might have used land connections that occurred repeatedly during the Pliocene and Pleistocene. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 715–727.  相似文献   

4.
Using mitochondrial DNA cytochrome c oxidase subunit I and nuclear DNA 28S rRNA data, we explored the phylogenetic relationships of the family Pimoidae (Arachnida: Araneae) and tested the North America to Asia dispersal hypothesis. Sequence data were analysed using maximum parsimony and Bayesian inference. A phylogenetic analysis suggested that vicariance, instead of dispersal, better explained the present distribution pattern of Pimoidae. Times of divergence events were estimated using penalized likelihood method. The dating analysis suggested that the emergence time of Pimoidae was approximately 140 million years ago (Ma). The divergence time of the North American and Asian species of Pimoa was approximately 110 Ma. Our phylogenetic hypothesis supports the current morphology‐based taxonomy and suggests that the cave dwelling might have played an important role in the speciation of pimoids in arid areas.  相似文献   

5.
To reveal differences in phylogeographic patterns of flightless insect species occurring in different regions of Japan, we studied the phylogeography and demographic history of Silpha beetles occurring in cool-temperate habitats of two major islands, Honshu and Hokkaido, using sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene. Honshu has a more mountainous topography, and cool-temperate habitats occur discontinuously, whereas Hokkaido, located to the north of Honshu, has more continuous cool-temperate habitats. A species endemic to Honshu, S. longicornis occurs on Honshu, whereas S. perforata occurs on Hokkaido and the East Asian continent. Our results indicate that the ancestors of S. longicornis colonized Honshu via a south-west route c . 0.7 Mya and the species has highly divergent populations in isolated mountainous areas of Honshu, whereas S. perforata colonized Hokkaido via a northern route less than 90 000 years ago and has less divergent geographic populations. During the last glacial period, S. perforata was probably restricted to refugia in southern Hokkaido and later expanded into northern Hokkaido, whereas S. longicornis populations existed in many isolated refugia, probably because of the complex topography of Honshu. Thus, our study demonstrates that, even between closely related species, interactions among biology, latitudinal climatic gradients and topography can produce different phylogeographic patterns.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 452–467.  相似文献   

6.
Megacrania tsudai, a peripherally distributed member of Megacrania, requires conservation in Taiwan; it has limited distribution in Taiwan and its eastern offshore islands. It feeds on screw pines (Pandanus odoratissimus) in nature and has demonstrated a specific defensive mechanism involving actinidine secretion from the prothoracic gland. However, details of its distribution area, life cycle and developmental phenology remain largely unknown. In this study, a field survey and review of published works revealed M. tsudai distribution in coastal zones and along river shores near estuaries. At room temperature, the egg period was 128 days. The development of the first to sixth instars required 17, 26, 27, 26, 34 and 43 days, respectively, on average; and a generation cycle required approximately 204 days. The phenology of the mesonotal granules was recorded. Moreover, genetic analysis of the mitochondrial cytochrome oxidase I (COI), 16S ribosomal DNA (16S rDNA) and the nuclear ribosomal spacer indicated the occurrence of genetic drift. Therefore, the rearing procedures proposed in this study for the primary and last instars of M. tsudai can facilitate its conservation. Megacrania tsudai was previously recorded as parthenogenetic; however, two male individuals were fostered unexpectedly. The male body length was 91 mm, which is shorter than the female length (120 mm). During mating, the male climbs onto the female's back and protrudes its genitalia downward. Geographical parthenogenesis is likely the reproductive strategy among peripheral M. tsudai; however, the rarely found M. tsudai male could be an intermediate link of reproductive strategy in the transition from tychoparthenogenesis to parthenogenesis.  相似文献   

7.
A new tiger beetle species, Cicindelidia melissa Duran & Roman, sp. n., of the tribe Cicindelini, is described from high elevation montane forests of southeastern Arizona and Mexico. It appears to be most closely related to Cicindelidia nebuligera (Bates) but is distinguished on the basis of multiple morphological characters and geographic range. The new species is also superficially similar to the widespread Cicindelidia sedecimpunctata (Klug), but distinguished on the basis of multiple morphological characters and habitat. Habitus, male and female reproductive structures, and known distribution map are presented.  相似文献   

8.
The Last Glacial Maximum (LGM) has affected the population size and spatial distribution of a number of organisms in southern Patagonia. It has been hypothesized that species were able to persist in isolated refuges, which has generated processes of population expansion and genetic structure of populations after the LGM. In the present study, we evaluate these hypotheses and their association with local morphotypes in the endemic species Nyctelia confusa, a coleopteran that has low vagility and restricted distribution in the region. Accordingly, sixty‐nine specimens were sequenced for the gene for mitochondrial cytochrome c oxidase I. Effective population size was estimated through time, along with population structure and the phylogenetic signal of the morphs. The results suggest the existence of recent population expansion (10 Kyr BP), although there was no evidence of population structure or the phylogenetic signal for the described morphs. We propose that, during the LGM, N. confusa survived in multiple refuges, probably in the oriental slopes of the Andes range. The surviving populations would have expanded once the steppe was re‐established after the glaciers receded. This may have produced various secondary contact zones, homogenizing the genetic diversity, which would explain the observed pattern of panmixia. The morphological differentiation reported previously may be a result of local ecological adaptation not associated with the historical events of the LGM.  相似文献   

9.
The distribution of Octopus vulgaris has not yet been completely clarified. For a long time, a cosmopolitan distribution with unknown distribution limits had been assumed. This assumption has recently been questioned and it has been postulated that the distribution is restricted to the Mediterranean and the northeastern Atlantic. However, as our previous studies show, the existence of O. vulgaris can be confirmed for the Mediterranean and the whole eastern Atlantic, and evidence is provided for its occurrence in the western Atlantic. The aim of the present work is to extend our previous data matrix and to clarify whether O. vulgaris exists in the northwestern Pacific. Therefore, the sequence variation in ostensible O. vulgaris from 13 localities in the Mediterranean (France), the Atlantic Ocean [Lanzarote, Senegal, South Africa (Atlantic, Indian Ocean), Tristan da Cunha, north, middle and south Brazil], the Caribbean Sea (Venezuela) and the Pacific Ocean (Taiwan, Japan and Costa Rica) was examined using the mitochondrial genes coding for the 16S rRNA and cytochrome oxidase subunit III (COIII). Sequence divergence was relatively low between populations of O. vulgaris from the Mediterranean, the eastern and western Atlantic (except north Brazil), Venezuela, Taiwan and Japan compared with other species of the genus Octopus . Trees constructed by using maximum likelihood, neighbour joining and maximum parsimony algorithms (PAUP) show the above-mentioned populations from the Mediterranean, the western and eastern Atlantic, Venezuela and the northwestern Pacific (Japan and Taiwan) as a monophyletic cluster. Thus, even if the Octopus vulgaris -like octopus from north Brazil should turn out a cryptic species, the data of this work not only support our hypothesis of the distribution of O. vulgaris in the Mediterranean, the eastern and western Atlantic but also show that O. vulgaris is present in the northwestern Pacific, namely in the waters of Taiwan and Japan.  相似文献   

10.
Extensive population structuring is known to occur in Anopheles darlingi , the primary malaria vector of the Neotropics. We analysed the phylogeographic structure of the species using the mitochondrial cytochrome oxidase I marker. Diversity is divided into six main population groups in South America: Colombia, central Amazonia, southern Brazil, south-eastern Brazil, and two groups in north-east Brazil. The ancestral distribution of the taxon is hypothesized to be central Amazonia, and there is evidence of expansion from this region during the late Pleistocene. The expansion was not a homogeneous front, however, with at least four subgroups being formed due to geographic barriers. As the species spread, populations became isolated from each other by the Amazon River and the coastal mountain ranges of south-eastern Brazil and the Andes. Analyses incorporating distances around these barriers suggest that the entire South American range of An. darlingi is at mutation–dispersal–drift equilibrium. Because the species is distributed throughout such a broad area, the limited dispersal across some landscape types promotes differentiation between otherwise proximate populations. Moreover, samples from the An. darlingi holotype location in Rio de Janeiro State are substantially derived from all other populations, implying that there may be additional genetic differences of epidemiological relevance. The results obtained contribute to our understanding of gene flow in this species and allow the formulation of human mosquito health protocols in light of the potential population differences in vector capacity or tolerance to control strategies.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 854–866.  相似文献   

11.
The Lozekia–Kovacsia species group comprises three species of high conservation concern, Lozekia transsilvanica (Westerlund, 1876), Lozekia deubeli (M. Kimakowicz, 1890) and Kovacsia kovacsi ( Varga and L. Pintér, 1972 ), which occupy relatively small ranges in the Carpathian‐Pannonian region. Despite their conservation concern, the phylogeny and biogeographical history of these species have not been studied by molecular methods up to now. This study, based on mitochondrial cytochrome oxidase subunit I gene sequences, has two main objectives: (i) to infer the phylogenetic relationships within the group in order to test the latest morphology‐based system, proposed by Nordsieck [1993, Das System der paläarktischen Hygromiidae (Gastropoda: Stylommatophora: Helicoidea). Arch Molluskenkunde 122:1] and (ii) to reconstruct the distribution history of the three species. The monophyly and thus the systematic distinctness of the three species was confirmed, but our findings do not support the monophyly of the Lozekia genus and therefore contradict the current system of the species group. Genetic diversity was found to be much higher within L. deubeli than within the other two species, a possible explanation of this phenomenon is that L. transsilvanica and K. kovacsi are more recently evolved, younger species. Nested clade phylogeographycal analysis showed that the three species evolved by fragmentation events; probably L. deubeli and the ancestor of the other two species split first. At the intraspecific level, fragmentation events, as well as range expansion, played a significant role in the biogeographical history of this species group. As our findings are based on a single mitochondrial gene, we feel premature to propose changes in the generally accepted system and nomenclature. Further molecular phylogenetic analyses, also involving nuclear DNA sequences, should clarify if the evolutionary scenario suggested by our data is valid, and the three species can indeed be placed within the same genus, Lozekia.  相似文献   

12.
Isopods of the species Ligia oceanica are typical inhabitants of the rocky intertidal of the northern European coastline. The aim of this study was to assess the genetic structure of this species using mitochondrial and nuclear sequence data. We analysed partial mitochondrial cytochrome c oxidase subunit I (CO1) and 16S rRNA gene sequence data of 161 specimens collected from ten sites ranging from Spain to Norway. For selected specimens, we also sequenced the hypervariable V7 expansion segment of the nuclear 18S rRNA gene as a supplementary marker. Furthermore, we studied the infection rate of all analysed specimens by the alphaproteobacterium Wolbachia. Our analyses revealed two deeply divergent mitochondrial lineages for Ligia oceanica that probably diverged in the late Pliocene to mid Pleistocene. One lineage comprised specimens from northern populations (‘lineage N’) and one primarily those from France and Spain (‘lineage S’). Distribution patterns of the haplotypes and the genetic distances between both lineages revealed two populations that diverged before the Last Glacial Maximum. Given that we found no homogenization of mitochondrial haplotypes, our present results also reject any influence of Wolbachia on the observed mtDNA variability. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112 , 16–30.  相似文献   

13.
Relationships within Chilopoda (centipedes) are assessed based on 222 morphological characters, complete 18S rRNA sequences for 70 chilopod terminals, the D3 region of 28S rRNA for 65 terminals, 16S rRNA sequences for 54 terminals and cytochrome c oxidase subunit I sequences for 45 terminals. Morphological and molecular data for seven orders of Diplopoda are used to root cladograms for Chilopoda. Analyses use direct character optimization for 15 gap and substitution models. The Pleurostigmophora and Epimorpha s.l. hypotheses are largely stable to parameter variation for the combined data; the latter clade is formalized as the new taxon Phylactometria. The combined data include parameter sets that support either the monophyly of Epimorpha s.str. (=Scolopendromorpha + Geophilomorpha) or Craterostigmus + Geophilomorpha; the former derives its support from morphology and the nuclear ribosomal genes. Monophyly of Lithobiomorpha and the sister group relationship between Lithobiidae and Henicopidae are stable for morphological and combined data, and are also resolved for the molecular data for 14 of 15 parameter sets. The fundamental split in Scolopendromorpha is between Cryptopidae and Scolopendridae sensu Attems. Blind scolopendromorphs unite as a clade in most molecular and combined analyses, including those that minimize incongruence between data partitions. Geophilomorpha divides into Placodesmata and Adesmata under nine of 15 explored parameter sets.  相似文献   

14.
The aquatic larvae of the family Elmidae (Coleoptera) have been considered unable to swim because they lack swimming setae on their body and legs. We discovered that riffle beetle larvae (Leptelmis gracilis Sharp) are in fact able to swim. After opening the tuft‐like gills on the last abdominal segment they swim by repeatedly bending the abdomen into a U‐shape very quickly and in a wavy manner, while their head and thorax move anteriorly, resulting in a sigmoidal body shape. The flat bodies of L. gracilis larvae could be advantageous for swimming compared to the cylindrical or semicylindrical bodies of larvae in related genera.  相似文献   

15.
The California Floristic Province (CFP) is considered a global biodiversity hotspot because of its confluence of high species diversity across a wide range of threatened habitats. To understand how biodiversity hotspots such as the CFP maintain and generate diversity, we conducted a phylogeographic analysis of the flightless darkling beetle, Nyctoporis carinata, using multiple genetic markers. Analyses of both nuclear and mitochondrial loci revealed an east–west genetic break through the Transverse Ranges and high genetic diversity and isolation of the southern Sierra Nevada Mountains. Overall, the results obtained suggest that this species has a deep evolutionary history whose current distribution resulted from migration out of a glacial refugium in the southern Sierra Nevada via the Transverse Ranges. This finding is discussed in light of similar genetic patterns found in other taxa to develop a foundation for understanding the biodiversity patterns of this dynamic area. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 424–444.  相似文献   

16.
The checkered beetle, Thanasimus dubius F., is an important predator of scolytid bark beetles that attack conifers. Relatively few studies exist that have addressed the population genetics of predatory beetles, especially those with potential as biological control agents. This study was conducted to investigate the population genetics of T. dubius across a large part of its range in the eastern United States. A 464-base pair portion of the mitochondrial cytochrome c oxidase subunit I was sequenced for 85 individuals resulting in 60 haplotypes. Analysis of molecular variance was conducted on the resulting haplotypes for all populations and as a hierarchical analysis between populations defined as broad-scale northern and southern groups. Results indicate a significant overall Phi ST = 0.220 (P < 0.001) for all populations with the hierarchical analysis revealing that this significant Phi ST is due to structuring of the populations between northern and southern regions (Phi CT = 0.388, P < 0.009). The observed genetic structure is possibly due to the discontinuous distribution of pine trees, which act as hosts for the prey of T. dubius, which has occurred historically in the central region of the United States that has been covered by prairie.  相似文献   

17.
Aim Dispersal barriers between areas within some regions have appeared and disappeared throughout evolutionary time. Here we describe the distributional patterns displayed by three taxa living in such kind of regions. These patterns can be better explained considering a reticulated rather than a hierarchically branched palaeogeography. Location Western Mediterranean. Methods The taxa studied are Misolampus (Coleoptera, Tenebrionidae), Tentyria (Coleoptera, Tenebrionidae) and Thorectes (Coleoptera, Geotrupidae). All them are flightless and show a high degree of endemicity. The individual pattern of area relationships was determined separately for each genus by Brooks Parsimony Analysis (BPA). A theoretical general area cladogram was constructed based on the palaeogeographical history of the region. Finally, the general area cladogram is reconciled with the individual ones. Results The ancestor of Misolampus probably was North African. Land dispersal toward the Iberian Peninsula is proposed. Speciation within Iberia is related to specific vicariance events, and the presence of insular (Balearic Islands) populations is explained by sea‐surface or, more probably, human‐mediated dispersal. The ancestor of Tentyria was Iberic. The proposed hypothesis to explain the current species distribution mainly relies on the occurrence of specific vicariance events. However, the occurrence of some sea‐surface dispersal event is not discarded. Almost all possible vicariance events can be recognized in the first clade of the Thorectes genus. There is evidence for dispersal between Africa and Europe at different dates and in both directions. In spite of some uncertainties, the appearance of the second Thorectes clade can also be explained by the occurrence of specific historical events. An ancient dispersal toward the eastern Mediterranean and several dispersal events during the Messinian seem likely. Main conclusions The same historical events have specific outcomes in every tree (even in every branch within a tree) depending on the ability for dispersal and speciation of each taxon. Connection‐disjunction cycles of dispersal barriers have acted as diversity producers.  相似文献   

18.
Comparative phylogeography seeks for commonalities in the spatial demographic history of sympatric organisms to characterize the mechanisms that shaped such patterns. The unveiling of incongruent phylogeographic patterns in co‐occurring species, on the other hand, may hint to overlooked differences in their life histories or microhabitat preferences. The woodlouse‐hunter spiders of the genus Dysdera have undergone a major diversification on the Canary Islands. The species pair Dysdera alegranzaensis and Dysdera nesiotes are endemic to the island of Lanzarote and nearby islets, where they co‐occur at most of their known localities. The two species stand in sharp contrast to other sympatric endemic Dysdera in showing no evidence of somatic (non‐genitalic) differentiation. Phylogenetic and population genetic analyses of mitochondrial cox1 sequences from an exhaustive sample of D. alegranzaensis and D. nesiotes specimens, and additional mitochondrial (16S, L1, nad1) and nuclear genes (28S, H3) were analysed to reveal their phylogeographic patterns and clarify their phylogenetic relationships. Relaxed molecular clock models using five calibration points were further used to estimate divergence times between species and populations. Striking differences in phylogeography and population structure between the two species were observed. Dysdera nesiotes displayed a metapopulation‐like structure, while D. alegranzaensis was characterized by a weaker geographical structure but greater genetic divergences among its main haplotype lineages, suggesting more complex population dynamics. Our study confirms that co‐distributed sibling species may exhibit contrasting phylogeographic patterns in the absence of somatic differentiation. Further ecological studies, however, will be necessary to clarify whether the contrasting phylogeographies may hint at an overlooked niche partitioning between the two species. In addition, further comparisons with available phylogeographic data of other eastern Canarian Dysdera endemics confirm the key role of lava flows in structuring local populations in oceanic islands and identify localities that acted as refugia during volcanic eruptions.  相似文献   

19.
We performed a molecular phylogenetic analysis of the ground beetles Apatrobus (Carabidae), endemic to Japan, using the mitochondrial cytochrome c oxidase subunit I (COI) and the nuclear 28S rRNA (28S) genes. We focused on the species divergence in Kyushu, Shikoku and western Honshu and used 15 of 19 species and three populations with undetermined species in the DNA analysis. The gene trees showed that, of the Apatrobus species studied, A. hayachinensis Nakane from northern Honshu was not included in the monophyletic group of the other Apatrobus species and likely to be of a different genus. Divergence time estimation suggested that Apatrobus species excluding A. hayachinensis diverged 5.2 million years ago and the subsequent divergence of species occurred during the Pliocene and Pleistocene. In each of the main islands, Kyushu, Shikoku and Honshu, two or more distinct lineages occurred and all species had restricted distribution areas, suggesting that ancient dispersal and vicariance among the three main islands resulted in the nested biogeographical pattern of species distribution.  相似文献   

20.
The green lacewing Chrysoperla carnea is a complex of cryptic species whose differentiation has been so far based upon morphology, ecophysiology, behaviour and preliminary mitochondrial DNA data using cytochrome oxidase subunit II (COII) and NADH dehydrogenase subunit II. In this work we extended the DNA data by screening nucleotide sequences of COII, cytochrome oxidase I, cytochrome b and the large ribosomal subunit of the mtDNA. These new data suggest that C. carnea s.s. is a well-supported, separate taxon, but that other taxa of the complex are not consistently differentiated by the current DNA data.  相似文献   

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