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1.
A supertree for Adephaga was reconstructed based on 43 independent source trees – including cladograms based on Hennigian and numerical cladistic analyses of morphological and molecular data – and on a backbone taxonomy. To overcome problems associated with both the size of the group and the comparative paucity of available information, our analysis was made at the genus level (requiring synonymizing taxa at different levels across the trees) and used Safe Taxonomic Reduction to remove especially poorly known species. The final supertree contained 401 genera, making it the most comprehensive phylogenetic estimate yet published for the group. Interrelationships among the families are well resolved. Gyrinidae constitute the basal sister group, Haliplidae appear as the sister taxon of Geadephaga+Dytiscoidea, Noteridae are the sister group of the remaining Dytiscoidea, Amphizoidae and Aspidytidae are sister groups, and Hygrobiidae forms a clade with Dytiscidae. Resolution within the species-rich Dytiscidae is generally high, but some relations remain unclear. Trachypachidae are the sister group of Carabidae (including Rhysodidae), in contrast to a proposed sister-group relationship between Trachypachidae and Dytiscoidea. Carabidae are only monophyletic with the inclusion of a non-monophyletic Rhysodidae, but resolution within this megadiverse group is generally low. Non-monophyly of Rhysodidae is extremely unlikely from a morphological point of view, and this group remains the greatest enigma in adephagan systematics. Despite the insights gained, our findings highlight that a combined and coordinated effort of morphologists and molecular systematists is still required to expand the phylogenetic database to enable a solid and comprehensive reconstruction of adephagan phylogeny. See also Supplementary material in the online edition at doi:10.1016/j.ode.2006.05.003  相似文献   

2.
The evolution of the coleopteran suborder Adephaga is discussed based on a robust phylogenetic background. Analyses of morphological characters yield results nearly identical to recent molecular phylogenies, with the highly specialized Gyrinidae placed as sister to the remaining families, which form two large, reciprocally monophyletic subunits, the aquatic Haliplidae + Dytiscoidea (Meruidae, Noteridae, Aspidytidae, Amphizoidae, Hygrobiidae, Dytiscidae) on one hand, and the terrestrial Geadephaga (Trachypachidae + Carabidae) on the other. The ancestral habitat of Adephaga, either terrestrial or aquatic, remains ambiguous. The former option would imply two or three independent invasions of aquatic habitats, with very different structural adaptations in larvae of Gyrinidae, Haliplidae and Dytiscoidea.  相似文献   

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J. Serrano 《Genetica》1981,57(2):131-137
The meiotic process was studied in fifty-three species belonging to the caraboid families Bembidiidae (48). Trechidae (3), Pogonidae (1), and Harpalidae (1). Males show achiasmatic meiosis patterns of the Callimantis type. In females only early prophase stages were observed, that are similar to those of the males. The characteristics of this abnormal meiosis and its evolutionary and cytotaxonomic significance are discussed.  相似文献   

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Abstract Quediina, a mega‐diverse conventional subtribe of the rove beetle tribe Staphylinini, is remarkably species rich in the north and south temperate regions of the world. Tropical faunas of this group, and the fauna of the entire Afrotropical biogeographical region (= Ethiopian region, = sub‐Saharan Africa), in contrast, are remarkably poor. The taxonomic study of the quediine genera of Staphylinini from the Afrotropical region reveals misidentifications for many of them. Their phylogenetic study demonstrates polyphyly of Quediina and reveals a new evolutionary pattern for the entire tribe Staphylinini. In particular, the formerly quediine genera Euristus Fauvel, 1899 , Ioma Blackwelder, 1952, Natalignathus Solodovnikov, 2005 , all endemic in the Afrotropical region, belong to the non‐related ‘Staphylinina’, ‘Philonthina propria’ and ‘Tanygnathinina sensu novo’ lineages of Staphylinini, respectively. Contrary to earlier records, the genus Quedius Stephens, 1929 does not occur in Africa south of Sahara: Quedius angularis Cameron, 1948 and Quedius cinctipennis Cameron, 1951 are moved to the genus Philonthus Stephens, 1829. The same is established for the Asian genus Algon Sharp, 1874, formerly for a long time associated with Quediina: African species Algon robustus Wendeler, 1928 is moved to the genus Moeocerus Fauvel, 1899 (here in the ‘Philonthina propria’ lineage); and the misidentification of Algon africanus Bernhauer, 1915, a species that probably belongs to a new genus, is discussed. The phylogenetic affiliation of Afroquedius Solodovnikov, 2006 , a South African endemic, is still ambiguous. Overall, the formerly seen bipolar distribution pattern for the ‘Quediina’ is demonstrated to be an artefact, not a reality to explain. Historical biogeographical explanations are proposed for some of the Afrotropical endemics, partly as an attempt to apply biogeography as an external criterion for the evaluation of the new phylogenetic pattern revealed for Staphylinini. The monotypic genera Euristus and Ioma, as well as Heterothops megalops Cameron, 1959 , the only representative of this widespread genus in the Afrotropical region, are redescribed. Limits and synapomorphies of the genus Heterothops are discussed. The following new combinations and new names are proposed: Philonthus cinctipennis ( Cameron, 1951 ) comb.n. (preoccupied by Philonthus cinctipennis Fauvel, 1875), here replaced by Philonthus pseudoquedius Solodovnikov nom.n. ; Philonthus angularis ( Cameron, 1948 ) comb.n. ; Moeocerus robustus ( Wendeler, 1928 ) comb.n. [preoccupied by Moeocerus robustus (Gestro, 1881)], here replaced by Moeocerus wendeleri Solodovnikov nom.n. A lectotype is designated for Heterothops megalops Cameron, 1959 .  相似文献   

7.
Siegel D.S., Miralles A, Trauth S.E. and Aldridge R.D. 2011. The phylogenetic distribution and morphological variation of the ‘pouch’ in female snakes. —Acta Zoologica (Stockholm) 93 : 400–408. The urodaeum of female snakes is a chamber that receives the oviducts, urinary ducts, and intestine. Previous studies have indicated that a derived region of unknown function persists between the urodaeum and oviducts in some snakes of the Colubroides. This structure was recently termed the ‘pouch’; however, it is also commonly referred to as the vaginal pouch. A broad sampling of female snakes revealed that the pouch evolved once on the branch leading to Colubroides. The presence of the pouch in Colubroides is not unambiguous, as this feature was lost in some members of the Atractaspididae and Lamprophiidae. Variation was also observed in pouch morphology between taxa of the Colubroides. Variation included the following: (1) whether the pouch was bifurcated and if so, were the arms of the pouch separated caudally, (2) whether separated pouch arms were split by a caudal bifurcation of the urodaeum or through medial septa of the pouch arms, and (3) the absence or presence of oviducal papillae invading the cranial/lateral extremity of the pouch. The variation in pouch morphology observed does not appear to be correlated with the evolutionary history of Colubroides and polymorphism within families is common.  相似文献   

8.
This article addresses a classic ethnographic problem in the study of Italy: how is it that people can subscribe simultaneously to seemingly contradictory ideologies, such as Catholicism and Communism? It does so by describing examples from Italy's ‘showcase city’ of the left, ‘Red Bologna’, in which to be ‘red’ is ubiquitous but each person's ‘red’ is a different thing: being ‘red’ (differently) is the idiom in which real political distinctions are expressed over issues like religion or immigration. In parallel, I discuss the relationship between the ‘field’ as a location and the ‘field’ as a conceptual topic. My account replicates internal ethnographic differences at the analytical level by highlighting the differences between being left‐wing in Bologna and its meaning as a concept in anthropology. Hence the ‘equivocal location’: a field‐site that is productively different, from what an inexperienced ethnographer expected from it, from conceptual discussions in anthropology, and from itself.  相似文献   

9.
Plant population genetic surveys are starting to take full advantage of technological advances in genotyping methods and of methodological advances in demographic inference. In this issue of Molecular Ecology, Keller et al. (2010) illustrate this trend with a particularly convincing study of rangewide genetic variation in a North American poplar, using both SNP and sequence data. They first investigate population genetic structure by estimating the most likely number of genetic clusters using a more formal approach than most other studies to date. They proceed by estimating gene flow among the inferred populations and by testing predictions on the distribution of low frequency alleles derived from recent work on range expansions.  相似文献   

10.
Burying beetles tend their young on small vertebrate carcasses, which serve as the sole source of food for the developing larvae. Single females are as proficient at rearing offspring as male-female pairs, yet males opt to remain with their broods throughout most of the larval development. One potential benefit of a male's extended residency is that it affords him the opportunity of additional copulations with the female, which could ensure his paternity in a replacement brood should the female's first egg clutch fail to hatch. We tested this hypothesis by manipulating males' access to their mates during the production of replacement clutches, using genetic colour markers to determine the paternity of offspring. Females were induced to produce a replacement brood by removing their first clutch of eggs. In one experimental treatment, we removed the female's mate upon the removal of her first egg clutch (‘widowed’ females); in a second treatment, the female was permitted to retain her mate up until she produced a replacement clutch. There was no significant difference in paternity between males removed from females before the initiation of replacement clutches and those permitted to remain with their mates. However, widowed females produced fewer offspring in replacement broods than did females permitted to retain their mates. This difference occurred primarily because a significantly greater proportion of widowed females opted not to produce a replacement clutch, a result we refer to as the ‘widow effect’. This widow effect was further shown in those replicates in which females of both treatments produced replacement clutches: widowed females took significantly longer to produce a replacement clutch than did females permitted to retain their mates. The loss of her mate could be a signal to a female that a take-over of the carcass is imminent. Her reluctance to produce a replacement clutch under these circumstances might constitute a strategy by which she conserves carrion for a subsequent reproductive attempt with an intruding male successful at ousting her previous mate. Regardless of its functional significance, the widow effect favours the extended residency of males and therefore contributes to the selective maintenance of male parental care.  相似文献   

11.
Throughout Australia, many Aboriginal responses to the legislative and administrative pressures of the native title regime have been couched in a nation‐building idiom expressed through legally incorporated Aboriginal associations. The membership criteria of these umbrella associations are often derived from definitions of the ‘tribe’ or ‘language group’. Yet, in a kind of Balkanisation, those who see themselves as marginalised to positions of uncertainty on the peripheries of the nation often seek to establish their own independent corporations on the basis of exclusive ties to specific areas of land within it, in search of greater recognition and in competition for scarce resources. In Katherine, in the Northern Territory of Australia, the administrative and legislative gaze of the State, particularly the Aboriginal Land Rights (Northern Territory) Act 1976, brought into focus a Jawoyn ‘tribe’, soon to express itself in the idiom of nationhood, closely followed by a Wardaman ‘tribe’ and ‘nation’. More recently, a native title gaze has now brought into focus ‘new’ configurations of kindred clusters, apparently located on the ‘peripheries' of the Jawoyn and Wardaman nations, and named and valued them as Dagoman. This paper discusses the processes associated with an emerging, but seemingly already fragmenting, Dagoman nation. It argues that divergent and changing Aboriginal subjectivities disrupt what might be seen as mimetic processes as Aboriginal people employ strategies of transforming essentialist representations of their collective selves in changing conditions of possibility.  相似文献   

12.
Daohugounectes primitivus, a new genus and species of coptoclavid beetles, is described from 67 fossil larvae from the Jurassic locality of Daohugou, northeastern China. It differs from other coptoclavids in the combination of the following characters: lateral lobes of nasale present; legs relatively short, with tarsi flat and slightly dilated; abdominal tergite VIII almost circular; derivative of abdominal segment IX present; urogomphi short; and helical thickening of tracheae weak. Most of these features are plesiomorphic for the family Coptoclavidae and the superfamily Dytiscoidea. Among dytiscoids, a derivative of abdominal segment IX is present only in the larvae of the recently discovered relic family Aspidytidae.  相似文献   

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Thorough sampling is necessary to delineate lineage diversity for polytypic ‘species’ such as Cyprinella lutrensis. We conducted extensive mtDNA sampling (cytochrome b and ND4) from the Pecos River, Rio Grande, and South Canadian River, New Mexico. Our study focussed on the Pecos River due to its complex geological history and potential to harbour multiple lineages. We used geometric–morphometric, morphometric, and meristic analyses to test for phenotypic divergence and combined nucDNA with mtDNA to test for cytonuclear disequilibrium and combined our sequences with published data to conduct a phylogenetic re‐assessment of the entire C. lutrensis clade. We detected five co‐occurring mtDNA lineages in the Pecos River, but no evidence for cytonuclear disequilibrium or phenotypic divergence. Recognized species were interspersed amongst divergent lineages of ‘C. lutrensis’. Allopatric divergence among drainages isolated in the Late Miocene and Pliocene apparently produced several recognized species and major divisions within ‘C. lutrensis’. Pleistocene re‐expansion and subsequent re‐fragmentation of a centralized lineage founded younger, divergent lineages throughout the Rio Grande basin and Edwards Plateau. There is also evidence of recent introductions to the Rio Grande, Pecos and South Canadian Rivers. Nonetheless, deeply divergent lineages have coexisted since the Pleistocene.  相似文献   

15.
Recently, two quite different approaches exemplifying ‘bottom-up’ and ‘top-down’ philosophies have shed new light on basal ganglia function. In vitro work using organotypic co-cultures has implicated the subthalamic nucleus (STN) and the external segment of the globus pallidus (GPe) as pacemakers for low-frequency bursting that is reminiscent of the activity produced in Parkinsonian tremor. A circuit essential for avian song learning has been identified as part of the basal ganglia with surprisingly well conserved cellular details; investigation of this system may help to address general issues of basal ganglia function.  相似文献   

16.
For several years, aid programs in the Mekong region have taken an increasing interest in cross‐border mobility and human trafficking and its relationship with development. More recently, there has been an increasing interest in the identification of trafficked victims and the investigation, arrest and prosecution of traffickers. Whereas anti‐trafficking programs ubiquitously define themselves as being in a battle with traffickers, this article argues that although they are not homologous social actors, both engage in acts of bad faith. The article elaborates this argument by drawing attention to the recruitment process within the Lao sex industry as well as to the way in which aid programs attempt to identify trafficked victims. It concludes that imaginary aspects of development underpin a simultaneous disjuncture yet enable the social reproduction of the life worlds of ‘traffickers’ and ‘anti‐traffickers’ alike.  相似文献   

17.
Neotropical genera of Cephenniini characterized by an additional leg ‘segment’ (‘trochantellus’) are revised, and the following new taxa are described: Shyri gen.n. , Shyri pichincha sp.n. (type species of Shyri) (Ecuador), Shyri perversus sp.n. (Ecuador), Shyri quitu sp.n. (Ecuador), Shyri microphthalmus sp.n. (Ecuador), Monstrophennium gen.n. (type species: Cephennium spinicolle Schaufuss), Furcodes gen.n. , Furcodes apicalis sp.n. (type species of Furcodes) (Mexico), Furcodes tutule sp.n. (Honduras), Paracephennium pumilio sp.n. (Costa Rica), Pseudocephennium iwokramanum sp.n. (Guyana), Pseudocephennium trilineatum sp.n. (Guyana), Pseudocephennium araguanum sp.n. (Venezuela), Pseudocephennium maximum sp.n. (Venezuela), Pseudocephennium peruvianum sp.n. (Peru), Pseudocephennium cochabambanum sp.n. (Bolivia), Pseudocephennium saramaccanum sp.n. (Suriname) and Pseudocephennium brokopondonum sp.n. (Suriname). Pseudocephennium spinicolle (Schaufuss) is transferred to Monstrophennium. Cladistic analysis of characters from adult morphology of all genera of Cephenniini and a large outgroup sample from Cyrtoscydmini, Eutheiini, Scydmaenini, Clidicini and Mastigini strongly supported the monophyly of Cephenniini. However, only the Cephennomicrus group comprising nine genera was strongly supported as a monophyletic clade, while only weak support was found for the previously suggested Cephennodes group and Cephennium group. Two alternative hypotheses concerning the phylogeny of Cephenniini are put forward and discussed: (i) the Cephennium group is sister to all remaining Cephenniini; or (ii) the Cephennomicrus group is sister to all remaining Cephenniini. The Neotropical genera with ‘trochantellus’ form a well‐supported clade derived from the ancestral lineage of the Cephennodes group.  相似文献   

18.
Aim We test whether species of western Mediterranean aquatic Coleoptera of the ‘Haenydra’ lineage (Hydraenidae, Hydraena) originated through: (1) successive periods of dispersal and speciation, (2) range fragmentation by random vicariance, or (3) range fragmentation by geographic isolation owing to a general reduction of population density. Location Europe. Methods To discriminate between scenarios we use contrasting predictions of the relationship between phylogenetic and geographic distance. The phylogeny was based on 3 kb of four mitochondrial and two nuclear gene fragments of about half of the known species of ‘Haenydra’, including most western Mediterranean taxa. Divergences were estimated using a molecular clock. The relationship between phylogenetic and geographic distance was tested using bivariate plots, Mantel tests and comparison of the observed phylogeny with the one minimizing geographic distances between species, as measured using Euclidean minimum spanning trees (EMSTs). Results The monophyly of ‘Haenydra’ was strongly supported, although its phylogenetic placement was not resolved. ‘Haenydra’ was estimated to be of late Miocene age, with most species originating during the Pleistocene. In two clades (Hydraena tatii and Hydraena emarginata clades) there was a significant association between geographic and phylogenetic distance, and the reconstructed phylogeny was identical to that obtained through the EMST, demonstrating a strong non‐randomness of the geographic distribution of the species. In two other clades (Hydraena iberica and Hydraena bitruncata clades) there was no association between geographic and phylogenetic distance, and the observed phylogeny was not the one minimizing geographic distances. In one of the clades this seems to be due to a secondary, recent range expansion of one species (H. iberica), which erased the geographic signal of their distributions. Main conclusions We show that it is possible to obtain strong evidence of stasis of the geographic ranges of narrow‐range endemic species through the study of their phylogenetic relationships and current distributions. In at least two of the studied clades, current species seem to have originated through the fragmentation of a more widely distributed species, without further range movements. A process of range expansion and fragmentation may have occurred repeatedly within the ‘Haenydra’ lineage, contributing to the accumulation of narrow‐range endemics in Mediterranean Pleistocene refugia.  相似文献   

19.
Abstract. The growth in volume of human peripheral blood lymphocytes after stimulation with various concentrations of PHA was measured with an electronic particle counter. The percentage of growing cells and averaged values describing their growth rates during the elapsed period of culture were estimated by fitting to the observed data the volume distributions derived from a mathematical model. With sub-optimal doses, the percentage of cells stimulated, and their incremental growth rate, increased with increasing dose of PHA, but the time-course of recruitment into the G1-phase was similar with all PHA concentrations studied. The results provide strong support for the 'trigger' hypothesis that there is a distribution of stimulation thresholds within the lymphocyte population: consequently, increasing mitogen concentration will be expected to result in increased numbers of responding cells within the suboptimal concentration range.  相似文献   

20.
A survey was made to determine the incidence of phytoplasmas in 39 sweet and sour cherry, peach, nectarine, apricot and plum commercial and experimental orchards in seven growing regions of Poland. Nested polymerase chain reaction (PCR) using the phytoplasma‐universal primer pairs P1/P7 followed by R16F2n/R16R2 showed the presence of phytoplasmas in 29 of 435 tested stone fruit trees. The random fragment length polymorphism (RFLP) patterns obtained after digestion of the nested PCR products separately with RsaI, AluI and SspI endonucleases indicated that selected Prunus spp. trees were infected by phytoplasmas belonging to three different subgroups of the apple proliferation group (16SrX‐A, ‐B, ‐C). Nucleotide sequence analysis of 16S rDNA fragment amplified with primers R16F2n/R16R2 confirmed the PCR/Restriction Fragment Length Polymorphism (RFLP) results and revealed that phytoplasma infecting sweet cherry cv. Regina (Reg), sour cherry cv. Sokowka (Sok), apricots cv. Early Orange (EO) and AI/5, Japanese plum cv. Ozark Premier (OzPr) and peach cv. Redhaven (RedH) was closely related to isolate European stone fruit yellows‐G1 of the ‘Candidatus Phytoplasma prunorum’ (16SrX‐B). Sequence and phylogenetic analyses resulted in the highest similarity of the 16S rDNA fragment of phytoplasma from nectarine cv. Super Queen (SQ) with the parallel sequence of the strain AP15 of the ‘Candidatus Phytoplasma mali’ (16SrX‐A). The phytoplasma infecting sweet cherry cv. Kordia (Kord) was most similar to the PD1 strain of the ‘Candidatus Phytoplasma pyri’ (16SrX‐C). This is the first report of the occurrence of ‘Ca. P. prunorum’, ‘Ca. P. mali’ and ‘Ca. P. pyri’ in naturally infected stone fruit trees in Poland.  相似文献   

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