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SANTIAGO MERINO RODRIGO A. VÁSQUEZ JAVIER MARTÍNEZ JUAN LUIS CELIS-DIEZ LETICIA GUTIÉRREZ-JIMÉNEZ SILVINA IPPI INOCENCIA SÁNCHEZ-MONSALVEZ JOSUÉ MARTÍNEZ-DE LA PUENTE 《Biological journal of the Linnean Society. Linnean Society of London》2009,98(3):568-576
The Microbiotheriid Dromiciops gliroides , also known as 'Monito del Monte', is considered to be a threatened species and the only living representative of this group of South American marsupials. During the last few years, several blood samples from specimens of 'Monito del Monte' captured at Chiloé island in Chile have been investigated for blood parasites. Inspection of blood smears detected a Hepatozoon species infecting red blood cells. The sequences of DNA fragments corresponding to small subunit ribosomal RNA gene revealed two parasitic lineages belonging to Hepatozoon genus. These parasite lineages showed a basal position with respect to Hepatozoon species infecting rodents, reptiles, and amphibians but are phylogenetically distinct from Hepatozoon species infecting the order Carnivora. In addition, the Hepatozoon lineages infecting D. gliroides are also different from those infecting other micro-mammals living in sympatry, as well as from some that have been described to infect an Australian species of bandicoot. The potential vector of this parasite appears to be the host-specific tick Ixodes neuquenensis because the sequencing of a long amplicon determined the presence of one of the two lineages found in the marsupial. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 568–576. 相似文献
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Hypotheses on the taxonomic status of two Bolivian Pristimantis with taxonomic problems are assessed by an integrative taxonomic approach that integrates three independent lines of evidence: external morphology, prezygotic reproductive barriers (advertisement calls) and reciprocal monophyly (phylogenetic analyses of partial 16S mtDNA sequences). Central Andean Bolivian populations previously assigned to either P. peruvianus or P. dundeei, and lowland Amazonian populations from southern Peru and northern Bolivia previously considered P. peruvianus do not correspond to these species. Indeed, multivariate analyses of qualitative and quantitative morphological and bioacoustic characters, and phylogenetic analyses support the hypothesis that they represent different, previously unknown, cryptic lineages. They are herein described as new species. The former is a sibling species of P. fenestratus that inhabits the Amazonian and semideciduous forests of the Andean foothills in central Bolivia. The latter is sibling to the Andean species P. danae and is parapatric to it in the Amazonian lowland forests and adjacent foothills of northern Bolivia, southern Peru and adjacent Brazil. Most species of Neotropical frogs, and especially Pristimantis, have been described by using external qualitative morphological characters only. An extended integrative taxonomic approach, as exemplified herein, may lead to the discovery of many other cryptic and sibling lineages that would increase the species numbers of tropical areas. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 97–122. 相似文献
95.
IVÁN DE LA HERA JAVIER PÉREZ-TRIS JOSÉ LUIS TELLERÍA 《Biological journal of the Linnean Society. Linnean Society of London》2009,97(1):98-105
Migratory birds have less time for moulting than sedentary birds, which may force them to produce their feathers faster at the expense of reducing feather quality. However, the effects of migration on the trade-off between moult speed and plumage quality remain to be studied in natural populations. We analysed the relationship between growth rate and quality of individual feathers, taking advantage of natural variation between migratory and sedentary populations of blackcaps Sylvia atricapilla . As predicted by life-history theory, individual blackcaps showed variable individual quality, which was revealed by positive correlations between feather growth rate and feather mass within populations. However, migrants grew up their feathers faster, producing lighter feathers than sedentary blackcaps. These results support the idea that feather growth rate and feather quality are traded against each other in blackcaps. Such a trade-off is apparently caused by different selection associated to migratory and sedentary life styles, which opens new insights into the diversification of moult patterns in birds. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 98–105. 相似文献
96.
F. BAGNOLI G. G. VENDRAMIN† A. BUONAMICI† A. G. DOULIS‡ S. C. GONZÁLEZ-MARTÍNEZ§ N. LA PORTA¶ D. MAGRI P. RADDI F. SEBASTIANI†† S. FINESCHI 《Molecular ecology》2009,18(10):2276-2286
This study represents the first large-scale analysis using nuclear molecular markers to assess genetic diversity and structure of Cupressus sempervirens L.. Genetic and fossil data were combined to infer the possible role of human activity and evolutionary history in shaping the diversity of cypress populations. We analysed 30 populations with six polymorphic nuclear microsatellite markers. Dramatic reductions in heterozygosity and allelic richness were observed from east to west across the species range. Structure analysis assigned individuals to two main groups separating central Mediterranean and eastern populations. The two main groups could be further divided into five subgroups which showed the following geographical distributions: Turkey with the Greek islands Rhodes and Samos, Greece (Crete), Southern Italy, Northern Italy, Tunisia with Central Italy. This pattern of genetic structure is also supported by samova and Barrier analyses. Palaeobotanical data indicated that Cupressus was present in Italy in the Pliocene, Pleistocene and Holocene. Furthermore, our molecular survey showed that Italian cypress populations experienced bottlenecks that resulted in reduced genetic diversity and allelic richness and greater genetic differentiation. Recent colonization or introduction may also have influenced levels of diversity detected in the Italian populations, as most individuals found in this range today have multilocus genotypes that are also present in the eastern range of the species. The data reveal a new interpretation of the history of cypress distribution characterized by ancient eastern populations (Turkey and Greek islands) and a mosaic of recently introduced trees and remnants of ancient, depauperate populations in the central Mediterranean range. 相似文献
97.
Primary production dynamics and climate variability: ecological consequences in semiarid Chile 总被引:1,自引:0,他引:1
MARIANO DE LA MAZA MAURICIO LIMA PETER L. MESERVE† JULIO R. GUTIÉRREZ‡§ FABIAN M. JAKSIC 《Global Change Biology》2009,15(5):1116-1126
Increase in rainfall variability has important consequences for organisms in arid and semiarid regions around the world. In South American and Australian deserts, the El Niño/Southern Oscillation (ENSO) phenomenon greatly influences rainfall patterns, and therefore the dynamics of plant communities. However, the field data needed to assess the effect of climate change on vegetational patterns is difficult to obtain because of the large spatial scale required for such studies. Normalized Difference Vegetation Index (NDVI) characteristics allow the use of several indexes related to vegetational structure. Due to its direct relationship with primary productivity, it is possible to obtain several measures of annual productivity. These include annual plant yield, annual maximum yield, onset of 'greening-up' and senescence phases, length of the 'green' season, vegetation peak, and therefore, the periods when more or less food is available for herbivores. After verification with ground-truth measures, we used NDVI data from two semiarid localities in north-central Chile (Fray Jorge and Aucó) to determine the relationship between rainfall patterns and vegetation cover and productivity related to El Niño phenomenon. With this information we gauge the influence of climatic processes on primary productivity in western South America, an area subject to strong climate variability. We predict significant variation in Chilean semiarid regions due to climate change, affecting mainly the extent and timing of annual growth season of vegetation, and also including a shorter and delayed greening-up season. Also, we predict that important decreases in rainfall levels will not have strong effects on primary production in these semiarid ecosystems. 相似文献
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1. Eucalyptus globulus, a tree species planted worldwide in many riparian zones, has been reported to affect benthic macroinvertebrates negatively. Although there is no consensus about the effects of Eucalyptus on aquatic macrobenthos, its removal is sometimes proposed as a means of ecological restoration. 2. We combined the sampling of macroinvertebrates with measurement of the colonisation of leaf packs in mesh bags, to examine the effects of riparian Eucalyptus and its litter on benthic macroinvertebrates in three small streams in California, U.S.A. Each stream included one reach bordered by Eucalyptus (E‐site) and a second bordered by native vegetation (N‐site). 3. The macrobenthos was sampled and two sets of litter bags were deployed at each site: one set with Eucalyptus litter (Euc‐bags) and one with mixed native tree litter (Nat‐bags) containing Quercus, Umbellularia, Acer and Alnus. Bags were exposed for 28, 56 and 90 days and this experiment was repeated in the autumn, winter and spring to account for effects of changing stream flow and insect phenology. 4. Litter input (average dry mass: 950 g m?2 year?1 in E‐sites versus 669 g m?2 year?1 in N‐sites) was similar, although in‐stream litter composition differed between E‐ and N‐sites. Litter broke down at similar rates in Euc‐bags and Nat‐bags (0.0193 day?1 versus 0.0134 day?1), perhaps reflecting the refractory nature of some of the leaves of the native trees (Quercus agrifolia). 5. Summary metrics for macroinvertebrates (taxon richness, Shannon diversity, pollution tolerance index) did not differ significantly between the E and N sites, or between Euc‐bags and Nat‐bags. No effect of exposure time or site was detected by ordination of the taxa sampled. However, distinct seasonal ordination clusters were observed in winter, spring and autumn, and one of the three streams formed a separate cluster. 6. The presence of Eucalyptus was less important in explaining the taxonomic composition of the macrobenthos than either ‘season’ or ‘stream’. Similarly, these same two factors (but not litter species) also helped explain the variation in leaf breakdown. We conclude that patches of riparian Eucalyptus and its litter have little effect on stream macrobenthos in this region. 相似文献
99.
HAO WANG LA QIONG KUN SUN FAN LU YUGUO WANG ZHIPING SONG QIANHONG WU JIAKUAN CHEN WENJU ZHANG 《Molecular ecology》2010,19(14):2964-2979
The uplift of the Qinghai‐Tibetan Plateau (QTP) dramatically changed the topography and climate of Asia and affected the biodiversity of the plateau and its adjacent areas. However, the effects of the uplift on the dispersal, differentiation and adaptation of plants remain a puzzle when the date and processes of the uplift cannot be determined with certainty and the impacts of the Quaternary glaciations on plants on the QTP are unknown. To clarify the relationships among plants on the QTP with the plateau uplift and the Quaternary glaciations, the cpDNA trnT‐trnF regions of 891 individuals from 37 populations of Hippophae tibetana, endemic to the QTP, were sequenced in the present study. A total of 50 haplotypes were found and a strong phylogeographic structure was revealed (NST = 0.854, GST = 0.611, NST > GST, P < 0.01). The results show that three main lineages of the present populations of H. tibetana occupy the western, the middle, and the eastern geographical range, respectively, and their divergence time dates back to 3.15 Ma before present. Of 50 haplotypes, 33 (66%) are private haplotypes, which are restricted to single populations. These private haplotypes are scattered throughout the present geographical range of H. tibetana and originated from multiple differentiations in many lineages during more than 1.0 Ma period, strongly suggesting that multiple microrefugia of H. tibetana existed throughout the present geographical range during the last glacial maximum (LGM) and even earlier glaciations. Additionally, the average elevation of present populations is over 4500 m in the west and the equilibrium‐line of glaciers in the LGM was 500–300 m lower than present in the major interior part of the plateau suggesting that at most sites in the west, LGM microrefugia of H. tibetana may have been above 4000 m above sea level, the highest of all known refugia. Moreover, the divergence times among and within the three lineages and their distinct distributions as well as dispersal barriers support the theory of the recent and rapid uplift of the QTP. The rapid uplift of the plateau within the last 3.4 Ma and the associated environmental changes may have affected the dispersal and differentiation of H .tibetana and shaped its phylogeographic structure. 相似文献
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