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151.
We address the question why papers dealing with the ecology of primates are so sparsely represented in the general ecological literature. A literature analyses based on entries in Web of Science and PrimateLit reveals that despite a large number of papers published on primates in general and on the ecology of primates, only a very small fraction of these papers is published in high-ranking international ecological journals. We discuss a number of potential reasons for the disproportion and highlight the problems associated with experimental research on wild primates and constraints on sample size as major issues. 相似文献
152.
To evaluate the conservation status of a species or population it is necessary to gain insight into its ecological requirements, reproduction, genetic population structure, and overall genetic diversity. In our study we examined the genetic diversity of Rhinopithecus brelichi by analyzing microsatellite data and compared them with already existing data derived from mitochondrial DNA, which revealed that R. brelichi exhibits the lowest mitochondrial diversity of all so far studied Rhinopithecus species. In contrast, the genetic diversity of nuclear DNA is high and comparable to other Rhinopithecus species, i.e. the examined microsatellite loci are similarly highly polymorphic as in other species of the genus. An explanation for these differences in mitochondrial and nuclear genetic diversity could be a male biased dispersal. Females most likely stay within their natal band and males migrate between bands, thus mitochondrial DNA will not be exchanged between bands but nuclear DNA via males. A Bayesian Skyline Plot based on mitochondrial DNA sequences shows a strong decrease of the female effective population size (Nef) starting about 3,500 to 4,000 years ago, which concurs with the increasing human population in the area and respective expansion of agriculture. Given that we found no indication for a loss of nuclear DNA diversity in R. brelichi it seems that this factor does not represent the most prominent conservation threat for the long-term survival of the species. Conservation efforts should therefore focus more on immediate threats such as development of tourism and habitat destruction. 相似文献
153.
Knut Finstermeier Dietmar Zinner Markus Brameier Matthias Meyer Eva Kreuz Michael Hofreiter Christian Roos 《PloS one》2013,8(7)
Primates, the mammalian order including our own species, comprise 480 species in 78 genera. Thus, they represent the third largest of the 18 orders of eutherian mammals. Although recent phylogenetic studies on primates are increasingly built on molecular datasets, most of these studies have focused on taxonomic subgroups within the order. Complete mitochondrial (mt) genomes have proven to be extremely useful in deciphering within-order relationships even up to deep nodes. Using 454 sequencing, we sequenced 32 new complete mt genomes adding 20 previously not represented genera to the phylogenetic reconstruction of the primate tree. With 13 new sequences, the number of complete mt genomes within the parvorder Platyrrhini was widely extended, resulting in a largely resolved branching pattern among New World monkey families. We added 10 new Strepsirrhini mt genomes to the 15 previously available ones, thus almost doubling the number of mt genomes within this clade. Our data allow precise date estimates of all nodes and offer new insights into primate evolution. One major result is a relatively young date for the most recent common ancestor of all living primates which was estimated to 66-69 million years ago, suggesting that the divergence of extant primates started close to the K/T-boundary. Although some relationships remain unclear, the large number of mt genomes used allowed us to reconstruct a robust primate phylogeny which is largely in agreement with previous publications. Finally, we show that mt genomes are a useful tool for resolving primate phylogenetic relationships on various taxonomic levels. 相似文献
154.
1. In order to characterise phytoplankton patchiness at fine scales, a profiling multiwavelength fluorometer was cast at numerous locations throughout Winam Gulf in Lake Victoria to measure fluorescent excitation spectra, which are indicators of both phytoplankton diversity and coloured dissolved organic matter (CDOM). 2. Processing the spectral data with principal component analysis (PCA) revealed that linear combinations of four fundamental ‘base’ spectra could explain almost all of the variation in spectral measurements. Three of the base spectra were associated with spatially distinct patches of phytoplankton containing different species assemblages, while the fourth base spectrum was due to CDOM fluorescence. 3. The locations of the phytoplankton patches were traced to the south‐east of Winam Gulf, the western end of the Rusinga Channel and the open waters of Lake Victoria adjacent to Winam Gulf, respectively. The high CDOM fluorescence was traced mainly to relatively deep water in the Rusinga Channel. 4. The phytoplankton and CDOM patchiness were interpreted in the context of physical and chemical gradients that were measured at the site at the same scale as the spectral data. Strong relationships were found between the gradients in spectral data and other environmental variables, which suggested several underlying explanations for the phytoplankton and CDOM patchiness. 相似文献
155.
RUSSELL K. MONSON RYAN T. JONES TODD N. ROSENSTIEL JÖRG‐PETER SCHNITZLER 《Plant, cell & environment》2013,36(3):503-516
Isoprene (2‐methyl‐1,3‐butadiene) is emitted from many plants and it appears to have an adaptive role in protecting leaves from abiotic stress. However, only some species emit isoprene. Isoprene emission has appeared and been lost many times independently during the evolution of plants. As an example, our phylogenetic analysis shows that isoprene emission is likely ancestral within the family Fabaceae (= Leguminosae), but that it has been lost at least 16 times and secondarily gained at least 10 times through independent evolutionary events. Within the division Pteridophyta (ferns), we conservatively estimate that isoprene emissions have been gained five times and lost two times through independent evolutionary events. Within the genus Quercus (oaks), isoprene emissions have been lost from one clade, but replaced by a novel type of light‐dependent monoterpene emissions that uses the same metabolic pathways and substrates as isoprene emissions. This novel type of monoterpene emissions has appeared at least twice independently within Quercus, and has been lost from 9% of the individuals within a single population of Quercus suber. Gain and loss of gene function for isoprene synthase is possible through relatively few mutations. Thus, this trait appears frequently in lineages; but, once it appears, the time available for evolutionary radiation into environments that select for the trait is short relative to the time required for mutations capable of producing a non‐functional isoprene synthase gene. The high frequency of gains and losses of the trait and its heterogeneous taxonomic distribution in plants may be explained by the relatively few mutations necessary to produce or lose the isoprene synthase gene combined with the assumption that isoprene emission is advantageous in a narrow range of environments and phenotypes. 相似文献
156.
JÖRG MALETZ 《Palaeontology》2005,48(4):763-780
Abstract: Early Middle Ordovician graptolites from the Albjära and Lovisefred drill cores (Scania, southern Sweden) can be differentiated into the Isograptus victoriae , Isograptus sp. nov. 2 and Maeandrograptus schmalenseei , Arienigraptus dumosus type/ Pseudisograptus manubriatus biozones of Castlemainian and Yapeenian age and the Arienigraptus zhejiangensis and Undulograptus sinicus biozones of early Darriwilian age, replacing the old, long-ranging Didymograptus hirundo Biozone. Faunas from the drill cores include a number of species not previously recognized in Scandinavia. 相似文献
157.
Zinner SH 《The new microbiologica》2007,30(3):321-325
Antibiotics were initially viewed as "wonder drugs" primarily because they were introduced at a time when only surgical drainage or spontaneous cures were available to treat serious bacterial infections. During the five or six decades since their introduction, several classes of these drugs became available including sulfonamides and trimethoprim, penicillins, cephalosporins, chloramphenicol, tetracyclines, colimycins, macrolides, lincosamides, streptogramins, rifamycins, glycopeptides, aminoglycosides, fluoroquinolones, oxazolidinones, glycylglycines, lipoglycopeptides, and variations on these themes. Unfortunately, through a variety of mechanisms and perhaps as a result of their profligate use, many bacterial groups are exhibiting resistance to these antibiotics. At present, most bacterial infections can still be treated with available antibiotics used alone or in combination, but increasing numbers of clinical failures with the current armamentarium can be expected. Optimizing drug dosing and duration might help minimize the emergence of resistance in some situations. However, the future could look dim, as there are relatively few new agents on the horizon. A bold new look for antibacterial targets is needed. Surely our scientific abilities are up to this challenge. New approaches to antimicrobial chemotherapy are needed if we are to survive the increasing rates of antibiotic resistance predicted for the future. 相似文献
158.
Jenn M Croke Luke RG Pike Daniel J MacPhee 《Reproductive biology and endocrinology : RB&E》2007,5(1):22
Background
Myometrial growth and remodeling of the cytoskeleton and focal adhesions during late pregnancy may be critical aspects of myometrial activation and thus labour. Yet our understanding of these aspects is inhibited by the paucity of information concerning the components of focal adhesions in the myometrium. The focal adhesion protein hydrogen peroxide-inducible clone-5 (Hic-5) has recently been found in mononuclear smooth muscle but was not examined in the myometrium during pregnancy. Thus, the goal of this study was to characterize Hic-5 mRNA and protein expression in the rat myometrium during pregnancy and labour. 相似文献159.
Roos Christian Liedigk Rasmus Thinh Van Ngoc Nadler Tilo Zinner Dietmar 《International journal of primatology》2019,40(1):9-27
International Journal of Primatology - Hybridization among formerly separated lineages is a common phenomenon in almost all groups of organisms, including primates. Indicators of hybridization... 相似文献
160.
Cortés-Ortiz Liliana Roos Christian Zinner Dietmar 《International journal of primatology》2019,40(1):1-8
International Journal of Primatology - 相似文献