共查询到20条相似文献,搜索用时 15 毫秒
1.
Background
Faculty perception of student knowledge and acceptance of subject matter affects the choice of what to teach and how to teach it. Accurate assessment of student acceptance of evolution, then, is relevant to how the subject should be taught. To explore the accuracy of such assessment, we compared how community college instructors of life sciences courses perceive students’ attitudes towards evolution with those students’ actual attitudes towards evolution.Results
The research had two components: (1) a survey of students of several biology classes at a community college about their acceptance of evolutionary theory and (2) interviews with the biology faculty teaching those classes about their perceptions of their students’ attitudes towards evolution. Results of the study indicate relatively high levels of acceptance of evolution among community college students at this West Coast institution. We also found that community college instructors of life sciences courses varied in accuracy of their perceptions of their students’ attitudes towards evolution–but not systematically. Although one professor assessed each class quite accurately, the other two professors frequently underestimated the acceptance of evolution among their students.Conclusions
Errors in perception seemed independent of whether the class was composed of majors, nonmajors, or a combination. Clearly, in our sample there is much idiosyncrasy regarding community college instructor accuracy concerning student opinions about evolution.2.
Oksanen L 《Trends in ecology & evolution》1991,6(9):294-296
Much of the apparent progress in community ecology amounts to little more than re-inventing the wheel, albeit with technical improvements. Many central ideas in the field were stated by A.K. Cajander at the turn of the century. Thereafter, community ecology has moved back and forth between competition-centered and individualistic views of community structure. The chief problems have probably been inappropriate methodology (lack of rigorous formulation and/or critical experimental testing of theories) and a tendency to work only on subcommunities that are delimited by taxonomic criteria. Although these problems are beginning to be remedied, a new one has emerged: ignorance of history and a tendency to re-invent old ideas under new, flashy names. This problem is potentially as dangerous as the old ones and must be tackled by improving our first-hand contact with the classics in our field. 相似文献
3.
S. Sendacz 《Hydrobiologia》1984,113(1):121-127
The composition of the zooplankton of the Billings Reservoir and its variation in an eutrophic environment, subject to frequent blooms of algae (chiefly Cyanophyceae) was studied during one year (from October, 1977 to September, 1978) in two stations in the littoral and in the limnetic zone.The zooplankton community in the limnetic zone was dominated by cyclopoid copepods (Thermocyclops crassus and Metacyclops mendocinus) and by rotifers (Brachionus, Polyarthra and others) which represented, respectively 38.5 and 35.5% of the total zooplankton. At the littoral zone, cyclopoids were the most abundant (42.3%).The cladocerans were the least significant group at both stations, and calanoid copepods were found only at the littoral zone.A higher production of small filtrators, such as rotifers, cyclopoid nauplii and Bosmina sp was observed. 相似文献
4.
Ethno-religious community organizations in Western countries have often been described as being disconnected from mainstream society, and Muslim community groups have been a special focus of such critique. This article offers a counter-narrative to these widespread allegations. It draws on a synthesis of emerging research on the citizenship-enhancing effects of mosque involvement and on an explorative study involving thirty in-depth interviews with civically active Muslims in Australia and Germany. The article examines the potential of Muslim community organizations to mobilize their member into performing their citizenship through civic and political participation. It offers empirical evidence that many Muslim community organizations, rather than promoting social segregation, act as accessible entry point for Muslims’ civic participation, facilitate cross-community engagement and provide gateways to political involvement. These civic potentials of Muslim community organization have remained underestimated in the public and political discourse on cohesive societies and healthy democracies. 相似文献
5.
1. Phytoplankton, zooplankton and grazing were monitored throughout the growing season for three years (1994–96) in the Belgian section of the River Meuse.
2. A size structure analysis of the algal community shows that there was a summer shift toward larger algal units, following a decline in phytoplankton biomass. These changes occurred after an increase in zooplankton biomass and diversity.
3. Daily filtration rates of grazers ranged from 1 to 113% day–1 and maxima were observed during the summer period. Higher rates tended to correspond with peaks of rotifer biomass. A decline in total phytoplankton biomass within two weeks followed the increase in zooplankton biomass and filtration rate. A rapid biomass recovery was then observed, along with a shift of the algal community toward larger units. When grazing activity was not sustained, due to zooplankton fluctuations, the change in phytoplankton size structure was less marked.
4. We suggest that the composition of the phytoplankton community of large rivers may at times be controlled by grazers. However, such biotic interactions can take place only when physical constraints are reduced, i.e. when discharge is low, and when increased transfer time, high temperature and availability of grazeable algae allow high zooplankton biomass. 相似文献
2. A size structure analysis of the algal community shows that there was a summer shift toward larger algal units, following a decline in phytoplankton biomass. These changes occurred after an increase in zooplankton biomass and diversity.
3. Daily filtration rates of grazers ranged from 1 to 113% day
4. We suggest that the composition of the phytoplankton community of large rivers may at times be controlled by grazers. However, such biotic interactions can take place only when physical constraints are reduced, i.e. when discharge is low, and when increased transfer time, high temperature and availability of grazeable algae allow high zooplankton biomass. 相似文献
6.
The structure of the plankton community of the Öregrundsgrepen (southwest Bothnian Sea) 总被引:1,自引:0,他引:1
Taxonomic composition and variations in density and biomass of the plankton community in the Öregrundsgrepen, a shallow coastal area, were investigated from June 1972 to November 1973. The phytoplankton biomass was large in spring but small during the rest of the year. The spring bloom was dominated by diatoms and dinoflagellates, especially byThalassiosira spp. which were also important during other seasons. Small forms, such asCryptomonas spp.,Rhodomonas spp. and monads, dominated during summer. Blue-green algae were never of any major importance. During the summer, the trophogenic layer exceeded 10 m in thickness. The metazoan fauna was of lower diversity than the plankton flora. The dominating species, the copepodsAcartia bifilosa andEurytemora affinis, constituted on the average 83% of the standing crop. The low salinities, 5–6 S, were regarded as the principal pertinent limiting factor. The metazoan fauna reached large biomass values from July to October. The protozoan fauna (in the case of ciliates), obtained biomass maxima during the spring bloom. It is suggested that the Öregrundsgrepen represents an area of elevated productivity within a region of low overall production, presumably due to local upwelling. From June 1972 to May 1973, the average biomasses were: phytoplankton 0.464 g C m–2, ciliates 0.040 g C m–2, copepod nauplii 0.010 g C m–2, micro-rotifers 0.004 g C m–2, and mesozooplankton (larger than 0.2 mm) 0.312 g C m–2. It is estimated that about than 60% of the phytoplankton production is consumed by the microzooplankton (<0.2 mm). 相似文献
7.
8.
In a previous study, we showed that the geographic proximity of hybrid plants to the allopatric areas of parental species
increases their morphological and genetic similarity with them. In the present work, we explored whether the endophagous fauna
of hybrid plants show the same pattern. We studied the canopy species richness, diversity and composition of leaf-mining moths
(Lepidoptera: Tischeridae, Citheraniidae) and gall-forming wasps (Hymenoptera: Cynipidae) associated with two species of red
oaks (Quercus crassifolia and Quercus crassipes) and their interspecific hybrid (Quercus×dysophylla Benth pro sp.) in seven hybrid zones in central Mexico, during four seasons in 2 years. The study was conducted on 194 oak
trees with known genetic status [identified by leaf morphology and molecular markers (random amplified polymorphic DNAs)],
and the results indicate a bidirectional pattern of gene flow. Hybrid plants supported intermediate levels of infestation
of gall-forming and leaf-mining insects compared to their putative parental species. The infestation level of leaf-mining
insects varied significantly following the pattern: Q. crassifolia>hybrids>Q. crassipes, whereas the gall-forming insects showed an inverse pattern. A negative and significant relationship was found between these
two types of insect guilds in each host taxa, when the infestation percentage was evaluated. It was found that 31.5% (n=11) of the endophagous insects were specific to Q. crassipes, 22.9% (n=8) to Q. crassifolia, and 8.6% (n=3) to hybrid individuals. The hybrid bridge hypothesis was supported in the case of 25.7% (n=9) of insects, which suggests that the presence of a hybrid intermediary plant may favor a host herbivore shift from one
plant species to another. Greater genetic diversity in a hybrid zone is associated with greater diversity in the endophagous
community. The geographic proximity of hybrid plants to the allopatric site of a parental species increases their similarity
in terms of endophagous insects and the Eje Neovolcánico acts as a corridor favoring this pattern.
Electronic Supplementary Material Supplementary material is available for this article at 相似文献
9.
《Acta Oecologica》2004,25(1-2):61-65
A desirable property of a diversity index is the so-called sum property. For a diversity index that possesses the sum property, such as species richness N, Shannon’s entropy H or Simpson’s index 1/D, the community diversity is decomposable into species-level patterns and the sum of single species diversities gives the pooled diversity of the species collection. In this paper, parametric diversity of type α is used to quantify how fertilizer applied to soil affects the relative contribution of species endemic or preferential to serpentine soils within a garigue plant community in Tuscany (Italy). Soil fertilizer significantly improved the biomass production of the original species pool without any significant colonization by alien species. However, the major biomass increments were experienced by species that are not exclusive to serpentine soils. In this view, the reduced abundance of species endemic or preferential to serpentine soils can be interpreted as a loss of ‘ecological quality’ of the analyzed community. 相似文献
10.
Electrokinetic remediation and microbial community shift of β-cyclodextrin-dissolved petroleum hydrocarbon-contaminated soil 总被引:1,自引:0,他引:1
Electrokinetic (EK) migration of β-cyclodextrin (β-CD), which is inclusive of total petroleum hydrocarbon (TPH), is an economically
beneficial and environmentally friendly remediation process for oil-contaminated soils. Remediation studies of oil-contaminated
soils generally prepared samples using particular TPHs. This study investigates the removal of TPHs from, and electromigration
of microbial cells in field samples via EK remediation. Both TPH content and soil respiration declined after the EK remediation
process. The strains in the original soil sample included Bacillus sp., Sporosarcina sp., Beta proteobacterium, Streptomyces sp., Pontibacter sp., Azorhizobium sp., Taxeobacter sp., and Williamsia sp. Electromigration of microbial cells reduced the biodiversity of the microbial community in soil following EK remediation.
At 200 V m−1 for 10 days, 36% TPH was removed, with a small population of microbial cells flushed out, demonstrating that EK remediation
is effective for the present oil-contaminated soils collected in field. 相似文献
11.
There has been a recent revival in attempts to understand changes in patterns of abundance of Plasmodium spp. that infect humans. This has been driven by the purportedly beneficial effects of co-infection on clinical pathology and the recognition of Plasmodium vivax as a public health problem in its own right. In contrast to the attention given to mixed-species infections in humans, parasite infections and interactions within the mosquito vector remain poorly documented, even though the distribution of vector-borne parasites such as Plasmodium spp. depends on vector-vertebrate and, crucially, vector-parasite interactions. To understand malaria epidemiology and to design appropriate control measures, this gap must be re-addressed. 相似文献
12.
13.
The effects of community dynamics in birds on the optimisation of their migratory strategies is a neglected area. For three years, we captured migrating warblers on autumn passage at a coastal site in western Britain. We used canonical correspondence analysis (CCA) to assess spatio‐temporal patterns of occurrence, and principal components analysis (PCA) to assess morphological variation. We calculated Euclidean distance in ordination and morphological space to assess separation between species pairs, and used Monte‐Carlo simulations to assess the probability of pattern occurring by chance. Ordination revealed five species‐groups separated by habitat type and time of passage. Reed Warbler Acrocephalus scirpaceus and Sedge Warbler A. schoenobaenus (Group 1) occurred in wet habitats and peaked simultaneously. In drier habitats with scrub, a first wave of Blackcap Sylvia atricapilla (Group 2) significantly preceded Grasshopper Warbler Locustella naevia, Willow Warbler Phylloscopus trochilus, Whitethroat Sylvia communis and Lesser Whitethroat Sylvia curruca (Group 3), which in all but one case (Lesser Whitethroat) significantly preceded Garden Warbler Sylvia borin (Group 4); peak numbers of Chiffchaffs Phylloscopus collybita and a second wave of Blackcaps (Group 5) occurred later still. Age effects were found only in Acrocephalus, with adults peaking before juveniles. For seven out of eight pairings within genera, separation in time of passage increased significantly in species that were morphologically similar. The only exception was Blackcap and Lesser Whitethroat which differed substantially in both passage time and morphology. Monte‐Carlo simulations showed that chance was unlikely to be responsible for ordination patterns, nor for inter‐specific variation in passage time and its relationship with species morphology. These data provide annually consistent evidence that migrating sylviid warblers are separated ecologically by habitat use, time of passage and morphology: we cannot refute the hypothesis that community dynamics have influenced niche use and autumn migratory strategy. We call for further tests of the ‘migrant interaction’ hypothesis in other geographical locations and taxa, particularly where migrants are allopatric and interact ecologically only on migration. 相似文献
14.
15.
Kevin Liautaud Egbert H. van Nes Matthieu Barbier Marten Scheffer Michel Loreau 《Ecology letters》2019,22(8):1243-1252
The question whether communities should be viewed as superorganisms or loose collections of individual species has been the subject of a long‐standing debate in ecology. Each view implies different spatiotemporal community patterns. Along spatial environmental gradients, the organismic view predicts that species turnover is discontinuous, with sharp boundaries between communities, while the individualistic view predicts gradual changes in species composition. Using a spatially explicit multispecies competition model, we show that organismic and individualistic forms of community organisation are two limiting cases along a continuum of outcomes. A high variance of competition strength leads to the emergence of organism‐like communities due to the presence of alternative stable states, while weak and uniform interactions induce gradual changes in species composition. Dispersal can play a confounding role in these patterns. Our work highlights the critical importance of considering species interactions to understand and predict the responses of species and communities to environmental changes. 相似文献
16.
This study investigates whether the process of pressing and drying a macrophyte host affects community structure and composition of epiphytic diatom communities. Epiphytic diatoms on submerged macrophytes from carbonate rivers and streams in southern Bavaria, Germany were sampled in order to study community structure and composition. Simultaneously, a specimen of the submerged macrophyte was taken to create a collection of dried plants. After 6months of preservation, diatom samples were taken from the herbarium macrophytes. Detrended correspondence analysis, diversity and evenness results indicate that recent and dried communities are indistinguishable. These results suggest that epiphytic diatom communities sampled from historic herbarium macrophytes can be utilised as bioindicators to assess former water quality. 相似文献
17.
Gao Lin Liu Xin-min Du Yong-mei Zong Hao Shen Guo-ming 《Annals of microbiology》2019,69(13):1531-1536
A reasonable cultivation pattern is beneficial to maintain soil microbial activity and optimize the structure of the soil microbial community. To determine the effect of tobacco−peanut (Nicotiana tabacum−Arachis hypogaea) relay intercropping on the microbial community structure in soil, we compared the effects of relay intercropping and continuous cropping on the soil bacteria community structure. We collected soil samples from three different cropping patterns and analyzed microbial community structure and diversity using high-throughput sequencing technology. The number of operational taxonomic units (OTU) for bacterial species in the soil was maximal under continuous peanut cropping. At the phylum level, the main bacteria identified in soil were Proteobacteria, Actinobacteria, and Acidobacteria, which accounted for approximately 70% of the total. The proportions of Actinobacteria and Firmicutes increased, whereas the proportion of Proteobacteria decreased in soil with tobacco–peanut relay intercropping. Moreover, the proportions of Firmicutes and Proteobacteria among the soil bacteria further shifted over time with tobacco–peanut relay intercropping. At the genus level, the proportions of Bacillus and Lactococcus increased in soil with tobacco–peanut relay intercropping. The community structure of soil bacteria differed considerably with tobacco–peanut relay intercropping from that detected under peanut continuous cropping, and the proportions of beneficial bacteria (the phyla Actinobacteria and Firmicutes, and the genera Bacillus and Lactococcus) increased while the proportion of potentially pathogenic bacteria (the genera Variibacter and Burkholderia) decreased. These results provide a basis for adopting tobacco–peanut relay intercropping to improve soil ecology and microorganisms, while making better use of limited cultivable land. 相似文献
18.
Wuchang Zhang Danling Tang Bo Yang Shangwu Gao Jun Sun Zhencheng Tao Song Sun Xiuren Ning 《Hydrobiologia》2009,630(1):257-269
Previous studies which have tested the feeding preferences of shredders for fungal species and the food quality of fungi used
detritus uniformly colonized by a fungus, which is not the case for decaying leaves in streams. It is not known whether shredders
in different development stages exhibit variations in feeding preference and larval performance. This study examined the feeding
preferences and the growth of the third and the fifth instars of Pycnopsyche gentilis larvae using fungal-colonized patches and whole leaves, respectively, having different fungal species compositions (Alatospora acuminata, Anguillospora filiformis, Articulospora tetracladia, Tetrachaetum elegans, and all species combined). The aquatic hyphomycetes used were co-dominant on leaves in the stream inhabited by the caddisfly.
During 14 d of feeding, the larvae of both instars did not show significant differences in feeding preferences for the patches
growing on oak leaves, although the third instar larvae were slightly more selective than the fifth instar larvae. When fed
with maple leaves for 18 d, larval growth rates, gross growth efficiencies, and survivorship were not significantly different
among the fungal treatments. However, the larval growth of both instars fed with fungal-colonized leaves was always significantly
greater than the growth of larvae fed with diets of uncolonized leaves. The third instar larvae grew faster than the fifth
instar larvae, but the growth efficiencies of the two instars were similar. These results suggest that P. gentilis larvae exhibit less selectivity in their feeding than other caddisfly shredders that have been examined and that the dominant
fungi colonizing leaves in their habitat are similar in palatability and food quality for this shredder.
Handling editor: B. Oertli 相似文献
19.
O. N. Pavlyuk Yu. A. Trebukhova L. S. Belogurova 《Russian Journal of Marine Biology》2007,33(4):213-221
The effect of the Razdol’naya River on the littoral and sublittoral nematode community was studied in the innermost part of the Amursky Bay. Thanks to the seasonal abundance of juveniles of macrobenthic animals, pseudomacrobenthic species prevailed in the meiobenthos littoral community. Juvenile amphipods dominated (39.5%), the percentage of nematodes was 18.4% (45 species). The nematodes dominated in the meiobenthos community (65.7%, 71 species) at the sublittoral zone. The similarity of the species structure of littoral and sublittoral nematodes reached 36.5%. Low population density (2.6±1.7 thousand ind/m2) and poor species diversity of nematodes (7 species), the dominating form being Oncholaimium paraolium, were recorded at the littoral zone, which was subjected to direct riverine influence (1‰salinity). The correlation analysis revealed no relationship between salinity and population density of nematodes at the littoral zone. At the sublittoral zone (at stations of salinity less than 2.85‰) the parameters of population density (73.9±32.3 thousand ind/m2) and species diversity (12 species) of nematodes were the lowest, Parodontophora timmica dominated. A poor expressed dependence between the density of nematode populations and salinity was revealed. The correlation between the average size of ground particles and population density of nematodes was recorded. The greatest similarity of the species structure of littoral and sublittoral nematodes (26.67%) was recorded on gravel-sand bottoms. 相似文献