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21.
The genitalia of internally fertilizing animals are among the most diverse of all sexual characters. It is currently argued
that genitalia evolve rapidly and divergently due to intense post-copulatory sexual selection. If true, male genital morphology
should be subject to directional selection, whereby males with particular genital morphologies achieve greater paternity success.
There is mounting evidence that male genital morphology can influence competitive fertilization success; however, the form
of selection acting on genitalia has rarely been explored. We conducted competitive fertilization experiments using Antichiropus variabilis millipedes. Using microsatellite loci, we determined the paternity of offspring following double matings. The last male to
mate had a significant paternity advantage. While no aspect of the behavior of last males was correlated with paternity success,
variation in genital morphology did account for variation in last male paternity. Male genitalia were subject to nonlinear
selection, with both convex (stabilizing) selection and concave (disruptive) selection acting on genital shape. This is the
first study to provide evidence for sperm precedence in a millipede and only the second to document the form of post-copulatory
sexual selection operating on male genital morphology. We discuss the implications of our results for the evolution of genitalia
in A. variabilis and, more broadly, how our findings relate to alternative theories of genital evolution. 相似文献
22.
Theresa M. Marteau Irma Nippert Sue Hall Caroline Limbert Margaret Reid Martin Bobrow Alan Cameron Martina Cornel Mariet van Diem Bernd Eiben Sixto García-Miñaur Janine Goujard Donna Kirwan Karen McIntosh Peter Soothill Corien Verschuuren-Bemelmans Catherine de Vigan Stephen Walkinshaw Lenore Abramsky Frank Louwen Peter Miny Jürgen Horst 《黑龙江环境通报》2002,22(7):562-566
23.
Janine Martinazzo Daniela K. Muenchen Alexandra N. Brezolin Alana M. Cezaro Aline A. Rigo Alexandra Manzoli 《Journal of environmental science and health. Part. B》2018,53(4):229-236
The aim of this study was to develop a cantilever nanobiosensor for atrazine detection in liquid medium by immobilising the biological recognition element (tyrosinase vegetal extract) on its surface with self-assembled monolayers using gold, 16-mercaptohexadecanoic acid, 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/n-hydroxysuccinimide. Cantilever nanobiosensors presented a surface compression tension increase when atrazine concentrations were increased, with a limit of detection and limit of quantification of 7.754 ppb (parts per billion) and 22.792 ppb, respectively. From the voltage results obtained, the evaluation of atrazine contamination in river and drinking water were very close to those of the reference sample and ultrapure water, demonstrating the ability of the cantilever nanobiosensor to distinguish different water samples and different concentrations of atrazine. Cantilever nanosensor surface functionalization was characterised by combining polarisation modulation infrared reflection-absorption spectroscopy and atomic force microscopy and indicating film thickness in nanometric scale (80.2 ± 0.4 nm). Thus, the cantilever nanobiosensor developed for this study using low cost tyrosinase vegetal extract was adequate for atrazine detection, a potential tool in the environmental field. 相似文献
24.
Hierarchical spatial point process analysis for a plant community with high biodiversity 总被引:1,自引:0,他引:1
Janine B. Illian Jesper Møller Rasmus P. Waagepetersen 《Environmental and Ecological Statistics》2009,16(3):389-405
A complex multivariate spatial point pattern of a plant community with high biodiversity is modelled using a hierarchical
multivariate point process model. In the model, interactions between plants with different post-fire regeneration strategies
are of key interest. We consider initially a maximum likelihood approach to inference where problems arise due to unknown
interaction radii for the plants. We next demonstrate that a Bayesian approach provides a flexible framework for incorporating
prior information concerning the interaction radii. From an ecological perspective, we are able both to confirm existing knowledge
on species’ interactions and to generate new biological questions and hypotheses on species’ interactions.
相似文献
Rasmus P. WaagepetersenEmail: |
25.
The effects of ultraviolet radiation (UVR), desiccation and conditions in tidal pools on embryonic survival were examined
for two common pulmonate limpets that lay intertidal benthic egg masses on rocky shores in New Zealand: Benhamina obliquata and Siphonaria australis. Field surveys and manipulative experiments were conducted between December 2006 and September 2007 in the Wellington region
of New Zealand (41°17′S, 174°47′E). Egg mass deposition sites in the field were species-specific: B. obliquata deposited eggs primarily in shaded crevices, whereas S. australis predominantly deposited egg masses in the sun and in tidal pools. For both species, however, embryonic mortality was greater
in egg masses that had been in full sun compared to shade. For S. australis, there was also high mortality in egg masses in tidal pools or desiccated compared to those that remained submerged in flowing
seawater at low tide. In outdoor experiments, embryonic mortality was also always greatest for egg masses exposed to full
sun, and lowest for those in shaded treatments. Mortality was also higher if egg masses were in simulated tidal pools, and
for S. australis, if desiccated, compared to those submerged in flowing seawater. Periods of particularly sunny conditions with high temperatures
also resulted in higher overall mortality. Finally, egg masses of both species that were initially deposited in the shade had greater mortality in response to subsequent
UV exposure compared to egg masses initially deposited in full sun. Results from this study suggest that the egg masses of
these two species are highly vulnerable to UVR, as well as other intertidal stressors. Embryos of both of these species may
be at risk of high mortality particularly during summer when extreme conditions of UV intensity and high temperature coincide
with low tide cycles.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
26.
Microbial breakthrough curves of 12 soils, generated by the application of dairy shed effluent followed by continuous artificial rainfall for one pore volume at 5 mm h(-1) onto large undisturbed soil cores, have been ranked as high, medium, or low potential for microbial bypass flow. The ranking is based on the position of the peak in the breakthrough curve. Knowledge of soil properties that affect microbial transport through soil gained from the microbial breakthrough curves was linked to soil classes, or to their accessory properties, of the New Zealand Soil Classification. Spatial depiction of the ratings has been achieved via the national 1:50,000 scale soil map. Soils with a drainage impediment or those with well developed soil structure have a high potential for microbial bypass flow, whereas soils from tephra and Recent Soils with less developed, porous, soil structure have a low potential for microbial bypass flow. The risk rankings should be considered as maxima because management may change some rankings. 相似文献
27.
Research on environmental activism remains poorly integrated and ill-defined and to date, there has been little examination of the relationship of environmental activism, pro-environmental behaviour and social identity. 131 students from an Australian University (M = 25.04 years old, SD = 8.17) voluntarily participated by returning an anonymous questionnaire containing an environmental activism scale, a pro-environmental behaviour scale and a social identity scale. The results revealed that while there was a significant relationship between social identity and environmental behaviour, only the citizenship component of environmental behaviour significantly predicted environmental activism. In other words, the relationship between social identity and environmental activism was indirect. This research presents the opportunity for further exploration of these relationships and to further investigate their relationship to inter-group processes. 相似文献
28.
Landscape multifunctionality: a powerful concept to identify effects of environmental change 总被引:2,自引:0,他引:2
Janine Bolliger Michèle Bättig Justus Gallati Andreas Kläy Michael Stauffacher Felix Kienast 《Regional Environmental Change》2011,11(1):203-206
The interdisciplinary concept of landscape multifunctionality provides a suitable platform to combine or disentangle effects
of multiple environmental stressors acting on the landscape. The concept allows mapping of trade-offs, synergies, and priority
conflicts between individual landscape functions, thus providing easily accessible, hands-on means to communicate findings
of environmental research to decision makers and society. This rapid communication provides an overview of current developments
and potential future research avenues in landscape multifunctionality. 相似文献
29.
Timber harvest transforms ecological roles of salmon in southeast Alaska rain forest streams 总被引:1,自引:0,他引:1
Scott D Tiegs Dominic T Chaloner Peter Levi Janine Rüegg Jennifer L Tank Gary A Lamberti 《Ecological applications》2008,18(1):4-11
Although species commonly modify habitats and thereby influence ecosystem structure and function, the factors governing the ecological importance of these modifications are not well understood. Pacific salmon have repeatedly been shown to positively influence the abundance of benthic biota by annually transferring large quantities of nutrients from marine systems to the nutrient-poor freshwaters in which they spawn. Conversely, other studies have demonstrated that salmon can negatively influence the abundance of freshwater biota, an effect attributed to bioturbation during upstream migration and nest construction. The factors determining which of these contrasting ecological effects predominates are unknown, including how human activities, such as land use, influence ecological responses to salmon. We sampled a key basal food resource, sediment biofilm, in seven southeast Alaskan streams impacted to varying degrees by timber harvest. Biofilm abundance (measured as chlorophyll a and ash-free dry mass) was positively related to timber-harvest intensity prior to salmon arrival. However, during the salmon run, an inverse relationship emerged of more abundant biofilm in less-harvested watersheds. Among-stream variability in biofilm response to salmon was largely explained by sediment particle size, which was larger in less-harvested watersheds. Collectively, these results suggest that, by altering stream sediment size, timber harvest transformed the dominant effect of salmon from nutrient enrichment to physical disturbance, thus modifying nutrient linkages between marine and freshwater ecosystems. 相似文献
30.
Janine M. Castro Philip L. Jackson 《Journal of the American Water Resources Association》2001,37(5):1249-1262
ABSTRACT: The model bankfull discharge recurrence interval (annual series) (Ta) in streams has been approximated at a 1.5‐year flow event. This study tests the linkage between regional factors (climate, physiography, and ecoregion) and the frequency of bank‐full discharge events in the Pacific Northwest (PNW). Patterns of Ta were found to be significant when stratified by EPA Ecoregion. The mean value for Ta in the PNW is 1.4 years; however, when the data is stratified by ecoregion, the humid areas of western Oregon and Washington have a mean value of 1.2 years, while the dryer areas of Idaho and eastern Oregon and Washington have a mean value of 1.4 to 1.5 years. Among the four factors evaluated, vegetation association and average annual precipitation are the primary factors related to channel form and Ta. Based on the results of the Ta analyses, regional hydraulic geometry relationships of streams were developed for the PNW, which relate variables, such as bank‐full cross‐sectional area, width, depth, and velocity, to bankfull discharge and drainage area. The verification of Ta values, combined with the development of regional hydraulic geometry relationships, provides geographically relevant information that will result in more accurate estimates of hydraulic geometry variables in the PNW. 相似文献