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61.
Many animals have color vision systems that are well suited to their local environments. Changes in color vision can occur over long periods (evolutionary time), or over relatively short periods such as during development. A select few animals, including stomatopod crustaceans, are able to adjust their systems of color vision directly in response to varying environmental stimuli. Recently, it has been shown that juveniles of some stomatopod species that inhabit a range of depths can spectrally tune their color vision to local light conditions through spectral changes in filters contained in specialized photoreceptors. The present study quantifies the potential for spectral tuning in adults of three species of Caribbean Neogonodactylus stomatopods that differ in their depth ranges to assess how ecology and evolutionary history influence the expression of phenotypically plastic color vision in adult stomatopods. After 12 weeks in either a full-spectrum “white” or a narrow-spectrum “blue” light treatment, each of the three species evidenced distinctive tuning abilities with respect to the light environment that could be related to its natural depth range. A molecular phylogeny generated using mitochondrial cytochrome oxidase C subunit 1 (CO-1) was used to determine whether tuning abilities were phylogenetically or ecologically constrained. Although the sister taxa Neogonodactylus wennerae and N. bredini both exhibited spectral tuning, their ecology (i.e. preferred depth range) strongly influenced the expression of the phenotypically plastic color vision trait. Our results indicate that adult stomatopods have evolved the ability to undergo habitat-specific spectral tuning, allowing rapid facultative physiological modification to suit ecological constraints. 相似文献
62.
Estimation of population size has traditionally been viewed from a finite population sampling perspective. Typically, the
objective is to obtain an estimate of the total population count of individuals within some region. Often, some stratification
scheme is used to estimate counts on subregions, whereby the total count is obtained by aggregation with weights, say, proportional
to the areas of the subregions.
We offer an alternative to the finite population sampling approach for estimating population size. The method does not require
that the subregions on which counts are available form a complete partition of the region of interest. In fact, we envision
counts coming from areal units that are small relative to the entire study region and that the total area sampled is a very
small proportion of the total study area. In extrapolating to the entire region, we might benefit from assuming that there
is spatial structure to the counts. We implement this by modeling the intensity surface as a realization from a spatially
correlated random process. In the case of multiple population or species counts, we use the linear model of coregionalization
to specify a multivariate process which provides associated intensity surfaces hence association between counts within and
across areal units.
We illustrate the method of population size estimation with simulated data and with tree counts from a Southwestern pinyon-juniper
woodland data set. 相似文献
63.
This study is based on the theses that
- early diagnosis is indispensable in the context of precautionary policy for the management of environmental problems which have the character of a “creeping disaster” and that
- the public must play the active role that is adequate within a democratic society. In the context of the study, three existing advisory committees for environmental policy as well as two concepts which have not been put into effect are investigated.
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Hepatitis E Virus in Farmed Rabbits,Wild Rabbits and Petting Farm Rabbits in the Netherlands 总被引:1,自引:0,他引:1
Sara?A.?BurtEmail author Jorg?Veltman Renate?Hakze-van der Honing Heike?Schmitt Wim?H.?M.?van der?Poel 《Food and environmental virology》2016,8(3):227-229
Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates. Dutch rabbits are unlikely to be a zoonotic source. 相似文献
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