scholarly journals Attraction of Drosophila Buzzatii and D. Aldrichi to Species of Yeasts Isolated From their Natural Environment. I. Laboratory Experiments

1981 ◽  
Vol 34 (6) ◽  
pp. 593 ◽  
Author(s):  
JSF Barker ◽  
GJ Parker ◽  
GL Toll ◽  
PR Widders
Keyword(s):  
Natural Environment ◽  
Laboratory Experiments ◽  
Yeast Species ◽  
Multiple Choice ◽  
Drosophila Species ◽  
Drosophila Buzzatii

The attractiveness of yeast species isolated from rotting c1adodes of Opuntia inermis for adults of the cactophilic species D. buzzatii and D. aldrichi was determined by giving the flies a multiple choice of yeast species and counting the numbers on each yeast at regular intervals throughout 1 day in each of five experiments. Consistent effects implying behavioural differences between sexes, between immature and mature flies, and between the two Drosophila species were found. For immature flies of each species, there were significant differences in the numbers of flies attracted to each yeast, but preferences were more marked for females than for males.

Attraction of Larvae of Drosophila-Buzzatii and Drosophila-Aldrichi to Yeast Species Isolated From Their Natural-Environment

1988 ◽  
Vol 36 (1) ◽  
pp. 53 ◽  
Author(s):  
JSF Barker ◽  
DC Vacek ◽  
PD East
Keyword(s):  
Natural Environment ◽  
Yeast Species ◽  
Food Resource ◽  
Drosophila Species ◽  
Larval Feeding ◽  
Larval Food ◽  
Drosophila Buzzatii ◽  
Adult Females ◽  
Relative Attractiveness

The nine most common yeast species isolated from rots in cactus in Australia were shown to be differentially attractive to larvae, with relative attractiveness very similar for the two Drosophila species. To the extent that relative attractiveness measures larval feeding prefere~ces, there is no evidence for partitioning of the larval food resource between D. buzzatii and D. aldrichi. For D. buzzatii, the yeasts most attractive to larvae are also those preferred by adult females for feeding and oviposition.

Dispersal of an Insect Parasite Over a Small Plot

1958 ◽  
Vol 90 (5) ◽  
pp. 279-283 ◽  
Author(s):  
T. Burnett
Keyword(s):  
Natural Environment ◽  
Physical Environment ◽  
Laboratory Experiments ◽  
Meteorological Factors ◽  
Host Density ◽  
Insect Parasite ◽  
Small Plot

The relation of host density to reproduction of the chalcid parasite Dahlbominus fuscipennis (Zett.) was examined in a previous study (Burnett, 1954). When the parasite searched in a naturally varying physical environment for hosts–cocoons of sawflies that attack conifers–distributed over plots on a grass lawn, the influence of host density on parasitism was similar to that obtained in laboratory experiments. As the irregularities of the meteorological factors did not appreciably alter the relation of parasitism to host density it was of interest to determine whether the additional discontinuities of a natural environment would.

scholarly journals Metagenomic chromosome conformation capture (meta3C) unveils the diversity of chromosome organization in microorganisms

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Martial Marbouty ◽  
Axel Cournac ◽  
Jean-François Flot ◽  
Hervé Marie-Nelly ◽  
Julien Mozziconacci ◽  
...  
Keyword(s):  
Natural Environment ◽  
Yeast Species ◽  
Integrated Approach ◽  
Chromosome Conformation Capture ◽  
Microbial Populations ◽  
Individual Species ◽  
Chromosome Organization ◽  
Model Species ◽  
Chromosome Conformation ◽  
Genomic Analyses

Genomic analyses of microbial populations in their natural environment remain limited by the difficulty to assemble full genomes of individual species. Consequently, the chromosome organization of microorganisms has been investigated in a few model species, but the extent to which the features described can be generalized to other taxa remains unknown. Using controlled mixes of bacterial and yeast species, we developed meta3C, a metagenomic chromosome conformation capture approach that allows characterizing individual genomes and their average organization within a mix of organisms. Not only can meta3C be applied to species already sequenced, but a single meta3C library can be used for assembling, scaffolding and characterizing the tridimensional organization of unknown genomes. By applying meta3C to a semi-complex environmental sample, we confirmed its promising potential. Overall, this first meta3C study highlights the remarkable diversity of microorganisms chromosome organization, while providing an elegant and integrated approach to metagenomic analysis.

scholarly journals Genetic Architecture of Autosome-Mediated Hybrid Male Sterility in Drosophila

Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1169-1180
Author(s):  
Ignacio Marín
Keyword(s):  
Male Sterility ◽  
Genetic Architecture ◽  
Relative Size ◽  
Drosophila Species ◽  
Hybrid Male ◽  
Hybrid Male Sterility ◽  
Reciprocal Crosses ◽  
Drosophila Buzzatii ◽  
Number Of Factors ◽  
Two Factors

Abstract Several estimators have been developed for assesing the number of sterility factors in a chromosome based on the sizes of fertile and sterile introgressed fragments. Assuming that two factors are required for producing sterility, simulations show that one of these, twice the inverse of the relative size of the largest fertile fragment, provides good average approximations when as few as five fertile fragments are analyzed. The estimators have been used for deducing the number of factors from previous data on several pairs of species. A particular result contrasts with the authors' interpretations: instead of the high number of sterility factors suggested, only a few per autosome are estimated in both reciprocal crosses involving Drosophila buzzatii and D. koepferae. It has been possible to map these factors, between three and six per chromosome, in the autosomes 3 and 4 of these species. Out of 203 introgressions of different fragments or combinations of fragments, the outcome of at least 192 is explained by the mapped zones. These results suggest that autosome-mediated sterility in the male hybrids of these species is mediated by a few epistatic factors, similarly to X-mediated sterility in the hybrids of other Drosophila species.

Physical experiments in geomorphology

2021 ◽  
pp. M58-2021-3
Author(s):  
Michael Church
Keyword(s):  
Natural Environment ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Field Studies ◽  
Turn Of The Century ◽  
Critical Test ◽  
Wide Acceptance ◽  
Physical Experiments ◽  
Geomorphological Processes ◽  
Firm Evidence

AbstractAn experiment is a program of observations specially constructed to provide a critical test of theory or generalization about nature. It is designed to acquire firm evidence for or against the effect in question. Accordingly, it must be arranged to control all sources of variability contributing to the phenomena under examination save those it is intended to study. In the natural environment this is difficult to achieve. Consequently, classical geomorphology had no established tradition of experimentation. However, in the latter third of the 20th century, geomorphologists began to explore experimentation as a means to resolve questions that arise in the study of geomorphological processes. In the period 1976-84 an IGU commission on field experiments in geomorphology formally established an interest in the approach. Although few field studies before the turn of the century achieved experimental status, valuable experience was gained in laboratory experiments, scaled and unscaled, leading to present wide acceptance of experimentation as a means to approach questions about geomorphological processes.

scholarly journals Ecological aspects of the heritability of body size in Drosophila buzzatii.

Genetics ◽  
1989 ◽  
Vol 123 (4) ◽  
pp. 803-813 ◽  
Author(s):  
T Prout ◽  
J S Barker
Keyword(s):  
Emerging Adults ◽  
Natural Environment ◽  
Selection Response ◽  
Stabilizing Selection ◽  
Environment Interaction ◽  
Thorax Length ◽  
Laboratory Environment ◽  
Drosophila Buzzatii ◽  
Genotype Environment Interaction ◽  
Ecological Aspects

Abstract The heritability of thorax length in the cactophilic Drosophila buzzatii was determined for flies from each of 10 rotting cactus cladodes. For each rot, emerging flies were used as parents of progeny reared in the laboratory. The methods used were full sib analysis with the parents mated assortatively and also offspring-parent regression. From this, heritabilities were measured for the laboratory environment and for the natural environment of the rotting cladode. For the laboratory environment, h2 = 0.3770 +/- 0.0203 and for the natural environment h2 = 0.0936 +/- 0.0087 within rots and h2 = 0.0595 +/- 0.0123 for a population drawn randomly from different rots. Because of the possibility of genotype-environment interaction between the laboratory and rot environments, the methods of B. Riska, T. Prout and M. Turelli were used to show it is possible that there is no such interaction, but if there is, the above natural heritabilities are approximate lower bounds. These results are related to the general problem of determining heritabilities in nature where it is impractical to measure both parents and progeny in nature. Determining heritability not only in nature but in relation to subdivision into ephemeral patches (cladodes in this case) has an important bearing on natural selection response and to general theories of stabilizing selection proposed to explain the existence of genetic variation. Attempts were made to detect selection by using the size of emerging adults as an indicator of various levels of larval stress. No selection was detected, but the power to do so was very weak. Differences between progeny means from different rots indicated some genetic differences between rots which can be adequately explained by small numbers of founders. This suggests a random fine scale subdivision amounting to FST = 0.1483 +/- 0.0462.

Random isn't real: How the patchy distribution of ecological rewards may generate “incentive hope”

2019 ◽  
Vol 42 ◽  
Author(s):  
Laurel Symes ◽  
Thalia Wheatley
Keyword(s):  
Natural Environment ◽  
Random Distribution ◽  
Spatiotemporal Distribution ◽  
Patchy Distribution ◽  
Distribution Of Resources

AbstractAnselme & Güntürkün generate exciting new insights by integrating two disparate fields to explain why uncertain rewards produce strong motivational effects. Their conclusions are developed in a framework that assumes a random distribution of resources, uncommon in the natural environment. We argue that, by considering a realistically clumped spatiotemporal distribution of resources, their conclusions will be stronger and more complete.

Extreme self-sacrifice beyond fusion: Moral expansiveness and the special case of allyship

2018 ◽  
Vol 41 ◽  
Author(s):  
Daniel Crimston ◽  
Matthew J. Hornsey
Keyword(s):  
General Theory ◽  
Biological Markers ◽  
Natural Environment ◽  
Relevant Dimension ◽  
Special Case

AbstractAs a general theory of extreme self-sacrifice, Whitehouse's article misses one relevant dimension: people's willingness to fight and die in support of entities not bound by biological markers or ancestral kinship (allyship). We discuss research on moral expansiveness, which highlights individuals’ capacity to self-sacrifice for targets that lie outside traditional in-group markers, including racial out-groups, animals, and the natural environment.

Covering of cometary nucleus by refractory crust and its evolution into asteroid-like body

1999 ◽  
Vol 173 ◽  
pp. 365-370
Author(s):  
Kh.I. Ibadinov
Keyword(s):  
Laboratory Experiments ◽  
Cometary Nucleus ◽  
Sublimation Rate ◽  
Cometary Nuclei ◽  
Short Period Comet ◽  
Short Period ◽  
Brightness Decrease ◽  
Crust Thickness ◽  
Ice Sublimation ◽  
Period Comet

AbstractFrom the established dependence of the brightness decrease of a short-period comet dependence on the perihelion distance of its orbit it follows that part of the surface of these cometary nuclei gradually covers by a refractory crust. The results of cometary nucleus simulation show that at constant insolation energy the crust thickness is proportional to the square root of the insolation time and the ice sublimation rate is inversely proportional to the crust thickness. From laboratory experiments resulted the thermal regime, the gas productivity of the nucleus, covering of the nucleus by the crust, and the tempo of evolution of a short-period comet into the asteroid-like body studied.

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