Dinosaur Evolution: Student Response to Dinosaur Ramblings

Abstract: In the 2007 Journal of Wildlife Management article “Dinosaur Ramblings,” Scalet described a shift in university and agency programs away from applied management research toward basic ecological research. We interpret Scalet's commentary as primarily synonymizing applied management research to game management and basic ecological research to nongame management and theoretical research. Although we agree with Scalet that a change in management practices has occurred, we believe that change is more an integration of applied and basic research as opposed to a shift away from management. We provide a hierarchical framework to alternatively explain Scalet's perceived shift in which we place applied management and basic theoretical research under the science of ecology. We believe integration of basic and applied research has been driven by the evolving structure of society and the public's changing view of natural resources. The integration of basic and applied research is necessary for informed and, thence, better management practices.     

Non-glaucousness, a probable aphid-resistance character of wheat

Cuticular waxes from wheat cultivars that have a bluish-green waxy bloom under field conditions were compared with those of non-glaucous (NG) variants that appeared dark green and glossy in the field. Cuticular wax from NG variants was deficient in diketones and hydroxydiketones, and did not form the micro-spicules of epicuticular wax which were characteristic of the normal bloom. Typically, NG wheats were resistant to Sitobion avenae in the field, but in environments where wax secretion was diminished, resistance was reduced or absent. Possible causes of this resistance, which appears likely to be easy to exploit, are discussed.     

Local genetic differentiation for disease resistance in a selfing annual

Electrophoretic analysis of a population of the annual legume Amphicarpaea bracteata revealed that plants in two areas 50 m apart were fixed or nearly fixed for different alleles at eight polymorphic allozyme loci. This multilocus differentiation was highly correlated with variation in disease resistance to the specialist pathogen Synchytrium decipiens : in both laboratory and field experiments, all plants from one area were susceptible, and all plants from the other area were resistant to local pathogen isolates. Analysis of F2 plants from a cross between the two plant biotypes suggested polygenic inheritance of disease resistance, with a minimum of 7–8 loci contributing to the difference among parental lines. The high degree of self-fertilization in A. bracteata , together with spatially restricted seed dispersal, may account for perpetuation of the two divergent plant lineages at this site with little introgression or mixing. Although pathogens could influence the relative frequency of the two host lineages in this habitat, the restricted diversity of local pathogens implies that there may be little selection on plants for outcrossing as a mechanism to reduce pathogen impact.     

Protein accumulation in developing endosperm of a high-protein line of Triticum dicoccoides

Abstract. Endosperm tissue from developing grains of a line of wheat ( Triticum dicoccoides ) which accumulates up to 30% protein in the mature grain, was examined by electron microscopy to establish the ontogeny of the storage protein bodies. Ultrastructural evidence suggests that storage proteins of wheat may be transported from their site of synthesis on the rough endoplasmic reticulum (ER) to protein bodies by two different routes within the endomembrane system. The first route, which probably functions throughout protein deposition, involves the transport of protein from the cisternal rough ER to the protein vacuoles via the Golgi apparatus. The second route, observed 20 d after anthesis, appears to lead directly from dilated regions of the rough ER to protein vacuoles, bypassing the dictyosomes. Phytin inclusions are found in protein vacuoles of starchy endosperm cells adjacent to the aleurone layer of developing grain.     

Regulators of Cell Division in Plant Tissues1: XIX. THE METABOLISM OF 6-BENZYLAMINOPURINE IN RADISH COTYLEDONS AND SEEDLINGS

Excised immature radish cotyledons were allowed to take up [³H]6-benzylaminopurinefor up to 5 h and were then transferred to cytokinin.free mediumfor various intervals, after which they were extracted. Thecytokinin was rapidly metabolized by the tissue to two mainproducts which accounted for 20 per cent of the extracted radioactivityafter 1 h of uptake, and for 95 per cent after transfer to thecytokinin-free medium. These metabolites were coincident withcytokinin activity on chromatograms of the cotyledon extractand were also formed when 6-benzylaminopurine was supplied to9-d-old derooted seedlings through the transpiration stream.The metabolites were identified by mass spectrometry, u.v. spectroscopy and chemical degradation as 6-benzylarnino-7-glucosylpurineand 6-benzylamino-9. glucosylpurine. Several minor metaboliteswere detected in the derooted seedlings; one was 6-benzylaminopurineriboside while another appeared to possess high cytokinin activity.     

Ecological Implications of Clonal Diversity in Parthenogenetic Morphospecies

Most parthenogenetic animal taxa which have been investigatedelectrophoretically, cytologically, or with tissue graftingtechniques are clonally diverse. I have examined data on multiclonalparthenogenetic populations using ecological diversity measuresto elucidate patterns of clonal coexistence. Analysis of a discretepopulation cage experiment on clones of Drosophila mercatorumrevealed monotonic decay of clonal diversity and evenness; however,in a continuous generation cage, clonal diversity appeared tostabilize. Clonal diversity and evenness fluctuated widely overtime in several multiclonal populations of Daphnia magna althoughno clonal extinction was observed. There were few spatial trendsin clonal diversity and evenness within parthenogenetic taxa.It is suggested that the degree of clonal differentiation, determinedby the mode of clonal origin, is important in determining whetheror not selection occurs among sympatric clones