Reflections on Ernst Mayr's This is Biology

In this essay I argue that Ernst Mayr's idea that the emergence of evolutionary biology in Western thought was delayed by the pernicious influence of the false ideologies of Platonism, Christianity, and physicalism is ahistorical and anti-evolutionary, that similar ideas, especially his antipathy to physicalism, prejudice his account of the transformation of natural history and medical science into biology, that his organicist resolution of the perennial conflict between mechanism and vitalism is an unstable compound of semi-holism and semi-mechanism, that his conception of biology as the true bridge between the sciences and the humanities, ethics, and social theory is open to question (especially as to the adequacy of the theory of natural selection to account for every aspect of human nature), and that his depiction of science as the sovereign key to understanding everything known to exist or happen in this universe cannot be justified at the bar of reason.     

The adaptive significance of cultural behavior: Comments and reply

Summary Fundamentally, theoretically, there is only one process underlying genetic and cultural evolution: natural selection. Organism fitness-enhancement (adaptive significance) is one of its practical mechanisms; group formation and maintenance is another, often but not always through fitness-enhancement; and need-fulfillment is still another. If Durham can accept that formulation, and switch from organism-thinking to instruction-thinking (Cloak, 1975: 178), he will free himself from two handicaps: First, he can forget his worries about reductionism and determinism (1976a: 100, 101). Under this general theory of natural selection, cultural evolutionis biological evolution, continued by other (nongenetic) means. Second, he will spare himself the appearance of anthropomorphism, mentalism, and wishy-washiness attendant on his discussion of kinds of significance, other than adaptive significance, of cultural behaviors (1976a: 102–106, 115).     

On genetic components in autoimmunity: a critical review based on evolutionarily oriented rationality

The immune system furnishes the organism with the utmost effective defence mechanisms against foreign and changes in self without doing self-harm. However, optimized efficacy in the defence against the immense variety of foreign antigens generates a higher risk for inadvertent self challenge. Such inherent short-comings are the inevitable burden traded for the benefits of an optimally organized defence system. The central molecules involved in specific immune reactions include antigen receptors of B and T lymphocytes, and antigen-presenting proteins encoded by the major histocompatibility complex (MHC; in man HLA). The genetics and evolution of these multigene families is discussed here with respect to their potential contributions to disturbances of self recognition. Simple molecular biological tools and procedures for efficiently screening the immunologically relevant genes are described.Dedicated to Professor Dr. U. Wolf on the occasion of his 60th birthday     

Comparative residual toxicities of pesticides to the predator Agistemus industani (Acari: Stigmaeidae) on citrus in Florida

Residual toxicities of registered and selected experimental pesticides used on citrus against Agistemus industani Gonzalez (Acari: Stigmaeidae) were compared. Pesticides considered highly toxic to A. industani were: abamectin 0.15 EC at 731ml/ha+FC 435-66 petroleum oil at 46.8l/ha, pyridaben 75WP at 469g/ha, ethion 4EC at 7.01l/ha+FC 435-66 petroleum oil at 46.8l/ha, propargite 6.55 EC at 3.51l/ha, chlorfenapyr 2SC at 1.46l/ha applied alone or in combination with FC 435-66 petroleum oil at 46.8l/ha, sulphur 80DF at 16.81kg/ha, dicofol 4EC at 7.01l/ha, fenbutatin oxide 50WP at 2.24kg/ha, benomyl 50WP at 2.24kg/ha, benomyl 50WP at 1.68kg/ha+ferbam 76 GF at 5.60kg/ha, ferbam 76GF at 11.21kg/ha, neem oil 90EC at 46.8l/ha, and copper hydroxide DF (40% metallic copper) at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha. Pesticides that were moderately to slightly toxic included: copper sulphate 98% at 4.48kg metallic copper/ha+FC 435-66 petroleum oil at 46.8l/ha, fenbuconazole 2F at 280ml/ha+FC 435-66 petroleum oil at 46.8l/ha, FC 435-66 petroleum oil applied alone at 46.8l/ha or 23.4l/ha, and diflubenzuron 25WP at 1.40kg/ha. Pesticides that were non-toxic included: fenbuconazole 2F at 585ml/ha, malathion 57EC at 5.85l/ha, FC 435-66 petroleum oil at 46.8l/ha, carbaryl 80S at 3.36kg/ha, chlorpyrifos 4EC at 4.68l/ha, and formetanate 92SP at 1.12kg/ha. Understanding the toxic effects of field weathered pesticides against key predacious mite species is important for effective IPM. The results of this study provide a comparison of direct and indirect toxic effects of various pesticides to A. industani under field conditions.     

God's magnificent law: The bad influence of theistic metaphysics on Darwin's estimation of natural selection

Conclusion It is natural for us — living after the Darwinian Revolution and the neo-Darwinian synthesis — to consider the adoption of evolution by natural selection as unconditionally rational, because it now seems the best theory or explanation of many phenomena. Nonetheless, if we take historical inquiry seriously, as allowing us to probe into the ground of our knowledge, the roots of even this rational Darwinism might be unearthed. Darwinian doctrine betrays a deceptive desire for unity and simplicity of principle, and belief that the mechanistic aspect of nature is of the highest significance. Such crucial but questionable presuppositions are more easily discerned historically, insofar as they chronologically preceded Darwin's particular theoretical conviction and were even set off as a metaphysics of divine law.We have seen how Darwin's teaching about nature emerged within that theistic metaphysics. It emerged in a prior metaphysical debate in his mind between the contemporary belief in special creations and the belief in a designed hierarchy of physical laws. One can hardly deny that Darwin favored the superior side in this contest; but the contest was a narrow one whose basic premises he never clearly criticized. On the one hand, of course, his conviction about a lawful genesis inspired him to take a broad view of things and to seek out important general phenomena. But, on the other hand, it ensured that his new empirical notions would be easily drawn into the preferred cosmology. Historically, this seems to have occurred in Darwin's adoption of Malthus' principle of population and his extension of it to the whole account of descent: Malthusianism was readily attached to an ultimate scheme of things. Consequently, the key concepts that Darwin developed out of his Malthusian views — perfect adaptation and selection — reflect his cosmological prepossession, his desire to express a total and teleological process of creation. Perhaps our most valuable, and most undervalued, token of Darwin's metaphysical orientation is his reliance on a human technique (selective breeding) to explain Nature's way. In sum, to understand Darwin's faith in his grand view of life, we should not ignore the metaphysics that preceded and structured it, the metaphysics that linked the principles of contemporary science to primordial creation. Nor should we fail to see that such a metaphysics leads natural philosophy into a shadowy realm, where system can come to look like science, and one insight like an absolute.     

Disease and illness Distinctions between professional and popular ideas of sickness

The dysfunctional consequences of the Cartesian dichotomy have been enhanced by the power of biomedical technology. Technical virtuosity reifies the mechanical model and widens the gap between what patients seek and doctors provide.Patients suffer illnesses; doctors diagnose and treat diseases. Illnesses are experiences of discontinuities in states of being and perceived role performances. Diseases, in the scientific paradigm of modern medicine, are abnormalities in the function and/or structure of body organs and systems. Traditional healers also redefine illness as disease: because they share symbols and metaphors consonant with lay beliefs, their healing rituals are more responsive to the psychosocial context of illness.Psychiatric disorders offer an illuminating perspective on the basic medical dilemma. The paradigms for psychiatric practice include multiple and ostensibly contradictory models: organic, psychodynamic, behavioural and social. This melange of concepts stems from the fact that the fundamental manifestations of psychosis are disordered behaviours. The psychotic patient remains a person; his self-concept and relationships with others are central to the therapeutic encounter, whatever pharmacological adjuncts are employed.The same truths hold for all patients. The social matrix determines when and how the patient seeks what kind of help, his compliance with the recommended regimen and, to a significant extent, the functional outcome. When physicians dismiss illness because ascertainable disease is absent, they fail to meet their socially assigned responsibility. It is essential to reintegrate scientific and social concepts of disease and illness as a basis for a functional system of medical research and care.Harvard Medical School     

Concluding remarks

On the basis of symposium contributions onChlorella, Hibbertia, Eucalyptus, Ambrosia and on numerical approaches some fundamental problems of (bio)systematics, evolution, and taxonomic categories are discussed: Methods available for analysing affinities; conflicting evidence from phenetic, biochemical, cytogenetic and other analyses; further classification problems in cases of intermediacy, etc. While sibs of various levels and their natural hierarchy often can be objectively defined, this appears impossible for particular taxonomic levels itself (e. g. species). A single objective taxonomic system of organisms is unrealistic. Certain guiding lines for relative and practicable concepts of species and genus are proposed.Presented at the symposium Speciation and the Species Concept during the XIIth International Botanical Congress, Leningrad, July 8, 1975.     

Binding of the galactose-specificPseudomonas aeruginosa lectin,PA-I,to glycosphingolipids and other glycoconjugates

The carbohydrate-binding specificity ofPseudomonas aeruginosa lectin I (PA-I) in iodinated or biotinylated form was studied. A large number of glycosphingolipids, as well as some glycoproteins and neoglycoproteins were used as ligands. Also, inhibition by free saccharides of PA-I binding to glycosphingolipids was tested. It was found that the lectin binds most strongly to terminal and nonsubstituted Gal3Gal- or Gal4Gal-structures.Abbreviations PA-I Pseudomonas aeruginosa lectin I - Cer ceramide - lactosylceramide Gal4GlcCer - iso globotriaosylcerami Gal3Gal4GlcCer - globotriaosylceramide Gal4Gal4GlcCer - globoside or globotetraosylceramide GalNAc3Gal4Gal4GlcCer - Forssman glycolipid GalNAc3GalNAc3Gal4Gal4GlcCer - P1 glycolipid Gal4Gal4GlcNAc3Gal4GlcCer - lactoneotetraosylceramide Gal4GlcNAc3Gal4GlcCer - B5 glycolipid Gal3Gal4GlcNAc3Gal4GlcCer - gangliotetraosylceramide Gal3GalNAc4Gal4GlcCer - GM1 Gal3GalNAc4(NeuAc3)Gal4GlcCer - RBC red blood cells - BSA bovine serum albumin - PBS phosphate-buffered saline - SDS sodium dodecyl sulfate - TLC thin-layer chromatography - HPLC high pressure liquid chromatography - MS mass spectrometry - FAB fast-atom bombardment - EI electron impact     

Large scale preparation of PA-oligosaccharides from glycoproteins using an improved extraction method

We have developed a new method for the large scale preparation of pyridylaminated (PA-) oligosaccharides from glycoproteins. Phenol/chloroform extration was adapted for the removal of protein and excess 2-aminopyridine, improving the efficiency of preparation. From a 2.5 g sample of human apo-transferrin, 25–30 mol of agalacto biantennary PA-oligosaccharide could be obtained. By increasing the concentration of PA-oligosaccharide substrate, we were able to detect a very low level ofN-acetylglucosaminlytransferase IV activity in CHO cell extracts.Abbreviations PA 2-aminopyridine - SDS sodium dodecyl sulfate - GlcNAc N-acetylglucosamine - GnT N-acetylglucosaminyltransferase - Gn,Gn-bi-PA GlcNAc1-2Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine - Gn,Gn,Gn-tri-PA GlcNAc1-2(GlcNAc1-4)Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine - Gn,Gn,Gn-trí-PA GlcNAc1-2Man1-3({GlcNAc1-2(GlcNAc1-6)Man1-6})Man1-4GlcNac1-4GlcNAc-2-aminopyridine - Gn,(Gn),Gn-bi-PA GlcNAc1-2Man1-3(GlcNAc1-4)(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc-2-aminopyridine     

Activation of peritoneal macrophages in patients with gynecological malignancies by sizofiran and recombinant interferon-γ

We investigated the influence of the combined use of sizofiran, a-1,3-glucan and a recombinant interferon- (rIFN-) upon biological activities of peritoneal macrophages (M). The number of peritoneal M and the production of cytokines (interleukin-1, interferon- and tumor necrosis factor) was increased by the combined treatment. Fully activated peritoneal M based on the increased number of elongated pseudopods were observed by electromicroscope. Sizofiran seems to assure a sufficient supply of M to kill tumor cells in the peritoneal cavity and co-administered rIFN- seems to directly stimulate the accumulated M in addition to its direct cytotoxicity against tumor cells. This combination therapy may be a step to the prevention of the recurrence of gynecological malignancies including ovarian cancer, after a negative second-look laparotomy.Abbreviations rIFN- recombinant interferon- - IL-1 interleukin-1 - TNF tumor necrosis factor - SLL second look laparotomy     

The “biological ego”. From Garrod's “chemical individuality” to Burnet's “self”

Starting from the conceptual premises of Garrod, who as long ago as 1902 spoke of chemical individuality, and of Burnet (1949), who recognized as self one's own molecular antigenic structures (as opposed to the antigenic alien: the non- self), the discovery and understanding of HLA antigens and of their extraordinarily individual and differentiated polymorphisms have gained universal recognition. Transplant medicine has now dramatically stressed, within man's knowledge of himself, the characteristic of his biological uniqueness. Today man, having become aware of being a biological antigenic-molecular individuality which is unique and different from that of all of his fellow men (except for monozygotic twins), can therefore easily consider himself a true biological Ego.Abbreviations BMT bone marrow transplantation - GVHD graft versus host disease - HLA human leukocyte antigens - MHC major histocompatibility complex - MLC mixed lymphocyte culture - MLR mixed lymphocyte reaction     

Adoptions expérimentales de larves entre des fourmis de genres différents:Leptothorax nylanderi Förster etSolenopsis fugax Latreille

Résumé En l'absence de son propre couvain,Solenopsis fugax a élevé des larves deLeptothorax nylanderi, à la température de 22°C. Les ouvrières deSolenopsis détruisirent une partie de ces larves mais nourrirent celles qu'elles épargnèrent; ces dernières grossirent lentement pendant cinq à six mois, sans atteindre le stade prénymphe. Lorsque les ouvrières deS. fugax et les larves deL. nylanderi furent soumises ensemble à un hivernage préalable, elles donnèrent les mêmes résultats que sans hivernage. La présence d'une jeune reine deSolenopsis fut défavorable aux larves deLeptothorax.Inversement,L. nylanderi fut capable d'élever, à la température de 22°C, des larves deS. fugax et de les amener jusqu'au stade adulte. En présence de leurs propres larves, les ouvrières deL. nylanderi détruisirent tapidement toutes les larves deS. fugax introduites dans leur nid. D'autre part, un jeune couvain deLeptothorax remplaçait plus ou moins rapidement les larves deLeptothorax enlevées au préalable; sa présence était alors défavorable au développement des larves deSolenopsis. Un hivernage en début d'expérience fut plutôt favorable auxS. fugax, de même que la présence d'une reine féconde deLeptothorax. LesSolenopsis ainsi obtenus n'ont pas vécu plus de sept semaines. Ils étaient tous de caste ouvrière et de taille très petite.

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Summary When its own eggs and larvae missed,Solenopsis fugax bred larvae ofLeptothorax nylanderi, at a temperature of 22°C. TheSolenopsis workers killed some of this larvae and fed the others; these slowly grew bigger during five or six months but never reached the pre-pupa stage. The result was the same if the workers ofS. fugax and the larvae ofL. nylanderi overwintered together or not at all. A youngSolenopsis queen being there was noxious to the larvae ofLeptothorax.On the contrary,L. nylanderi has been able to breed larvae ofS. fugax up to the imago stage, at a temperature of 22°C. When its own larvae were in the nest, together with larvae ofS. fugax, the workers ofL. nylanderi killed the larvae ofS. fugax. On the other hand, new eggs and young larvae ofLeptothorax had to replace, more or less quickly, the larvae which had been taken away, and that was noxious to the growth ofSolenopsis larvae. An overwintering at the beginning of the experiment was rather favourable toS. fugax as was the presence of a fecundLeptothorax queen. TheSolenopsis thus obtained lived no longer than seven weeks. They all were workers and very small.

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S. Fugax L. Nylanderi 22° . Leptothorax , , , , . . S. Fugax Leptothorax.,L. Nylanderi 22° S. Fugax . L. Nylanderi ( )Leptothorax ; S. Fugax Solenopsis, Leptothorax. S. Fugax . .

     

The carotenoids of Flavobacterium strain R1560

The main carotenoid of Flavobacterium strain R1560 has been identified as (3R,3R)-zeaxanthin. Also present were small amounts of 15-cis-phytoene, phytofluene, -carotene (7,8,7,8-tetrahydro-, -carotene plus 7,8,11,12-tetrahydro-, -carotene), neurosporene, lycopene, -zeacarotene, -carotene, -carotene, -cryptoxanthin, rubixanthin, 3-hydroxy--zeacarotene and several apo-carotenals. Zeaxanthin production was inhibited by nicotine (10 mM), and lycopene and rubixanthin accumulated. The biosynthesis of zeaxanthin is discussed in terms of pathways and also of half-molecule reaction sequences. The presence of zeaxanthin may be a characteristic of a group of Flavobacterium species, and may thus be useful in the taxonomic classification of these organisms.     

Against “Revolution” and “Evolution”

Those standard historiographic themes of evolution and revolution need replacing. They perpetuate mid-Victorian scientists history of science. Historians history of science does well to take in the long run from the Greek and Hebrew heritages on, and to work at avoiding misleading anachronism and teleology. As an alternative to the usual evo-revo themes, a historiography of origins and species, of cosmologies (including microcosmogonies and macrocosmogonies) and ontologies, is developed here. The advantages of such a historiography are illustrated by looking briefly at a number of transitions the transition from Greek and Hebrew doctrines to their integrations by medieval authors; the transition from the Platonist, Aristotelian, Christian Aquinas to the Newtonian Buffon and to the no less Newtonian Lamarck; the departures the early Darwin made away from Lamarcks and from Lyells views. Issues concerning historical thinking about nature, concerning essentialism and concerning classification are addressed in an attempt to challenge customary stereotypes. Questions about originality and influence are raised, especially concerning Darwins tree of life scheme. The broader historiography of Darwinian science as a social ideology, and as a worldview, is examined and the scope for revisions emphasised. Throughout, graduate students are encouraged to see this topic area not as worked out, but as full of opportunities for fresh contributions.     

The relationships between the structure of paddy levees and the plant species diversity in cultural landscapes on the west side of Lake Biwa,Shiga, Japan

Paddy levees form networks of narrow linear habitats and play various roles in cultural landscapes. Traditional landscapes on the west side of Lake Biwa consist of paddy field terraces and both stone and soil levees that have been maintained by paddy field management using local resources. Paddy levees in this study site are principally classified into five different types. Our study points out how differences in paddy levee structure as well as in management practices influence the plant species. Seventeen paddy levee transects were split into four habitat types based on their species components by TWINSPAN. Spatial characteristics and physical structures of paddy levees depended on natural conditions and human activities. The species–area curves of each levee type showed a clear distinction: the soil, stone and abandoned curves were steep, while the concrete and consolidated ones were gentle. The vegetation on consolidated levees was utterly different from the vegetation on traditional levee types from the aspect of species richness and species components. Soil type levees contained various woody plant species and included more diverse and indigenous plant species than abandoned type levees.     

Electrophoretic variation between class II molecules expressed on HLA-DRw8 homozygous typing cells reveals multiple distinct haplotypes

Two-dimensional (2D) gel electrophoresis of immunoprecipitated HLA-DR antigens from eight homozygous typing cells (HTC) expressing the HLA-DRw8 specificity revealed a clustering of polymorphic chain patterns into distinct electrophoretic variants. The variant patterns correlate with three discrete HLA-D clusters that are defined in the mixed leukocyte culture reaction (MLR) using DRw8-positive HTC. These HLA-D clusters have been provisionally designated Dw8.1, detected primarily in Caucasoids, Dw8.2, detected primarily in American Indians, and Dw8.3, detected predominantly in Orientals. All three HLA-Dw8.1 cell lines express a single DR-locus product as defined by immunoprecipitation with a DR-specific monoclonal antibody, P4.1. This DR chain is identical among the Dw8.1 cell lines and different from the DR chains of the Dw8.2 and Dw8.3 cell lines. Two separate Dw8.2 HTC express a shared DR chain that is slightly more basic than the 8.1 DR molecule; interestingly, one of these lines also expresses an additional DR-like chain not found in the other cells. Thus, the two lines defining the Dw8.2 cluster share one distinct class 11 molecule, but differ in another and therefore are not biochemically HLA-identical. Cells from the Dw8.3 cluster are likewise distinct from all other Dw8 clusters. One additional DRw8-positive HTC has been analyzed and found to be distinct from the Dw8.1, 8.2 and 8.3 clusters by both MLR and 2D gels. lmmunoprecipitates using monoclonal antibody 1B5 [anti-DR and anti-DQ(DS)] identify additional polymorphic class II variants among the cell lines tested. These data indicate that HLA-DRw8 is a public serologic specificity present on class II molecules expressed on multiple distinct haplotypes. These haplotypes differ from each other in expression of polymorphic class II molecules encoded by at least two HLA loci. They also differ in HLA-D, even though they all type as HLA-DRw8 homozygous. In Dw8.2, variation in expressed chains is not reflected in variation in HLA-D, indicating that MLR, as well as serologic typing, does not detect the full degree of allelic polymorphism within HLA.     

Action of rat liver Galβ1-4GlcNAc α(2-6)-sialyltransferase on Manβ1-4GlcNAcβ-OMe,GalNAcβ1-4GlcNAcβ-OMe,Glcβ1-4GlcNAcβ-OMe and GlcNAcβ1-4GlcNAcβ-OMe as synthetic substrates

Incubation of synthetic Man\1-4GlcNAc-OMe, GalNAc1-4GlcNAc-OMe, Glc1-4GlcNAc-OMe, and GlcNAc1-4GlcNac-OMe with CMP-Neu5Ac and rat liver Gal1-4GlcNAc (2-6)-sialyltransferase resulted in the formation of Neu5Ac2-6Man1-4GlcNAc-OMe, Neu5Ac2-6GalNAc1-4GlcNAc-OMe, Neu5Ac2-6Glc1-4GlcNAc-OMe and Neu5Ac2-6GlcNAc1-4GlcNAc-OMe, respectively. Under conditions which led to quantitative conversion of Gal1-4GlcNAc-OEt into Neu5Ac2-6Gal1-4GlcNAc-OEt, the aforementioned products were obtained in yields of 4%, 48%, 16% and 8%, respectively. HPLC on Partisil 10 SAX was used to isolate the various sialyltrisaccharides, and identification was carried out using 1- and 2-dimensional 500-MHz¹H-NMR spectroscopy.Abbreviations 2D 2-dimensional - CMP cytidine 5-monophosphate - CMP-Neu5Ac cytidine 5-monophospho--N-acetylneuraminic acid - COSY correlation spectroscopy - DQF double quantum filtered - HOHAHA homonuclear Hartmann-Hahn - MLEV composite pulse devised by M. Levitt - Neu5Ac N-acetylneuraminic acid - Neu5Ac2en 2-deoxy-2,3-didehydro-N-acetylneuraminic acid     

Dihydropteridine reductase variation in man and the characid fish “Cheirodon axelrodi”: Evidence for a dimeric enzyme structure

Summary Genetic evidence for a dimeric structure of dihydropteridine reductase in man and in the fish species Cheirodon axelrodi and Salmo irideus is presented. A single locus in man and two loci in the fishes examined encode this enzyme. Zymograms revealed two alleles for the locus in man and two alleles for each locus in the fish Cheirodon axelrodi. The liver homogenate of a patient with dihydropteridine reductase deficiency showed no detectable activity in the gel, while his parents showed the normal electrophoretic phenotype.     

Protoplasmic streaming in the giant unicellular green algaAcetabularia mediterranea

Summary Protoplasmic Streaming inAcetabularia mediteranea has been studied by microcinematography in 1. germinating zygotes, 2. germlings before the differentiation of rhizoids and apices, 3. young cells with rhizoids and apices, 4. vegetative cells-several centimeters in length, 5. cells with a maximum sized cap, containing secondary nuclei, and 6. cells after cyst formation. Intracellular transport is found to occur at a network-system of thin filaments and at a different system of headed streaming bands. At the network of filaments chloroplasts are found to move at a velocity of 1–2 m/sec. Headed streaming bands move along the filaments and may lead without interruption from the rhizoid to the apex of the cell andvice versa. The front zone of the streaming bands is occupied by a leading cytoplasmic head-structure. Small vesicles, polyphosphate granula and secondary nuclei are the predominant moving structures in headed streaming bands. The velocity of these particles is found to be 3–11 m/sec. The filament system is found during all developmental stages. Headed streaming bands are undetectable in germinating zygotes and develop from small cytoplasmic droplets in germlings to broad heavily loaded bands in the huge vegetative cell.Transport of secondary nuclei by headed streaming bands is not observed during mitotic divisions and after cyst formation, though moving bands are still present for several weeks after cyst formation.     

Ernst Mayr as community architect: Launching the society for the study of evolution and the journalEvolution

Ernst Mayr's contributions to 20th century biology extend far beyond his defense of certain elements in evolutionary theory. At the center of mid-century efforts in American evolutionary studies to build large research communities, Mayr spearheaded campaigns to create a Society for the Study of Evolution and a dedicated journal,Evolution, in 1946. Begun to offset the prominence ofDrosophila biology and evolutionary genetics, these campaigns changed course repeatedly, as impediments appeared, tactics shifted, and compromises built a growing coalition of support. Preserved, however, were designs to balance the community and journal with careful equation of status and explicit partitioning of responsibilities within the working coalition. Choice terms such as cooperation and unity carried a strong political message. Mayr's editorship ofEvolution provides a superb example of these balancing efforts. The mid-century infrastructural activities described herein also represented aggressive attempts to leverage control across several layers of community. Leaders of these campaigns sought: (1) to promote evolutionary studies as a modernized research discipline and place it at the center of American biology, (2) to promote evolutionary studies within existing disciplines — e.g. systematics, genetics, and paleontology, (3) to foster certain research styles within evolutionary studies, and (4) to emphasize certain solutions to prominent research questions. Throughout, Mayr interjected his priorities, tactics and energy.