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  • Artikel  (93)
  • evolution  (93)
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  • Oxford University Press
  • Periodicals Archive Online (PAO)
  • 1995-1999
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  • Springer  (93)
  • American Meteorological Society
  • Oxford University Press
  • Periodicals Archive Online (PAO)
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  • 1995-1999
  • 1990-1994  (93)
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  • 1
    Digitale Medien
    Digitale Medien
    Ancient DNA: An introduction (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 521-523 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Ancient DNA ; evolution ; conservation ; biology ; anthropology ; plant biology ; PCR (polymerase chain reaction)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01921719
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  • 2
    Digitale Medien
    Digitale Medien
    A novel mechanism for jumping in the indian antHarpegnathos saltator (Jerdon) (Formicidae, Ponerinae) (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 63-71 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Insect ; behaviour ; high-speed cinematography ; jumping ; electrophysiology ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The Indian antHarpegnathos saltator may be unique among insects in using its jumping capacity not only as an escape mechanism but also as a normal means of locomotion, and for catching its prey in flight. High-speed cinematography used to analyse the various phases of the jump suggests thatHarpegnathos employs a novel jumping mechanism to mediate these behaviours: namely the synchronous activation of its middle and hindlegs. Electrophysiological recordings from muscles or nerves in pairs of middle and hindlegs show remarkably synchronous activity during fictive jumping, supporting the synchronous activation hypothesis.Harpegnathos is not the only ant to jump, and a cladistic analysis suggests that jumping behaviour evolved independently three times during ant evolutionary history.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01992052
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  • 3
    Digitale Medien
    Digitale Medien
    Presence of a partial urea cycle in the leech,Poecilobdella granulosa (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 729-731 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Urea cycle ; leech ; botryoidal tissue ; hirudineans ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Ornithine carbamoyltransferase (OCT) and arginase, but not arginine synthetase (AS), were detected in the body wall and gut tissues of the leech. The activities of these enzymes were not altered by starvation. The high activity of arginase in body wall is probably due to the association of the latter with botryoidal tissue. Hirudineans, which evolved from oligochaete ancestors, appear to have lost the citrulline-arginine segment of the urea cycle due to their ammonotelic mode of nitrogen excretion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02124288
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  • 4
    Digitale Medien
    Digitale Medien
    Genetic aspects of the hsp70 multigene family in vertebrates (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 987-1001 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Hsp70 ; evolution ; gene duplication ; gene homology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The family of genes encoding heat shock proteins of about 70 kDa (hsp70) in vertebrates is reviewed under genetic aspects. After a detailed description of the various hsp70 genes more general characteristics of the organization and evolution of the multigene family are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01923453
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  • 5
    Digitale Medien
    Digitale Medien
    Genetic ecology: A new interdisciplinary science, fundamental for evolution, biodiversity and biosafety evaluations (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 429-437 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Genetics ; ecology ; DNA-transfer ; conjugation ; transformation ; transduction ; transposons ; dormant cells ; epilithon ; microbial colonisation ; symbiosis ; virus resistance ; biosafety ; release of genes ; insults to humanity ; evolution ; biodiversity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01920741
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  • 6
    Digitale Medien
    Digitale Medien
    Life and teleology (1992)
    Springer
    Journal for general philosophy of science 23 (1992), S. 85-103 
    Details
    ISSN: 1572-8587
    Schlagwort(e): life ; teleology ; evolution ; reality ; representation ; experience
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Philosophie , Wissenschaftskunde und Wissenschaftsorganisation, Hochschul- und Universitätswesen, Museumswissenschaft
    Notizen: Summary A comprehensive definition of the phenomenon called “life” led to the addition of many dimensions to the natural sciences, and especially the conscious mental dimension. Historical attention is paid not only to those employing the natural philosophical paradigms, but also to evolutionary theories and to the Kantian teleological philosophy. The belief that science can solve the riddle of life is a category of purposal thinking. A revised version of critical teleology is essential for comprehension of life.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01801797
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  • 7
    Digitale Medien
    Digitale Medien
    Charophyta: their use in paleolimnology (1994)
    Springer
    Journal of paleolimnology 10 (1994), S. 43-52 
    Details
    ISSN: 1573-0417
    Schlagwort(e): Charophyta ; evolution ; gyrogonite morphology ; ecology-paleoecology ; Argentina ; South America
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract Charophyta are common algae in limnic waters from many regions and are an interesting group from an evolutionary point-of-view, as they are believed to be related to the Chlorophyceae and land plants. Paleontological-botanical systematics are discussed, taking into consideration some new advances. Charophytes live in all types of inland waters and are sensitive to ecological change, and so they are very useful paleolimnological markers. Gaps concerning gyrogonite morphology in extant taxa and their responses to different environmental conditions must be described. This paper discusses data concerning ecological factors affecting the distribution of Argentinian Charophyta (principally distributed between 30°S and 40°S), gyrogonite morphology related to different ecological conditions, and the way that Charophyta can modify the environment.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00683145
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  • 8
    Digitale Medien
    Digitale Medien
    Pleistocene Charophyta from Arroyo Perucho Verna, Province of Entre Rios, Argentina (1994)
    Springer
    Journal of paleolimnology 10 (1994), S. 53-58 
    Details
    ISSN: 1573-0417
    Schlagwort(e): Charophyta ; evolution ; gyrogonite morphology ; ecology-paleoecology ; Argentina ; South America
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract The Pleistocene charophytes from Arroyo Perucho Verna, Province of Entre Ríos, were analyzed.Chara contraria Br. ex Kütz.,C. contraria var.longilinea Cáceres,C. globularis Thuill. andTolypella intricata (Trent. ex Roth.) Leonh. var.apiculata (A. Br.) Wood were described and illustrated with scanning electron microscope. The assemblage indicates fresh alkaline to slightly saline waters, not very deep, in a lentic or sometimes lotic environment. Extant assemblages provide data for this paleoecological reconstruction.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00683146
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  • 9
    Digitale Medien
    Digitale Medien
    Metabolic pathways inParacoccus denitrificans and closely related bacteria in relation to the phylogeny of prokaryotes (1992)
    Springer
    Antonie van Leeuwenhoek 61 (1992), S. 1-33 
    Details
    ISSN: 1572-9699
    Schlagwort(e): Paracoccus denitrificans ; denitrification ; methylotrophy ; cytochromec ; cytochrome oxidase ; phylogeny ; evolution ; lateral gene transfer ; nitrogen fixation ; Thiosphaera pantotropha
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Denitrification and methylotrophy inParacoccus denitrificans are discussed. The properties of the enzymes of denitrification: the nitrate-nitrite antiporter, nitrate reductase, nitrite reductase, nitric oxide reductase and nitrous oxide reductase are described. The genes for none of these proteins have yet been cloned and sequenced fromP. denitrificans. A number of sequences are available for enzymes fromEscherichia coli, Pseudomonas stutzeri andPseudomonas aeruginosa. It is concluded that pathway specificc-type cytochromes are involved in denitrification. At least 40 genes are involved in denitrification. In methanol oxidation at least 20 genes are involved. In this case too pathway specificc-type cytochromes are involved. The sequence homology between the quinoproteins methanol dehydrogenase, alcoholdehydrogenase and glucose dehydrogenase is discussed. This superfamily of proteins is believed to be derived from a common ancestor. ThemoxFJGI operon determines the structural components of methanol dehydrogenase and the associatedc-type cytochrome. Upstream of this operon 3 regulatory proteins were found. The mox Y protein shows the general features of a sensor protein and the moxX protein those of a regulatory protein. Thus a two component regulatory system is involved in both denitrification and methylotrophy. The phylogeny of prokaryotes based on 16S rRNA sequence is discussed. It is remarkable that the 16S rRNA ofThiosphaera pantotropha is identical to that ofP. denitrificans. Still these bacteria show a number of differences.T. pantotropha is able to denitrify under aerobic circumstances and it shows heterotrophic nitrification. Nitrification and heterotrophic nitrification are found in species belonging to the β-and γ-subdivisions of purple non-sulfur bacteria. Thus the occurrence of heterotrophic nitrification inT. pantotropha which belongs to the α-subdivision of purple non-sulfur bacteria is a remarkable property. FurthermoreT. pantotropha contains two nitrate reductases of which the periplasmic one is supposed to be involved in aerobic denitrification. The nitrite reductase is of the Cu-type and not of the cytochromecd 1 type as inP. denitrificans. Also the cytochromeb of theQbc complex ofT. pantotropha is highly similar to its counterpart inP. denitrificans. It is hypothesized that the differences between these two organisms which both contain large megaplasmids is due to a combination of loss of genetic information and plasmid-coded properties. The distribution of a number of complex metabolic systems in eubacteria and in a number of species belonging to the α-group of purple non sulphur bacteria is reviewed. Two possibilities to explain this haphazard distribution are considered: 1. Lateral gene transfer between distantly related micro organisms occurs frequently. 2. The eubacterial ancestors must have possessed already these properties. The distribution of these properties is due to sporadic loss during evolutionary divergence. With respect to the occurrence and frequency of lateral gene transfer two opposing views exist. According to molecular biologists lateral gene transfer occurs frequently and is very easy. Bacteria are supposed to form one large gene pool. On the other hand population geneticists have provided evidence that strong systems operate that establish reproductive isolation between diverged species and even between closely related cell lines. Data on amino acid sequences of nitrogenase proteins, cytochromesc, cytochrome oxidases, β-subunits of ATP synthase and tryptophan biosynthetic enzymes of various micro organisms were reviewed. In all these cases phylogenetic trees could be constructed based on the amino acid sequence data. In all cases this phylogenetic tree was similar to the one based on 16S rRNA homology. Only in one case evidence for the occurrence of lateral gene transfer was obtained. Therefore it is concluded that lateral gene transfer played a minor role in the distribution of complex metabolic systems among prokaryotes. It must be stressed that this does not exclude the possibility that lateral gene transfer occurred frequently in the initial stage of bacterial evolution. It is hypothesized that the appearance of nitrogen fixation, denitrification and cytochrome oxidase formation were early events in the evolution of micro organisms. Both systems are supposed to have evolved only once. Subsequently the capacity to fix nitrogen or to denitrifymust have been lost many times, just as photosynthetic capacity is supposed to have been lost many times. During evolution many systems have been lost leading to a haphazard distribution of metabolic characters among bacteria. As an example it is suggested that organisms with a respiratory chain similar to that ofEscherichia coli arose by loss of the capacity to form the Qbc complex andc-type cytochromes. The remaining systems could be controlled much better however than in the ancestral organisms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00572119
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  • 10
    Digitale Medien
    Digitale Medien
    The evolution of pathways for aromatic hydrocarbon oxidation inPseudomonas (1994)
    Springer
    Biodegradation 5 (1994), S. 195-217 
    Details
    ISSN: 1572-9729
    Schlagwort(e): Aromatic catabolism ; by bacteria (Pseudomonas) ; evolution ; of catabolic pathways ; hydrocarbons ; catabolism of aromatic ; Pseudomonas ; evolution of catabolism in ; oxygenases ; evolution of
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Energietechnik , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The organisation and nucleotide sequences coding for the catabolism of benzene, toluene (and xylenes), naphthalene and biphenylvia catechol and the extradiol (meta) cleavage pathway inPseudomonas are reviewed and the various factors which may have played a part in their evolution are considered. The data suggests that the complete pathways have evolved in a modular way probably from at least three elements. The commonmeta pathway operons, downstream from the ferredoxin-like protein adjacent to the gene for catechol 2,3-dioxygenase, are highly homologous and clearly share a common ancestry. This common module may have become fused to a gene or genes the product(s) of which could convert a stable chemical (benzoate, salicylate, toluene, benzene, phenol) to catechol, thus forming the lower pathway operons found in modern strains. The upper pathway operons might then have been acquired as a third module at a later stage thus increasing the catabolic versatility of the host strains.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00696460
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  • 11
    Digitale Medien
    Digitale Medien
    Progressive determination of cell fates along the dorsoventral axis in the sea urchin Heliocidaris erythrogramma (1994)
    Springer
    Development genes and evolution 204 (1994), S. 62-69 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Cell determination ; direct development dorsoventral axis ; echinoids ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the direct-developing sea urchinHeliocidaris erythrogramma the first cleavage division bisects the dorsoventral axis of the developing embryo along a frontal plane. In the two-celled embryo one of the blastomeres, the ventral cell (V), gives rise to all pigmented mesenchyme, as well as to the vestibule of the echinus rudiment. Upon isolation, however, the dorsal blastomere (D) displays some regulation, and is able to form a small number of pigmented mesenchyme cells and even a vestibule. We have examined the spatial and temporal determination of cell fates along the dorsoventral axis during subsequent development. We demonstrate that the dorsoventral axis is resident within both cells of the two-celled embryo, but only the ventral pole of this axis has a rigidly fixed identity this early in development. The polarity of this axis remains the same in half-embryos developing from isolated ventral (V) blastomeres, but it can flip 180° in half-embryos developing from isolated dorsal (D) blastomeres. We find that cell fates are progressively determined along the dorsoventral axis up to the time of gastrulation. The ability of dorsal half-embryos to differentiate ventral cell fates diminishes as they are isolated at progressively later stages of development. These results suggest that the determination of cell fates along the dorsoventral axis inH. erythrogramma is regulated via inductive interactions organized by cells within the ventral half of the embryo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00744874
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  • 12
    Digitale Medien
    Digitale Medien
    Development of non-reproductive castes in the neotropical termite generaCornitermes, Embiratermes andRhynchotermes (Isoptera, Nasutitermitinae) (1992)
    Springer
    Insectes sociaux 39 (1992), S. 313-324 
    Details
    ISSN: 1420-9098
    Schlagwort(e): Isoptera ; Termitidae ; Nasutitermitinae ; caste differentiation ; phylogeny ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The developmental pattern of the neuter castes was studied in the mandibulate nasute generaCornitermes, Embiratermes andRhynchotermes. InCornitermes walkeri, all the workers and soldiers are male. There are two larval and a single worker instar. Workers can molt into presoldiers. InEmbiratermes chagresi andRhynchotermes perarmatus, both sexes are present among the neuters. A slight sexual dimorphism (males 〉 females) is discernible among both larval instars and among workers ofE. chagresi; female workers can molt into presoldiers. InR. perarmatus, the sexual dimorphism is conspicuous from the first larval instar on. Male larvae go through two instars, then give rise to workers, which do not molt. InR. perarmatus, there is no worker stage in females, but a third larval instar, preceding the presoldier. Hypotheses are proposed as to the evolution of these caste patterns, attempting to conciliate present knowledge of Nasutitermitinae phylogeny and known evolutionary trends affecting termite caste patterns, according to the species' ecology.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01323951
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  • 13
    Digitale Medien
    Digitale Medien
    Social organization in some primitive Australian ants. I.Nothomyrmecia macrops Clark (1992)
    Springer
    Insectes sociaux 39 (1992), S. 425-438 
    Details
    ISSN: 1420-9098
    Schlagwort(e): Formicidae ; Nothomyrmecia ; evolution ; sociogram ; ethogram ; recognition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Results of laboratory-based ethological studies on twoNothomyrmecia macrops colonies with individually marked workers are reported. Interactive behavioural acts constituted less than 1% of all those recorded, revealing a strong tendency by the ants not to engage in social contact. Very few workers performed queen-directed acts. They stayed near the queen, though seldom in direct contact. Division of labour was otherwise barely apparent, except that some individuals showed a propensity to guard the nest entrance. No exchange of food was observed between workers, workers and queen, or adults and larvae (apart from worker placement of prey items with larvae). A queen fed from aDrosophila carcass retrieved from the nest floor, without assistance from workers. Systematic scanned observations confirmed levels of inactivity higher than previously observed in ants (comprising almost 2/3 of recorded behavioural acts). The time budget for activities directed toward the immature stages was the same in both colonies, and fluctuated during the circadian period. Non-nestmate larvae added to worker groups were more frequently licked than nestmate larvae, but this might not involve the particular recognition of nestmateversus non-nestmate brood. These observations support the hypothesis thatNothomyrmecia is primitively eusocial, and of special significance in myrmecology.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01240625
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  • 14
    Digitale Medien
    Digitale Medien
    Endogenous synthesis of peptidoglycan in eukaryotic cells; a novel concept involving its essential role in cell division, tumor formation and the biological clock (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 921-931 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Biological clock ; cell division cycle ; diaminopimelate ; evolution ; FSu ; lysine ; muramate ; muramyl dipeptide ; peptidoglycan ; sleep muropeptide ; tumor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Degradation products of peptidoglycan, the universal bacterial cell wall constituent, were previously found in animal tissues and urine. Reassessment and quantitative analysis of available data lead to an original concept, i.e. that eukaryotic cells synthesize peptidoglycan. We present a model in which this endogenously synthesized peptidoglycan is essential for the processes of eukaryotic cell division and sleep induction in animals. Genes for peptidoglycan metabolism, like those for lysine biosynthesis in plants, are probably inherited from endosymbiotic bacteria, the ancestors of mitochondria and chloroplasts. Corollaries of this concept, i.e. roles for peptidoglycan metabolism in tumor formation and in the biological clock, are supported by abundant evidence. We propose that many interactions between bacteria and eukaryotes are conditioned by their common genetic heritage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01919139
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  • 15
    Digitale Medien
    Digitale Medien
    Progressive determination of cell fates along the dorsoventral axis in the sea urchin Heliocidaris erythrogramma (1994)
    Springer
    Development genes and evolution 204 (1994), S. 62-69 
    Details
    ISSN: 1432-041X
    Schlagwort(e): Cell determination ; direct development dorsoventral axis ; echinoids ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the direct-developing sea urchin Heliocidaris erythrogramma the first cleavage division bisects the dorsoventral axis of the developing embryo along a frontal plane. In the two-celled embryo one of the blastomeres, the ventral cell (V), gives rise to all pigmented mesenchyme, as well as to the vestibule of the echinus rudiment. Upon isolation, however, the dorsal blastomere (D) displays some regulation, and is able to form a small number of pigmented mesenchyme cells and even a vestibule. We have examined the spatial and temporal determination of cell fates along the dorsoventral axis during subsequent development. We demonstrate that the dorsoventral axis is resident within both cells of the two-celled embryo, but only the ventral pole of this axis has a rigidly fixed identity this early in development. The polarity of this axis remains the same in half-embryos developing from isolated ventral (V) blastomeres, but it can flip 180° in half-embryos developing from isolated dorsal (D) blastomeres. We find that cell fates are progressively determined along the dorsoventral axis up to the time of gastrulation. The ability of dorsal half-embryos to differentiate ventral cell fates diminishes as they are isolated at progressively later stages of development. These results suggest that the determination of cell fates along the dorsoventral axis in H. erythrogramma is regulated via inductive interactions organized by cells within the ventral half of the embryo.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00189069
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  • 16
    Digitale Medien
    Digitale Medien
    The Light Green Cells ofLymnaea: A neuroendocrine model system for stimulus-induced expression of multiple peptide genes in a single cell type (1992)
    Springer
    Cellular and molecular life sciences 48 (1992), S. 464-473 
    Details
    ISSN: 1420-9071
    Schlagwort(e): Molluscan insulin-related peptides ; schistosomin ; neuropeptide gene family ; generation of neuropeptide diversity ; stimulus-dependent expression ; information-handling capacity ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract We review recent experiments showing that the cerebral neuroendocrine Light Green Cells (LGCs) of the freshwater snail,Lymnaea stagnalis, express a family of distinct though related molluscan insulin-related peptide (MIP) genes. The LGCs are involved in the regulation of a wide range of interrelated life processes associated with growth, (energy) metabolism and reproduction. We consider the mechanism of generation of diversity among MIPs, and present evidence that conditions with distinct effects on growth, metabolism and reproduction also can induce distinct patterns of expression of the MIP and schistosomin genes. The stimulus-dependent expression of multiple neuropeptide genes enormously increases the adaptive potential of a peptidergic neuron. We suggest that this contributes significantly to the information-handling capacity of the brain.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01928165
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  • 17
    Digitale Medien
    Digitale Medien
    Parental care in terrestrial gastropods (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 5-14 
    Details
    ISSN: 1420-9071
    Schlagwort(e): parental investment ; juvenile survival ; evolution ; gastropods ; molluscs ; ovoviviparity ; viviparity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Parental care in terrestrial gastropods includes the of oviposition sites, production of large, heavily-yolked eggs supplied with calcium carbonate, provisioning of hatchings with eggs in specis with facultative sibling cannibalism, egg retention, and ovoviviparity. Evidence for true viviparity is scarce in terrestrial gastropods, as it is for postlaying care of eggs, though external egg carrying on the shell occurs in a few species. Care of young has not been observed in any terrestrial gastropod species. Provisioning of eggs with nutrients and calcium carbonate might be the most common form of parental investment. Ovoviviparity allows terrestrial gastropods to persist in habitats otherwise unsuitable for oviparous species (e.g. exposed rock walls). An interspecific comparison demonstrates that egg-retaining and ovoviviparous species produce smaller clutches than oviparous species and suggests a cost of parental care.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01992042
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  • 18
    Digitale Medien
    Digitale Medien
    The origin of life — A task in molecular engineering (1992)
    Springer
    Molecular engineering 1 (1992), S. 377-399 
    Details
    ISSN: 1572-8951
    Schlagwort(e): Origin of life ; molecular engineering ; biology ; evolution ; genetic code ; translation machine ; self instruction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract In attempting to understand how life originated, we search for a detailed sequence of experimentally testable physico-chemical steps in an appropriately structured system. This goal is approached in two stages. First we search for the organizational structure of processes leading to systems with the basic features of living organisms. This is an engineering problem: finding a certain construct by taking care of logical requirements and restrictions from physics. Then we face this construct with the chemical and geophysical reality, and this leads to the view that systems with the essential features of early living organisms evolve following a distinct pathway. Energy supply and the presence of a particular structure in space and time are necessary to induce and drive the processes triggered by stochastic events; but if these particular conditions are given, the broad line of the evolutionary processes is determined by logical requirements and by chemical and geophysical constrains and invariants. The genetic machinery considered to evolve in this manner agrees, in its organizational structure and in many details, with the actual genetic machinery of biosystems. A surprising simplicity and transparency is observed in the logic of the basic processes involved in the origin of life. In the present view, the processes leading to the origin of life begin in a very particular, highly structured, small region where the relevant chemistry can be quite different from overall prebiotic chemistry. Energy-rich compounds are present in ample amounts and a succession of physico-chemical processes, which are per se thermodynamically allowed, takes place. This is in contrast to popular views that the origin of life is connected with fundamental thermodynamic questions related to the problem of getting order out of chaos.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00176808
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  • 19
    Digitale Medien
    Digitale Medien
    Poly(ADP-ribose) polymerase: Structural conservation among different classes of animals and its implications (1994)
    Springer
    Molecular and cellular biochemistry 138 (1994), S. 25-32 
    Details
    ISSN: 1573-4919
    Schlagwort(e): NAD ; evolution ; polymerase chain reaction ; zinc finger ; leucine zipper
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Poly(ADP-ribose) polymerase cDNAs have been isolated from different classes of animals. Cloning of genes from lower eukaryotes has allowed us to investigate directly the biological functions of poly(ADP-ribosyl)ationin vivo. The conservation of specific regions among mammals, chicken,Xenopus laevis, andDrosophila melanogaster reveals the essential structural elements required for recognition of breaks in DNA and for catalytic activity. Cys, His and basic residues in the zinc-finger consensus region are conserved. The carboxyl terminal region corresponding to an NAD-binding domain is strongly conserved. The dinucleotide-binding consensus sequence and β1-αA-β2, Rossmann fold structure, and β-sheet structures are completely conserved from mammals to insect. InDrosophila, a putative leucine-zipper motif has been identified, and other poly(ADP-ribose) polymerases also contain an α-helical, amphipathic structure in the auto-modification domain. In this article, we review the recent structural analyses of the functional domains of poly(ADP-ribose) polymerase in phylogenetically divergent species, and discuss the implications of structural conservation for its biological functions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00928439
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  • 20
    Digitale Medien
    Digitale Medien
    Sequence homology and structure predictions of the creatine kinase isoenzymes (1994)
    Springer
    Molecular and cellular biochemistry 133-134 (1994), S. 245-262 
    Details
    ISSN: 1573-4919
    Schlagwort(e): creatine kinase ; arginine kinase ; protein sequence comparison ; evolution ; CK framework ; ‘diagnostic boxes’ ; secondary structure prediction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract Comparisons of the protein sequences and gene structures of the known creatine kinase isoenzymes and other guanidino kinases revealed high homology and were used to determine the evolutionary relationships of the various guamidino kinases. A ‘CK framework’ is defined, consisting of the most conserved sequence blocks, and ‘diagnostic boxes’ are identified which are characteristic for anyone creatine kinase isoenzyme (e.g. for vertebrate B-CK) and which may serve to distinguish this isoenzyme from all others (e.g. from M-CKs and Mi-CKs). Comparison of the guanidino kinases by near-UV and far-UV circular dichroism further indicates pronounced conservation of secondary structure as well as of aromatic amino acids that are involved in catalysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01267958
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  • 21
    Digitale Medien
    Digitale Medien
    Evolution of behavioral responses to sex pheromone in mutant laboratory colonies ofTrichoplusia ni (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 231-238 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Trichoplusia ni ; Lepidoptera ; Noctuidae ; sex pheromone ; behavior ; evolution ; sexual selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Male cabbage looper moths,Trichoplusia ni, from two colonies in which all females express an abnormal sex pheromone production phenotype were evaluated in a laboratory wind tunnel for upwind flight responses to the normal and abnormal sex pheromones. The abnormal sex pheromone blend consisted of 20 times as much (Z)-9-tetradecenyl acetate and 30-fold less (Z)-5-dodecenyl acetate compared to the normal pheromone blend. Initially, these males exhibited poor behavioral responses to the abnormal sex pheromone and maximum responses to the normal pheromone blend, indicating that there was no linkage between signal production and response. After 49 generations of laboratory rearing, males from the mutant colonies maintained good responses to the normal pheromone and increased their behavioral response to the abnormal sex pheromone to the same levels as for the normal pheromone. Over the same period, normal males maintained their preference for the normal pheromone. These results indicated that evolution had occurred in mutant colonies in favor of greater male responsiveness to the abnormal sex pheromone, resulting in the broadening of the response spectrum to pheromone blend ratios. This evolution presumably resulted from a mating advantage to those males that did not discriminate against mutant-type females in the mutant colonies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02064433
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  • 22
    Digitale Medien
    Digitale Medien
    Nucleotide sequence ofatpB,rbcL,trnR,dedB andpsaI chloroplast genes from a fernAngiopteris lygodiifolia: a possible emergence of Spermatophyta lineage before the separation of Bryophyta and Pteridophyta (1992)
    Springer
    Plant molecular biology 18 (1992), S. 79-82 
    Details
    ISSN: 1573-5028
    Schlagwort(e): Angiopteris lygodiifolia ; atpB ; chloroplast genome ; evolution ; rbcL ; trnR
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract To elucidate the evolutionary relationship between the Spermatophyta, Pteridophyta and Bryophyta, we cloned a fragment of chloroplast DNA from the fernAngiopteris lygodiifolia (Pteridophyta) and determined its nucleotide sequence. The fragment contained theatpB,rbcL,trnR-CCG,dedB andpsaI genes. Comparisons of the deduced amino acid and nucleotide sequences of these genes from the three plant groups indicate thatAngiopteris sequences are more closely related to those of Bryophyta species (85% identity on average) than to those of seed plants (76% identity on average), supporting a hypothesis that the Bryophyta and Pteridophyta diverged more recently from one another than their common progenitor diverged from that of the Spermatophyta.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00018458
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  • 23
    Digitale Medien
    Digitale Medien
    The activation process of Arabidopsis thaliana A1 gene encoding the translation elongation factor EF-1α is conserved among angiosperms (1992)
    Springer
    Plant molecular biology 18 (1992), S. 1083-1089 
    Details
    ISSN: 1573-5028
    Schlagwort(e): translation elongation factor genes ; promoter analysis ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In Arabidopsis thaliana, the activation process of the A1 EF-1α gene depends on several elements. Using the GUS reporter gene, transient expression experiments have shown that mutations of upstream cis-acting elements of the A1 promoter, or the deletion of an intron located within the 5′ non-coding region, similarly affect expression in dicot or monocot protoplasts. The results reported here strongly suggest that this 5′ intron is properly spliced in Zea mays. We show that two trans-acting factors, specifically interacting with an upstream activating sequence (the TEF 1 box), are present in nuclear extracts prepared from A. thaliana, Brassica rapa, Nicotiana tabacum and Z. mays. In addition, a DNA sequence homologous to the TEF 1 box, found at approximately the same location within a Lycopersicon esculentum EF-1α promoter, interacts with the same trans-acting factors. Homologies found between the A. thaliana and L. esculentum TEF 1 box sequences have allowed us to define mutations of this upstream element which affect the interaction with the corresponding trans-acting factors. These results support the notion that the activation processes of A. thaliana EF-1α genes have been conserved among angiosperms and provide interesting data on the functional structure of the TEF 1 box.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00047711
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  • 24
    Digitale Medien
    Digitale Medien
    A 16 kb small single-copy region separates the plastid DNA inverted repeat of the unicellular red alga Cyanidium caldarium: physical mapping of the IR-flanking regions and nucleotide sequences of the psbD-psbC, rps16, 5S rRNA and rpl21 genes (1992)
    Springer
    Plant molecular biology 19 (1992), S. 1001-1010 
    Details
    ISSN: 1573-5028
    Schlagwort(e): Cyanidium caldarium Geitler ; evolution ; Galdieria sulphuraria ; inverted repeat ; plastid DNA ; psbD-psbC operon ; red algae ; 5S rRNA ; rpl21 ; rps16
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The four inverted repeat (IR) flanking regions of the Cyanidium caldarium plastid DNA were cloned. Southern blotting, transcript and sequence analyses of the border regions revealed the psbD-psbC operon and the rps16 gene within the large single-copy region upstream of the 16S rDNA gene and the rpl21 gene downstream of the 5S rDNA within the 16 kb small single-copy region. The size of the IR is ca. 5 kb. The nucleotide sequences of the psbD-psbC, rps16, rpl21 and 5S rRNA genes with the corresponding alignments and physical maps of the regions are presented. Northern analysis revealed a less complex psbD-psbC transcription pattern than has been found in higher plants. Comparisons to other red algal data point to structural diversity within red algal plastid DNA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00040531
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  • 25
    Digitale Medien
    Digitale Medien
    Comparison of regions coding for tRNAHis genes of mitochondrial and chloroplast DNA in sunflower: a proposal concerning the classification of ‘CP-like’ tRNA genes (1992)
    Springer
    Plant molecular biology 20 (1992), S. 1-4 
    Details
    ISSN: 1573-5028
    Schlagwort(e): higher plants ; sunflower ; chloroplast genome ; mitochondrial genome ; tRNAHis genes ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00029143
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  • 26
    Digitale Medien
    Digitale Medien
    Genomic structure, expression and evolution of the alfalfa aspartate aminotransferase genes (1994)
    Springer
    Plant molecular biology 25 (1994), S. 387-399 
    Details
    ISSN: 1573-5028
    Schlagwort(e): aspartate aminotransferase ; gene structure ; nodule ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Genomic clones encoding two isozymes of aspartate aminotransferase (AAT) were isolated from an alfalfa genomic library and their DNA sequences were determined. The AAT1 gene contains 12 exons that encode a cytosolic protein expressed at similar levels in roots, stems and nodules. In nodules, the amount of AAT1 mRNA was similar at all stages of development, and was slightly reduced in nodules incapable of fixing nitrogen. The AAT1 mRNA is polyadenylated at multiple sites differing by more than 250 bp. The AAT2 gene contains 11 exons, with 5 introns located in positions identical to those found in animal AAT genes, and encodes a plastid-localized isozyme. The AAT2 mRNA is polyadenylated at a very limited range of sites. The transit peptide of AAT2 is encoded by the first two and part of the third exon. AAT2 mRNA is much more abundant in nodules than in other organs, and increases dramatically during the course of nodule development. Unlike AAT1, expression of AAT2 is significantly reduced in nodules incapable of fixing nitrogen. Phylogenetic analysis of deduced AAT proteins revealed 4 separate but related groups of AAT proteins; the animal cytosolic AATs, the plant cytosolic AATs, the plant plastid AATs, and the mitochondrial AATs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00043868
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  • 27
    Digitale Medien
    Digitale Medien
    Models of the three-dimensional structures of echidna, horse, and pigeon lysozymes: Calcium-binding lysozymes and their relationship with α-lactalbumins (1994)
    Springer
    The protein journal 13 (1994), S. 569-584 
    Details
    ISSN: 1573-4943
    Schlagwort(e): Calcium-binding lysozyme ; α-lactalbumin ; three-dimensional structure ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Similarities in amino acid sequences, three-dimensional structures, and the exon-intron patterns of their genes have indicated thatc-type lysozymes andα-lactalbumins are homologous proteins, i.e., descended by divergent evolution from a common ancestor. Like theα-lactalbumins, echidna milk, horse milk, and pigeon eggwhite lysozymes all bind Ca(II). Models of their three-dimensional structures, based on their amino acid sequences and the known crystal structures of domestic hen eggwhite and human lysozymes and baboon and humanα-lactalbumins, have been built. The several structures have been compared and their relationships discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01901539
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  • 28
    Digitale Medien
    Digitale Medien
    An equivalent to bacterialompR genes is encoded on the plastid genome of red algae (1992)
    Springer
    Plant molecular biology 18 (1992), S. 777-780 
    Details
    ISSN: 1573-5028
    Schlagwort(e): Cyanidium caldarium ; evolution ; Galdieria sulphuraria ; rRNA operon
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00020019
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  • 29
    Digitale Medien
    Digitale Medien
    Perspectives on zinc finger protein function and evolution - an update (1994)
    Springer
    Molecular biology reports 20 (1994), S. 1-8 
    Details
    ISSN: 1573-4978
    Schlagwort(e): review ; zinc finger protein ; DNA recognition ; evolution ; development
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Complexity is one of the hallmarks that applies to C2H2 type zinc finger proteins (ZFPs). Structurally distinct clusters of zinc finger modules define an extremely large superfamily of nucleic acid binding proteins with several hundred, perhaps thousands of different members in vertebrates. Recent discoveries have provided new insights into the biochemistry of RNA and DNA recognition, into ZFP evolution and genomic organization, and also into basic aspects of their biological function. However, as much as we have learned, other fundamental questions about ZFP function remain highly enigmatic. This essay is meant to define what we personally feel are important questions, rather than trying to provide a comprehensive, encyclopaedic review.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00999848
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  • 30
    Digitale Medien
    Digitale Medien
    Chloroplast encoded thioredoxin genes in the red algae Porphyra yezoensis and Griffithsia pacifica: evolutionary implications (1994)
    Springer
    Plant molecular biology 25 (1994), S. 13-21 
    Details
    ISSN: 1573-5028
    Schlagwort(e): chloroplast ; evolution ; red algae ; thioredoxin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A gene encoding a thioredoxin protein was identified in the chloroplast genome of the rhodophyte Porphyra yezoensis. The P. yezoensis trxA gene contains 324 bp and is transcribed into a 0.7 kb messenger RNA. Analysis of the transcription start site demonstrates that canonical chloroplast −10 and −35 sequences are not present. The deduced amino acid sequence of the thioredoxin gene from the red algae has the greatest similarity to type m thioredoxins, providing strong support for the hypothesis that type m thioredoxins in photosynthetic eukaryotes originated from an engulfed bacterial endosymbiont. Hybridization analysis of nuclear and chloroplast DNAs from several members of the phyla Chromophyta and Rhodophyta using P. yezoensis DNA as a probe demonstrated strong hybridization to the chloroplast and nuclear genomes of Griffithsia pacifica and a weak cross-hybridization to the chromophyte P. foliaceum. The G. pacifica chloroplast gene has a 66% identity with the P. yezoensis DNA, contains conserved active site amino acid residues, but lacks a methionine start codon.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00024194
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  • 31
    Digitale Medien
    Digitale Medien
    Differential abundance of simple repetitive sequences in species ofBrassica and relatedBrassicaceae (1994)
    Springer
    Plant systematics and evolution 190 (1994), S. 21-30 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Brassicaceae ; Brassica ; Sinapis ; Raphanus ; Eruca ; Repetitive DNA ; fingerprinting ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract SixBrassica species, known as the “triangle of U”, and four species from related genera were characterized by DNA fingerprinting with simple repetitive oligonucleotide probes. Our results show that CT-, TCC-, and GTG-repeat motifs are equally abundant in the genomes of the sixBrassica species. In contrast, GATA-, GGAT-, and GACA-multimers are unevenly distributed among different species. As judged from the number and strength of hybridization signals, the highest copy number of all three motifs occurs inBrassica nigra, while the lowest is observed inB. oleracea. The abundance of GATA-and GACA-repeats varies in a coordinate way. The amphidiploid genomes ofB. juncea, B. carinata, andB. napus each harbour intermediate amounts of (GATA)4 and (GACA)4-detected repeats as compared to their diploid progenitors, thus supporting the concept of the “U triangle”. GATA-, GACA-, and GGAT-repeats were also abundant inEruca sativa andSinapis arvensis, but not inRaphanus sativus andSinapis alba. These results support the idea thatBrassica nigra is more closely related toSinapis arvensis than to otherBrassica species such asB. rapa andB. oleracea.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00937856
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  • 32
    Digitale Medien
    Digitale Medien
    Domatia as most important adaptations in the evolution of myrmecophytes in the paleotropical tree genusMacaranga (Euphorbiaceae) (1992)
    Springer
    Plant systematics and evolution 180 (1992), S. 53-64 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Euphorbiaceae ; Macaranga ; Ant-plant interactions ; domatia ; evolution ; myrmecophytism ; Flora of Malaysia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The paleotropical tree genusMacaranga (Euphorbiaceae) comprises all stages of interaction with ants, from facultative associations to obligate myrmecophytes. In SE.-Asia food availability does not seem to be the limiting factor for the development of a close relationship since all species provide food for ants in form of extrafloral nectar and/or food bodies. Only myrmecophyticMacaranga species offer nesting space for ants (domatia) inside internodes which become hollow due to degeneration of the pith. Non-myrmecophytic species have a solid stem with a compact and wet pith and many resin ducts. The stem interior of some transitional species remains solid, but the soft pith can be excavated. The role of different ant-attracting attributes for the development of obligate ant-plant interactions is discussed. In the genusMacaranga, the provision of nesting space seems to be the most important factor for the evolution of obligate myrmecophytism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940397
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  • 33
    Digitale Medien
    Digitale Medien
    Phylogenetic evidence for the herbaceous origin of angiosperms (1992)
    Springer
    Plant systematics and evolution 180 (1992), S. 137-156 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; evolution ; origin ; ancestral angiosperm ; morphology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The ancestral angiosperm is commonly interpreted as an arborescent to shrubby magnolialean with large, multiparted, complex flowers. We examined this hypothesis using a phylogenetic analysis of new and reevaluated characters polarizabled with outgroup comparison. Our cladistic analysis of basal angiosperms placed the nonmagnolialeanChloranthaceae andPiperaceae at the bottom of the tree. We further inferred the probable ancestral states of characters not polarizable with outgroup comparison by examining their distribution among taxa at the base of our cladogram. The sum of ancestral character states suggests that the protoangiosperm was a diminutive, rhizomatous to scrambling perennial herb, with small, simple flowers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00941148
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  • 34
    Digitale Medien
    Digitale Medien
    Isozyme variation and alleged progenitor-derivative relationships in theMedicago murex complex (Fabaceae) (1992)
    Springer
    Plant systematics and evolution 181 (1992), S. 33-43 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Fabaceae ; Medicago murex ; M. lesinsii ; Systematics ; evolution ; isozymes ; chromosomes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Chromosomal studies ofMedicago lesinsii (n = 8) and its close relativeM. murex (n = 7) have led to the competing hypotheses that the latter is derived directly from the former, or that both originated from a common ancestor. In contrast to the relatively variableM. murex, M. lesinsii proved to be almost uniform isozymically, except that most populations of Greece differed by one allele from plants of the remainder of the range. This Greek variant ofM. lesinsii was indistinguishable from one of the isozyme variants ofM. murex. The greater level of allozyme variation inM. murex was consistent with its greater ecological amplitude and competitive ability. Also, this suggests thatM. murex is unlikely to have originated directly from the less variableM. lesinsii. The data suggest that either both species originated from a common ancestor, or that the n = 8 species evolved from the n = 7 species, a mode of chromosome evolution not previously hypothesized for the genus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00937585
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  • 35
    Digitale Medien
    Digitale Medien
    Phenetic, biogeographical, and evolutionary study ofOrnithogalum subg.Heliocharmos (Hyacinthaceae) in the western Mediterranean basin (1992)
    Springer
    Plant systematics and evolution 181 (1992), S. 179-202 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Hyacinthaceae ; Ornithogalum ; Heliocharmos ; O. algeriense ; O. kochii ; O. orthophyllum ; O. umbellatum ; Numerical taxonomy ; phenetics ; systematics ; biogeography ; evolution ; Flora of North Africa ; Mediterranean ; Morocco ; Spain ; France
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A macromorphological study is made on taxa of the genusOrnithogalum subg.Heliocharmos in North Africa, Spain, and France. The results obtained are consistent with data from cytogenetics, reproductive biology and strategies of reproduction. They allow the retention of two species:O. algeriense andO. umbellatum. A biogeographical and phylogenetic interpretation of the subgenus is proposed for the western Mediterranean. Theoretical views on phenetics are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00937443
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  • 36
    Digitale Medien
    Digitale Medien
    The 5S DNA units ofAcacia species (Mimosaceae) (1992)
    Springer
    Plant systematics and evolution 183 (1992), S. 235-247 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Mimosaceae ; Acacia ; 5S DNA ; evolution ; phylogeny ; chromosomal lineages
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The DNA sequence structure of 5S DNA units inAcacia species, including representatives from the three subgenera ofAcacia, have been determined. The data was interpreted to suggest that at least three lineages of 5S DNA sequences exist inAcacia and the proposal was made that the lineages be named5S Dna-1, 5S Dna-2, and5S Dna-3. The5S Dna-1 lineage was represented by units fromA. boliviana andA. bidwilli, the5S Dna-2 lineage by units fromA. melanoxylon, A. pycnantha, A. ulicifolia, A. boliviana, A. bidwillii, andA. albida, and the5S Dna-3 lineage by units fromA. bidwillii, A. boliviana, andA. senegal. Based on this interpretation of the sequence data, the Australian species of subg.Phyllodineae grouped together as a cluster, quite separate from the subgeneraAculeiferum andAcacia. As expected from the analyses of morphological characters, the 5S DNA units fromAcacia albida (syn.Faidherbia albida) were quite separate from the otherAcacia spp.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940806
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  • 37
    Digitale Medien
    Digitale Medien
    Relationships betweenOryza species (Poaceae) based on 5S DNA sequences (1992)
    Springer
    Plant systematics and evolution 183 (1992), S. 249-264 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Poaceae ; Oryza ; 5S DNA ; phylogeny ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Relationships between 9Oryza species, covering 6 different genomes, have been studied using hybridization and nucleotide sequence information from the5S Dna locus. Four to five units of the major size class of 5S DNA in each species, 55 units in all, were cloned and sequenced. Both hybridization and sequence data confirmed the basic differences between the A and B, C, D genome species suggested by morphological and cytological data. The 5S DNA units of the A genome species were very similar, as were the ones from the B, C, and D genome-containing species. The 5S DNA ofO. australiensis (E genome) grouped with the B, C, D cluster, while the units ofO. brachyantha (F genome) were quite different and grouped away from all other species. 5S DNA units fromO. minuta, O. latifolia, O. australiensis, andO. brachyantha hybridized strongly, and preferentially, to the genomic DNA from which the units were isolated and hence could be useful as species/genome specific probes. The 5S DNA units fromO. sativa, O. nivara, andO. rufipogon provided A genome-specific probes as they hybridized preferentially to A genome DNA. The units fromO. punctata andO. officinalis displayed weaker preferential hybridization toO. punctata DNA, possibly reflecting their shared genome (C genome).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940807
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  • 38
    Digitale Medien
    Digitale Medien
    Relationships between species ofLeymus, Psathyrostachys, andHordeum (Poaceae, Triticeae) inferred from Southern hybridization of genomic and cloned DNA probes (1994)
    Springer
    Plant systematics and evolution 189 (1994), S. 217-231 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Poaceae ; Triticeae ; Leymus ; Hordeum ; Psathyrostachys ; Taxonomy ; evolution ; molecular evolution ; repetitive DNA ; rDNA polymorphisms ; RFLP analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have used total genomic DNA as a probe to size-fractionated restriction enzyme digests of genomic DNA from a range ofTriticeae species from the generaLeymus Hochst.,Psathyrostachys Nevski, andHordeum L., and hybrids betweenHordeum andLeymus to investigate their taxonomic relationships. Genomic Southern hybridization was found to be an effective and simple way to assess the distribution and diversity of essentially species-specific and common, repetitive DNA sequences, and is hence especially useful in evolutionary studies. The DNA sequences ofH. vulgare seem to diverge substantially from those ofH. brachyantherum, H. lechleri, H. procerum, andH. depressum. The genome ofThinopyron bessarabicum shows little homology to those of theLeymus species investigated, confirming thatT. bessarabicum is not an ancestral genome inLeymus. Although the genomes ofLeymus andPsathyrostachys share substantial proportions of DNA sequences, they include divergent repeated sequences as well. Hybridization with a ribosomal DNA probe (pTa 71) showed that the coding regions containing structural genes encoding the 18 S, 5.8 S, and 26 S ribosomal RNA were conserved among the species investigated, whereas the intergenic spacer region was more variable, presenting different sizes of restriction fragments and enabling a classification of the species. The rye heterochromatin probe pSc 119.2 hybridized to DNA fromH. lechleri andT. bessarabicum, but not to DNA from the other species investigated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00939728
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  • 39
    Digitale Medien
    Digitale Medien
    Evidence from RAPD markers in the evolution ofEchinochloa millets (Poaceae) (1994)
    Springer
    Plant systematics and evolution 189 (1994), S. 247-257 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Poaceae ; Echinochloa ; sawa and barnyard millets ; RAPD analysis ; evolution ; genetic resources
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Echinochloa (Poaceae) includes two domesticated species,Echinochloa utilis (Japanese barnyard millet) andE. frumentacea (Indian sawa millet) and 20–30 wild species. The two millets are morphologically very variable and overlap in spikelet and inflorescence characteristics. Both species are hexaploids based on x = 9. Cytogenetic studies point to the hexaploid wild speciesE. crusgalli andE. colona as possible progenitors ofE. utilis andE. frumentacea, respectively. The tetraploidE. oryzoides is considered as a possible genome donor to wild and domesticated barnyard millet. Markers from Random Amplified Polymorphic DNA method were used to assess the proposed phylogeny and examine the genetic diversity in both domesticated and wild species. The data were analyzed numerically.Echinochloa utilis andE. frumentacea appear very distinct, but grouped withE. crusgalli andE. colona, respectively. The tetraploidE. oryzoides show strong genetic affinity to theE. utilis—E. crusgalli group. The data are in general agreement with the cytogenetic information; however, some disagreements on the interpretation of some of the cytogenetic information is raised. The variability in DNA markers observed in the domesticated species, particularlyE. frumentacea, points to the feasibility of using RAPD markers in cultivar fingerprinting and breeding programs of these millets.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00939730
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  • 40
    Digitale Medien
    Digitale Medien
    Allozymic and morphological relationships amongAndrocymbium gramineum, A. europaeum, andA. psammophilum (Colchicaceae) (1994)
    Springer
    Plant systematics and evolution 191 (1994), S. 111-126 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Colchicaceae ; Androcymbium ; Allozymes ; evolution ; taxonomy ; genetic conservation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Levels of allozymic and morphological diversity amongAndrocymbium gramineum, A. europaeum, andA. psammophilum have been assessed using data on 17 allozyme loci and 18 morphological characters. No apparent pattern of geographic or ecological variation was found. Our results also suggest thatA. gramineum andA. europaeum should be considered members of a single species and that the insular speciesA. psammophilum can no longer be thought of as the result of a founder effect fromA. gramineum. Intrapopulational variability was greater than inter-populational variability at both levels studied, which is of strategic interest for the “ex-situ” conservation of these threatened endemic species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985346
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  • 41
    Digitale Medien
    Digitale Medien
    Bioaltruism reconsidered (1994)
    Springer
    Biology and philosophy 9 (1994), S. 75-84 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Altruism ; ethics ; ethology ; evolution ; sociobiology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract Altruistic behavior is often regarded as sociobiology's most central theoretical problem, but is it? Altruism in biology, bioaltruism, has many meanings, which can be grouped into two categories. The first I will callcommon bioaltruism. It is primarily of ethological relevance. The second,evolutionary bioaltruism, is a special category in evolutionary respects in that it may indeed pose a problem for evolutionary theory. These categories are logically independent. Moreover, both of them are logically different from altruism in its everyday psychological or moral sense. Sociobiological examples of bioaltruistic behavior concern bioaltruism in the first sense only, so the theoretical problem ‘altruism’ is supposed to pose, is indeed nothing but a theoretical problem and the bioaltruism that actually occurs has no evolutionary relevance. Nevertheless, evolutionary theory is relevant to our understanding of the possibility of common bioaltruism, and that possibility — even though bioaltruism is conceptually different from ethical altruism — is relevant for ethicists: it sheds light on what we can ask people to do or not to do.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00849915
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  • 42
    Digitale Medien
    Digitale Medien
    Ernst Mayr, naturalist: His contributions to systematics and evolution (1994)
    Springer
    Biology and philosophy 9 (1994), S. 267-327 
    Details
    ISSN: 1572-8404
    Schlagwort(e): biogeography ; Ernst Mayr ; evolution ; naturalist ; nomenclature ; systematics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract Ernst Mayr's scientific career continues strongly 70 years after he published his first scientific paper in 1923. He is primarily a naturalist and ornithologist which has influenced his basic approach in science and later in philosophy and history of science. Mayr studied at the Natural History Museum in Berlin with Professor E. Stresemann, a leader in the most progressive school of avian systematics of the time. The contracts gained through Stresemann were central to Mayr's participation in a three year expedition to New Guinea and The Solomons, and the offer of a position in the Department of Ornithology, American Museum of Natural History, beginning in 1931. At the AMNH, Mayr was able to blend the best of the academic traditions of Europe with those of North America in developing a unified research program in biodiversity embracing systematics, biogeography and nomenclature. His tasks at the AMNH were to curate and study the huge collections amassed by the Whitney South Sea Expedition plus the just purchased Rothschild collection of birds. These studies provided Mayr with the empirical foundation essential for his 1942Systematics and the Origin of Species and his subsequent theoretical work in evolutionary biology as well as all his later work in the philosophy and history of science. Without a detailed understanding of Mayr's empirical systematic and biogeographic work, one cannot possibly comprehend fully his immense contributions to evolutionary biology and his later analyses in the philosophy and history of science.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00857938
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  • 43
    Digitale Medien
    Digitale Medien
    Mental content and evolutionary explanation (1992)
    Springer
    Biology and philosophy 7 (1992), S. 1-12 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Cognitive ethology ; mental content ; mental representations ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract Cognitive ethology is the comparative study of animal cognition from an evolutionary perspective. As a sub-discipline of biology it shares interest in questions concerning the immediate causes and development of behavior. As a part of ethology it is also concerned with questions about the function and evolution of behavior. I examine some recent work in cognitive ethology, and I argue that the notions of mental content and representation are important to enable researchers to answer questions and state generalizations about the function and volution of behavior.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00130160
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  • 44
    Digitale Medien
    Digitale Medien
    What is hierarchical selection? (1992)
    Springer
    Biology and philosophy 7 (1992), S. 27-33 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Additivity ; ANOVA ; evolution ; hierarchical selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract It has been proposed that natural selection occurs on a hierarchy of levels, of which the organismic level is neither the top nor the bottom. This hypothesis leads to the following practical problem: in general, how does one tell if a given phenomenon is a result of selection on level X or level Y. How does one tell what the units of selection actually are? It is convenient to assume that a unit of selection may be defined as a type of entity for which there exists, among all entities on the same “level” as that entity, an additive component of variance for some specific component F of fitness which does not appear as an additive component of variance in any decomposition of this F among entities at any lower level. But such a definition implicitly assumes that if f(x, y) depends nonadditively on its arguments, there must be interaction between the quantities which x and y represent. This assumption is incorrect. And one cannot avoid this error by speaking of “transformability to additivity” instead of merely “additivity”. A general mathematical formulation of the concepts of interaction and non-interaction is proposed, followed by a correspondingly modified approach to the definition of a unit of selection. The practical difficulty of verifying the presence of hierarchical selection is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00130162
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  • 45
    Digitale Medien
    Digitale Medien
    An ecological approach to biosystem thermodynamics (1992)
    Springer
    Biology and philosophy 7 (1992), S. 35-60 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Action principles ; ecosystem structure ; evolution ; information ; natural selection ; non-equilibrium thermodynamics ; teleology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract The general attributes of ecosystems are examined and a naturally occurring “reference ecosystem” is established, comparable with the “isolated” system of classical thermodynamics. Such an autonomous system with a stable, periodic input of energy is shown to assume certain structural characteristics that have an identifiable thermodynamic basis. Individual species tend to assume a state of “least dissipation”; this is most clearly evident in the dominant species (the species with the best integration of energy acquisition and conservation). It is concluded that ecosystem structure results from the antagonistic interaction of two nearly equal forces. These forces have their origin in the Principle of Most Action (“least dissipation” or “least entropy production”) and the universal Principle of Least Action. “Most action” is contingent on the equipartitioning of the energy available, through uniform interaction of similar individuals. The trend to “Least action” is contingent on increased dissipation attained through increasing diversity and increasing complexity. These principles exhibit a basic asymmetry. Given the operation of these opposing principles over evolutionary time, it is argued that ecosystems originated in the vicinity of thermodynamic equilibrium through the resonant amplification of reversible fluctuations. On account of the basic asymmetry the system was able to evolve away from thermodynamic equilibrium provided that it remained within the vicinity of “ergodynamic equilibrium” (equilibrium maintained by internal work, where the opposing forces are equal and opposite). At the highest level of generalization there appear to be three principles operating: i) maximum association of free-energy and materials; ii) energy conservation (deceleration of the energy flow) through symmetric interaction and increased homogeneity; and iii) the principle of least action which induces acceleration of the energy flow through asymmetrical interaction. The opposition and asymmetry of the two forces give rise to natural selection and evolution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00130163
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  • 46
    Digitale Medien
    Digitale Medien
    On the relationship between evolutionary and psychological definitions of altruism and selfishness (1992)
    Springer
    Biology and philosophy 7 (1992), S. 61-68 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Altruism ; evolution ; group selection ; selfishness
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract I examine the relationship between evolutionary definitions of altruism that are based on fitness effects and psychological definitions that are based on the motives of the actor. I show that evolutionary altruism can be motivated by proximate mechanisms that are psychologically either altruistic or selfish. I also show that evolutionary definitions do rely upon motives as a metaphor in which the outcome of natural selection is compared to the decisions of a psychologically selfish (or altruistic) individual. Ignoring the precise nature of both psychological and evolutionary definitions has obscured many important issues, including the biological roots of psychological altruism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00130164
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  • 47
    Digitale Medien
    Digitale Medien
    Evolution, altruism, and the prisoner's dilemma (1992)
    Springer
    Biology and philosophy 7 (1992), S. 161-175 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Altruism ; evolution ; Prisoner's Dilemma ; sociobiology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract I first argue against Peter Singer's exciting thesis that the Prisoner's Dilemma explains why there could be an evolutionary advantage in making reciprocal exchanges that are ultimately motivated by genuine altruism over making such exchanges on the basis of enlightened long-term self-interest. I then show that an alternative to Singer's thesis — one that is also meant to corroborate the view that natural selection favors genuine altruism, recently defended by Gregory Kavka, fails as well. Finally, I show that even granting Singer's and Kavka's claim about the selective advantage of altruism proper, it is doubtful whether that type of claim can be used in a particular sort of sociobiological argument against psychological egoism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00129881
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  • 48
    Digitale Medien
    Digitale Medien
    The evolution of altruism: Correlation, cost, and benefit (1992)
    Springer
    Biology and philosophy 7 (1992), S. 177-187 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Altruism ; evolution ; game theory ; group selection ; kin selection ; prisoner's dilemma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract A simple and general criterion is derived for the evolution of altruism when individuals interact in pairs. It is argued that the treatment of this problem in kin selection theory and in game theory are special cases of this general criterion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00129882
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  • 49
    Digitale Medien
    Digitale Medien
    Phylogenetic definitions and taxonomic philosophy (1992)
    Springer
    Biology and philosophy 7 (1992), S. 295-313 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Clade ; class ; composite whole ; definition ; defining property ; essentialism ; evolution ; individual ; intension ; name ; ostensive definition ; phylogeny ; population ; set ; species ; taxon ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract An examination of the post-Darwinian history of biological taxonomy reveals an implicit assumption that the definitions of taxon names consist of lists of organismal traits. That assumption represents a failure to grant the concept of evolution a central role in taxonomy, and it causes conflicts between traditional methods of defining taxon names and evolutionary concepts of taxa. Phylogenetic definitions of taxon names (de Queiroz and Gauthier 1990) grant the concept of common ancestry a central role in the definitions of taxon names and thus constitute an important step in the development of phylogenetic taxonomy. By treating phylogenetic relationships rather than organismal traits as necessary and sufficient properties, phylogenetic definitions remove conflicts between the definitions of taxon names and evolutionary concepts of taxa. The general method of definition represented by phylogenetic definitions of clade names can be applied to the names of other kinds of composite wholes, including populations and biological species. That the names of individuals (composite wholes) can be defined in terms of necessary and sufficient properties provides the foundation for a synthesis of seemingly incompatible positions held by contemporary individualists and essentialists concerning the nature of taxa and the definitions of taxon names.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00129972
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  • 50
    Digitale Medien
    Digitale Medien
    Intentionality, social play, and definition (1994)
    Springer
    Biology and philosophy 9 (1994), S. 63-74 
    Details
    ISSN: 1572-8404
    Schlagwort(e): Ethology ; cognitive ethology ; play ; intentionality ; evolution ; definition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract Social play is naturally characterized in intentional terms. An evolutionary account of social play could help scientists to understand the evolution of cognition and intentionality. Alexander Rosenberg (1990) has argued that if play is characterized intentionally or functionally, it is not a behavioral phenotype suitable for evolutionary explanation. If he is right, his arguments would threaten many projects in cognitive ethology. We argue that Rosenberg's arguments are unsound and that intentionally and functionally characterized phenotypes are a proper domain for ethological investigation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00849914
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  • 51
    Digitale Medien
    Digitale Medien
    Domain-oriented design environments (1994)
    Springer
    Automated software engineering 1 (1994), S. 177-203 
    Details
    ISSN: 1573-7535
    Schlagwort(e): automatic programming ; cooperative problem solving ; co-evolution of specification and construction ; critiquing ; design ; domain-oriented design environments ; design rationale ; end-user modifiability ; evolution ; FRAMER ; formal specifications ; JANUS ; knowledge-based software assistant ; languages of doing ; software reuse and redesign ; stakeholders ; upstream and downstream activities
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Notizen: Abstract The field of knowledge-based software engineering has been undergoing a shift in emphasis from automatic programming to human augmentation and empowerment. In our research work, we support this shift with an approach that embedshuman-computer cooperative problem-solving tools intodomain-oriented, knowledge-based design environments. Domain orientation reduces the large conceptual distance between problem-domain semantics and software artifacts. Integrated environments support the coevolution of specification and construction while allowing designers to access relevant knowledge at each stage within the software development process. This paper argues thatdomain-oriented design environments (DODEs) are complementary to the approaches pursued withknowledge-based software assistant systems (KBSAs). The DODE extends the KBSA framework by emphasizing a human-centered and domain-oriented approach facilitating communication about evolving systems among all stakeholders. The paper discusses the major challenges for software systems, develops a conceptual framework to address these problems, illustrates DODE with two examples, and assesses the contributions of the KBSA and DODE approaches toward solving these problems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00872289
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  • 52
    Digitale Medien
    Digitale Medien
    The origin of human chromosome 2 analyzed by comparative chromosome mapping with a DNA microlibrary (1994)
    Springer
    Chromosome research 2 (1994), S. 405-410 
    Details
    ISSN: 1573-6849
    Schlagwort(e): evolution ; fluorescentin situ hybridization ; microdissection ; phylogeny ; primates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Fluorescencein situ hybridization (FISH) of microlibraries established from distinct chromosome subregions can test the evolutionary conservation of chromosome bands as well as chromosomal rearrangements that occurred during primate evolution and will help to clarify phylogenetic relationships. We used a DNA library established by microdissection and microcloning from the entire long arm of human chromosome 2 for fluorescencein situ hybridization and comparative mapping of the chromosomes of human, great apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus) and Old World monkeys (Macaca fuscata andCercopithecus aethiops). Inversions were found in the pericentric region of the primate chromosome 2p homologs in great apes, and the hybridization pattern demonstrates the known phylogenetically derived telomere fusion in the line that leads to human chromosome 2. The hybridization of the 2q microlibrary to chromosomes of Old World monkeys gave a different pattern from that in the gorilla and the orang-utan, but a pattern similar to that of chimpanzees. This suggests convergence of chromosomal rearrangements in different phylogenetic lines.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01552800
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  • 53
    Digitale Medien
    Digitale Medien
    Parental care and the allocation of resources across generations (1992)
    Springer
    Evolutionary ecology 6 (1992), S. 187-197 
    Details
    ISSN: 1573-8477
    Schlagwort(e): parental care ; resource allocation ; ESS ; inclusive fitness ; menopause ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary To understand the evolution of parental care behaviour, the cost of care must be evaluated in terms of lost reproductive potential. Using population genetics theory, a quantitative model of parental care is presented here to evaluate the allocation of resources between production and care of offspring, and care of grandoffspring. The results show that the evolutionarily stable investment ratio of resources to offspring versus grandoffspring is equal to 2∶1. The expected investment in grandoffspring will decrease when there is a lower probability of survival of the parents to a late stage of the life cycle. These results are discussed in the context of general life history theory, inclusive fitness models, animal behaviour field studies, and the evolution of human menopause.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02214161
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  • 54
    Digitale Medien
    Digitale Medien
    The evolution of flightlessness: Is history important? (1994)
    Springer
    Evolutionary ecology 8 (1994), S. 639-657 
    Details
    ISSN: 1573-8477
    Schlagwort(e): flightlessness ; wing dimorphism ; phylogeny ; evolution ; birds ; insects ; constraints
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Though most birds and insects are capable of flight (‘volant’) some species are flightless. In this paper I test the hypothesis that phylogenetic constraints have played a role in the evolution of flightlessness. If speciation occurred after the evolutionary transition to flightlessness, inferences concerning the importance of particular aspects of the environment on the probability of the evolution of flightlessness may be statistically spurious because of the inflation of the sample size. Among birds, ratites and penguins illustrate the phenomenon of considerable speciation subsequent to the transition to the evolution of flightlessness. In contrast, the rails represent a group in which each flightless species probably represents a separate evolutionary transition. There are many more flightless insect species than bird species and several orders are monomorphically flightless, the sometimes enormous speciation within the order following and possibly being a consequence of the evolution of flightlessness. While it can be shown in insects that flightlessness has evolved independently many times, there are at least as many cases in which the question cannot be resolved. Therefore, in both birds and insects phylogenetic effects should not be ignored, for the number of evolutionary transitions may be much less than the number of species. The effect of incorporating phylogenetic (or at least taxonomic) constraints into the analysis of habitat factors associated with flightlessness is considered.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01237847
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  • 55
    Digitale Medien
    Digitale Medien
    Phylogenetic analysis of pines using ribosomal DNA restriction fragment length polymorphisms (1992)
    Springer
    Plant systematics and evolution 179 (1992), S. 141-153 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Gymnosperms ; Conifers ; Pinaceae ; Pinus ; rDNA ; restriction fragments ; molecular systematics ; evolution ; phylogeny
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Phylogenetic relationships among 30 species of the genusPinus were studied using restriction site polymorphism in the large subunit of nuclear rDNA. Of the 58 restriction sites scored, 48 were phylogenetically informative, and the 30 species reduced to ten taxa when species with identical restriction site patterns were combined. These ten taxa corresponded to the currently recognized subsections of the genus, with the sole exception ofP. leiophylla, which was identical in its pattern of restriction sites to all three species included from subsect.Oocarpae despite its being in a different section of subg.Pinus (Pinea instead ofPinus). A measure of the proportion of phylogenetic information contained within the data set (Homoplasy Excess Ratio, or HER) revealed that the character states were significantly non-randomly distributed among the ten taxa (HER = 0.71, p 〈 0.01). Branchand-bound searches using either Wagner or Dollo parsimony as the optimization criterion were carried out using PAUP in order to estimate phylogenetic relationships among the ten taxa. Three taxa (Picea pungens, Tsuga canadensis, andLarix decidua) were used independently as outgroups for purposes of rooting the trees. Despite the extreme differences in the assumptions underlying the Wagner and Dollo parsimony, the two gave surprisingly similar estimates of phylogeny, with both analyses supporting the monophyly of the two major subgeneraPinus andStrobus and differing in topology only in the placement of subsect.Ponderosae within subg.Pinus. The likelihood for the Wagner tree was only slightly higher than that computed for the Dollo tree.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00937592
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  • 56
    Digitale Medien
    Digitale Medien
    A phylogenetic analysis ofLeucaena (Leguminosae: Mimosoideae) (1994)
    Springer
    Plant systematics and evolution 191 (1994), S. 1-26 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Leguminosae ; Mimoseae ; Leucaena ; Phylogeny ; chloroplast DNA ; polyploidy ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Chloroplast DNA restriction fragment length polymorphisms have been used to reconstruct the maternal phylogeny of all the known taxa in the small neotropical legume genusLeucaena. Three major plastome clades were recognized, but these did not conform with relationships between the taxa proposed on other characters from morphology, cytology or hybridization. The maternal parentage of tetraploids within the genus has been proposed. Evidence for introgression was found between “diploid”L. diversifolia and “tetraploid”L. diversifolia. The implications of these results for the origin of the cultivated taxa are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985339
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  • 57
    Digitale Medien
    Digitale Medien
    Comparative structure of ovules and seeds inRafflesiaceae (1994)
    Springer
    Plant systematics and evolution 193 (1994), S. 187-212 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Rafflesiaceae ; Ovule ; seed structure ; seed dispersal ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genera of theRafflesiaceae show a marked diversity in the structure of their ovules and seeds. Evolutionary trends are recognizable in ovule orientation and number of integuments. A change from anatropous ovules inApodantheae andMitrastemoideae towards incomplete anatropy inRafflesieae and orthotropy inCytineae occurs, next to a change from bitegmic ovules inApodantheae towards unitegmy with rudimentary outer integuments inRafflesieae andCytineae and full unitegmy inMitrastemoideae.—The differences in ovule structure are clearly reflected in the seeds. The seeds are essentially exotegmic, have very small embryos and an oily endosperm.—Seed structure strongly confirms the existing subfamilial classification and supports additional arguments for the generic status ofApodanthes. It does not support a separate status of the genusBerlinianche. InRafflesiaceae, seed micromorphology is only of limited use at the species level. As far as known seed dispersal is endo- or exozoochorous in all genera.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00983550
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  • 58
    Digitale Medien
    Digitale Medien
    The importance of Endosperm Balance Number in potato breeding and the evolution of tuber-bearing Solanum species (1992)
    Springer
    Euphytica 60 (1992), S. 105-113 
    Details
    ISSN: 1573-5060
    Schlagwort(e): bridging crosses ; chromosome addition lines ; Endosperm Balance Number ; evolution ; 2n gametes ; imprinting ; interspecific crosses ; ploidy manipulations ; tuber-bearing Solanum species
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Endosperm failure is considered the primary reason for the lack of success in intra-and interspecific crosses. The Endosperm Balance Number (EBN) hypothesis is a unifying concept for predicting endosperm function in intraspecific, interploidy, and interspecific crosses. In the EBN system, every species has an ‘effective ploidy’ (EBN), which must be in a 2:1 maternal to paternal ratio in the endosperm for crosses to succeed. The knowledge of EBN is very useful in the transfer of genes from exotic germplasm, and in the development of new breeding schemes in potato. The paper describes the strategies for introducing 2x(1EBN), 2x(2EBN), 4x(2EBN) and 6x(4EBN) germplasm into the cultivated 4x(4EBN) potato gene pool. A new methodology for producing 4x(4EBN) and 2x(2EBN) chromosome addition lines is also discussed. EBN has evolutionary importance in the origin of tuber-bearing Solanums. The role of the EBN in the origin of diploid and polyploid potato species, and as a barrier for hybridization and speciation of sympatric species within the same ploidy level is demonstrated. The origin of 3x and 5x cultivated tuber-bearing Solanums may also be explained using the EBN concept. EBN has been reported to exist in other plant species: alfalfa, beans, blueberries, rice, soybeans, squashes, tomato, forage legumes, grasses, ornamentals and Datura stramonium. This indicates that EBN may have broad application and could be useful for germplasm transfer and breeding in other crop species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00029665
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  • 59
    Digitale Medien
    Digitale Medien
    Taxonomy of Portuguese Tronchuda cabbage and Galega kale landraces using morphological characters, nuclear RFLPs, and isozyme analysis: A review (1994)
    Springer
    Euphytica 79 (1994), S. 115-126 
    Details
    ISSN: 1573-5060
    Schlagwort(e): Brassica oleracea ; evolution ; landrace group ; numerical taxonomy ; Portuguese coles
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Morphological characters, nuclear RFLPs, and isozyme analysis were used to study the similarity between 32 Portuguese Tronchuda cabbage and Galega kale landraces, and some cabbage cultivars traditionally grown in Portugal. Forty-six morphological characters observed in two consecutive years, RFLP data from 55 nuclear probes, detecting 291 polymorphic nuclear DNA restriction fragments, and allelic frequencies in 21 putative loci, generated by nine isozymes, were analyzed by the unweighted pair group method, using arithmetic averages (UPGMA), in order to present the results in the form of a phenogram. The three methods resulted in different clustering patterns of the 32 cole accessions. Morphological characters gave consistent clustering according to the traditional landrace definition and denomination, producing clear separation between Tronchuda cabbages and Galega kales. RFLPs were unable to separate Tronchuda cabbages from Galega kales and defined five landrace groups corresponding to their geographic origins rather than to their morphological similarities. Isozymes showed poor accession discrimination and an intermediate clustering pattern with some accessions being clustered according to their geographic origins and others according to their morphological similarities. Portuguese Tronchuda cabbages and Galega kales constitute a distinct and relatively homogenous group within Brassica oleracea, sharing the same genetic background. It is concluded that Portuguese coles have evolved independently from a common ancestor to the present cultivated forms. Portugal should be considered as an important region of domestication of specialized leafy coles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00023583
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  • 60
    Digitale Medien
    Digitale Medien
    Isozyme variation in cultivated and wild pineapple (1994)
    Springer
    Euphytica 79 (1994), S. 87-99 
    Details
    ISSN: 1573-5060
    Schlagwort(e): electrophoresis ; evolution ; genetic differentiation ; genetic variation ; pineapple ; Ananas comosus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Isozyme variation was studied in 161 accessions of pineapple including four species of Ananas and one of Pseudananas. Six enzyme systems (ADH, GPI, PGM, SKDH, TPI, UGPP) involving seven putative loci revealed 35 electromorphs. Considerable variation exists within and between species of Ananas. Sixty-six distinct zymotypes were identified. Multivariate analyses of isozyme variation indicated that A. comosus contains five genetically diverse groups that do not match perfectly with the traditional varietal groups. Isozyme evidence also suggests that A. erectifolius is a conspecific variant of A. comosus, and that among other wild species, A. ananassoides is more closely related to A. comosus than A. bracteatus. Pseudananas is genetically distinct from all species of Ananas. It is evident from our study that differentiation among the species of Ananas may be due to ecological isolation rather than genetic divergence with breeding barriers and therefore may represent a species complex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00023580
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  • 61
    Digitale Medien
    Digitale Medien
    Chloroplast DNA diversity in eggplant (Solanum melongena) and its related species S. incanum and S. marginatum (1994)
    Springer
    Euphytica 80 (1994), S. 1-4 
    Details
    ISSN: 1573-5060
    Schlagwort(e): chloroplast DNA ; eggplant ; evolution ; Solanum incanum ; Solanum melongena ; Solanum marginatum ; taxonomy ; variation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Total chloroplast DNA (cpDNA) from Solanum incanum, a wild relative of eggplant, was used to probe total DNAs from 27 accessions of S. melongena (eggplant), S. incanum sensu lato and S. marginatum, all of which are quite similar in their morphology. There is a wide diversity in plastotypes within S. incanum sensu lato. On the other hand, only one restriction fragment pattern difference was detected between S. melongena and S. incanum sensu lato. The restriction fragment patterns generated by eight enzymes were recorded as present or absent, and a matrix for all fragment positions, enzymes and accessions was used for cluster analysis. In the dendrogram, it is suggested that S. marginatum is not nearly as closely related to S. melongena and S. incanum sensu lato as previously supposed, and some of accessions treated as S. incanum sensu lato, originated from Southern Africa, should be called S. lichtensteinii.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00039291
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  • 62
    Digitale Medien
    Digitale Medien
    Light, iron, Sam Granick and the origin of life (1992)
    Springer
    Photosynthesis research 33 (1992), S. 163-170 
    Details
    ISSN: 1573-5079
    Schlagwort(e): biosynthetic pathway ; evolution ; free energy ; photochemistry ; photosynthesis ; porphyrin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Living matter is an organized system which requires a continual flux of energy for its survival. As a working assumption, the flux of energy required for the origin of a self-duplicating cell is taken as the power required for the maintenance of a modern cell: 10 mW per g of carbon or some 105 times the output per gram of the sun. Solar photochemistry supplies the energy for the continuing evolution of life and, by continuity, for its origin. The iron oxide-sulfide photosynthetic unit proposed by S. Granick 35 years ago was meant to supply this energy. The evolution of complex organic photosensitizers is rationalized by the Granick hypothesis that biosynthetic pathways recapitulate their evolution. These concepts are discussed in the context of the evolution of photosynthetic systems and the known properties of these pigments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00039178
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  • 63
    Digitale Medien
    Digitale Medien
    Protein sequences and redox titrations indicate that the electron acceptors in reaction centers from heliobacteria are similar to Photosystem I (1992)
    Springer
    Photosynthesis research 32 (1992), S. 11-22 
    Details
    ISSN: 1573-5079
    Schlagwort(e): iron-sulfur centers ; evolution ; green sulfur bacteria ; bacteriochlorophyll g
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Photosynthetic reaction centers isolated from Heliobacillus mobilis exhibit a single major protein on SDS-PAGE of 47 000 Mr. Attempts to sequence the reaction center polypeptide indicated that the N-terminus is blocked. After enzymatic and chemical cleavage, four peptide fragments were sequenced from the Heliobacillus mobilis apoprotein. Only one of these sequences showed significant specific similarity to any of the protein and deduced protein sequences in the GenBank data base. This fragment is identical with 56% of the residues, including both cysteines, found in the highly conserved region that is proposed to bind iron-sulfur center FX in the Photosystem I reaction center peptide that is the psaB gene product. The similarity to the psaA gene product in this region is 48%. Redox titrations of laser-flash-induced photobleaching with millisecond decay kinetics on isolated reaction centers from Heliobacterium gestii indicate a midpoint potential of −414 mV with n=2 titration behavior. In membranes, the behavior is intermediate between n=1 and n=2, and the apparent midpoint potential is −444 mV. This is compared to the behavior in Photosystem I, where the intermediate electron acceptor A1, thought to be a phylloquinone molecule, has been proposed to undergo a double reduction at low redox potentials in the presence of viologen redox mediators. These results strongly suggest that the acceptor side electron transfer system in reaction centers from heliobacteria is indeed analogous to that found in Photosystem I. The sequence similarities indicate that the divergence of the heliobacteria from the Photosystem I line occurred before the gene duplication and subsequent divergence that lead to the heterodimeric protein core of the Photosystem I reaction center.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00028794
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  • 64
    Digitale Medien
    Digitale Medien
    The evolutionary genetics of thehobo transposable element in theDrosophila melanogaster complex (1994)
    Springer
    Genetica 93 (1994), S. 79-90 
    Details
    ISSN: 1573-6857
    Schlagwort(e): evolution ; transposable element ; hobo ; Drosophila melanogaster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Hobo elements are a family of transposable elements found inDrosophila melanogaster and its three sibling species:D. simulans, D. mauritiana andD. sechellia. Studies inD. melanogaster have shown thathobo may be mobilized, and that the genetic effects of such mobilizations included the general features of hybrid dysgenesis: mutations, chromosomal rearrangements and gonadal dysgenis in F1 individuals. At the evolutionary level somehobo-hybridizing sequences have also been found in the other members of themelanogaster subgroup and in many members of the relatedmontium subgroup. Surveys of older collected strains ofD. melanogaster suggest that completehobo elements were absent prior to 50 years ago and that they have recently been introduced into this species by horizontal transfer. In this paper we review our findings and those of others, in order to precisely describe the geographical distribution and the evolutionary history ofhobo in theD. melanogaster complex. Studies of the DNA sequences reveal a different level of divergence between the groupD. melanogaster, D. simulans andD. mauritiana and the fourth speciesD. sechellia. The hypothesis of multiple transfers in the recent past into theD. melanogaster complex from a common outside source is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01435241
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  • 65
    Digitale Medien
    Digitale Medien
    Quantitative nuclear DNA differences associated with genome evolution in Guizotia (Compositae) (1992)
    Springer
    Genetica 85 (1992), S. 241-247 
    Details
    ISSN: 1573-6857
    Schlagwort(e): Compositae ; DNA amount ; evolution ; Guizotia ; karyotype
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The present communication deals with 2C nuclear genome size variation in a fairly small genus Guizotia. Twenty-four accessions belonging to six species, out of seven known, were analysed in order to elucidate the extent of DNA variation both at an intra—as well as interspecific level. At the intraspecific level none of the species exhibited significant differences in their genome size. Between the species, the 2C DNA amounts ranged from 3.61 pg in G. reptans to 11.37 pg in G. zavattarii; over three-fold DNA variation is evident. Apparently these interspecific DNA differences have been achieved independent of the numerical chromosomal change(s), as all the Guizotias share a common chromosome number 2n=2x=30. The cultivated oilseed crop, G. abyssinica (7.57 pg), has accommodated nearly 78% extra DNA in its chromosome complement during the evolutionary time scale of its origin and domestication from the wild progenitor G. schimperi (4.25 pg). The extent of genomic DNA difference(s) between the species has been discussed in the light of their interrelationships and diversity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00132276
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  • 66
    Digitale Medien
    Digitale Medien
    TheDoc transposable element inDrosophila melanogaster andDrosophila simulans: Genomic distribution and transcription (1994)
    Springer
    Genetica 93 (1994), S. 117-124 
    Details
    ISSN: 1573-6857
    Schlagwort(e): Doc ; evolution ; transcription ; transposable element
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The mobile elementDoc is similar in structure and coding potential to the LINE families found in various organisms. In this paper, we analyze the insertional and structural polymorphism of this element and show that it appears to have a long evolutionary history in the genome ofD. melanogaster. Like the family ofI elements, theDoc family seems to display three types of elements: full length elements, defective members that have recently transposed and long since immobilized members common to eachD. melanogaster strain. These three classes ofDoc elements seem to be present inD. simulans, a closely related species toD. melanogaster. Furthermore, we show thatDoc is transcribed as a polyadenylated RNA of about 5 kb in length, presumed to be a full length RNA. This transcript is present in different tissues and at different stages ofDrosophila development. These results are compared with previous records on the chromosomal distribution of LINEs or other transposable element families.Doc transcription is analyzed in an attempt to understand the link betweenDoc transcription and transposition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01435244
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  • 67
    Digitale Medien
    Digitale Medien
    Ty1-copia group retrotransposons and the evolution of retroelements in the eukaryotes (1992)
    Springer
    Genetica 86 (1992), S. 203-214 
    Details
    ISSN: 1573-6857
    Schlagwort(e): Copia ; Ty element ; evolution ; retrotransposon
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Ty1-copia group retrotransposons are among the best studied transposable elements in the eukaryotes. This review discusses the extent of these transposons in the eukaryote kingdoms and compares models for the evolution of these genetic elements in the light of recent phylogenetic data. These data show that the Ty1-copia group is widespread among invertebrate eukaryotes, especially in the higher plant kingdom, where these genetic elements are unusually common and heterogeneous in their sequence. The phylogenetic data also suggest that the present day spectrum of Ty1-copia group retrotransposons has been influenced both by divergence during vertical transmission down evolving lineages and by horizontal transmission between distantly related species. Lastly, the factors affecting Ty1-copia group retrotransposon copy number and sequence heterogeneity in eukaryotic genomes and the effects of transpositional quiescence and defective retrotransposons upon evolution of Ty1-copia group retrotransposons are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00133721
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  • 68
    Digitale Medien
    Digitale Medien
    Transposable elements and adaptation of host bacteria (1994)
    Springer
    Genetica 93 (1994), S. 5-12 
    Details
    ISSN: 1573-6857
    Schlagwort(e): Escherichia coli ; transposable elements ; adaptation ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A transposable element (TE) is a mobile sequence present in the genome of an organism. TEs can cause lethal mutations by inserting into essential, genes, promoting deletions or leaving short sequences upon excision. They therefore may be gradually eliminated from mixed populations of haploid micro-organisms such asEscherichia coli if they cannot balance this mutation load. Horizontal transmission between cells is known to occur and promote the transfer of TEs, but at rates often too low to compensate for the burden to their hosts. Therefore, alternative mechanisms should be found by these elements to earn their keep in the cells. Several theories have been suggested to explain their long-term maintenance in prokaryotic genomes, but little molecular evidence has been experimentally obtained. In this paper, the permanence of transposable elements in bacterial populations is discussed in terms of costs or benefits for the element and for the host. It is observed that, in all studies yet reported, the elements do not behave in their host as selfish DNA but as a co-operative component for the evolution of the couple.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01435235
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  • 69
    Digitale Medien
    Digitale Medien
    Emergence of master sequences in families of retroposons derived from 7sl RNA (1994)
    Springer
    Genetica 93 (1994), S. 203-215 
    Details
    ISSN: 1573-6857
    Schlagwort(e): evolution ; alu ; b1 ; 4.5s RNA ; bc200 RNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The past few years have brought new insight into the evolution of families of retroposons. These are composed of a very small number of master sequences able to duplicate, and a large majority of copies that are inactive for retroposition. During the course of time, successive replacements of master sequences have produced waves of amplification that are recognizable as subfamilies. In the Alu and the B1 families, one can distinguish two evolutionary periods. The first involves only monomeric elements that are now extinguished (fossil elements) and is characterized by deep remodeling of the sequences. This period ends, in primates, with the fusion of a free left and a free right Alu monomer, producing the first modern Alu dimeric element; in rodents it ends with a tandem duplication of 29 bp to create the first modern B1 element. The second period is characterized by a great stability of the master sequences. The observed turn-over of master sequences is still an enigma. However, analysis of the contemporary master sequences and of the oldest master sequences provide some clues. Here, we review the very first stages of the appearance of the Alu and the B1 families in mammalian genomes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01435252
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  • 70
    Digitale Medien
    Digitale Medien
    Evolution of structure and function of V-ATPases (1992)
    Springer
    Journal of bioenergetics and biomembranes 24 (1992), S. 415-424 
    Details
    ISSN: 1573-6881
    Schlagwort(e): ATPases ; evolution ; eukaryotes ; endomembranes ; archaebacteria ; progenote ; bioenergetics ; flagella assembly ; endosymbiont theory
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Physik
    Notizen: Abstract Proton pumping ATPases/ATPsynthases are found in all groups of present-day organisms. The structure of V- and F-type ATPases/ATP synthases is very conserved throughout evolution. Sequence analysis shows that the V- and F-type ATPases evolved from the same enzyme already present in the last common ancestor of all known extant life forms. The catalytic and noncatalytic subunits found in the dissociable head groups of the V/F-type ATPases are paralogous subunits, i.e., these two types of subunits evolved from a common ancestral gene. The gene duplication giving rise to these two genes (i.e., encoding the catalytic and noncatalytic subunits) predates the time of the last common ancestor. Mapping of gene duplication events that occurred in the evolution of the proteolipid, the noncatalytic and the catalytic subunits, onto the tree of life leads to a prediction for the likely subunit structure of the encoded ATPases. A correlation between structure and function of V/F-ATPases has been established for present-day organisms. Implications resulting from this correlation for the bioenergetics operative in proto-eukaryotes and in the last common ancestor are presented. The similarities of the V/F-ATPase subunits to an ATPase-like protein that was implicated to play a role in flagellar assembly are evaluated. Different V-ATPase isoforms have been detected in some higher eukaryotes. These data are analyzed with respect to the possible function of the different isoforms (tissue specific, organelle specific) and with respect to the point in their evolution when these gene duplications giving rise to the isoforms had occurred, i.e., how far these isoforms are distributed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00762534
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  • 71
    Digitale Medien
    Digitale Medien
    Further data on the occurrence and evolution of satellite DNA families in the lacertid genome (1994)
    Springer
    Chromosome research 2 (1994), S. 327-330 
    Details
    ISSN: 1573-6849
    Schlagwort(e): evolution ; reptiles ; satellite DNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This paper reports the isolation and characterization of twoHindIII repetitive DNA families from the genome of two lacertid lizards,Podarcis sicula andLacerta saxicola. These satellites did not appear to be related to each other. The consensus sequences of their monomeric units did not show any similarity, though both DNAs were A-T rich. Moreover, each of them was found only in closely related species. The monomeric unit of theHindIII DNA family isolated fromP. sicula (pLHS) showed a close resemblance to pLCS, a centromeric satellite DNA previously isolated from the same species; it was, however, mainly localized at pericentromeric, interstitial and telomeric levels. The results also provide interesting information on the systematics of the lacertids studied.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01552726
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  • 72
    Digitale Medien
    Digitale Medien
    The evolution of kinetoplastid glycosomes (1994)
    Springer
    Journal of bioenergetics and biomembranes 26 (1994), S. 213-219 
    Details
    ISSN: 1573-6881
    Schlagwort(e): Glycosome ; microbody ; glycolysis ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Physik
    Notizen: Abstract The available data on carbohydrate metabolism in Kinetoplastida have been reviewed. Based on the metabolic pattern of different kinetoplastid organisms, on the subcellular distribution of their glycolytic enzymes, and on the structural and regulatory properties of these proteins, we propose that the glycosome developed from an endosymbiont, as a specific manner to control carbohydrate and energy metabolism. It is discussed how the enzymes were subcellularly recompartmentalized during evolution as adaptation to the environment encountered by the organisms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00763070
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  • 73
    Digitale Medien
    Digitale Medien
    On the systematic position ofChaetomys subspinosus (Rodentia: Caviomorpha) based on evidence from the incisor enamel microstructure (1994)
    Springer
    Journal of mammalian evolution 2 (1994), S. 117-131 
    Details
    ISSN: 1573-7055
    Schlagwort(e): enamel microstructure ; evolution ; Chaetomys ; incisors ; Caviomorpha
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have studied the incisor enamel microstructure ofChaetomys subspinosus and other possibly closely related caviomorph rodents.Chaetomys subspinosus lacks the important synapomorphy of the Octodontoidea, reactangular plate-like interprismatic matrix (IPM) in the portio interna (PI) of the incisor Schmelzmuster. Therefore its transfer from the Erethizontidae to the Echimyidae, as proposed by Patterson and Wood (Bull. Mus. Comp. Zool. 149, 371–543, 1982) based on retention of dP4, is contested. The parallel to acute angular IPM in the PI ofChaetomys and the Erethizontidae is a symplesiomorphy and does not indicate close relationship. Contrary to previous claims, a posterior carotid foramen is also retained inChaetomys. Chaetomys is characterized by an unusual thin enamel which is considered primitive after outgroup comparison. Therefore, it is proposed to leaveChaetomys in the monospecific erethizontid subfamily Chaetomyinae, until additional information on the species is available.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01464364
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  • 74
    Digitale Medien
    Digitale Medien
    Responses of fig wasps to host plant volatile cues (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 785-802 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Hymenoptera ; Agaonidae ; evolution ; fig wasps ; host finding ; volatile attractants ; Ficus ; Moraceae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Fig wasps (Chalcidoidea; Agaonidae) are intimately associated with the 750 or so species of fig trees (Ficus, Moraceae). Each tree species is usually pollinated by a single species of wasp belonging to the subfamily Agaoninae, while other wasps of the family are parasitoids or seed predators. Previous experiments have shown that the wasps are attracted to the trees by volatiles emanating from the figs. Using fig-bearing trees and arrays of sticky traps baited with figs, we investigated the specificity of wasp attraction and its timing. The pollinators of two closely relatedFicus species were specifically attracted to figs of their host species and only at the time when figs were ready to be pollinated. Some nonpollinating fig wasps appear to respond to the same volatile cues.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02059613
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  • 75
    Digitale Medien
    Digitale Medien
    Evolution of chlorocatechol catabolic pathways (1994)
    Springer
    Biodegradation 5 (1994), S. 301-321 
    Details
    ISSN: 1572-9729
    Schlagwort(e): catabolic pathways ; chlorocatechol ; degradation ; dienelactone hydrolase ; 3-oxoadipate enol-lactone hydrolase ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Energietechnik , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The aerobic bacterial degradation of chloroaromatic compounds often involves chlorosubstituted catechols as central intermediates. They are converted to 3-oxoadipate in a series of reactions similar to that for catechol catabolism and therefore designated as modifiedortho-cleavage pathway. Among the enzymes of this catabolic route, the chlorocatechol 1,2-dioxygenases are known to have a relaxed substrate specificity. In contrast, several chloromuconate cycloisomerases are more specific, and the dienelactone hydrolases of chlorocatechol catabolic pathways do not even convert the corresponding intermediate of catechol degradation, 3-oxoadipate enol-lactone. While the sequences of chlorocatechol 1,2-dioxygenases and chloromuconate cycloisomerases are very similar to those of catechol 1,2-dioxygenases and muconate cycloisomerases, respectively, the relationship between dienelactone hydrolases and 3-oxoadipate enol-lactone hydrolases is more distant. They seem to share an α/β hydrolase fold, but the sequences comprising the fold are quite dissimilar. Therefore, for chlorocatechol catabolism, dienelactone hydrolases might have been recruited from some other, preexisting pathway. Their relationship to dienelactone (hydrolases identified in 4-fluorobenzoate utilizing strains ofAlcaligenes andBurkholderia (Pseudomonas) cepacia is investigated). Sequence evidence suggests that the chlorocatechol catabolic operons of the plasmids pJP4, pAC27, and pP51 have been derived from a common precursor. The latter seems to have evolved for the purpose of halocatechol catabolism, and may be considerably older than the chemical industry.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00696467
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  • 76
    Digitale Medien
    Digitale Medien
    Structure and evolution of cytochrome oxidase (1994)
    Springer
    Antonie van Leeuwenhoek 65 (1994), S. 285-287 
    Details
    ISSN: 1572-9699
    Schlagwort(e): cytochromec oxidase ; quinol oxidase ; metal centres ; respiration ; denitrification ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The structural features of cytochrome oxidases are reviewed in light of their evolution. The substrate specificity (quinol vs. cytochromec) is reflected in the presence of a unique copper centre (Cu A ) in cytochromec oxidases. In several lines of evolution, quinol oxidases have independently lost this copper. Also, the most primitive cytochromec oxidases do not contain this copper, and electron entry takes place viac-type haems. These enzymes, exemplified by the rhizobial FixN complex, probably remind the first oxidases. They are related to the denitrification enzyme nitric oxide reductase.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00872214
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  • 77
    Digitale Medien
    Digitale Medien
    Bioenergetics: the evolution of molecular mechanisms and the development of bioenergetic concepts (1994)
    Springer
    Antonie van Leeuwenhoek 65 (1994), S. 271-284 
    Details
    ISSN: 1572-9699
    Schlagwort(e): bioenergetics ; evolution ; history of science ; H+ cycle ; Na+ cycle ; flagellar motor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Possible routes for the evolution of cell energetics are considered. It is assumed that u.v. light was the primary energy source for the precursors of the primordial living cell and that primitive energetics might have been based on the use of the adenine moiety of ADP as the u.v. chromophore. It is proposed that the excitation of the adenine residue facilitated phosphorylation of its amino group with subsequent transfer of a phosphoryl group to the terminal phosphate of ADP to form ATP. ATP-driven carbohydrate synthesis is considered as a mechanism for storing u.v.-derived energy, which was then used in the dark. Glycolysis presumably produced compounds like ethanol and CO2 which easily penetrate the membrane and therefore were lost by the cell. Later lactate-producing glycolysis appeared, the end product being non-penetrant and, hence, retained inside the cell to be utilized to regenerate carboxydrates when light energy became available. Production of lactate was accompanied by accumulation of equimolar H+. To avoid acidification of the cell interior, an F0-type H+ channel was employed. Later it was supplemented with F1. This allowed the ATP energy to be used for ‘uphill’ H+ pumping to the medium, which was acidified due to glycolytic activity of the cells. In the subsequent course of evolution, u.v. light was replaced by visible light, which has lower energy but is less dangerous for the cell. It is assumed that bacteriorhodopsin, a simple and very stable light-driven H+ pump which still exists in halophilic and thermophilic Archaea, was the primary system utilizing visible light. The $$\Delta \bar \mu _{{\rm H}^ + } $$ formed was used to reverse the H+-ATPase, which began to function as H+-ATP-synthase. Later, bacteriorhodopsin photosynthesis was substituted by a more efficient chlorophyll photosynthesis, producing not only ATP, but also carbohydrates. O2, a side product of this process, was consumed by the H+-motive respiratory chain to form $$\Delta \bar \mu _{{\rm H}^ + } $$ in the dark. At the next stage of evolution, a parallel energy-transducing mechanism appeared which employed Na+ instead of H+ as the coupling ion (the Na+ cycle). As a result, the bioenergetic system became more stable under unfavorable conditions. Apparently, the latest inventions of evolution of biological energy transducers are those which can utilize $$\Delta \bar \mu _{{\rm H}^ + } $$ and $$\Delta \bar \mu _{Na^ + } $$ outside the coupling membrane, like the bacterial flagellar motor and the TonB-mediated uphill transport of solutes across the outer membrane of bacteria.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00872213
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  • 78
    Digitale Medien
    Digitale Medien
    Protein structure, electron transfer and evolution of prokaryotic photosynthetic reaction centers (1994)
    Springer
    Antonie van Leeuwenhoek 65 (1994), S. 311-329 
    Details
    ISSN: 1572-9699
    Schlagwort(e): photosynthesis ; chlorophyll ; bacteriochlorophyll ; reaction center ; electron transfer ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Photosynthetic reaction centers from a variety of organisms have been isolated and characterized. The groups of prokaryotic photosynthetic organisms include the purple bacteria, the filamentous green bacteria, the green sulfur bacteria and the heliobacteria as anoxygenic representatives as well as the cyanobacteria and prochlorophytes as oxygenic representatives. This review focuses on structural and functional comparisons of the various groups of photosynthetic reaction centers and considers possible evolutionary scenarios to explain the diversity of existing photosynthetic organisms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00872216
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  • 79
    Digitale Medien
    Digitale Medien
    The Cuban homegarden ‘conuco’: a perspective environment for evolution and in situ conservation of plant genetic resources (1992)
    Springer
    Genetic resources and crop evolution 39 (1992), S. 9-22 
    Details
    ISSN: 1573-5109
    Schlagwort(e): Cuba ; evolution ; genetic resources ; homegarden ; in situ conservation ; landraces
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Cuban homegardens are called ‘conucos’. On the basis of new case studies additional information is provided about these ‘conucos’, their history, composition and importance. They and other gardens of similar type are characterized as suitable environment for in situ conservation and for the continuation of evolutionary processes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00052650
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  • 80
    Digitale Medien
    Digitale Medien
    Insect resistance in potatoes: sources, evolutionary relationships, morphological and chemical defenses, and ecogeographical associations (1992)
    Springer
    Euphytica 61 (1992), S. 83-111 
    Details
    ISSN: 1573-5060
    Schlagwort(e): chemical defense ; Colorado potato beetle ; Empoasca fabae ; Epitrix cucumeris ; evolution ; germplasm ; green peach aphid ; insect resistance ; Leptinotarsa decemlineata ; Macrosiphum euphorbiae ; morphology ; Myzus persicae ; potato aphid ; potato flea beetle ; potato leafhopper ; relationship ; Solanum ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The past 25 years, 1686 potato accessions, representing 100 species in the genus Solanum L., subgenus Potatoe, section Petota, were evaluated for field resistance to one or more of the following insect pests: green peach aphid, Myzus persicae (Sulzer); potato aphid, Macrosiphum euphorbiae (Thomas); Colorado potato beetle, Leptinotarsa decemlineata (Say); potato flea beetle, Epitrix cucumeris (Harris); and potato leafhopper, Empoasca fabae (Harris). Accessions highly resistant to green peach aphid were identified within 36 species, to potato aphid within 24 species, to Colorado potato beetle within 10 species, to potato flea beetle within 25 species, and to potato leafhopper within 39 species. Resistance levels were characteristic within Solanum species. Insect resistance appears to be a primitive trait in wild potatoes. Susceptibility was most common in the primitive and cultivated Tuberosa. Insect resistance was also characteristic of the most advanced species. The glycoalkaloid tomatine was associated with field resistance to Colorado potato beetle and potato leafhopper. Other glycoalkaloids were not associated with field resistance at the species level. Dense hairs were associated with resistance to green peach aphid, potato flea beetle, and potato leafhopper. Glandular trichomes were associated with field resistance to Colorado potato beetle, potato flea beetle, and potato leafhopper. Significant correlations between insect score and altitude of original collection were observed in six of thirteen species. Species from hot and arid areas were associated with resistance to Colorado potato beetle, potato flea beetle, and potato leafhopper. Species from cool or moist areas tended to be resistant to potato aphid.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00026800
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  • 81
    Digitale Medien
    Digitale Medien
    Horizontal gene transfer in plants, a biohazard? Outcome of a literature review (1994)
    Springer
    Euphytica 76 (1994), S. 133-138 
    Details
    ISSN: 1573-5060
    Schlagwort(e): vertical gene transfer ; sequence homology ; gene swapping ; risk analysis ; evolution ; HGT
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Presented here is an assessment on the putative biohazard of spontaneous horizontal gene transfer (HGT) in plants. Suggestions for spontaneous HGT between sexually incompatible plant species and between plants and microorganisms are numerous. The novel argument is sequence homology, but this argument is known to be invalid or at least inadequate. Only one case was found for HGT from a bacterium to a plant. This most probably took place in the evolutionary past. None of the supposed HGT cases brought forward up to the end of 1992 include the description of a mechanism by which a DNA fragment is detached from one genome, passed at least one membrane, and is inserted into another plant genome. Spontaneous HGT to plants with subsequent vertical (trans) gene transfer through normal seed set cannot be totally excluded, however, the literature up to 1993 does not provide any scientifically valid indication that such an HGT should be considered as a realistic biohazard.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00024031
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  • 82
    Digitale Medien
    Digitale Medien
    Cytogenetic and genetic relationships between populations of Aegilops ventricosa Tausch (1994)
    Springer
    Euphytica 79 (1994), S. 81-85 
    Details
    ISSN: 1573-5060
    Schlagwort(e): wild wheats ; Aegilops ventricosa ; chromosomal polymorphism ; cytogenetics ; seed proteins ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary Five samples of Aegilops ventricosa (2n=4x=28, genome formula DDNN) from different geographical origins, were crossed in a diallelic scheme. Metaphase I chromosome pairing of the hybrids, accounting for all the possible genetic combinations, was analysed. Only bivalents were formed in some hybrids, while multivalents were scored in other ones. Seed storage proteins, gliadins and albumins, were also analysed by means of polyacrylamide gel electrophoresis. Based on the presence of multivalents in hybrids, and on the differences in seed protein profiles, the samples could be grouped into two clusters. Meiosis was regular in hybrids obtained within samples of the same group, while multivalents were present in hybrids involving a sample of one group and one of the other. The evolutionary trends in Ae. ventricosa are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00023579
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  • 83
    Digitale Medien
    Digitale Medien
    Levels of diversity in endomycorrhizal fungi (Glomales, Zygomycetes) and their role in defining taxonomic and non-taxonomic groups (1994)
    Springer
    Plant and soil 159 (1994), S. 47-59 
    Details
    ISSN: 1573-5036
    Schlagwort(e): developmental biology ; ecology ; evolution ; molecular biology ; morphology ; ontogeny ; phylogeny ; vesicular-arbuscular mycorrhizal fungi
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Diversity in glomalean fungi is manifested at the molecular, morphological, and ecological levels. Characters at any of these levels can be ordered into hierarchical patterns defining taxonomic groups if they are conserved enough to be heritable through geologic time in all descendants of a common ancestor. At present, only morphological characters associated with mode of spore formation and in subcellular structure of spores are sufficiently stable and diverse to recognize at least 150 species. Ontogenetic comparisons indicate that species integrity, despite asexual reproduction, is the result of rigid internal constraints imposed on variation during the process of spore subcellular differentiation. Epigenetic factors dominate because the differentiation sequence is linear and each new stage is causally linked to preceding stages. Some morphological characters of the fungal mycelium also exist, but they define more inclusive groups at the family level and above. Most diversity in the mycorrhizae consists of life-history traits associated with abundance and architecture of fungal components, their rate of formation and longevity, and their cost in the symbiosis. These characters participate in processes at the molecular and ecological levels, so they are autonomous from morphological determinants. They often are labile or affected by external environmental conditions, so fewer stable taxonomic characters are likely to be discovered. Instead, molecular and ecological diversity has greater potential to define; (a) niche specificity of organisms/populations and (b) causal processes linked to host-fungus compatibility and mycorrhizal efficiency. Any taxonomic characters that relate to mycorrhizal functions will come only from comparative studies involving organisms from shared habitats rather than those having shared spore morphologies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000094
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  • 84
    Digitale Medien
    Digitale Medien
    Evolution and diversity in the legume-rhizobium symbiosis: chaos theory? (1994)
    Springer
    Plant and soil 161 (1994), S. 1-10 
    Details
    ISSN: 1573-5036
    Schlagwort(e): Bradyrhizobium ; diversity ; evolution ; legumes ; N2 fixation ; Rhizobium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Diversity in both legumes and rhizobia is discussed, in the light of evolution of nodulation. An hypothesis is developed that two separate nodulation events occurred in the humid tropics during the evolution of legumes in the late Cretaceous. One of these involved an ancestor ofRhizobium and a root infection. This was initially parasitic and provided little benefit until bacteria were released from infection threads as in modern crop species. The other involved a photosynthetic ancestor ofBradyrhizobium with a wound infection on stems, and has never involved infection threads. As continents moved and climates changed to a seasonal type, involving either rainfall or temperature extremes, further constraints were imposed. The argument is pursued for the case of acacias and their rhizobia in arid regions. Here selection pressures on rhizobia led to the evolution of stress tolerant forms, not all of which are capable of symbiosis, and where symbiotic genes may be an expensive encumbrance. Lateral transfer of material on megaplasmids led to a wide range of symbiotic and non-symbiotic forms in response to local pressures. When environmental constraints are superimposed on initial evolutionary developments, the result is an apparently chaotic situation where there is no obvious pattern of co-evolution between hosts and rhizobia. Evidence of such coevolution may still be buried in this chaos and may be amenable to molecular analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02183080
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  • 85
    Digitale Medien
    Digitale Medien
    Digestive enzyme activities and their distribution in the alimentary canal of larvae of the three extant lamprey families (1992)
    Springer
    Fish physiology and biochemistry 10 (1992), S. 1-10 
    Details
    ISSN: 1573-5168
    Schlagwort(e): larval lampreys ; exocrine pancreas ; lipase ; amylase ; chymotrypsin ; trypsin ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The activities of trypsin (EC 3.4.21.4), chymotrypsin (EC 3.4.21.1), lipase (EC 3.1.1.3) and amylase (EC 3.2.1.1) were measured in different regions of the alimentary tract of ammocoetes from each of the three extant lamprey families. In the southern hemisphere speciesGeotria australis (Geotriidae), and even more particularlyMordacia mordax (Mordaciidae), enzymatic activity was almost entirely confined to prominent diverticular extensions which arise at the oesophageal-intestinal junction. However, in the holarcticLampetra richardsoni (Petromyzontidae), which does not possess a diverticulum, the enzymatic activity was highest in the upper anterior intestine. It is not clear whether the presence of significantly higher amylolytic and lower lipolytic activities in the diverticulum ofG. australis than in the exocrine tissue of the other two species reflects interspecific differences in the composition of their diets. The capacity of exocrine tissue extracts for chymotryptic and tryptic digestion was assayed before and afterin vitro exposure to trypsin and enteropeptidase, their respective catalytic activators. Prior to exposure to these exogenous activators, both proteolytic enzymes were fully active inL. richardsoni, partially active inG. australis and totally inactive inM. mordax. Maximal chymotryptic activity was greater inM. mordax than inL. richardsoni andG. australis. In contrast, maximal tryptic activity was greater inL. richardsoni than inG. australis and was very low inM. mordax. Since trypsin is the only known activator of chymotrypsinogen, the negligible activity of trypsin inM. mordax would appear anomalous unless a trypsin inhibitor is present in the protopancreas of this species. Differences in the distribution of enzymatic activity within the alimentary tract of the three species is discussed in relation to proposed phylogenetic relationships amongst the extant lamprey families.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00004649
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  • 86
    Digitale Medien
    Digitale Medien
    Different species-specific chromosome translocations inTriticum timopheevii andT. turgidum support the diphyletic origin of polyploid wheats (1994)
    Springer
    Chromosome research 2 (1994), S. 59-64 
    Details
    ISSN: 1573-6849
    Schlagwort(e): evolution ; polyploid wheat ; species-specific translocation ; Triticum timopheevii ; Triticum turgidum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Triticum timopheevii ssp.timopheevii andT. timopheevii ssp.araraticum were analysed by sequential N-banding and genomicin situ hybridization. Three chromosomes, 6At, 1G and 4G, were involved in At-G intergenomic translocations in all six lines analysed. These chromosomes may be derived from a cyclic translocation that is species-specific toT. timopheevii. In contrast,Triticum turgidum has a species-specific cyclic translocation involving chromosomes 4A, 5A and 7B. The discovery of different species-specific chromosome translocations supports the diphyletic hypothesis of the evolution of tetraploid wheats. The results from genomic blocking analysis also revealed that the chromosomes ofAegilops speltoides are closer to the G genome than the B genome chromosomes. The possible role of speciesspecific translocations in the evolution of wheat is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01539455
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  • 87
    Digitale Medien
    Digitale Medien
    On the concepts of the taxonomic distinction, nature and essence of man (1992)
    Springer
    Human evolution 7 (1992), S. 41-47 
    Details
    ISSN: 1824-310X
    Schlagwort(e): evolution ; origin of man ; nature and essence of humanity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract It is proposed that the peculiarity of the specific nature of man consists in his polarisation into an ape-like «Australopithecoid» and specifically human sides. Its possible origin, as well as, differences between the concepts of the taxonomic distinction, species specific nature and essence of man are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02436259
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  • 88
    Digitale Medien
    Digitale Medien
    Human evolution and epigenesis (1992)
    Springer
    Human evolution 7 (1992), S. 25-31 
    Details
    ISSN: 1824-310X
    Schlagwort(e): Epigenesis ; evolution ; history
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02436410
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  • 89
    Digitale Medien
    Digitale Medien
    Japan and human evolutionary research (1992)
    Springer
    Human evolution 7 (1992), S. 85-91 
    Details
    ISSN: 1824-310X
    Schlagwort(e): Japan ; Japanese ; evolution ; microevolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The trends in evolutionary research in Japan have largely changed through the introduction of new methodologies such as molecular genetics and multivariate statistics since the 1960’s. The development of ecology and primatology brought another new wave into fields of physical anthropology. This paper reviews briefly general trends in anthropological research now on-going in Japan. Microevolutionary studies of the Japanese and neighboring populations which have a long history in Japan will be reviewed in more detail.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02437456
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  • 90
    Digitale Medien
    Digitale Medien
    Systematic classification of Asian colobines (1994)
    Springer
    Human evolution 9 (1994), S. 25-33 
    Details
    ISSN: 1824-310X
    Schlagwort(e): Colobinae ; cranial morphology ; evolution ; phylogeny ; systematic classification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In order to study the differentiation of Asian colobines, fourteen variables were analysed in one way, on 123 skulls, includingRhinopithecus, Presbytis, Presbytiscus, Pygathrix, andNasalis with both cluster and differentiated functions tests. Information on paleoenvironment changes in China and South-East Asia since late Tertiary have been used to examine the influences of migratory habits and the distribution range in Asian colobines. The cladogram among different Asian colobines genera was made from the results of various analysis. Some new points or revisions were suggested: 1. Following the second migratory way, ancient species of Asian colobines perhaps passed through Xizang along the northern bank of Tethis sea and Heng-Duan Shan regions, across Yunnan into Vietnam, since the ancient continent between Yunnan and Xizang was already located in on eastern bank of Tethis sea. Thus, during the evolution, Asian colobines must have had two original centres, i.e. “Sundaland” and Heng-Duan Shan Chinese regions; 2. Pygatrix possesses a lot of cranial features more similar toPresbytiscus than toRhinopithecus. The small difference from the modification combinesPygatrix with other two genera as shown by Groves (1970), but it is better to putPygatrix andPresbytiscus together as one genus; 3.Nasalis (2n=48) may be the most primitive genus within Asian colobines. Some features shared withRhinopithecus, for example body size, terrestrial activities, limb proportion etc. ...seem to be considered as a common inheritance of symlesiomorphus characters; 4.Rhinopithecus, with reference to cranioface and cranium or to its origin, is a special genus of Asian colobine. It may represent the highest level of evolutionary position within various genera (Peng et al., 1985).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02438137
    Standort Signatur Erwartet Verfügbarkeit
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  • 91
    Digitale Medien
    Digitale Medien
    High conservation of the trinucleotide [CTG]n repeat at the myotonic dystrophy locus in nonhuman primates (1994)
    Springer
    Human evolution 9 (1994), S. 315-321 
    Details
    ISSN: 1824-310X
    Schlagwort(e): Myotonic dystrophy ; trinucleotide repeats ; sequence analysis ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Myotonic dystrophy is due to instability of a [CTG] repeat in the myotonin-protein kinase gene. We have sequenced the complete 3′ untranslated region of this gene which contains the repeat, in seven nonhuman primates. We found that the genomic organisation was conserved, suggesting that this region has important regulatory functions. These data also argue that the human state is derived from a primate ancestor in which the mutational event did not involve the loss of cryptic sequences interrupting or surrounding the repeat, but likely affected only the original length of the repeat.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02435517
    Standort Signatur Erwartet Verfügbarkeit
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  • 92
    Digitale Medien
    Digitale Medien
    Aimed throwing of stones by tufted capuchin monkeys (Cebus apella) (1994)
    Springer
    Human evolution 9 (1994), S. 323-329 
    Details
    ISSN: 1824-310X
    Schlagwort(e): Capuchin ; evolution ; hominid ; throwing ; tool-use
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The purpose of this research was to examine aimed throwing of stones by tufted capuchin monkeys (Cebus apella). Three capuchins (two adults and one juvenile) threw stones at a stationary target located outside their home cages. The monkeys subsequently discriminated between stationary targets and threw stones at a moving target. Each subject exhibited a distinct manual and postural throwing preference. These results demonstrate that capuchins have throwing capabilities which are thought to have been associated with early hominid evolution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02435518
    Standort Signatur Erwartet Verfügbarkeit
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  • 93
    Digitale Medien
    Digitale Medien
    Environmental networks, compensating life histories and habitat selection by white-footed mice (1992)
    Springer
    Evolutionary ecology 6 (1992), S. 1-14 
    Details
    ISSN: 1573-8477
    Schlagwort(e): evolution ; habitat selection ; life history ; litter size ; Ontario ; Peromyscus ; seasonality
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Analysis of 6 years' data on a population of free-living white-footed mice documents both phenotypic and environmental control of litter size. Litter size was positively correlated with maternal body size. Maternal size depended upon both seasonal and annual variation. Paradoxically, the proportion of small versus large litters varied among habitats independently of the effects of body size. The result is an influence of habitat on life history that yields patterns of reproduction and survival opposite to the predictions of demographic theory. The habitat producing the largest litters had a relatively high ratio of adult/juvenile survival. Litter size was small in the habitat where the adult/juvenile survival ratio was smallest. All of these anomalous patterns can be explained through density-dependent habitat selection by female white-footed mice. Life-history studies that ignore habitat and habitat selection may find spurious correlations among traits that result in serious misinterpretations about life history and its evolution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02285330
    Standort Signatur Erwartet Verfügbarkeit
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