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  • 1
    Electronic Resource
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    Springer
    Journal of ornithology 141 (2000), S. 263-274 
    ISSN: 1439-0361
    Keywords: Systematics ; evolution ; anagenesis ; genealogy ; reference system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Verglichen mit anderen Tiergruppen, scheint die artliche Bestandsaufnahme der rezenten Vögel nahezu abgeschlossen zu sein. Doch ist das System der Vögel weiterhin umstritten und mit vielen Neuerungen konfrontiert. Die Gründe dafür liegen hauptsächlich in neuen, vor allem molekularbiologischen Methoden und in den unerwartet reichen Fossilfunden der jüngsten Zeit. Als Beispiele werden Altgaumenvögel, Kranichvögel, Ibisse, Flamingos, Mausvögel, Hopfe und Sperlingsvögel kurz behandelt. Die hier erzielten Fortschritte lassen die Befürchtung Stresemanns, die Großsystematik der Vögel sei mit den vorhandenen Methoden phylogenetisch nicht interpretierbar, zunächst als unbergründet erscheinen. Doch erwachsen einer solchen Interpretation andere Hindernisse, deren Bedeutung bisher zu wenig beachtet wurde, nämlich Parallelentwicklungen, die viel verbreiteter sind als gemeinhin angenommen. Ihre Häufigkeit lässt sich sogar mit evolutionsbiologischen Argumenten begründen. Es ist deshalb nicht zu erwarten, dass die Diskussionen um das „richtige“ System bald verstummen. Um dennoch die Eindeutigkeit der Information in nicht-systematischen Veröffentlichungen zu wahren, wird empfohlen ein etabliertes Referenzsystem auf Zeit zu wählen.
    Notes: Summary Unlike in most animal classes the inventory of extant species of the class Aves seems to be almost complete. Nevertheless avian systematics is challenged by many novelties and seems far from being settled. This is caused mainly by the application of novel methods of molecular analysis to phylogenetic problems and by the unexpectedly rich fossil record collected within the last 10–20 years. Examples from the Palaeognathae, Gruiformes, Threskiornithidae, Phoenicopteridae, Coliiformes, Upupiformes and Passeriformes are briefly treated. The progress in the field seems to disprove Stresemann's pessimistic view that the phylogeny of higher categories (orders) cannot be reconstructed by the available methods. However, phylogenetic interpretations are impeded by obstacles not considered by Stresemann and highly underestimated in most cases, namely by multiple independent developments leading to identical features. Frequent parallel developments are to be expected for theoretical evolutionary reasons. The diagnosis of such homoplasies can be extremely difficult or even impossible. Therefore we cannot expect the discussion about the “best” system of birds to end in the near future. Considering this dynamic situation in systematics, it is recommended to maintain unambiguousness of information in not strictly systematic publications by refering to a well established system as a temporally limited reference.
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  • 2
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    Entomologia experimentalis et applicata 80 (1996), S. 163-165 
    ISSN: 1570-7458
    Keywords: olfaction ; EAG ; sensory physiology ; antennal sensitivity ; interspecies hybrids ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 3
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    Entomologia experimentalis et applicata 91 (1999), S. 359-368 
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ssp. arcuata ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; host plant range ; near-isogenic ; Y-linkage ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A Y-linked gene (R-gene) in the flea beetle Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) confer the ability of larvae to survive on types of the plant Barbarea vulgaris R.Br. (Brassicaceae) which are immune to attack by susceptible conspecifics. Two near-isogenic flea beetle lines were developed. The YE-line contained the Y-linked R-gene, and male larvae from this line survived on B. vulgaris. The ST-line did not contain the gene and did not survive on the plant. The YE-line had been developed through 8–9 generations of backcrosses (YE-males with ST-females) and the two lines were considered to be isogenic except for genes located on the Y-chromosome. A single copy of the Y-linked gene is sufficient to transfer a susceptible genotype (ST) into a resistant genotype (YE) which is able to utilize a plant that is immune to attack by specimens without R-genes. The Y-linked gene had no effects on survival on other plant species tested. The gene did not have any effect on developmental times and weights of adult beetles reared on other plants than B. vulgaris. Developmental times of larvae with the Y-linked gene were longer on B. vulgaris than on normal host plants, R. sativus and S. arvensis, but the adults obtained the same size on these plant species. No trade-offs of the Y-linked gene were discovered. The results suggest that the occurrence of the Y-linked gene is a derived trait which has enabled the flea beetle to expand its host plant range. The evolution of a host shift to B. vulgaris seems not to be favoured by the presence of this single gene.
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  • 4
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    Acta biotheoretica 48 (2000), S. 137-147 
    ISSN: 1572-8358
    Keywords: Sex ; sexual selection ; mate selection ; evolution ; ploidy ; assortative mating ; recombination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using computer simulations I studied the simultaneous effect of variable environments, mutation rates, ploidy, number of loci subject to evolution and random and assortative mating on various reproductive systems. The simulations showed that mutants for sex and recombination are evolutionarily stable, displacing alleles for monosexuality in diploid populations mating assortatively under variable selection pressure. Assortative mating reduced excessive allelic variance induced by recombination and sex, especially among diploids. Results suggest a novel adaptive value for sex and recombination. They show that the adaptive value of diploidy and that of the segregation of sexes is different to that of sex and recombination. The results suggest that the emergence of sex had to be preceded by the emergence of diploid monosexual organisms and provide an explanation for the emergence and maintenance of sex among diploids and for the scarcity of sex among haploid organisms.
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  • 5
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    Acta biotheoretica 46 (1998), S. 141-156 
    ISSN: 1572-8358
    Keywords: locomotion ; Squamata ; lizards ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In lower quadrupedal vertebrates locomotor efficiency seems to result from the associate movements of the axial and appendicular systems, which are totally independent in structure and embryological origin. The curvature of the trunk, produced by a standing wave, magnifies the propulsive action of the limbs. In intermediate forms, the association of an elongate trunk with limbs reduced in size brings about functional consequences which may be noticeably diverse according to the degree of trunk elongation and limb reduction. According to environmental constraints, animals search for better locomotor efficiency, which implies the maintenance or breakage of this association of both locomotor systems. In some cases, limb action on the ground is added to the axial wave action through a perfect mutual adjustment of rhythmic activity, until mechanical inefficiency of the limbs is reached by possible loss of contact with the ground. In other cases, the limbs dragged on the ground during the stance phase act against the axial action or, on the contrary, are inhibited by the axial system. A review of available data tries to contribute to an understanding of the respective roles of both systems in the transition to limblessness.
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  • 6
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    Entomologia experimentalis et applicata 80 (1996), S. 7-13 
    ISSN: 1570-7458
    Keywords: host-plant selection ; sensory physiology ; neural coding ; deterrents ; peripheral interactions ; receptor sites ; genetics of insects ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recent advances in our understanding of the relationship between chemosensory and behavioural responses to phytochemicals come from a number of studies on ovipositional and food selection behaviour of flies, butterflies, moths and beetles. Establishing input-output relationships has provided insight into the way in which the activity of chemoreceptors is translated into host-plant selection behaviour. This was achieved for both the qualitative contrast acceptance/rejection and for quantifiable preference hierarchies. By now it is clear that the subtlety of coding the complex phytochemical profiles offered by potential host plants relies on across-fibre patterns or ensemblefiring of taste neurons. Progress along these lines depends on unravelling processing pathways in the central nervous system, still a largely unexplored area in herbivorous insects. Increased interest can be noted for the mechanisms operating during the most peripheral events of chemoreception: the interaction of phytochemical and chemoreceptor, determining the specificity of recognition. Evidence for ‘peripheral integration’ has accumulated. Deterrent receptors have an especially puzzling nature. Although such cells respond to a wide array of structurally diverse secondary plant metabolites, their sensitivity profile differs between closely related species. To what extent membrane-bound receptor molecules are involved and what degree of specificity is conferred by these, is largely unknown. Sensitivity to a certain group or class of compounds is determined by single genes in several cases. This allows for a scenario in which single gene mutations affect stimulus-receptor interactions, which might concurrently affect host-plant selection behaviour.
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  • 7
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    Entomologia experimentalis et applicata 80 (1996), S. 320-324 
    ISSN: 1570-7458
    Keywords: multitrophic interactions ; phylogeny ; evolution ; fitness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 8
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    Entomologia experimentalis et applicata 97 (2000), S. 237-249 
    ISSN: 1570-7458
    Keywords: herbivores ; predators ; parasitoids ; mutualism ; induced defence ; behaviour ; ecology ; evolution ; sensory physiology ; plant fitness ; pathogens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Herbivorous and carnivorous arthropods use plant volatiles when foraging for food. In response to herbivory, plants emit a blend that may be quantitatively and qualitatively different from the blend emitted when intact. This induced volatile blend alters the interactions of the plant with its environment. We review recent developments regarding the induction mechanism as well as the ecological consequences in a multitrophic and evolutionary context. It has been well established that carnivores (predators and parasitoids) are attracted by the volatiles induced by their herbivorous victims. This concerns an active plant response. In the case of attraction of predators, this is likely to result in a fitness benefit to the plant, because through consumption a predator removes the herbivores from the plant. However, the benefit to the plant is less clear when parasitoids are attracted, because parasitisation does usually not result in an instantaneous or in a complete termination of consumption by the herbivore. Recently, empirical evidence has been obtained that shows that the plant's response can increase plant fitness, in terms of seed production, due to a reduced consumption rate of parasitized herbivores. However, apart from a benefit from attracting carnivores, the induced volatiles can have a serious cost because there is an increasing number of studies that show that herbivores can be attracted. However, this does not necessarily result in settlement of the herbivores on the emitting plant. The presence of cues from herbivores and/or carnivores that indicate that the plant is a competitor- and/or enemy-dense space, may lead to an avoidance response. Thus, the benefit of emission of induced volatiles is likely to depend on the prevailing faunal composition. Whether plants can adjust their response and influence the emission of the induced volatiles, taking the prevalent environmental conditions into account, is an interesting question that needs to be addressed. The induced volatiles may also affect interactions of the emitting plant with its neighbours, e.g., through altered competitive ability or by the neighbour exploiting the emitted information. Major questions to be addressed in this research field comprise mechanistic aspects, such as the identification of the minimally effective blend of volatiles that explains the attraction of carnivores to herbivore-infested plants, and evolutionary aspects such as the fitness consequences of induced volatiles. The elucidation of mechanistic aspects is important for addressing ecological and evolutionary questions. For instance, an important tool to address ecological and evolutionary aspects would be to have plant pairs that differ in only a single trait. Such plants are likely to become available in the near future as a result of mechanistic studies on signal-transduction pathways and an increased interest in molecular genetics.
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  • 9
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    Entomologia experimentalis et applicata 91 (1999), S. 29-35 
    ISSN: 1570-7458
    Keywords: chemoreception ; deterrents ; Pieris ; Brassicaceae ; cardenolides ; host-plant selection ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pieris butterflies (Lepidoptera: Pieridae) are specialist herbivores of cruciferous plants. They exploit glucosinolates, secondary plant metabolites chemotaxonomically characteristic for this plant family, as token stimuli. In addition to particular glucosinolates, some genera of the Cruciferae contain cardenolides, steroidal allelochemicals that act as potent feeding and oviposition deterrents to several Pieris species. We investigated the sensory mechanisms by which these compounds are perceived in larvae. Pieris caterpillars and many other lepidopterous species are endowed with so-called generalist deterrent receptors, that respond to a broad spectrum of secondary plant substances. In Pieris caterpillars we found a second type of deterrent chemoreceptor in maxillary styloconic taste sensilla. This neuron is very sensitive to cardenolides (threshold 0.1–0.3 μM). The generalist deterrent receptor also responds to these substances but its threshold lies at 50–100× higher concentrations. In behavioural preference experiments Pieris brassicae L. caterpillars preferred cardenolide-treated cabbage leaf discs when confronted with a choice between them and a deterrent substance that does not occur in the Brassicaceae. The cardenolides acted as potent deterrents when offered against untreated cabbage leaf discs. This demonstrates that the balance of activity elicited in the two types of deterrent chemoreceptors determines the behavioural decision.
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  • 10
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    Acta biotheoretica 47 (1999), S. 29-40 
    ISSN: 1572-8358
    Keywords: Sexual selection ; mate selection ; gamete selection ; evolution ; ploidy ; asssortative mating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Results of an agent-based computer simulation of the evolution of diploid sexual organisms showed that several mate selection strategies confer much higher average fitness to the simulated populations, and higher evolutionary stability to the alleles coding for these strategies, than random mating. Strategies which select for 'good genes' were very successful, and so were strategies based on assortative mating. The results support the hypothesis that mating is not likely to be random in nature and that the most successful mate selection strategies are those based on assortative mating or on advantageous genes.
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  • 11
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    Entomologia experimentalis et applicata 82 (1997), S. 37-44 
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; genetics ; sex-linkage ; X- and Y-chromosome ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A polymorphism in host plant exploitation has been discovered in the flea beetle, Phyllotreta nemorum L. (Coleoptera: Chrysomelidae: Alticinae) where one resistant population is able to use Barbarea vulgaris R.Br. ssp. arcuata (Opiz.) Simkovics (Brassicaceae) as a host plant while a susceptible population is not. Crosses (F1, F2, and backcrosses) between the two flea beetle populations were made, and survival of the progeny on B. v. ssp. arcuata was measured. The ability of P. nemorum larvae to survive in this plant species depended on the presence of major, dominant genes (R-genes). The two most abundant R-genes in the resistant flea beetle population were X- and Y-linked, respectively. The use of B. v. ssp. arcuata as a natural host plant by the resistant population of P. nemorum seems to be an extension of the host plant range of the species. The role of sex-linked genes in the evolution of host range is discussed.
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  • 12
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    Entomologia experimentalis et applicata 82 (1997), S. 25-35 
    ISSN: 1570-7458
    Keywords: Barbarea vulgaris ; Cruciferae ; Phyllotreta nemorum ; Chrysomelidae ; Alticinae ; flea beetle ; plant defence ; resistance ; host plant ; variation ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several sorts of variation in the interaction between the insect, Phyllotreta nemorum L. (Coleoptera:Chrysomelidae:Alticinae), and the plant, Barbarea vulgaris R.Br. (Brassicaceae), have been discovered: 1) genetic differences in the levels of defences in the plant, 2) genetic differences in the ability of insects to cope with the plant defences, 3) seasonal variation in levels of defences in the plant, and 4) differences between leaf types in levels of defences. Two plant accessions were suitable for larval development throughout the season while the remaining nine accessions were more or less unsuitable for larvae from the ‘susceptible’ T-population at least at certain times of the year. All accessions were suitable for the ‘resistant’ E-population throughout the year. There was a seasonal variation in levels of defences in some accessions which were unsuitable for the T-population during the summer period when beetles were present, but not during autumn and spring when the beetle were hibernating. Upper (younger) cauline leaves of these accessions had higher levels of defences than lower (older) cauline leaves. The resistant E-population used B. vulgaris as a natural host plant while the susceptible T-population did not. The use of B. vulgaris as a natural host plant by the E-population of P. nemorum seems to be an extension of the host plant range of the species. Variation in plant defences may have facilitated the switch in host plant use by the resistant flea beetle population.
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  • 13
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    Entomologia experimentalis et applicata 95 (2000), S. 141-149 
    ISSN: 1570-7458
    Keywords: ecology ; reproductive success ; fecundity ; intraspecific competition ; evolution ; pest outbreaks ; pest control ; chemical control ; economic threshold ; oilseed rape ; turnip rape
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Populations of the rapeseed pollen beetle Meligethes aeneus F. (Col., Nitidulidae) from areas with 0–16 years of history of intensive rapeseed growing were compared for key ecological characters. During the first 16 years of rapeseed cultivation the reproductive success of M. aeneus increased 200–300% over that of the beetles living on the natural host plants, cruciferous weeds. The increase was linear over time and statistically highly significant, and it did not appear to be related to food quality or to the size of the beetles. During the same period the tolerance to intraspecific competition decreased, possibly due to the relative absence of such competition on the new crop. Furthermore, the optimum population density for M. aeneus to maximize the size of its next generation on summer turnip rape was determined to be 0.5–1.0 beetles/plant, which is slightly below the economic threshold for chemical control (1 beetle/plant). Therefore the practical protection of the rapeseed yield also ensures the highest possible pest population size for the next year. These mechanisms may in part explain the particular noxiousness of the species as a pest all over Europe. In general these data show that after the introduction of a new crop plant into a region, significant changes during the recruitment process in a pestiferous insect may take place, contributing to the future pest status of the insect. It is suggested that such genetic and ecological changes in insects may be a more common mechanism than previously thought in initiating and sustaining pest outbreaks, and that conventional pest management methods may enhance that effect.
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  • 14
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    Journal of insect behavior 13 (2000), S. 71-86 
    ISSN: 1572-8889
    Keywords: copulatory courtship ; behavioral interactions ; songs ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract D. birchii and D. serrata, two endemic Australian Drosophila species, have a copulatory courtship. The males of these species begin to court the female after mounting her and often go on with the courtship after the copulation is over. In the present paper we have described behavioral interactions between the male and the female and analyzed acoustic signals produced by the flies during courtship. Species differences were more pronounced in female than in male behavior. Variation within the species was obvious in the relative proportions of time the flies spent in different behaviors. Even though courtship took place nearly solely during copulation, some remains of precopulatory courtship were observed in both species. It is suggested that copulatory courtship exhibited by D. birchii and D. serrata flies is a derived rather than a primitive character.
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  • 15
    ISSN: 1572-9028
    Keywords: rutile supported V2O5–WO3 catalyst ; evolution ; NO reduction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This paper concerns the relation between surface structure of crystalline vanadia-like active species on vanadia–tungsta catalyst and their activity in the selective reduction of NO by ammonia to nitrogen. The investigations were performed for Ti–Sn-rutile-supported isopropoxy-derived catalyst. The SCR activity and surface species structure were determined for the freshly prepared catalyst, for the catalyst previously used in NO reduction by ammonia (320 ppm NO, 335 ppm NH3 and 2.35 vol% O2) at 573 K as well as for the catalyst previously annealed at 573 K in helium stream containing 2.35 vol% O2. The crystalline islands, exposing main V2O5 surface, with some tungsten atoms substituted for V-ones, were found, with XPS and FT Raman spectroscopy, to be present at the surface of the freshly prepared catalyst. A profound evolution of the active species during the catalyst use at 573 K was observed. Dissociative water adsorption on V5+OW6+ sites is discussed as mainly responsible for the catalyst activity at 473 K and that on both V5+OW6+ and V4+OW6+ sites as determining the activity at 523 K.
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  • 16
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    Cellular and molecular life sciences 52 (1996), S. 14-24 
    ISSN: 1420-9071
    Keywords: Lycaenidae ; Formicidae ; symbiosis ; mutualism ; parasitism ; communication ; ecology ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Associations with ants, termed myrmecophily, are widespread in the butterfly family Lycaenidae and range from mere co-existence to more or less specific mutualistic or even parasitic interactions. Secretions of specialized epidermal glands are crucial for mediating the interactions. Transfer of nutrients (carbohydrates, amino acids) from butterfly larvae to ants plays a major role, but manipulative communication with the help of odour signals is also involved. By means of myrmecophily, lycaenid butterflies largely escape ant predation, and certain species gain protection through attendant ants or achieve developmental benefits from ant-attendance. Benefits to the ants range from minimal to substantial food rewards. While most lycaenid species maintain facultative relationships with a variety of ant genera, highly specific and obligatory associations have convergently evolved in a number of butterfly lineages. As a corollary, communication systems are largely unspecific in the former, but may be highly specialized in the latter. The sophisticated communication between obligate myrmecophiles and their host ants is tightly connected with the evolutionary rise of specialized life-cycles and thus is a source of augmenting diversity within the butterflies.
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    Cellular and molecular life sciences 51 (1995), S. 454-464 
    ISSN: 1420-9071
    Keywords: Quantitative genetics ; life history ; evolution ; cladocera ; heritability ; Daphnia ; zooplankton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Quantitative genetic techniques are powerful tools for use in understanding the microevolutionary process. Because of their size, lifespan, and ease of culture, many zooplankton species are ideal for quantitative genetic approaches. As model systems, studies of zooplankton life histories are becoming increasingly used for examination of the central paradigms of evolutionary theory. Two of the fundamental empirical questions that zooplankton quantitative genetics studies can answer are: 1) How much genetic variance exists in natural populations for life history traits? 2) What is the empirical evidence for trade-offs that permeate life history theory based on optimality approaches? A review of existing data onDaphnia indicates substantial genetic variance for body size, clutch size, and age at first reproduction. Average broad-sense heritabilities for these three characters across 19 populations of 6 species are 0.31, 0.31, and 0.34, respectively. Although there is some discrepancy between the two pertinent studies that were designed to decompose the total genetic variance into its additive and non-additive components, a crude average seems to suggest that approximately 60% of the total genetic variance has an additive basis. The existing data are somewhat inconsistent with respect to presence/absence of trade-offs (negative genetic correlations) among life history traits. A composite of the existing data seems to argue against the existence of strong trade-offs between offspring size and offspring number, between present and future reproduction, and between developmental rate and fecundity. However, there is some evidence for a shift toward more negative (less positive) covariances in more stressful environments (e.g., low food). Zooplankton will prove to be very useful in future study in several important areas of research, including the genetics and physiology of aging, the importance of genotype-environment interaction for life history traits, and the evolution of phenotypic plasticity.
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    Cellular and molecular life sciences 52 (1996), S. 503-510 
    ISSN: 1420-9071
    Keywords: Drosophila ; accessory gland ; reproduction ; sexual behavior ; sperm displacement ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Recent results from biochemical and molecular genetic studies of the accessory gland proteins in maleDrosophila are reviewed. The most prominent feature is the species-specific variability. However, the analysis of the sex peptide inD. melanogaster shows that there is a strong homology in the molecular structure to the closely related sibling species, and that divergence increases with increasing phylogenetic distance. For this reason the sex peptide, after being transferred to the female genital tract during copulation, reduces receptivity and increases oviposition only in virgin females belonging to the same species group and subgroup. Even though studies were hitherto limited to a small number of the secretory components, it is evident that the accessory gland proteins play a key role in reproductive success of the fruit fly by changing female sexual behavior, supporting sperm transfer, storage and displacement. Thus, genes encoding the accessory gland proteins are apparently under strong evolutionary selection.
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  • 19
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    BioMetals 11 (1998), S. 277-295 
    ISSN: 1572-8773
    Keywords: evolution ; classification ; EF-hand ; domain ; homology ; chimera ; congruence ; gene duplication ; gene fusion ; eukaryote ; dendrogram ; calmodulin ; troponin C ; light chain of myosin ; S100 ; parvalbumin ; calcineurin ; recoverin ; calpain ; sorcin ; diacylglycerol ; calbindin ; aequorin ; phospholipase C ; BM-40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Forty-five distinct subfamilies of EF-hand proteins have been identified. They contain from two to eight EF-hands that are recognizable by amino acid sequence as being statistically similar to other EF-hand domains. All proteins within one subfamily are congruent to one another, i.e. the dendrogram computed from one of the EF-hand domains is similar, within statistical error, to the dendrogram computed from another(s) domain. Thirteen subfamilies - including Calmodulin, Troponin C, Essential light chain, Regulatory light chain - referred to collectively as CTER, are congruent with one another. They appear to have evolved from a single ur-domain by two cycles of gene duplication and fusion. The subfamilies of CTER subsequently evolved by gene duplications and speciations. The remaining 32 subfamilies do not show such general patterns of congruence; however, some - such as S100, intestinal calcium binding protein (calbindin 9kd), and trichohylin - do not form congruent clusters of subfamilies. Nearly all of the domains 1, 3, 5, and 7 are most similar to other ODD domains. Correspondingly the EVEN numbered domains of all 45 subfamilies most closely resemble EVEN domains of other subfamilies. Many sequence and chem-ical characteristics do not show systemic trends by subfamily or species of host organisms; such homoplasy is widespread. Eighteen of the subfamilies are heterochimeric; in addition to multiple EF-hands they contain domains of other evolutionary origins.© Kluwer Academic Publishers
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  • 20
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    Foundations of science 5 (2000), S. 429-456 
    ISSN: 1572-8471
    Keywords: awareness ; reflexive awareness and consciousness ; evolution ; experience and pattern matching ; symbolic language
    Source: Springer Online Journal Archives 1860-2000
    Topics: Natural Sciences in General
    Notes: Abstract An evolutionary point of view is proposed to make more appropriate distinctions between experience, awareness and consciousness. Experience can be defined as a characteristic linked closely to specific pattern matching, a characteristic already apparent at the molecular level at least. Awareness can be regarded as the special experience of one or more central, final modules in the animal neuronal brain. Awareness is what experience is to animals. Finally, consciousness could be defined as reflexive awareness. The ability for reflexive awareness is distinctly different from animal and human awareness and depends upon the availability of a separate frame of reference, as provided by symbolic language. As such, words have made reflexive awareness – a specific and infrequent form of awareness – possible. Conciousness might be defined as the experience evoked by considering, i.e. thinking about experiences themselves. If there is a hard problem of explaining consciousness, than this actually must be considered as the hard problem already met when trying to explain basic experience, since its nature remains elusive.
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    Minds and machines 6 (1996), S. 463-480 
    ISSN: 1572-8641
    Keywords: Human reasoning ; evolution ; deontic reasoning ; transitive reasoning ; non-human primates ; neocortical ratio ; dominance hierarchy
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    Topics: Computer Science , Philosophy
    Notes: Abstract Research from ethology and evolutionary biology indicates the following about the evolution of reasoning capacity. First, solving problems of social competition and cooperation have direct impact on survival rates and reproductive success. Second, the social structure that evolved from this pressure is the dominance hierarchy. Third, primates that live in large groups with complex dominance hierarchies also show greater neocortical development, and concomitantly greater cognitive capacity. These facts suggest that the necessity of reasoning effectively about dominance hierarchies left an indelible mark on primate reasoning architectures, including that of humans. In order to survive in a dominance hierarchy, an individual must be capable of (a) making rank discriminations, (b) recognizing what is forbidden and what is permitted based one's rank, and (c) deciding whether to engage in or refriin from activities that will allow one to move up in rank. The first problem is closely tied to the capacity for transitive reasoning, while the second and third are intimately related to the capacity for deontic reasoning. I argue that the human capacity for these types of reasoning have evolutionary roots that reach deeper into our ancestral past than the emergence of the hominid line, and the operation of these evolutionarily primitive reasoning systems can be seen in the development of human reasoning and domain-specific effects in adult reasoning.
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    Minds and machines 9 (1999), S. 309-346 
    ISSN: 1572-8641
    Keywords: language ; grammar ; syntax ; semantics ; evolution ; emergence ; brain size
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    Topics: Computer Science , Philosophy
    Notes: Abstract It is commonly argued that the rules of language, as distinct from its semantic features, are the characteristics which most clearly distinguish language from the communication systems of other species. A number of linguists (e.g., Chomsky 1972, 1980; Pinker 1994) have suggested that the universal features of grammar (UG) are unique human adaptations showing no evolutionary continuities with any other species. However, recent summaries of the substantive features of UG are quite remarkable in the very general nature of the features proposed. While the syntax of any given language can be quite complex, the specific rules vary so much between languages that the truly universal (i.e. innate) aspects of grammar are not complex at all. In fact, these features most closely resemble a set of general descriptions of our richly complex semantic cognition, and not a list of specific rules. General principles of the evolutionary process suggest that syntax is more properly understood as an emergent characteristic of the explosion of semantic complexity that occurred during hominid evolution. It is argued that grammatical rules used in given languages are likely to be simply conventionalized, invented features of language, and not the result of an innate, grammar-specific module. The grammatical and syntactic regularities that are found across languages occur simply because all languages attempt to communicate the same sorts of semantic information.
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    Journal for general philosophy of science 31 (2000), S. 57-73 
    ISSN: 1572-8587
    Keywords: complex systems ; evolution ; nonlinearity ; pre-determination ; self-organization ; soft management ; structure-attractors ; synergetics
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    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract The philosophical consequences of synergetics, the interdisciplinary theory of evolution and self-organization of complex systems, are being drawn in the paper. The idea of discreteness of evolutionary paths is in the focus of attention. Although the future is open, and there are many alternative evolutionary paths for complex systems, not any arbitrary (either conceivable or desirable) evolutionary path is feasible in a given system. There are discrete spectra of possible evolutionary paths which are determined exclusively by inner properties of the corresponding systems. Synergetics allows us to reveal general laws of self-organization and, therefore, certain limits of arbitrariness of nature in choosing possible paths of evolution as well as in constructing of a complex evolutionary whole. A comparative analysis between the modern synergetic notions and a few ideas of the Western philosophy (F. Nietzsche, N. Hartmann, M. Heidegger) and of the Eastern teachings (Taoism, Buddhism) is made.
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    International journal of value-based management 13 (2000), S. 297-308 
    ISSN: 1572-8528
    Keywords: morality ; moral systems ; behavior ; evolution ; adaptation ; natural selection ; altruism ; reciprocal altruism ; fitness ; reciprocity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract The ethical and moral behavior of Homo sapiens is no longer the exclusive domain of religion and philosophy because we recognize that such behavior affects the reproductive success of individuals within the species. We are a social species and therefore our survival is influenced by our capacity for cooperation and our willingness to take risks for kin. Emotions, some of which are found in other species, help to mediate our altruistic behavior. The reproductive benefits of helping kin, especially offspring, are readily seen. Helping non-kin can be beneficial if individuals can differentiate between ‘reciprocators’ and ‘non-reciprocators’ and direct altruistic behavior toward reciprocators. Also, if third parties are favorably impressed by observing altruistic behavior, the rewards need not come from the recipient of the altruistic behavior.
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    Journal for general philosophy of science 30 (1999), S. 37-58 
    ISSN: 1572-8587
    Keywords: protein ; experimentation ; conceptual variation and selection ; evolution ; Mulder ; Liebig ; Pflüger ; Nägeli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Philosophy , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract A philosophically comprehended account is given of the genesis and evolution of the concept of protein. Characteristic of this development were not shifts in theory in response to new experimental data, but shifts in the range of questions that the available experimental resources were fit to cope with effectively. Apart from explanatory success with regard to its own range of questions, various other selecting factors acted on a conceptual variant, some stemming from a competing set of research questions, others from an altogether different field of inquiry, and still others from the external environment. These results are best explained on, hence support, an evolutionary model of the progress of experimental investigation, whose outlines are briefly discussed.
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    Minds and machines 6 (1996), S. 481-505 
    ISSN: 1572-8641
    Keywords: Neuroscience ; evolutionary psychology ; interfield theory ; evolution ; teleology ; function ; functionalism ; brain mapping ; language processing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Philosophy
    Notes: Abstract The idea of integrating evolutionary biology and psychology has great promise, but one that will be compromised if psychological functions are conceived too abstractly and neuroscience is not allowed to play a contructive role. We argue that the proper integration of neuroscience, psychology, and evolutionary biology requires a telelogical as opposed to a merely componential analysis of function. A teleological analysis is required in neuroscience itself; we point to traditional and curent research methods in neuroscience, which make critical use of distinctly teleological functional considerations in brain cartography. Only by invoking teleological criteria can researchers distinguish the fruitful ways of identifying brain components from the myriad of possible ways. One likely reason for reluctance to turn to neuroscience is fear of reduction, but we argue that, in the context of a teleological perspective on function, this concern is misplaced. Adducing such theoretical considerations as top-down and bottom-up constraints on neuroscientific and psychological models, as well as existing cases of productive, multidisciplinary cooperation, we argue that integration of neuroscience into psychology and evolutionary biology is likely to be mutually beneficial. We also show how it can be accommodated methodologically within the framework of an interfield theory.
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  • 27
    ISSN: 1573-0417
    Keywords: colonization ; evolution ; lakes ; Norway ; deglaciation ; land uplift ; invertebrates ; Chironomidae ; Porifera ; Bryozoa ; diatoms ; Charophyta ; tsunami
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Invertebrate colonization of lakes following the uplift of land from the sea was studied in four lakes, currently situated between 39 and 24 m a.s.l., on the central Norwegian coast. The lakes were isolated from the sea between 9500 and 7700 years B.P. Animal and algal remains picked from core samples showed that the first colonizers preserved as fossils were usually members of the Chironomidae, Daphnidae/Chydoridae, Acarina, Porifera (Ephydatia mülleri and Spongilla lacustris), Bryozoa (Cristatella mucedo and Plumatella spp.) and Charophyta (Chara sp.). Of the chironomids, the genus Chironomus was present in the oldest lacustrine layers of all four lakes, but other genera recorded at the marine/lacustrine boundary were Dicrotendipes, Procladius (?), Einfeldia, Microtendipes, and Glyptotendipes. Remains of the caddis fly family Limnephilidae were also present in the earliest lacustrine sediments in Kvennavatnet and Kvernavatnet. The oldest invertebrate fauna is typical for mesotrophic lakes. However, chironomids and mites have been present in this area from at least about 10 500 years B.P. A diverse chironomid community was established between 300 and 800 years after isolation from the sea at Kvernavatnet on the island of Hitra, while only between 80 and 120 years passed before a comparably diverse community developed at Kvennavatnet on the mainland coast. A similar development of the invertebrate fauna occurred in Kvennavatnet, Kvernavatnet and Storkuvatnet. However, Litjvatnet deviates greatly from the ‘normal’ pattern because a tsunami disturbed the bottom sediments and fauna. The tsunami, a gigantic sea wave, was caused by a submarine slide from the Norwegian continental slope. It reached Litjvatnet, today located 24 m a.s.l., but was not traced in Storkuvatnet at 30 m a.s.l. This event happened about 7200 years B.P.
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    Antonie van Leeuwenhoek 71 (1997), S. 159-178 
    ISSN: 1572-9699
    Keywords: aromatic pathways ; chlorobenzenes ; evolution ; genes ; plasmids ; pseudomonas
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    Topics: Biology
    Notes: Abstract Chlorobenzenes are substrates not easily metabolized by existing bacteria in the environment. Specific strains, however, have been isolated from polluted environments or in laboratory selection procedures that use chlorobenzenes as their sole carbon and energy source. Genetic analysis indicated that these bacteria have acquired a novel combination of previously existing genes. One of these gene clusters contains the genes for an aromatic ring dioxy-genase and a dihydrodiol dehydrogenase. The other contains the genes for a chlorocatechol oxidative pathway. Comparison of such gene clusters with those from other aromatics degrading bacteria reveals that this process of recombining or assembly of existing genetic material must have occurred in many of them. Similarities of gene functions between pathways suggest that incorporation of existing genetic material has been the most important mechanism of expanding a metabolic pathway. Only in a few cases a horizontal expansion, that is acqui sition of gene functions to accomodate a wider range of substrates which are then all transformed in one central pathway, is observed on the genetic level. Evidence is presented indicating that the assembly process may trigger a faster divergence of nearby gene sequences. Further ‘fine-tuning’, for example by developing a proper regulation, is then the next step in the adaptation.
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    Antonie van Leeuwenhoek 71 (1997), S. 265-270 
    ISSN: 1572-9699
    Keywords: bacteria ; DNA ; evolution ; genome ; RNA
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    Topics: Biology
    Notes: Abstract This review examines evolution of bacterial genomes with an emphasis on RNA based life, the transition to functional DNA and small evolving genomes (possibly plasmids) that led to larger, functional bacterial genomes.
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    Antonie van Leeuwenhoek 71 (1997), S. 257-263 
    ISSN: 1572-9699
    Keywords: bacteria ; energy ; evolution ; genome ; metabolism
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    Topics: Biology
    Notes: Abstract This article examines the relationship between (or dependence of) bacterial evolution in prokaryotes and metabolism, and the changing physical-chemical conditions present during early evolution.
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    Antonie van Leeuwenhoek 71 (1997), S. 363-368 
    ISSN: 1572-9699
    Keywords: assembly ; anode ; bacteria ; cathode ; DNA ; evolution ; genetics ; molecular ; surfaces
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    Topics: Biology
    Notes: Abstract Molecular evolution is examined in bacteria with an emphasis on mineral surfaces, membranes, cathodes and anodes. In early molecular evolution, cathode-anode system may have been naturally occurring on a nm to µm scale. Secondly, the cathode-anode system could have been separated by a primitive, permeable lipid or microsphere on a mineral surface, that was a precursor of a more advanced membrane with a charge differential on either side of the membrane. These aspects will be considered from a theoretical evolutionary perspective.
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    Antonie van Leeuwenhoek 72 (1997), S. 251-259 
    ISSN: 1572-9699
    Keywords: bacteria ; catalysis ; DNA ; enzyme ; evolution ; microorganisms ; optimization ; RNA ; time
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    Topics: Biology
    Notes: Abstract Microbial populations (and life) not only evolve, they optimize. The transition from a random, unorganized, lifeless Earth to the present situation, where the Earth is virtually covered with nucleic acids and diverse and complex species, required numerous molecular changes and the integration of metabolic pathways over billions of years. Primitive prokaryotic life was dependent on and constrained by the physical-chemical conditions on the Earth, while slowly reshaping conditions present. In this review, molecular evolution and molecular optimization are examined with an emphasis on the order in which evolutionary events occurred.
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    ISSN: 1572-9737
    Keywords: conservation genetics ; Equus ; evolution ; mitochondrial DNA control region ; mitochondrial 12S rRNA
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    Topics: Biology
    Notes: Abstract The evolution, taxonomy and conservation of the genus Equuswere investigated by examining the mitochondrial DNA sequences of thecontrol region and 12S rRNA gene. The phylogenetic analysis of thesesequences provides further evidence that the deepest node in thephylogeny of the extant species is a divergence between twolineages; one leading to the ancestor of modern horses (E.ferus, domestic and przewalskii) and the other to thezebra and ass ancestor, with the later speciation events of the zebrasand asses occurring either as one or more rapid radiations, or withextensive secondary contact after speciation. Examination of the geneticdiversity within species suggested that two of the E. hemionussubspecies (E. h. onager and E. h. kulan) onlyrecently diverged, and perhaps, are insufficiently different to beclassified as separate subspecies. The genetic divergence betweendomestic and wild forms of E. ferus (horse) and E.africanus (African ass) was no greater than expected within anequid species. In E. burchelli (plains zebra) there was anindication of mtDNA divergence between populations increasing withdistance. The implications of these results for equid conservation arediscussed and recommendations are made for conservation action.
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    Journal of the history of biology 32 (1999), S. 343-383 
    ISSN: 1573-0387
    Keywords: agnosticism ; Darwinian ; evolution ; materialism ; Malthusian ; nebular hypothesis ; popularization ; professionalization ; transitional forms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , History
    Notes: Abstract Robert Chambers and Thomas Henry Huxley helped popularize science by writing for general interest publications when science was becoming increasingly professionalized. A non-professional, Chambers used his family-owned Chambers' Edinburgh Journal to report on scientific discoveries, giving his audience access to ideas that were only available to scientists who regularly attended professional meetings or read published transactions of such forums. He had no formal training in the sciences and little interest in advancing the professional status of scientists; his course of action was determined by his disability and interest in scientific phenomena. His skillful reporting enabled readers to learn how the ideas that flowed from scientific innovation affected their lives, and his series of article in the Journal presenting his rudimentary ideas on evolution, served as a prelude to his important popular work, Vestiges of the Natural History of Creation. Huxley, an example of the new professional class of scientists, defended science and evolution from attacks by religious spokesmen and other opponents of evolution, informing the British public about science through his lectures and articles in such publications as Nineteenth Century. He understood that by popularizing scientific information, he could effectively challenge the old Tory establishment -- with its orthodox religious and political views -- and promote the ideas of the new class of professional scientists. In attempting to transform British society, he frequently came in conflict with theologians and others on issues in which science and religion seemed to contradict each other but refused to discuss matters of science with non-professionals like Chambers, whose popular writing struck a more resonant chord with working class readers.
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    De economist 144 (1996), S. 397-428 
    ISSN: 1572-9982
    Keywords: conventions ; institutions ; game theory ; evolution
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    Topics: Economics
    Notes: Summary This survey article starts with a game-theory interpretation of coordination problems that occur in an economy. Three types of games are discussed in which the degree of coordination versus conflict varies. It is shown that game-theoretic techniques for equilibrium selection or securing the highest pay-off outcome do not always suffice, which raises the need for exogenous information. Norms, such as conventions and institutions, may provide this information. The emergence and persistence of norms as well as the relationship between the type of game and the type of norm are discussed. After a discussion on conventions and rationality, some notions from Institutional Economics are introduced, in which institutions are explained as a way to deal with limited and costly information. Some applications are given in the last section.
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    Journal of the history of biology 33 (2000), S. 457-491 
    ISSN: 1573-0387
    Keywords: J. B. S. Haldane ; biology ; politics ; genetics ; evolution ; population genetics ; physiology ; Darwinism ; experimental biology ; eugenics ; Britain ; Russia ; India ; Soviet ; Communism ; socialism ; philosophy ; vision ; literature ; popularization ; religion ; human experimentation ; bioethics ; Venus ; Mars ; science fiction ; technocracy ; futurology ; H. G. Wells ; Julian Huxley ; Olaf Stapledon ; C. S. Lewis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , History
    Notes: Abstract This paper seeks to reinterpret the life and work of J. B. S. Haldane by focusing on an illuminating but largely ignored essay he published in1927, “The Last Judgment” – the sequel to his better known work, Daedalus (1924). This astonishing essay expresses a vision of the human future over the next 40,000,000 years, one that revises and updates Wellsian futurism with the long range implications of the “new biology” for human destiny. That vision served as a kind of lifelong credo, one that infused and informed his diverse scientific work, political activities, and popular writing, and that gave unity and coherence to his remarkable career.
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    Journal of the history of biology 33 (2000), S. 221-246 
    ISSN: 1573-0387
    Keywords: August Weismann ; ciliates ; Clifford Dobell ; cytology ; death ; Emile Maupas ; evolution ; Herbert Spencer Jennings ; Otto Bütschli ; Paramecium ; rejuvenescence ; sex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , History
    Notes: Abstract In the period 1875–1920, a debate about the generality and applicability of evolutionary theory to all organisms was motivated by work on unicellular ciliates like Paramecium because of their peculiar nuclear dualism and life cycles. The French cytologist Emile Maupas and the German zoologist August Weismann argued in the 1880s about the evolutionary origins and functions of sex (which in the ciliates is not linked to reproduction), and death (which appeared to be the inevitable fate of lineages denied sexual conjugation), an argument rooted in the question of whether the ciliates and their processes where homologous to other cellular organisms. In the beginning of the twentieth century, this question of homology came to be less important as the ciliates were used by the British protozoologist Clifford Dobell and the American zoologist Herbert Spencer Jennings to study evolutionary processes in general rather than problems of development and cytology. For them, homology mattered less than analogy. This story illustrates two partially distinct problems in evolutionary biology: first, the question of whether all living things have common features and origins; and second, whether their history and current nature can be described by identical mechanisms. Where Maupas (contra Weismann) made the ciliates qualitatively the same as all other organisms in order to create a cohesive evolutionary theory for biology, Jennings and Dobell made them qualitatively different in order to achieve the same end.
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    Insectes sociaux 42 (1995), S. 57-69 
    ISSN: 1420-9098
    Keywords: Hindgut ; alkalinity ; evolution ; symbionts ; gut morphology
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    Topics: Biology
    Notes: Summary The pH of the gut contents was measured in 52 species of higher termites (Termitidae), representing 36 genera in all four subfamilies. A statistically significant trend was shown from lower termites with low mean gut pH through to the Termitinae with higher mean gut pHs. Elevation of the pH occurred principally in the first and third proctodaeal segments, reaching values as high as 10.5 in 8 soil-feeding genera and 1 wood-feeding genus of Termitinae. Elevation of gut pH within the Termitidae appears to be independent of the general nature of the feeding substrate.
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    Insectes sociaux 43 (1996), S. 375-389 
    ISSN: 1420-9098
    Keywords: Nasutitermitinae ; Subulitermes ; Coatitermes ; Velocitermes ; evolution ; phylogeny
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    Topics: Biology
    Notes: Summary The developmental pathways of the neuter castes were studied in three species of Nasutitermitinae from central Panama. The humivorousSubulitermes denisae andCoatitermes clevelandi display several primitive traits: absence of sex dimorphism, representation of both sexes among workers and soldiers, and occurrence of successive worker instars. The litter-dwellingVelocitermes barrocoloradensis has a more complex caste system: female larvae are larger than males and give rise to the large workers, which constitute the bulk of the work force; male larvae proceed to soldiers through a small worker or a special larval instar. The resulting soldier caste is polymorphic. These results support previously formulated hypotheses regarding a link between humivorous diet and reduced polymorphism on the one hand, and between forest-floor foraging and large continuous size variation among soldiers on the other. Whereas the caste systems ofSubulitermes andCoatitermes probably represent a primitive condition,Velocitermes shares derived traits withNasutitermes and the other fully nasute genera previously studied. I therefore hypothesize that ancestors with these advanced features may have spread from the neotropics and be at the origin of most nasute genera, including humivorous taxa, present in other regions.
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  • 40
    ISSN: 1420-9098
    Keywords: Formicidae ; Leptothoracini ; Tetramoriini ; internal transcribed spacer ; social parasitism ; evolution ; phylogenetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A fragment of the internal transcribed spacer (ITS-1) adjacent to the 5.8S rRNA gene of 20 myrmicine ant species was sequenced. Sequence comparisons were carried out between 11 species of the tribe Leptothoracini, five species of the tribe Tetramoriini, three species of the tribe Solenopsidini and one species of the tribe Myrmicini. Additionally, the formicine antCamponotus ligniperda (tribe Camponotini) was analyzed as an outgroup species. Among all investigated species, the fragment had a variable length of ≈ 230–380 bp with only a few conserved sequence elements. The sequences of this fragment were perfectly identical within four palearctic populations ofLeptothorax acervorum indicating that intraspecific variation is rather low. Within the species of Tetramoriini (includingAnergates atratulus) 94.1% of sequence positions were identical, 95.6% within the species of theLeptothorax s.str.-group and 64.6% within the species of theMyrafant-group. Phylogenetic analysis reveals that the social parasitesHarpagoxenus sublaevis, Doronomyrmex goesswaldi, D. kutteri andD. pacis, Chalepoxenus muellerianus as well asStrongylognathus alpinus andTeleutomyrmex schneideri are most closely related to the groups of their respective host species, which generally confirms the taxonomical classifications of the subfamily Myrmicinae based on morphological criteria. The taxonomical positions of the speciesA. atratulus has as yet been uncertain, however, sequence comparison of the ITS-1 fragment leads to the conclusion thatA. atratulus rather belongs to the tribe Tetramoriini than to the Solenopsidini.
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    ISSN: 1423-0445
    Keywords: sex pheromone ; synergist ; antagonist ; mate recognition ; reproductive isolation ; chemotaxonomoy ; phylogeny ; evolution ; Lepidoptera ; Tortricidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The geometric isomers (E,E)-, (E,Z)-, (Z,E)-, and (Z,Z)-8,10-dodecadien-1-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males ofCydia andGrapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds.Pammene, as well as otherGrapholita andCydia responded to the monoenic 8- or 10-dodecen-1-yl acetates. Of the tribes Olethreutini and Eucosmini,Hedya, Epiblema, Eucosma, andNotocelia trimaculana were also attracted to 8,10-dodecadien-1-yl acetates, but several otherNotocelia to 10,12-tetradecadien-1-yl acetates. The female sex pheromones ofC. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella andNotocelia roborana were identified. (E,E)- and (E,Z)-8,10-dodecadien-1-yl acetate are producedvia a commonE9 desaturation pathway inC. splendana. CallingC. nigricana andC. fagiglandana females are attracted to wingfanning males.
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    Immunogenetics 49 (1999), S. 865-871 
    ISSN: 1432-1211
    Keywords: Key words Orangutan ; MHC class I ; HLA-C ; natural killer cells ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  HLA-B and C are related class I genes which are believed to have arisen by duplication of a common ancestor. Previous study showed the presence of orthologues for both HLA-B and C in African apes but only for HLA-B in Asian apes. These observations suggested that the primate C locus evolved subsequent to the divergence of the Pongidae and Hominidae. From an analysis of orangutan Tengku two HLA-C-like alleles (Popy C*0101 and Popy C*0201) were defined as well as three HLA-B-like (Popy-B) alleles. By contrast, no Popy-C alleles were obtained from orangutan Hati, although three Popy-B alleles were defined. Thus an HLA-C-like locus exists in the orangutan (as well as a duplicated B locus), implying that the primate C locus evolved prior to the divergence of the Pongidae and Hominidae and is at least 12–13 million years old. Uncertain is whether all orangutan MHC haplotypes contain a C locus, as the failure to find C alleles in some individuals could be due to a mispairing of HLA-C-specific primers with certain Popy-C alleles. These results raise the possibilities that other primate species have a C locus and that the regulation of natural killer cells by C allotypes evolved earlier in primate evolution than has been thought.
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    Ecological research 10 (1995), S. 321-325 
    ISSN: 1440-1703
    Keywords: body temperature ; brood parasitism ; cuckoo ; evolution ; telemetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Body temperatures of 11 bird species, including cuckoos, were measured in an artificial meteorological room. Ratios of change in body temperature to that in air temperature were thereby obtained for each species. Cuckoos demonstrate a remarkably high value, indicating a particularly low ability to regulate body temperature. Viewed in this light, the cuckoo's parasitic behavior is very likely an adaptation to overcome a physiological disadvantage. This in turn might be expected to reinforce delay in evolution of temperature homeostasis.
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  • 44
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    Journal of industrial microbiology and biotechnology 17 (1996), S. 151-158 
    ISSN: 1476-5535
    Keywords: bacteriocins ; colicins ; evolution ; ecology ; Escherichia coli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In this review we focus on the ecological and evolutionary forces that determine the frequency and diversity of colicins inEscherichia coli. To begin, we describe that this killing phenotype is ubiquitous inE. coli, with as many as 50% of the isolates from a population producing colicin toxins, and that each population sampled has its own unique distribution of the more than 20 known colicin types. Next, we explore the dynamics of colicinogeny, which exhibits a typical form of frequency dependence, where the likelihood of successful colicin invasion into a population increases as the initial density of colicinogenic cells increases. We then incorporate thoughts on the evolution of chromosomal resistance to colicins and describe how resistance might influence the dynamics of colicinogen invasion and maintenance and the resulting colicin diversity. The final section deals with a genetic and phylogenetic characterization of colicins and a discussion of the evolutionary mechanisms responsible for generating colicin diversity. In this final section we provide details of the different molecular mechanisms known to play a role in generating colicin diversity, including the two most dominant forces in colincin evolution: recombination and positive, deversifying, selection.
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  • 45
    ISSN: 1573-4927
    Keywords: glycophorins ; gorilla ; evolution ; gene family ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Homologues of MN blood group antigens, encoded by members of the glycophorin A (GPA) gene family, are expressed in man, anthropoid apes, and some species of Old World monkeys. Previous studies had shown that a three-gene framework, most closely related to that in man, is present in the chimpanzee. Here we report the genomic structure, transcript map, and protein expression of the GYPA locus in gorillas. Compared to the corresponding human and chimpanzee homologues, gorilla GPA, GPB, and GPB/E genes each showed a high degree of sequence identity, with the same exon-intron organization. However, the expression of exons III, IV, or V encoding the extracellular or membrane domains of homologous glycophorins varied among the three species. Gorilla GPA and GPB/E genes were unique in that the former occurred in two allelic forms with or without the expression of exon III, whereas the latter contained one (ψ exon III) instead of two silenced exons (ψ exons III and IV). Differences from human but not chimpanzee GPA also included the presence of a hybrid M/N epitope and the absence of the sequon for N-glycosylation. Owing to the retention of a functional exon III, gorilla GPB was more similar to chimpanzee GPB than human GPB. A transspecies allele was identified in the gorilla that gave rise to the Henshaw (He)-like antigen similar to that found in man. These results provide further insight into the model for evolution of the GPA gene family, indicating that the mechanisms underlying inter- and intraspecific polymorphism of glycophorins could predate the divergence of gorillas as the consequence of gene duplication and diversification.
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  • 46
    ISSN: 1573-1561
    Keywords: Eriocrania cicatricella ; Eriocrania sparrmannella ; Eriocraniidae ; Lepidoptera ; sex pheromone ; EAG ; GC-EAD ; mass spectrometry ; synthesis ; evolution ; (Z)-4-hepten-2-one ; (2R)-heptan-2-ol ; (2R)-(Z)-4-hepten-2-ol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Extracts from different body parts of adult femaleEriocrania cicatricella (Zett.) were tested for electrophysiological activity on conspecific male antennae. Extracts from the Vth abdominal segment, containing a pair of exocrine glands, elicited the largest electroantennographic response when compared to extracts of other body parts. Female extracts were analyzed by gas chromatography with simultaneous flame ionization and electroantennographic detection (EAD). The EAD active peaks were identified as (Z)-4-hepten-2-one, (2R)-heptane-2-ol, and (2R)-(Z)-4-hepten-2-ol by coinjection on a gas chromatography and by comparison of mass spectra with those of synthetic standards. In field tests, a blend of these three pheromone components was highly attractive to conspecific males, and a subtractive assay confirmed that the unsaturated alcohol is the major pheromone component, whereas no definite behavioral activity could be assigned to the ketone or the saturated alcohol. A bait containing the two alcohols withS-configuration was attractive to maleE. sparrmannella (Bosc), whereas no males ofE. cicatricella were found in these traps. The sex pheromone compounds inE. cicatricella are chemically similar to pheromones reported in Trichoptera and they are produced in homologous glands.
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  • 47
    ISSN: 1573-1561
    Keywords: Sex pheromone ; Idaea aversata ; Idaea straminata ; Idaea biselata ; (Z,Z)-9,11-tetradecadienyl acetate ; (Z,Z)-7,9-dodecadienyl acetate ; (Z,E)-7,9-dodecadienyl acetate ; Lepidoptera ; Geometridae ; electroantennography ; single cell recording ; biosynthesis ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Pheromone compounds so far identified from most geometrid moths consist of all-Z diene, triene, or tetraene hydrocarbons with chain lengths of C17 to C21, and their monoepoxide derivatives biosynthesized from linoleic and linolenic acids. The present study reports the occurrence of olefinic acetates as sex pheromones in three species of Geometridae. (Z,Z)-9,11-tetradecadienyl acetate and (Z,Z)-7,9-dodecadienyl acetate found in female gland extracts ofIdaea aversata elicited significant responses from conspecific male antennae in gas chromatography with electroantennographic detection (GCEAD). In extracts ofI. straminata, (Z,Z)-7,9-dodecadienyl acetate, (E,Z)-7,9-dodecadienyl acetate, and (Z,Z)-7,9-dodecadienyl acetate were found, and the synthetic compounds elicited strong responses from conspecific male antennae. In the third species,I. biselata, only (Z,Z)-7,9-dodecadienyl acetate was found in the female extracts, and this compound elicited a strong EAD response from the conspecific male antenna. The identities of the pheromone components inI. aversata andI. straminata were further confirmed according to their characteristic ions after GC-MS analyses. Single sensillum recordings fromI. aversata showed two types of pheromone-detecting sensilla present on the male antenna. One type contained two receptor neurons, one of which was specifically tuned to (Z,Z)-9,11-tetradecadienyl acetate, the other to (Z,E)-9,11-tetradecadienyl acetate. A second type contained one neuron responding to (Z,Z)-7,9-dodecadienyl acetate. The two types were clearly different also with respect to external morphology, the former being considerably longer and having a larger base diameter. Also inI. straminata two physiological types of sensilla could be distinguished. One type contained two neurons, one of which responded to (Z,Z)-7,9-dodecadienyl acetate, the other to (Z,E)-9,11-tetradecadienyl acetate. The second type contained one neuron, responding to (Z,Z)-7,9-dodecadienyl acetate. No correlation between external morphology and physiological response of the investigated sensilla was observed inI. straminata. In field tests, a two-component blend containing (Z,Z)-9,11-tetradecadienyl acetate and (Z,Z)-7,9-dodecadienyl acetate in a ratio of 10:1 was attractive to males ofI. aversata. This two-component blend was also attractive to males ofI. straminata, but in a ratio of 1:1. High numbers of maleI. biselata were caught in traps baited with (Z,Z)-7,9-dodecadienyl acetate alone. The incorporation of deuterium labels into pheromone components after topical application of deuterium-labeled palmitic acid confirmed that the pheromone components ofI. aversata could be synthesized from this precursor, as has been previously observed for acetate pheromone components of many other moth species. Our results suggest that an evolutionary reversal back to the production of palmitic acid-derived pheromone components has occurred within the geometrid subfamily Sterrhinae.
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  • 48
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    Journal of chemical ecology 23 (1997), S. 1527-1547 
    ISSN: 1573-1561
    Keywords: Secondary metabolites ; chemical defense ; evolution ; ascidians ; sponges
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We used three chemical fractions (spanning a wide range of polarities) from the extracts of four marine invertebrates, the spongesCrambe crambe andHemimycale columella and the ascidiansCystodytes dellechiajei andPolysyncraton lacazei, to test inhibition of cell division, photosynthesis, and settlement. We used assay organisms from the same habitat, seeking to determine whether a species may display diverse, ecologically relevant bioac-tivities and, if so, whether the same types of compound may be responsible for such activities. Cell division was strongly inhibited by the spongeC. crambe. A dichloromethane fraction fromC. crambe prevented development of sea urchinParacentrotus lividus eggs at a concentration of 10 μg/ml, as did the butanolic fraction, but at higher concentrations (50 and 100 μg/ml). At 50 μg/ml, the aqueous fraction ofC. crambe allowed cell division but prevented eggs from developing beyond the gastrula stage. Similar results were recorded with the dichloromethane fraction ofP. lacazei and from the aqueous fraction ofH. columella. Photosynthesis was unaffected by any of the species at 50 μg/ml. Larval settlement was inhibited by one or another fraction from the four species surveyed at a concentration of 50 μg/ml, althoughC. crambe exhibited the greatest amount of activity. We therefore found that various fractions displayed the same type of bioactivity, while compounds from the same fraction were responsible for multiple activities, suggesting that secondary metabolites are multiple-purpose tools in nature, which is relevant to our understanding of species ecology and evolution. Moreover, results showed that the assessment of the role of chemical compounds is significantly influenced by the assay organism, fractionation procedure, concentration, and duration of experiments. All these factors should be carefully considered when testing ecological hypotheses of the roles of chemically-mediated bioactivities.
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  • 49
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    Journal of chemical ecology 25 (1999), S. 31-49 
    ISSN: 1573-1561
    Keywords: Chemical ecology ; evolution ; variation ; population dynamics ; community ; species interactions ; infochemical ; semiochemical ; parasitoid ; foraging behavior ; learning ; phenotypic plasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The marriage of chemistry with ecology has been a productive one, providing a wealth of examples of how chemicals play important roles in the loves and lives of living organisms. At first the marriage may have been a simple and monogamous one with the major scientific aim of making proximate analyses of chemically mediated, individual level interactions. But times have changed and chemical ecology is broadening, embracing different approaches and disciplines. There is, for example, increasing appreciation of variability in the systems under study and an increase in evolutionary thinking. Another promising development is greater recognition of the potential importance of chemically mediated interactions for population dynamics and for structuring communities and species coexistence. The latter is an utterly underexplored area in chemical ecology. The field of chemical ecology of insect parasitoids shows some of these promising developments. Responses of parasitoids to infochemicals are increasingly studied with an integrated approach of mechanism and function. This integration of “how” and “why” questions significantly enhances the evolutionary and ecological understanding of stimulus–response patterns. The future challenge in chemical ecology is to demonstrate how chemically mediated interactions steer ecological and evolutionary processes at all levels of ecological organization. To reach this goal there is a need for interdisciplinary collaboration among chemists and ecologists working at different levels of organization and with different approaches, with other disciplines as partners.
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  • 50
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    The environmentalist 20 (2000), S. 257-271 
    ISSN: 1573-2991
    Keywords: evolution ; tides ; sea level ; time series
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The increasing use of computers since the 1960s, has implied the digitization of observations in meteorology, oceanography and other observational sciences. Enough data has been accumulated to suggest that some patterns of evolution in the world may be discernable. The present article deals with what appears as changing tides around Canada.
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  • 51
    ISSN: 1573-4919
    Keywords: guanine nucleotide-binding proteins ; evolution ; phylogeny ; structure-function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract ADP-ribosylation factors (ARFs) are ∼20-kDa guanine nucleotide-binding proteins that are allosteric activators of the NAD:arginine ADP-ribosyltransferase activity of cholera toxin and appear to play a role in intracellular vesicular trafficking. Although the physiological roles of these proteins have not been defined, it has been presumed that each has a specific intracellular function. To obtain genetic evidence that each ARF is under evolutionary pressure to maintain its structure, and presumably function, rat ARF cDNA clones were isolated and their nucleotide and deduced amino acid sequences were compared to those of other mammalian ARFs. Deduced amino acid sequences for rat ARFs 1, 2, 3, 5 and 6 were identical to those of the known cognate human and bovine ARFs; rat ARF4 was 96% identical to human ARF4. Nucleotide sequences of both the untranslated as well as the coding regions were highly conserved. These results indicate that the ARF proteins are, as a family, extraordinarily well conserved across mammalian species. The unusually high degree of conservation of the untranslated regions is consistent with these regions having important regulatory roles and that individual ARFs contain structurally unique elements required for specific functions.
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  • 52
    ISSN: 1573-4943
    Keywords: Klebsiella aerogenes ; ribitol dehydrogenase ; evolution ; mutant structures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A mutant ribitol dehydrogenase (RDH-F) was purified from Klebsiella aerogenes strain F which evolved from the wild-type strain A under selective pressure to improve growth on xylitol, a poor substrate used as sole carbon source. The ratio of activities on xylitol (500 mM) and ribitol (50 mM) was 0.154 for RDH-F compared to 0.033 for the wild-type (RDH-A) enzyme. The complete amino acid sequence of RDH-F showed the mutations. Q60 for E60 and V215 for L215 in the single polypeptide chain of 249 amino acid residues. Structural modeling based on homologies with two other microbial dehydrogenases suggests that E60 → Q60 is a neutral mutation, since it lies in a region far from the catalytic site and should not cause structural perturbations. In contrast, L215 → V215 lies in variable region II and would shift a loop that interacts with the NADH cofactor. Another improved ribitol dehydrogenase, RDH-D, contains an A196 → P196 mutation that would disrupt a surface α-helix in region II. Hence conformational changes in this region appear to be responsible for the improved xylitol specificity.
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  • 53
    ISSN: 1573-4927
    Keywords: Akodon ; Cricetidae rodents ; genetic diversity ; biochemical polymorphism ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The present study involved an electrophoretic survey of 22 protein loci in 269 individuals belonging to three species of the genusAkodon, A. aff.cursor (2n=16),A. cursor (2n=14/15), andA. montensis (2n=24/25/26), collected in Eastern Brazil. The joint results of gene diversity, genetic distances, phenetic analyses, and phylogenetic trees suggested thatA. aff.cursor has recently separated fromA. cursor and that the three species have experienced a recent chromosomal divergence followed by low allozyme differentiation. These data are in agreement with their classification as sibling species.
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  • 54
    ISSN: 1573-4935
    Keywords: Chemotaxis ; evolution ; oligopeptides ; Tetrahymena ; Dunaliella
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Chemotactic properties of amino acids (L-alanine, glycine and L-lysine) and their oligopeptides (10−6M) and binding sites to these ligands were investigated in two unicellular models, the heterotrophicTetrahymena pyriformis and the auxotrophicDunaliella salina. Chemotaxis ofDunaliella induced by simple amino acids and their derivatives demonstrated that binding sites (receptors) for food molecules are not only present in the membrane but are also able to induce their basic physiological response. InTetrahymena, substances with special molecular structure and properties (polar, hydrophilic character of the signal peptide chain)-5-L-Lys, 5-Glywere required for chemoattraction, other peptides tested, lacking the required structure, were repellent. Divergences in chemotaxis and binding assays of both species suggest that trends of functional and binding parameters do not run parallel at this level of evolution.
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  • 55
    ISSN: 1573-4927
    Keywords: ancient endogenous provirus ; evolution ; retrotransposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A new family of murine endogenous proviruses (VL6.0) is described here. The intact provirus is near 6 kb in length and shows a genomic organization of 5" LTR, gag, pol, env, and 3" LTR. The primer binding site (PBS) is that of a tRNAgly. The lack of functional open reading frames and occurrence of significant gaps in most, if not all, members of this group show it to be ancient. Our estimate of copy number per haploid genome is 30+. Members of this group have been isolated from Mus musculus domesticus, M. m. casteneus, M. m. hortulanus, M. caroli, and M. spretus. The occurrence of these sequences throughout such diverse members of the genus Mus may indicate that the date of the original infection predated the divergence of the extant Mus lineages at around 2.5 million years ago. Analysis of gap (deletion/insertion) patterns indicates that these sequences may have proliferated within the Mus genome by a mechanism of reverse transcriptase-mediated transposition. As yet, there are no closely related murine retroviruses described. The closest mammalian retrovirus based on sequence similarity is from the miniature swine (Sus scrofa).
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  • 56
    ISSN: 1573-4943
    Keywords: Ribosomal proteins ; protein sequencing ; evolution ; Haloarcula marismortui
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The ribosomal protein HS23 from the 30S subunit of the extreme halophilicHaloarcula marismortui, belonging to the group of archaea, was isolated either by RP-HLPLC or two-dimensional polyacrylamide gel electrophoresis. The complete amino acid sequence was determined by automated N-terminal microsequencing. The protein consists of 123 residues with a corresponding molecular mass of 12,552 Da as determined by electrospray mass spectroscopy; the pI is 11.04. Homology studies reveal similarities to the eukaryotic ribosomal protein S8 fromHomo sapiens, Rattus norvegicus, Leishmania major, andSaccharomyces cerevisiae.
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  • 57
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    Plant molecular biology 29 (1995), S. 1005-1014 
    ISSN: 1573-5028
    Keywords: evolution ; genome mapping ; isozymes ; oxygen radicals ; powdery mildew
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clones representing two distinct barley catalase genes, Cat1 and Cat2, were found in a cDNA library prepared from seedling polysomal mRNA. Both clones were sequenced, and their deduced amino acid sequences were found to have high homology with maize and rice catalase genes. Cat1 had a 91% deduced amino acid sequence identity to CAT-1 of maize and 92% to CAT B of rice. Cat2 had 72 and 79% amino acid sequence identities to maize CAT-2 and-3 and 89% to CAT A of rice. Barley, maize or rice isozymes could be divided into two distinct groups by amino acid homologies, with one group homologous to the mitochondria-associated CAT-3 of maize and the other homologous to the maize peroxisomal/glyoxysomal CAT-1. Both barley CATs contained possible peroxisomal targeting signals, but neither had favorable mitochondrial targeting sequences. Cat1 mRNA occurred in whole endosperms (aleurones plus starchy endosperm), in isolated aleurones and in developing seeds, but Cat2 mRNA was virtually absent. Both mRNAs displayed different developmental expression patterns in scutella of germinating seeds. Cat2 mRNA predominated in etiolated seedling shoots and leaf blades. Barley genomic DNA contained two genes for Cat1 and one gene for Cat2. The Cat2 gene was mapped to the long arm of chromosome 4, 2.9 cM in telomeric orientation from the mlo locus conferring resistance to the powdery mildew fungus (Erysiphe graminis f.sp. hordei).
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  • 58
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    Plant molecular biology 29 (1995), S. 1057-1070 
    ISSN: 1573-5028
    Keywords: Arabidopsis ; EF-Tu ; evolution ; gene families ; mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have characterized a second nuclear gene (tufM) in Arabidopsis thaliana that encodes a eubacterial-like protein synthesis elongation factor Tu (EF-Tu). This gene does not closely resemble the previously described Arabidopsis nuclear tufA gene, which encodes the plastid EF-Tu, and does not contain sequence elements found in all cyanobacterial and plastid tufA genes. However, the predicted amino acid sequence includes an N-terminal extension which resembles an organellar targeting sequence and shares three unique sequence elements with mitochondrial EF-Tu's, from Saccharomyces cerevisiae and Homo sapiens, suggesting that this gene encodes the Arabidopsis mitochondrial EF-Tu. Consistent with this interpretation, the gene is expressed at a higher level in flowers than in leaves. Phylogenetic analysis confirms the mitochondrial character of the sequence and indicates that the human, yeast, and Arabidopsis tufM genes have undergone considerably more sequence divergence than their cytoplasmic counterparts, perhaps reflecting a cross-compartmental acceleration of gene evolution for components of the mitochondrial translation apparatus. As previously observed for tufA, the tufM gene is present in one copy in Arabidopsis but in several copies in other species of crucifers.
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  • 59
    ISSN: 1573-5028
    Keywords: carbon fixation ; oxidative pentose phosphate pathway ; chloroplasts ; evolution ; endosymbiosis ; isoenzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Exploiting the differential expression of genes for Calvin cycle enzymes in bundle-sheath and mesophyll cells of the C4 plant Sorghum bicolor L., we isolated via subtractive hybridization a molecular probe for the Calvin cycle enzyme d-ribulose-5-phosphate 3-epimerase (R5P3E) (EC 5.1.3.1), with the help of which several full-size cDNAs were isolated from spinach. Functional identity of the encoded mature subunit was shown by R5P3E activity found in affinity-purified glutatione S-transferase fusions expressed in Escherichia coli and by three-fold increase of R5P3E activity upon induction of E. coli overexpressing the spinach subunit under the control of the bacteriophage T7 promoter, demonstrating that we have cloned the first functional ribulose-5-phosphate 3-epimerase from any eukaryotic source. The chloroplast enzyme from spinach shares about 50% amino acid identity with its homologues from the Calvin cycle operons of the autotrophic purple bacteria Alcaligenes eutrophus and Rhodospirillum rubrum. A R5P3E-related eubacterial gene family was identified which arose through ancient duplications in prokaryotic chromosomes, three R5P3E-related genes of yet unknown function have persisted to the present within the E. coli genome. A gene phylogeny reveals that spinach R5P3E is more similar to eubacterial homologues than to the yeast sequence, suggesting a eubacterial origin for this plant nuclear gene.
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  • 60
    ISSN: 1573-5028
    Keywords: carbon fixation ; chloroplasts ; evolution ; isoenzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA encoding the Calvin cycle enzyme transketolase (TKL; EC 2.2.1.1) was isolated from Sorghum bicolor via subtractive differential hybridization, and used to isolate several full-length cDNA clones for this enzyme from spinach. Functional identity of the encoded mature subunit was shown by an 8.6-fold increase of TKL activity upon induction of Escherichia coli cells that overexpress the spinach TKL subunit under the control of the bacteriophage T7 promoter. Chloroplast localization of the cloned enzyme is shown by processing of the in vitro synthesized precursor upon uptake by isolated chloroplasts. Southern blot-analysis suggests that TKL is encoded by a single gene in the spinach genome. TKL proteins of both higher-plant chloroplasts and the cytosol of non-photosynthetic eukaryotes are found to be unexpectedly similar to eubacterial homologues, suggesting a possible eubacterial origin of these nuclear genes. Chloroplast TKL is the last of the demonstrably chloroplast-localized Calvin cycle enzymes to have been cloned and thus completes the isolation of gene probes for all enzymes of the pathway in higher plants.
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  • 61
    ISSN: 1573-4927
    Keywords: Bubalus ; tamaraw ; anoa ; cytochromeb ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The cytochromeb genes of all living species ofBubalus, including the river type and the swamp type of domestic buffaloes (Bubalus bubalis), were sequenced to clarify their phylogenetic relationships. These sequences were compared together with the African buffalo (Syncerus caffer) and banteng (Bos javanicus) sequences as an outgroup. Phylogenetic trees ofBubalus species based on the DNA sequences of the cytochromeb gene demonstrated that the tamaraw (Bubalus mindorensis), endemic to the Philippines, could be classified into the subgenusBubalus, not the subgenusAnoa. The divergence time between the lowland anoa (B. depressicornis) and the mountain anoa (B. quarlesi) was estimated at approximately 2.0 million years (Myr), which is almost the same as the coalescence time for theBubalus sequences. This large genetic distance supports the idea that the lowland anoa and the mountain anoa are different species. An unexpectedly large genetic distance between the river and the swamp type of domestic buffaloes suggests a divergence time of about 1.7 Myr, while the swamp type was noticed to have the closest relationship with the tamaraw (1.5 Myr). This result implies that the two types of domestic buffaloes have differentiated at the full species level.
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  • 62
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    Molecular biology reports 22 (1995), S. 139-145 
    ISSN: 1573-4978
    Keywords: chloroplast ; cyanelle ; evolution ; pre-tRNA processing ; ribozyme ; wheat germ
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract RNase P consists of both protein and RNA subunits in all organisms and organelles investigated so far, with the exception of chloroplasts and plant nuclei where no enzyme-associated RNA has been detected to date. Studies on substrate specificity revealed that cleavage by plant nuclear RNase P is critically dependent on a complete and intact structure of the substrate. No clearcut answer is yet possible regarding the order of processing events at the 5′ or 3′ end of tRNAs in the case of nuclear or chloroplast processing enzymes. RNase P from a phylogenetically ancient photosynthetic organelle will be discussed in greater detail: The enzyme from theCyanophora paradoxa cyanelle is the first RNase P from a photosynthetic organelle which has been shown to contain an essential RNA subunit. This RNA is strikingly similar to its counterpart from cyanobacteria, yet it lacks catalytic activity. Properties of the holoenzyme suggest an intermediate position in RNA enzyme evolution, with an eukaryotic-type, inactive RNA and a prokaryotic-type small protein subunit. The possible presence of an RNA component in RNase P from plant nuclei and modern chloroplasts will be discussed, including a critical evaluation of some criteria that have been frequently applied to elucidate the subunit composition of RNase P from different organisms.
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  • 63
    ISSN: 1573-5028
    Keywords: ABA-inducible genes ; coding region repeats ; embryo-specific gene family ; evolution ; Hordeum vulgare L. ; phylogenetic analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The highly conserved Group 1 late embryogenesis abundant (Lea) genes are present in the genome of most plants as a gene family. Family members are conserved along the entire coding region, especially within the extremely hydrophilic internal 20 amino acid motif, which may be repeated. Cloning of Lea Group 1 genes from barley resulted in the characterization of four family members named B19.1, B19.1b, B19.3 and B19.4 after the presence of this motif 1, 1, 3 and 4 times in each gene, respectively. We present here the results of comparative and evolutionary analyses of the barley Group 1 Lea gene family (B19). The most important findings resulting from this work are (1) the tandem clustering of B19.3 and B19.4, (2) the spatial conservation of putative regulatory elements between the four B19 gene promoters, (3) the determination of the relative ‘age’ of the gene family members and (4) the ‘chimeric’ nature of B19.3 and B19.4, reflecting a cross-over or gene-conversion event in their common ancestor. We also show evidence for the presence of one or two additional expressed B19 genes in the barley genome. Based on our results, we present a model for the evolution of the family in barley, including the 20 amino acid motif. Comparisons of the relatedness between the barley family and all other known Group 1 Lea genes using maximum parsimony (PAUP) analysis provide evidence for the time of divergence between the barley genes containing the internal motif as a single copy and as a repeat. The PAUP analyses also provide evidence for independent duplications of Group 1 genes containing the internal motif as a repeat in both monocots and dicots.
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  • 64
    ISSN: 1573-5028
    Keywords: cDNA ; evolution ; p2 protein ; ribosome ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nucleotide sequence of a full-length ribosomal P2 protein cDNA from maize was determined and used for a sequence comparison with the P2 and P1 proteins from other organisms. The integration of these data into a phylogenetic tree shows that the P proteins separated into the subspecies P1 and P2 before the eukaryotic kingdoms including plants developed from their ancestor.
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  • 65
    ISSN: 1573-5028
    Keywords: RNA editing ; tRNA editing ; chloroplast ; mitochondrion ; post-transcriptional modification ; initiation codon ; stop codon ; deamination ; evolution ; guide RNA ; transgenic plants ; plastid transformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the mitochondria and chloroplasts of higher plants there is an RNA editing activity responsible for specific C-to-U conversions and for a few U-to-C conversions leading to RNA sequences different from the corresponding DNA sequences. RNA editing is a post-transcriptional process which essentially affects the transcripts of protein coding genes, but has also been found to modify non-coding transcribed regions, structural RNAs and intron sequences. RNA editing is essential for correct gene expression: proteins translated from edited transcripts are different from the ones deduced from the genes sequences and usually present higher similarity to the corresponding non-plant homologues. Initiation and stop codons can also be created by RNA editing. RNA editing has also been shown to be required for the stabilization of the secondary structure of introns and tRNAs. The biochemistry of RNA editing in plant organelles is still largely unknown. In mitochondria, recent experiments indicate that RNA editing may be a deamination process. A plastid transformation technique showed to be a powerful tool for the study of RNA editing. The biochemistry as well as the evolutionary features of RNA editing in both organelles are compared in order to identify common as well as organelle-specific components.
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  • 66
    ISSN: 1573-5028
    Keywords: Calvin cycle ; sedoheptulose-1,7-bisphosphatase ; isoenzymes ; endosymbiosis ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Full-size cDNAs encoding the precursors of chloroplast fructose-1,6-bisphosphatase (FBP), sedoheptulose-1,7-bisphosphatase (SBP), and the small subunit of Rubisco (RbcS) from spinach were cloned. These cDNAs complete the set of homologous probes for all nuclear-encoded enzymes of the Calvin cycle from spinach (Spinacia oleracea L.). FBP enzymes not only of higher plants but also of non-photosynthetic eukaryotes are found to be unexpectedly similar to eubacterial homologues, suggesting a eubacterial origin of these eukaryotic nuclear genes. Chloroplast and cytosolic FBP isoenzymes of higher plants arose through a gene duplication event which occurred early in eukaryotic evolution. Both FBP and SBP of higher plant chloroplasts have acquired substrate specificity, i.e. have undergone functional specialization since their divergence from bifunctional FBP/SBP enzymes of free-living eubacteria.
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  • 67
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    Plant molecular biology 32 (1996), S. 685-692 
    ISSN: 1573-5028
    Keywords: evolution ; protein transport ; sec apparatus ; secA ; secY ; thylakoid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Plastids possess a bacteria-like sec apparatus that is involved in protein import into the thylakoid lumen. We have analyzed one of the genes essential for this process, secY. A secY gene from the unicellular red alga Cyanidium caldarium was found to be transcriptionally active, demonstrating for the first time that secY is functional in a plastid. Unlike the situation seen in bacteria the C. caldarium gene is transcribed monocistronically, despite the fact that it is part of a large ribosomal gene cluster that resembles bacterial spc operons. A molecular phylogeny is presented for 8 plastid-encoded secY genes, four of which have not been published yet. In this analysis plastid secY genes fall into two classes. One of these, comprising of genes from multicellular red algae and Cryptophyta, clusters in a neighbour-joining tree with a cyanobacterial counterpart. Separated from the aforesaid are secY genes from Chromophyta, Glaucocystophyta and a unicellular red alga. All plastid and cyanobacterial sequences are located on the same branch, separated from bacterial homologues. We postulate that the two classes of secY genes are paralogous, i.e. their gene products are involved in different protein translocation processes. Based on this assumption a model for the evolution of the plastid sec apparatus is presented.
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  • 68
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    Biochemical genetics 33 (1995), S. 173-181 
    ISSN: 1573-4927
    Keywords: fragile-X DNA systems ; expandable triplet repeats ; dynamic mutations ; conserved genetic domains ; evolution ; heritable disease mechanism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A model explaining properties exhibited by fragile-X DNA systems arises from observations that time-dependent base substitutions are expressed at G-C sites but not at A–T sites (Biochem. Genet.32:383, 1994). [CGG]n sequences are classified as most sensitive to evolutionary base substitution processes involving time-dependent populating of G-C sites with enol-imine states having enhanced stability. Increased density of these states in oocyte DNA would introduce a ground-state collapse double-helix of reduced energy that would inhibit strand separation by the replicase. Evolutionarily altered G′ in CG′G triplets allows CG′G to be transcribed as CTG, an initiation codon. And this will cause reinitiation of DNA synthesis, thereby adding additional CGG units to the collapsed double helix. This situation would not occur in slower-evolving male haploid DNA that replicates frequently.
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  • 69
    ISSN: 1573-4927
    Keywords: Akodon ; Cricetidae rodents ; genetic diversity ; biochemical polymorphism ; evolution
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The present study involved an electrophoretic survey of 22 protein loci in 269 individuals belonging to three species of the genusAkodon, A. aff.cursor (2n=16),A. cursor (2n=14/15), andA. montensis (2n=24/25/26), collected in Eastern Brazil. The joint results of gene diversity, genetic distances, phenetic analyses, and phylogenetic trees suggested thatA. aff.cursor has recently separated fromA. cursor and that the three species have experienced a recent chromosomal divergence followed by low allozyme differentiation. These data are in agreement with their classification as sibling species.
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  • 70
    ISSN: 1573-4927
    Keywords: genome mapping ; evolution ; homology ; polymerase chain reaction
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We are developing a genetic map of the dog based partly upon markers contained within known genes. In order to facilitate the development of these markers, we have used polymerase chain reaction (PCR) primers designed to conserved regions of genes that have been sequenced in at least two species. We have refined the method for designing primers to maximize the number that produce successful amplifications across as many mammalian species as possible. We report the development of primer sets for 11 loci in detail:CFTR, COL10A1, CSFIR, CYP1A1, DCN1, FES, GHR, GLB1, PKLR, PVALB, andRB1. We also report an additional 75 primer sets in the appendices. The PCR products were sequenced to show that the primers amplify the expected canine genes. These primer sets thus define a class of gene-specific sequence-tagged sites (STSs). There are a number of uses for these STSs, including the rapid development of various linkage tools and the rapid testing of genomic and cDNA libraries for the presence of their corresponding genes. Six of the eleven gene targets reported in detail have been proposed to serve as “anchored reference loci” for the development of mammalian genetic maps [O'Brien, S. J.,et al., Nat. Genet. 3:103, 1993]. The primer sets should cover a significant portion of the canine genome for the development of a linkage map. In order to determine how useful these primer sets would be for the other genome projects, we tested the 11 primer sets on the DNA from species representing five mammalian orders. Eighty-four percent of the gene-species combinations amplified successfully. We have named these primer sets “universal mammalian sequence-tagged sites” because they should be useful for many mammalian genome projects.
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  • 71
    ISSN: 1573-4927
    Keywords: genome mapping ; evolution ; homology ; polymerase chain reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We are developing a genetic map of the dog based partly upon markers contained within known genes. In order to facilitate the development of these markers, we have used polymerase chain reaction (PCR) primers designed to conserved regions of genes that have been sequenced in at least two species. We have refined the method for designing primers to maximize the number that produce successful amplifications across as many mammalian species as possible. We report the development of primer sets for 11 loci in detail:CFTR, COL10A1, CSFIR, CYP1A1, DCN1, FES, GHR, GLB1, PKLR, PVALB, andRB1. We also report an additional 75 primer sets in the appendices. The PCR products were sequenced to show that the primers amplify the expected canine genes. These primer sets thus define a class of gene-specific sequence-tagged sites (STSs). There are a number of uses for these STSs, including the rapid development of various linkage tools and the rapid testing of genomic and cDNA libraries for the presence of their corresponding genes. Six of the eleven gene targets reported in detail have been proposed to serve as “anchored reference loci” for the development of mammalian genetic maps [O'Brien, S. J.,et al., Nat. Genet. 3:103, 1993]. The primer sets should cover a significant portion of the canine genome for the development of a linkage map. In order to determine how useful these primer sets would be for the other genome projects, we tested the 11 primer sets on the DNA from species representing five mammalian orders. Eighty-four percent of the gene-species combinations amplified successfully. We have named these primer sets “universal mammalian sequence-tagged sites” because they should be useful for many mammalian genome projects.
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  • 72
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    Molecular biology reports 21 (1995), S. 165-167 
    ISSN: 1573-4978
    Keywords: 5S ribosomal RNA ; Harpalus rufipes ; evolution
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    Topics: Biology
    Notes: Abstract The nucleotide sequence of 5S ribosomal RNA from the beetleHarpalus rufipes was determined and compared with primary structures of other insect 5S rRNAs. Sequence differences between two beetle 5S rRNAs may represent phylogenetic markers specific for two groups of Coleoptera — Adephaga and Polyphaga. Analysis of all insect sequences using parsimony allowed us to infer a phylogenetic tree of insects, which is consistent with morphological and paleobiological data.
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  • 73
    ISSN: 1573-5028
    Keywords: Arabidopsis ; evolution ; expression ; genomic clone ; in situ hybridization ; myrosinase
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    Notes: Abstract Myrosinase (thioglucoside glucohydrolase, EC 3.2.3.1.) is in Brassicaceae species such as Brassica napus and Sinapis alba encoded by two differentially expressed gene families, MA and MB, consisting of about 4 and 10 genes, respectively. Southern blot analysis showed that Arabidopsis thaliana contains three myrosinase genes. These genes were isolated from a genomic library and two of them, TGG1 and TGG2, were sequenced. They were found to be located in an inverted mode with their 3′ ends 4.4 kb apart. Their organization was highly conserved with 12 exons and 11 short introns. Comparison of nucleotide sequences of TGG1 and TGG2 exons revealed an overall 75% similarity. In contrast, the overall nucleotide sequence similarity in introns was only 42%. In intron 1 the unusual 5′ splice border GC was used. Phylogenetic analyses using both distance matrix and parsimony programs suggested that the Arabidopsis genes could not be grouped with either MA or MB genes. Consequently, these two gene families arose only after Arabidopsis had diverged from the other Brassicaceae species. In situ hybridization experiments showed that TGG1 and TGG2 expressing cells are present in leaf, sepal, petal, and gynoecium. In developing seeds, a few cells reacting with the TGG1 probe, but not with the TGG2 probe, were found indicating a partly different expression of these genes.
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  • 74
    ISSN: 1573-5028
    Keywords: evolution ; Chlamydomonas reinhardtii ; chloroplast ; site-specific recombination ; transcription ; transposition
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    Topics: Biology
    Notes: Abstract We have characterized two copies of a 2.4 kb DNA element that we call ‘Wendy’, in the chloroplast chromosome of Chlamydomonas reinhardtii. The two copies of Wendy reside in different single-copy regions at opposite positions in the chloroplast genome. Like many mobile DNA elements, both copies of Wendy are bordered by inverted repeats and contain several additional degenerate copies of these repeat sequences in direct or inverted orientation. In addition, four basepairs are repeated in direct orientation. Two major open reading frames (ORFs) are predicted from the DNA sequence of Wendy I. These ORFs are co-transcribed from a promoter inside the element. The deduced amino acid sequence of the larger of these ORFs shares some weak similarities with sequence motifs of transposases and integrases of other mobile elements. Wendy II appears to be altered relative to Wendy I by point mutations and small deletions and insertions which destroy the ORFs. The leader sequence of the Wendy transcript is nearly identical with the leader sequence of the rbcL transcript of C. reinhardtii, but not of C. moewusii (where the complete Wendy was also undetectable). Furthermore, both copies of Wendy are bracketed by gene clusters that are separated in C. reinhardtii but are contiguous in C. moewusii where they exist in an inverted orientation compared with C. reinhardtii. Wendy was not found in any of the completely sequenced chloroplast genomes of rice, tobacco, pine, Euglena or Marchantia, nor in any other GenBank entry. Our results suggest that Wendy has invaded C. reinhardtii after divergence from other species. Subsequent Wendy-dependent illegitimate homologous or site-specific recombination events or both may have contributed to scrambling of the C. reinhardtii chloroplast genome relative to genomes of other species.
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  • 75
    ISSN: 1573-5028
    Keywords: developmental regulation ; elongation factor ; evolution ; gene expression ; rhodophyte, sporophyte
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    Notes: Abstract The life cycle of the red alga Porphyra purpurea alternates between two morphologically distinct phases: a shell-boring, filamentous sporophyte and a free-living, foliose gametophyte. From a subtracted cDNA library enriched for sporophyte-specific sequences, we isolated a cDNA encoding an unusual elongation factor 1α (EF-1α) that is expressed only in the sporophyte. A second EF-1α gene that is expressed equally in the sporophyte and the gametophyte was isolated from a genomic library. These are the only EF-1α genes detectable in P. purpurea. The constitutively expressed gene encodes and EF-1α very similar to those of most eukaryotes. However, the sporophyte-specific EF-1α is one of the most divergent yet described, with nine insertions or deletions ranging in size from 1 to 26 amino acids. This is the first report of a developmental stage-specific EF-1α outside of the animal kingdom and suggests a fundamental role for EF-1α in the developmental process.
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  • 76
    ISSN: 1573-5028
    Keywords: carboxysomes ; evolution ; ribulose 1,5-bisphosphate carboxylase/oxygenase ; Synechococcus
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    Topics: Biology
    Notes: Abstract Marine phycoerythrin-containing cyanobacteria are major contributors to the overall productivity of the oceans. The present study indicates that the structural genes of the carbon assimilatory system are unusually arranged and possess a unique primary structure compared to previously studied cyanobacteria. Southern blot analyses of Synechococcus sp. strain WH7803 chromosomal DNA digests, using the ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunit gene from Synechococcus sp. strain PCC6301 as a heterologous probe, revealed the presence of a 6.4 kb HindIII fragment that was detectable at only low stringency. Three complete open reading frames (ORFs) were detected within this fragment. Two of these ORFs potentially encode the Synechococcus sp. strain WH7803 rbcL and rbcS genes. The third ORF, situated immediately upstream from rbcL, potentially encodes a homologue of the ccmK gene from Synechococcus sp. strain PCC7942. The deduced amino acid sequences of each of these ORFs are more similar to homologues among the β/γ purple bacteria than to existing cyanobacterial homologues and phylogenetic analysis of the Rubisco large and small subunit sequences confirmed an unexpected relationship to sequences from among the β/γ purple bacteria. This is the first instance in which the possibility has been considered that an operon encoding three genes involved in carbon fixation may have been laterally transferred from a purple bacterium. Analysis of mRNA extracted from cells grown under diel conditions indicated that rbcL, rbcS and ccmK were regulated at the transcriptional level; specifically rubisco transcripts were highest during the midday period, decreased at later times during the light period and eventually reached a level where they were all but undetectable during the dark period. Primer extension analysis indicated that the ccmK, rbcL and rbcS genes were co-transcribed.
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  • 77
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    Plant molecular biology 32 (1996), S. 923-936 
    ISSN: 1573-5028
    Keywords: PEPC ; C3 metabolism ; gene expression ; evolution ; gymnosperm ; Picea abies
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    Topics: Biology
    Notes: Abstract Phosphoenolpyruvate carboxylase (PEPC) genes and cDNA sequences have so far been isolated from a broad range of angiosperm but not from gymnosperm species. We constructed a cDNA library from seedlings of Norway spruce (Picea abies) and identified cDNAs coding for PEPC. A full-length PEPC cDNA was sequenced. It consists of 3522 nucleotides and has an open reading frame (ORF) that encodes a polypeptide (963 amino acids) with a molecular mass of 109 551. The deduced amino acid sequence revealed a higher similarity to the C3-form PEPC of angiosperm species (86–88%) than to the CAM and C4 forms (76–84%). The putative motif (Lys/Arg-X-X-Ser) for serine kinase, which is conserved in all angiosperm PEPCs analysed so far, is also present in this gymnosperm sequence. Southern blot analysis of spruce genomic DNA under low-stringency conditions using the PEPC cDNA as a hybridization probe showed a complex hybridization pattern, indicating the presence of additional PEPC-related sequences in the genome of the spruce. In contrast, the probe hybridized to only a few bands under high-stringency conditions. Whereas this PEPC gene is highly expressed in roots of seedlings, a low-level expression can be detected in cotyledons and adult needles. A molecular phyiogeny of plant PEPC including the spruce PEPC sequence revealed that the spruce PEPC sequence is clustered with monocot and dicot C3-form PEPCs including the only dicot C4 form characterized so far.
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  • 78
    ISSN: 1618-2545
    Keywords: biogeography ; calmodulin ; DNA sequence ; elongation factor EF-1α ; evolution
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    Notes: Abstract Phylogenetic relationships within theGibberella fujikuroi species complex were extended to newly discovered strains using nucleotide characters obtained by sequencing polymerase chain reaction (PCR) amplified DNA from 4 loci used in a previous study [nuclear large subunit 28S rDNA, nuclear ribosomal internal transcribed spacer (ITS) region, mitochondriaal small subunit (mtSSU) ribosomal DNA, and β-tubulin] together with two newly sampled protein-encoding nuclear genes, translation elongation factor EF-1α and calmodulin. Sequences from the ribosomal ITS region were analyzed separately and found to contain of two highly divergent, nonorthologous ITS2 types. Phylogenetic analysis of the individual and combined datasets identified 10 new phylogenetically distinct species distributed among the following three areas: 2 within Asia and 4 within both Africa and South America. Hypotheses of the monophyly ofFusarium subglutinans and its two formae speciales, f. sp.pini and f. sp.ananas, were strongly rejected by a likelihood analysis. Maximum parsimony results further indicate that the protein-encoding nuclear genes provide considerably more phylogenetic signal that the ribosomal genes sequenced. Relative apparent synapomorphy analysis was used to detect long-branch attraction taxa and to obtain a statistical measure of phylogenetic signal in the individual and combined datasets.
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  • 79
    ISSN: 1618-2545
    Keywords: Ascomycota ; evolution ; pyrenomycetes ; systematics
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    Notes: Abstract To investigate the systematic position of the unitunicate pyremomycetePapulosa amerospora, we performed phylogenetic analyses of SSU rDNA sequences from 37 ascomycetes. Among these sequences were some new ones from taxa that might be related toPapulosa: Hyponectriaceae (Hyponectria buxi, Monographella nivalis), Phyllachorales (Phyllachora graminis), and Xylariales (Barrmaelia melanotes, Poronia punctata). Our results showed 100% bootstrap support for a clade of all unitunicate pyrenomycetes, the class Sordariomycetes. We also found strong support for recognizing the subclasses Hypocreomycetidae and Xylariomycetidae. The remaining taxa, belonging to subclass Sordariomycetidae, appeared as a polyphyletic group in one analysis, but was monophyletic when shorter SSU sequences were used.Barrmaelia melanotes, Poronia punctata, Hyponectria buxi, andMonographella nivalis are members of Xylariomycetidae, but we could not determine whetherMonographella should be included in Hyponectriaceae. The new family Papulosaceae is erected forPapulosa on molecular and morphological bases, but the exact systematic position ofPapulosa within subclass Sordariomycetidae is still uncertain, since the genus did not cluster consistently with any of the included taxa. Phyllachorales are not closely related to Diaporthales, as previously suggested.
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  • 80
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    Plant systematics and evolution 196 (1995), S. 141-151 
    ISSN: 1615-6110
    Keywords: Orchidaceae ; Loroglossum hircinum ; Compound pollen ; pollinium ; pollen tubes ; generative cell ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The structure of the massulae composing the pollinium ofLoroglossum hircinum was studied before pollination and 12 and 24 hours afterwards. The grains are grouped in tetrads closely packed in massulae. The exine is only present on the outside of the massulae. The intine consists of two layers: a compact layer surrounding the pollen grain and a looser layer surrounding the pollen grain and a looser layer surrounding the tetrad. Twelve hours after pollination, pollen volume and the space between the tetrads increase due to vacuolization. Twenty-four hours after pollination, pollen volume and tetrad spacing are higher due to vacuolization and some grains have emitted pollen tubes. Pollen growth due to vacuole formation, and the absence of common walls between adjacent tetrads lead to crumbling of the massulae. The mature pollen grain does not have apertures: the site of pollen tube emission is determined after pollination. The first grains to germinate are those in the centre of the massula. The vegetative cell nucleus is the first to enter the pollen tube; the generative cell elongates and undergoes the second haploid mitosis shortly after entering the pollen tube.
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  • 81
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    Plant systematics and evolution 198 (1995), S. 167-178 
    ISSN: 1615-6110
    Keywords: Fabaceae ; Arachis ; Arachis hypogaea ; RAPD ; systematics ; evolution ; germplasm resources
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Twenty-six accessions of wildArachis species and domesticated peanuts,A. hypogaea, introduced from South America were analyzed for random amplified polymorphic DNA (RAPD). The objective of the study was to investigate inter- and intraspecific variation and affinities among species of sect.Arachis which have been proposed as possible progenitors for the domesticated peanut. Ten primers resolved 132 DNA bands which were useful for separating species and accessions. The most variation was observed among accessions ofA. cardenasii andA. glandulifera whereas the least amount of variation was observed inA. hypogaea andA. monticola. The two tetraploid species could not be separated by using RAPDs.Arachis duranensis was most closely related to the domesticated peanut and is believed to be the donor of the A genome. The data indicated thatA. batizocoi, a species previously hypothesized to contribute the B genome toA. hypogaea, was not involved in its evolution. The investigation showed that RAPDs can be used to analyze both inter- and intraspecific variation in peanut species. Southern hybridization of RAPD probes to blots containing RAPD of theArachis species provided information on genomic relationships and revealed the repetitive nature of the amplified DNA.
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    Plant systematics and evolution 201 (1996), S. 149-162 
    ISSN: 1615-6110
    Keywords: Colchicaceae ; Androcymbium ; Allozymes ; morphology ; endemism ; evolution ; conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Narrow endemism is a poor predictor of genetic potential in the six taxa that conform theAndrocymbium gramineum complex, as shown by the unexpectedly high values of variability associated with ten allozymic loci and 13 biometrical variables. Although both levels are shown not to be correlated, variability is always concentrated within populations. This result, together with environmental, reproductive and historical data strongly suggests differentiation in local isolates, where changes can be quickly assimilated by stochastic processes. A key implication for conservation is that sampling within the largest population will save effort while neglecting only very low frequency alleles.
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  • 83
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    Plant systematics and evolution 200 (1996), S. 1-11 
    ISSN: 1615-6110
    Keywords: Juncaceae ; Luzula sect.Luzula ; Taxonomy ; karyotypes ; evolution ; Flora of Spain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A survey ofLuzula sect.Luzula (Juncaceae) with data on karyology, morphology and distribution in the Iberian Peninsula is provided. Names published from the region are evaluated.L. campestris subsp.campestris, L. c. subsp.nevadensis, L. sudetica, L. ×heddae, L. congesta, L. ×danica, L. alpina, L. multiflora, andL. multiflora s. l. are discussed. A diploid taxon with agmatoploid karyotype, morphologically close toL. multiflora andL. alpina, has been revealed and is described asL. multiflora subsp.monticola. L. campestris subsp.iberica has been relegated to the synonymy of subsp.campestris, L. c. subsp.carpetana was found to belong toL. multiflora s. l.
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    Plant systematics and evolution 199 (1996), S. 17-32 
    ISSN: 1615-6110
    Keywords: Apiaceae ; Umbelliferae ; Anthriscus ; Taxonomy ; phylogeny ; evolution ; ecological radiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Species boundaries and phylogenetic relationships of 17 taxa ofAnthriscus (Apiaceae), with special emphasis on the critical sect.Cacosciadium, were explored using morphological data with principal component analysis, phenetics, and phylogenetics. The analyses did not provide satisfactory resolution of taxa from sect.Cacosciadium and only four species were retained. The total number of species was reduced to nine. Sect.Cacosciadium is distinguished by only two synapomorphies while sects.Anthriscus andCaroides are better supported. Present geographic and ecological variation suggests that the radiation ofAnthriscus occurred through divergence of peripheral isolated populations adapting to different habitats: high montane meadows and screes, shady climax forests, and seasonally dry habitats at lower altitudes. The adaptive significance of particular morphological traits is discussed.
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    Plant systematics and evolution 202 (1996), S. 121-135 
    ISSN: 1615-6110
    Keywords: Rubiaceae ; Galium ; Allozyme variation ; systematics ; ploidy level ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Allozyme variation at 11 loci (with 37 alleles) was studied electrophoretically in seven outbreeding, closely related diploid and tetraploid taxa, seven from sect.Leptogalium and two from sect.Leiogalium. Whereas the sections are clearly distinct by several different alleles, aggregates, species and subspecies differ only in the frequency or presence/absence of common alleles. The resulting dendrogram suggests phylogenetic relationships and is supported by other multidisciplinary evidence. Tetraploids have originated independently in several groups, and there is evidence for tetrasomic inheritance and thus for autopolyploidy in spite of normal meiotic bivalent pairing and partly suspected hybrid origin. Tetraploids differ from related diploids only little in number of alleles and expected heterozygosity within populations, but clearly exhibit higher numbers of genotypes. This often corresponds to their greater morphological variability, increased adaptive flexibility, and better colonizing capacity compared to related diploids.
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    Plant systematics and evolution 203 (1996), S. 111-142 
    ISSN: 1615-6110
    Keywords: Pelargonium ; sect.Hoarea ; Chromosomes ; B chromosomes ; Robertsonian translocation ; centric fusion ; evolution ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chromosome numbers of 65 species of sect.Hoarea have been determined. These show three basic chromosome numbers, x = 11, 10 and 9. Only a few species are tetraploid. In five species both diploid and tetraploid cytotypes are reported. Several cases of deviations in chromosome numbers and cytological abnormalities were found, most of these being related to the presence of B chromosomes that occur in eight species. Evidence is presented to suggest that the basic chromosome numbers of x = 10 and x = 9 are derived from x = 11 by centric fusion. Although variation in basic chromosome number withinPelargonium has been the subject of detailed study, this is the first time that evidence has been found for a mechanism of change in basic number, that of centric fusion by Robertsonian translocation. For the species of sect.Hoarea with x = 9, where the evidence for Robertsonian translocation is greatest, this process has probably taken place quite recently. In contrast to results from other sections of the genusPelargonium, the three different basic numbers of sect.Hoarea do not contradict its delimitation as a natural taxon.
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    Plant systematics and evolution 206 (1997), S. 33-45 
    ISSN: 1615-6110
    Keywords: Compositae ; Barnadesioideae ; Doniophyton ; Chuquiraga ; Argentina ; Chile ; evolution ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This revision describes, illustrates and documents morphological variation inDoniophyton (Compositae, Barnadesioideae), restricted to Argentina and Chile. Two species are recognized,D. anomalum andD. weddellii (sp. nova), possessing distinct morphological and chromosomal features, elevational tolerances, and nearly allopatric distributions.Doniophyton weddellii occurs primarily in central to northern Andean Chile and Argentina from 1900–4000 m a. s. l.;D. anomalum is found principally in centralwestern Argentina and south into Patagonia at 0–1800 m a. s. l. Close relationship exists withChuquiraga of subfam.Barnadesioideae. It is hypothesized thatDoniophyton evolved out ofChuquiraga in the high central Andes between Chile and Argentina. It is suggested thatD. weddellii differentiated first, correlating with an aneuploid chromosomal decrease from n = 27 (inChuquiraga) to n = 25. Further evolution and chromosomal decrease to n = 24 resulted inD. anomalum, with accompanying migration into southern Andes and Patagonia. Nomenclatural changes result from examination of protologues and type specimens:Doniophyton anomalum replaces the commonly used nameD. patagonicum, and a new species,D. weddellii, is described for the taxon masquerading under the routinely used superfluous nameD. andicola.
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    Plant systematics and evolution 210 (1998), S. 57-86 
    ISSN: 1615-6110
    Keywords: Alliaceae ; Allium ; Nuclear DNA amount ; adaptation ; evolution ; infrageneric classification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The 4C DNA amounts of 86 species fromAllium subgg.Allium, Rhizirideum, Bromatorrhiza, Melanocrommyum, Caloscordum andAmerallium show a 8.35-fold difference ranging from 35.60 pg (A. ledebourianum, 2n = 16) to 297.13 pg (A. validum 2n = 56). At diploid level the difference is 3.57-fold betweenA. ledebourianum (35.60 pg) andA. ursinum (127.14 pg). This shows that a significant loss and/or gain of DNA has occurred during evolution. On average subgg.Rhizirideum andAllium have less DNA amount than subgg.Melanocrommyum andAmerallium. The distribution of nuclear DNA amounts does not show discontinuous pattern and regular groups. The evolution of genome size has been discussed in relation to polyploidy and genomes, heterochromatin, adaptive changes in morphological characteristics, phenology and ecological factors, and infrageneric classification.
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    Plant systematics and evolution 215 (1999), S. 37-47 
    ISSN: 1615-6110
    Keywords: Ranunculaceae ; Aconitum ; Delphinium ; Helleborus ; Nigella ; Seed oil ; fatty acids ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Many members ofRanunculaceae contain unusual fatty acids in their seed oils. This leads to rather typical genus-specific fatty acid patterns or “fingerprints” in these seed oils. The members of theDelphinioideae and/orHelleboroideae, however, do not contain highly unusual fatty acids. Nevertheless, their seed oil fatty acid fingerprints are also fairly typical and genus-specific, and the patterns found are rather consistent throughout several species of one genus. It was found that species ofAconitum do not contain fatty acids with 20 carbon atoms.Delphinium, Consolida, Helleborus, Nigella and others do contain C20 fatty acids. In allHelleborus species, for example, there was a consistent C20 fatty acid pattern of 20:0≪20:1≫20:2〉20:3. Species ofNigella andGaridella contain high levels,Helleborus low levels, of 20:2n-6 in their seed oils.Delphinium andAconitum both contain low levels of 18:3n-3, whereasHelleborus spp. consistently show high levels of this fatty acid. The genus-specific fatty acid patterns found are discussed, and a correlation with the subfamily and tribe affiliation of the genera investigated here is attempted.
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    Plant systematics and evolution 216 (1999), S. 135-166 
    ISSN: 1615-6110
    Keywords: Dipsacaceae ; Pseudoscabiosa ; Scabiosa ; Sixalix ; Lomelosia ; Pycnocomon ; Scabiosiopsis ; Tremastelma ; Epicalyx ; fruit anatomy ; evolution ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fruits ofDipsacaceae are single-seeded, have bristle-shaped calyx segments and are tightly enclosed by four fused bracts forming an epicalyx. Comparative morphological and anatomical studies reveal a great diversity of epicalyx and calyx, often relevant to fruit dispersal. The present contribution deals with theScabiosa group of genera, the core of theScabioseae tribe. Most of its taxa develop a diaphragma from a meristem on the inside of the epicalyx. This diaphragma, together with the lower part of the epicalyx encloses the fruit proper, whereas the upper parts form a so-called “epi-diaphragma” (ed) and a ± hyaline corona. Differences of the epicalyx with respect to the size and position of the ed, elaboration of the corona, origin of pits (=foveoles) and other morphological and anatomical specializations can be demonstrated. Together with palynological and karyological data these new facts support an improved concept of relationships and systematics for the taxa studied:Scabiosa sect.Scabiosa and sect.Cyrtostemma are closely related and should be united to form the genusScabiosa s. str.;Pycnocomon can be maintained as an independent genus, sister toScabiosa sect.Trochocephalus which then has to be treated as a genus,Lomelosia. In contrast, the following genera have to be included inLomelosia:Tremastelma asLomelosia sect.Callistemma, andScabiosiopsis as part ofLomelosia sect.Lomelosia. Pseudoscabiosa deviates in so many features that it has to be excluded from the redefinedScabioseae s. str.
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  • 91
    ISSN: 1615-6110
    Keywords: Gymnosperms ; Pinaceae ; A. alba ; A. cephalonica ; A. borisii-regis ; A. bornmuelleriana ; A. nordmanniana ; A. equi-trojani ; A. pinsapo ; A. numidica ; A. cilicica ; Allozyme variation ; genetic diversity ; phylogenetic relationships ; evolution
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract Nineteen natural Mediterranean fir populations, belonging to eight species and to one natural hybrid (A. ×borisii-regis), were investigated by starch and polyacrylamide gel electrophoresis. A total of 31 alleles was scored at eight loci (IDH-B, ACP-A, PER-B, 6PGD-A, 6PGD-B, MNR-B, PGI-B, PGM-A. Great variation was observed in the heterozygosity among the population studied and ranged from 0.010 (A. pinsapo) to 0.328 (A. cephalonica). The interpopulation genetic diversity was about 26% of the total genetic diversity. From the dendrogram, new phylogenetic relationships were revealed. High affinity was observed between the Calabrian fir population and the one from north-west Greece as well as betweenA. equi-trojani grown in Asia Minor and the southern Greek populations. Species specific alleles were found inA. cilicica. From the findings of the present work, a new hypothesis concerning the taxonomy, distribution and evolution ofAbies species in the Balkan Peninsula is supported.
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  • 92
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    Keywords: Chlorococcales ; Microsporales ; Microspora ; Absolute configuration ; classification ; evolution ; flagellar apparatus ; ultrastructure ; zoospore
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The spatial configuration of the flagellar apparatus of the biflagellate zoospores of the green algal genusMicrospora is reconstructed by serial sectioning analysis using transmission electron microscopy. Along with the unequal length of the flagella, the most remarkable characteristics of the flagellar apparatus are: (1) the subapical emergence of the flagella (especially apparent with scanning electron microscopy); (2) the parallel orientation of the two basal bodies which are interconnected by a prominent one-piece distal connecting fiber; (3) the unique ultrastructure of the distal connecting fiber composed of a central tubular region which is bordered on both sides by a striated zone; (4) the different origin of the d-rootlets from their relative basal bodies; (5) the asymmetry of the papillar region which together with the subapical position of the basal bodies apparently cause the different paths of corresponding rootlets in the zoospore anterior; (6) the presence of single-membered d-rootlets and multi-membered s-rootlets resulting in a 7-1-7-1 cruciate microtubular root system which, through the different rootlet origin, does not exhibit a strict 180° rotational symmetry. It is speculated that the different basal body origin of the d-rootlets is correlated with the subapical implant of flagella. It is further hypothesized that in the course of evolution the ancestors ofMicrospora had a flagellar papilla that has migrated from a strictly apical position towards a subapical position. Simultaneously, ‘ancestral’ shift of flagella along the apical cell body periphery has taken place as can be concluded from the presence of an upper flagellum overlying a lower flagellum in the flagellar apparatus ofMicrospora. The basic features of the flagellar apparatus of theMicrospora zoospore resemble those of the coccoid green algal generaDictyochloris andBracteacoccus and also those of the flagellate green algal genusHeterochlamydomonas. This strengthens the general supposition thatMicrospora is evolutionarily closely related to taxa which were formerly classified in the traditionalChlorococcales.
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  • 93
    ISSN: 1573-5125
    Keywords: microcrustaceans ; Daphnia ; evolution ; interspecific hybridization ; molecular systematics ; aquatic ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cladoceran crustaceans are an important component of zooplankton in a wide range of freshwater habitats. Although the ecological characteristics of several cladoceran species have been well studied, biogeographical studies have been hampered by problematic taxonomic affiliations. However, recently developed molecular techniques, provide a powerful tool to subject aquatic taxa to comparative analyses. Here we highlight recent molecular approaches in aquatic ecology by presenting a simple method of DNA preparation and PCR amplification of the mitochondrial DNA (16S rDNA) in species from nine different families within the cladocera. On a broad taxonomic scale, sequence analysis of this mtDNA fragment has been used to produce the first molecular based phylogeny of the cladocera. This analysis clustered the cladoceran families in a fashion similar to that suggested by previous systematic classifications. In a more detailed analysis of the family Daphniidae, nuclear randomly amplified polymorphic DNA (RAPD), mitochondrial restriction fragment length polymorphism (RFLP) and morphological analyses were combined to identify species and interspecific hybrids within the Daphnia galeata species complex across 50 lakes in 13 European countries and one lake in Africa. The study revealed interspecific hybridization and backcrossing between some taxa (D. cucullata and D. galeata) to be widespread, and species and hybrids to frequently occur in sympatry. Genetic, as well as morphological information, suggests the occurrence of D. hyalina outside the Holarctic.
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    Glycoconjugate journal 17 (2000), S. 465-483 
    ISSN: 1573-4986
    Keywords: N-acetylglucosaminyltransferases ; glycosylation ; glycoproteins ; Golgi complex ; evolution ; development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract This review covers discoveries made over the past 30–35 years that were important to our understanding of the synthetic pathway required for initiation of the antennae or branches on complex N-glycans and O-glycans. The review deals primarily with the author's contributions but the relevant work of other laboratories is also discussed. The focus of the review is almost entirely on the glycosyltransferases involved in the process. The following topics are discussed. (1) The localization of the synthesis of complex N-glycan antennae to the Golgi apparatus. (2) The “evolutionary boundary” at the stage in N-glycan processing where there is a change from oligomannose to complex N-glycans; this switch correlates with the appearance of multicellular organisms. (3) The discovery of the three enzymes which play a key role in this switch, N-acetylglucosaminyltransferases I and II and mannosidase II. (4) The “yellow brick road” which leads from oligomannose to highly branched complex N-glycans with emphasis on the enzymes involved in the process and the factors which control the routes of synthesis. (5) A short discussion of the characteristics of the enzymes involved and of the genes that encode them. (6) The role of complex N-glycans in mammalian and Caenorhabditis elegans development. (7) The crystal structure of N-acetylglucosaminyltransferase I. (8) The discovery of the enzymes which synthesize O-glycan cores 1, 2, 3 and 4 and their elongation.
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    Journal of bioeconomics 1 (1999), S. 13-18 
    ISSN: 1573-6989
    Keywords: Malthus ; Darwin ; evolution ; policy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Economics
    Notes: Abstract This is a rather impressionist report of my recollections of the history of the bioeconomics field.
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    Journal of bioeconomics 1 (1999), S. 19-34 
    ISSN: 1573-6989
    Keywords: Darwinian world view ; evolution ; evolutionary economics ; development ; subjectivism ; natural selection ; analogy ; adaptation ; evolutionary progress ; preferences ; genetic endowment ; growth of consumption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Economics
    Notes: Abstract Bioeconomics—the merging of views from biology and economics—on the one hand invites the 'export' of situational logic and sophisticated optimization developed in economics into biology. On the other hand, human economic activity and its evolution, not least over the past few centuries, may be considered an instance for fruitfully applying ideas from evolutionary biology and Darwinian theory. The latter perspective is taken in the present paper. Three different aspects are discussed in detail. First, the Darwinian revolution provides an example of a paradigm shift which contrasts most significantly with the 'subjectivist revolution' that took place at about the same time in economics. Since many of the features of the paradigmatic change that were introduced into the sciences by Darwinism may be desirable for economics as well, the question is explored whether the Darwinian revolution can be a model for introducing a new paradigm in economic theory. Second, the success of Darwinism and its view of evolution have induced economists who are interested in an evolutionary approach in economics to borrow, more or less extensively, concepts and tools from Darwinian theory. Particularly prominent are constructions based on analogies to the theory of natural selection. Because several objections to such analogy constructions can be raised, generalization rather than analogy is advocated here as a research strategy. This means to search for abstract features which all evolutionary theories have in common. Third, the question of what a Darwinian world view might mean for assessing long term economic evolution is discussed. Such a view, it is argued, can provide a point of departure for reinterpreting the hedonistic approach to economic change and development. On the basis of such an interpretation bioeconomics may not only go beyond the optimization-cum-equilibrium paradigm currently prevailing in economics. It may also mean adding substantial qualifications to the subjectivism the neoclassical economists, at the turn of the century, were proud to establish in the course of their scientific revolution.
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    Journal of bioeconomics 2 (2000), S. 9-23 
    ISSN: 1573-6989
    Keywords: evolution ; altruism ; morality ; utilitarianism ; Marxism ; Rawls ; fairness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Economics
    Notes: Abstract Several evolutionary mechanisms have been identified in the literature that would generate altruism in humans. The most powerful (except for kin selection) and most controversial is group selection, as recently analyzed by Sober & D.S. Wilson. I do not take a stand on the issue of the existence of group selection. Instead, I examine the level of human altruism that could exist if group selection were an engine of human evolution. For the Sober & Wilson mechanism to work, groups practicing altruism must grow faster than other groups. I call altruistic behavior that would lead to faster growth ‘efficient altruism’. This often consists of cooperation in a prisoner's dilemma. ltruistic acts such as helping a temporarily hungry or injured person would qualify as efficient altruism. Efficient altruism would also require monitoring recipients to avoid shirking. Utilitarianism would be an ethical system consistent with efficient altruism, but Marxism or the Rawlsian system would not. Discussions of efficient altruism also help understand intuitions about fairness. We perceive those behaviors as ‘fair’ that are consistent with efficient altruism. It is important to understand that, even if humans are selected to be altruistic, the forms of altruism that might exist must be carefully considered and ircumscribed.
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    Biology and philosophy 14 (1999), S. 395-430 
    ISSN: 1572-8404
    Keywords: adaptationism ; Daniel C. Dennett ; electric fish ; electroreception ; evolution ; evolutionary function ; indeterminism ; mental content ; neuroethology ; sensory modality ; underdetermination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Are attributions of content and function determinate, or is there no fact of the matter to be fixed? Daniel Dennett has argued in favor of indeterminacy and concludes that, in practice, content and function cannot be fixed. The discovery of an electrical modality in vertebrates offers one concrete instance where attributions of function and content are supported by a strong scientific consensus. A century ago, electroreception was unimagined, whereas today it is widely believed that many species of bony fish, amphibians, sharks, skates, and rays possess this non-human sensory modality. A look at the history of science related to this discovery reveals a highly interdisciplinary endeavor, encompassing ethology, behavioral analysis, neuroscience, and evolutionary biology. While each area provides important evidence, none is sufficient on its own to fix content and function. Instead, I argue that an interdisciplinary, neuroethological approach is required to carry out such determinations. Further, a detailed consideration of biological research suggests that while content and function claims are empirically underdetermined and uncertain, there is insufficient reason to believe in an additional problem of indeterminism. In particular, Dennett's indeterminism arises from a research methodology -- logical adaptationism -- that generates evidence from only one of the areas of neuroethology. However, logical adaptationism does not reflect adaptationism as it is practiced in contemporary biology. I conclude that Dennett is faced with a dilemma: On the one hand, he can hold to logical adaptationism and the indeterminism that results from it, while giving up the relevance of his arguments to biological practice. On the other, he can embrace a more accurate version of adaptationism -- one which plays a role in a larger neuroethological framework -- but from which no strong indeterminacy claims follow.
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    Biology and philosophy 14 (1999), S. 561-584 
    ISSN: 1572-8404
    Keywords: change ; evolution ; evolutionary epistemology ; selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract This paper is concerned with the debate in evolutionary epistemology about the nature of the evolutionary process at work in the development of science: whether it is Darwinian or Lamarckian. It is claimed that if we are to make progress through the many arguments that have grown up around this issue, we must return to an examination of the concepts of change and evolution, and examine the basic kinds of mechanism capable of bringing evolution about. This examination results in two kinds of processes being identified, dubbed ‘direct’ and ‘indirect’, and these are claimed to exhaust all possibilities. These ideas are then applied to a selection of the debates within evolutionary epistemology. It is shown that while arguments about the pattern and rate of evolutionary change are necessarily inconclusive, those concerning the origin of novel variations and the mode of inheritance can be resolved by means of the distinctions made here. It is claimed that the process of selection in the evolution of science can also be clarified. The conclusion is that the main process producing the evolution of science is a direct or Lamarckian one although, if realism is correct, an indirect or Darwinian process plays a vital role.
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    Biology and philosophy 15 (2000), S. 443-463 
    ISSN: 1572-8404
    Keywords: David Hull ; evolution ; selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract One of the principal difficulties in assessing Science as aProcess (Hull 1988) is determining the relationship between the various elements of Hull's theory. In particular, it is hard to understand precisely how conceptual selection is related to Hull's account of the social dynamics of science. This essay aims to clarify the relation between these aspects of his theory by examining his discussion of the``demic structure'' of science. I conclude that the social account cando significant explanatory work independently of the selectionistaccount. Further, I maintain that Hull's treatment of the demicstructure of science points us toward an important set of issues insocial epistemology. If my reading of Science as a Process iscorrect, then most of Hull's critics (e.g., those who focus solelyon his account of conceptual selection) have ignored promisingaspects of his theory.
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