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  • evolution  (64)
  • conservation  (53)
  • Springer  (117)
  • Periodicals Archive Online (PAO)
  • 2000-2004  (117)
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  • 1
    Electronic Resource
    Electronic Resource
    Die Lage der Vogelsystematik (2000)
    Springer
    Journal of ornithology 141 (2000), S. 263-274 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02462236
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  • 2
    Electronic Resource
    Electronic Resource
    Emergence and Maintenance of Sex among Diploid Organisms Aided by Assortative Mating (2000)
    Springer
    Acta biotheoretica 48 (2000), S. 137-147 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002765101959
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  • 3
    Electronic Resource
    Electronic Resource
    Multitrophic effects of herbivore-induced plant volatiles in an evolutionary context (2000)
    Springer
    Entomologia experimentalis et applicata 97 (2000), S. 237-249 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004111624780
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  • 4
    Electronic Resource
    Electronic Resource
    The making of a pest: recruitment of Meligethes aeneus onto oilseed Brassicas (2000)
    Springer
    Entomologia experimentalis et applicata 95 (2000), S. 141-149 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003947706788
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  • 5
    Electronic Resource
    Electronic Resource
    Copulatory Courtship in Drosophila: Behavior and Songs of D. birchii and D. serrata (2000)
    Springer
    Journal of insect behavior 13 (2000), S. 71-86 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007715609756
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  • 6
    Electronic Resource
    Electronic Resource
    Evolution of Ti–Sn-rutile-supported V2O5–WO3 catalyst during its use in nitric oxide reduction by ammonia (2000)
    Springer
    Topics in catalysis 11-12 (2000), S. 131-138 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1027299931119
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  • 7
    Electronic Resource
    Electronic Resource
    Experience, Awareness and Consciousness:Suggestions for Definitions as Offered by an Evolutionary Approach (2000)
    Springer
    Foundations of science 5 (2000), S. 429-456 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011371811027
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  • 8
    Electronic Resource
    Electronic Resource
    Arbitrariness in nature: synergetics and evolutionary laws of prohibition (2000)
    Springer
    Journal for general philosophy of science 31 (2000), S. 57-73 
    Details
    ISSN: 1572-8587
    Keywords: complex systems ; evolution ; nonlinearity ; pre-determination ; self-organization ; soft management ; structure-attractors ; synergetics
    Source: Springer Online Journal Archives 1860-2000
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008369525041
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  • 9
    Electronic Resource
    Electronic Resource
    Morality De-Kanted or the Biological Roots of Moral Behavior (2000)
    Springer
    International journal of value-based management 13 (2000), S. 297-308 
    Details
    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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007897311267
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  • 10
    Electronic Resource
    Electronic Resource
    A set of microsatellite loci for the hairy-nosed wombats (Lasiorhinus krefftii and L. latifrons) (2000)
    Springer
    Conservation genetics 1 (2000), S. 89-92 
    Details
    ISSN: 1572-9737
    Keywords: conservation ; marsupial ; remote censusing ; microsatellites ; wombat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010146107009
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  • 11
    Electronic Resource
    Electronic Resource
    Farmers indigenous practices for conserving Garcinia kola and Gnetum africanum in southern Cameroon (2000)
    Springer
    Agroforestry systems 48 (2000), S. 289-302 
    Details
    ISSN: 1572-9680
    Keywords: conservation ; humidforest zone ; native plants ; non-timber forest products
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Traditional approaches to conservation of Garcinia kola and Gnetum africanum were assessed by a survey of 15 villages (three per province) in the humid forest zone of southern Cameroon. Four major land use systems [evergreen forest, degraded forest, bush fallow (10 years and over) and food crop fields] were identified as major niches for the species. The distribution of the plant stands varied from province to province. Gnetum africanum is intensively harvested (up to four times per week throughout the year) and reported to generate substantial income (averaging US$2,630 per household per annum). Indigenous practices used by farmers to protect the species include selective clearing during land preparation for cropping, sustainable bark harvesting of stands in wild population, transplantation of wildings, artificial propagation and recognition of individual property ownership on certain wild stands of G. kola.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006393709637
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  • 12
    Electronic Resource
    Electronic Resource
    Occurrence of Larca lata H.J. Hansen (Pseudoscorpionida: Garypidae) and Allochernes wideri C.L. Koch (Pseudoscorpionida: Chernetidae) in tree hollows in relation to habitat quality and density (2000)
    Springer
    Journal of insect conservation 4 (2000), S. 23-31 
    Details
    ISSN: 1572-9753
    Keywords: Allochernes wideri ; conservation ; hollow tree ; Larca lata ; pseudoscorpion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract Many beetles associated with old trees are on national red lists, but pseudoscorpions living in similar habitats have received little attention. This study reports the habitat and occurrence patterns of two species of pseudoscorpions living in hollow trees. Their occurrence has been assessed by sieving wood mould from 274 oaks in southeastern Sweden and from museum specimens collected in Sweden. Larca lata is confined to hollow oaks with a large girth and a plentiful supply of wood mould. Allochernes wideri is much less particular about wood mould volume, trunk diameter and tree species. Larca lata inhabits hollow trunks with characteristics that are typical of very old trees, whereas A. wideri predominantly occurs in trunks in an earlier stage of hollow formation. Larca lata was almost exclusively found in larger assemblages of hollow oaks, which suggests long-term survival may be difficult when the network of suitable hollow trees is too sparse. Larca lata is a rare species in Europe and probably vulnerable to extinction, since it is dependent on a habitat which has declined severely in the last few centuries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009682722905
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  • 13
    Electronic Resource
    Electronic Resource
    Genetic Status and Fluctuating Asymmetry in an Endangered Population of the Moth Dysauxes ancilla L. (Lepidoptera: Ctenuchidae) (2000)
    Springer
    Journal of insect conservation 4 (2000), S. 93-98 
    Details
    ISSN: 1572-9753
    Keywords: allozymes ; fluctuating asymmetry ; Dysauxes ancilla ; conservation ; Sweden
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract Genetic status and fluctuating asymmetry (FA) were assessed in a small, isolated and endangered population of the moth Dysauxes ancilla in Sweden. A sample from the German population, within the continuous breeding area of the species, was used for comparison. The levels of FA were significantly higher in the Swedish population, indicating a reduced ability to withstand developmental stress. Two polymorphic loci showed significantly higher variation in the Swedish population, indicating that there are no serious effects on genetic factors. Therefore, it is suggested that the increased level of FA in the Swedish population is due to the stress of living in an ecologically marginal habitat. The Swedish population is a northern outpost separated from the continuous distribution area of species and environmental stress caused by variable and extreme abiotic factors, for example climatic conditions, could explain a higher FA. However, it is still an open question if a higher FA from environmental stress also constitutes an increased extinction risk.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009648622775
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  • 14
    Electronic Resource
    Electronic Resource
    Comparative Biogeography of Grasshoppers (Orthoptera: Acrididae) in North America and Siberia: Applications to the Conservation of Biodiversity (2000)
    Springer
    Journal of insect conservation 4 (2000), S. 161-172 
    Details
    ISSN: 1572-9753
    Keywords: Acrididae ; conservation ; distribution ; diversity ; rarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract The objective of this study was to apply knowledge of holarctic grasshopper biogeography in representative, temperate ecosystems (Russia, South Siberia, Sayans region; 685,000 km2 and USA, Wyoming; 272,000 km2) to develop a comparative basis for understanding and conserving insect biodiversity. Maps of species distributions and vegetation zones were digitized, and a Geographic Information System was used to identify habitats with the greatest biodiversity and to characterize this diversity as a function of selected attributes. With respect to subfamilies, the greatest differences were in cold, mesic zones, where gomphocerines and melanoplines were dominant in Sayans and Wyoming, respectively. In terms of mobility, the Sayans has more flightless species and individuals, with the taiga supporting the greatest frequency of flightless acridids in both countries. With regard to feeding types, the diversity and richness of graminivores and forbivores were similar in the two regions, but mixed feeders were much more frequent in Wyoming. In the Sayans and Wyoming, pest species were most common in boreal and prairie zones, respectively. Ecoregions with a high diversity of pests also supported a high diversity of rare species. Shrub and desert zones supported many rare species in both countries. Thus, in terms of conservation, the Sayans' acridofauna appears to be at greater risk in terms of ecological vulnerability; acridid biodiversity is dispersed among habitats, with high frequencies of flightless and oligophagous species. The acridofauna of Wyoming could be conserved in fewer habitats than in the Sayans, but these habitats are subject to considerable human disturbance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009618425473
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  • 15
    Electronic Resource
    Electronic Resource
    Status and Breeding Sites of Three Presumed Endangered Scottish Saproxylic Syrphids (Diptera, Syrphidae) (2000)
    Springer
    Journal of insect conservation 4 (2000), S. 215-223 
    Details
    ISSN: 1572-9753
    Keywords: conservation ; red-listed ; flight period ; distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Nature of Science, Research, Systems of Higher Education, Museum Science
    Notes: Abstract From 1987 to 1999 efforts were made to understand the status and breeding sites of three presumed endangered flies in Britain: Blera fallax (Linnaeus), Hammerschmidtia ferruginea (Fallén) and Callicera rufa Schummel (Diptera, Syrphidae). Historical data on flight periods, localities and breeding sites were collated from the literature and captured specimens in museums and other collections. Using these data, life cycles were investigated, and cited and other localities searched for adults and early stages. Looking for early stages was more productive than looking for adults. B. fallax is the most endangered. It has declined in abundance, is restricted to two localities and, in 1999, breeding sites were destroyed at one of these localities. In contrast C. rufa is widespread and not uncommon throughout northern Scotland. H. ferruginea is not as endangered as B. fallax but adverse factors such as habitat destruction affect most of its sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011380316156
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  • 16
    Electronic Resource
    Electronic Resource
    Polyphyly of mtDNA lineages in the Russian sturgeon, Acipenser gueldenstaedtii: forensic and evolutionary implications (2000)
    Springer
    Conservation genetics 1 (2000), S. 81-88 
    Details
    ISSN: 1572-9737
    Keywords: caviar ; conservation ; genetics ; mtDNA ; sturgeon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Molecular species identification methods are an important component of CITES monitoring programs for trade in sturgeon and caviar. To date, obtaining molecular evidence for distinguishing caviar from four closely related Eurasian sturgeon species Acipenser baerii (Siberian sturgeon), A. gueldenstaedtii (osetra), A. persicus (Persian sturgeon), A. naccarii (Italian sturgeon) remains problematic. Using approximately 2.3 kb of mtDNA sequence data (cytochrome b, NADH5, control region), we find this to be attributable to the polyphyletic nature of these mitochondrial DNA markers in the Russian sturgeon, A. gueldenstaedtii. Two mitochondrial lineages are present within this species: one is phylogenetically affiliated with A. persicus and A. naccarii, while the other clusters with A. baerii. These findings have a direct impact on molecular testing of commercial caviar and demonstrate the necessity of using large sample sizes when constructing forensic databases. Furthermore, the results affect current taxonomic designations for these species as well as hypotheses concerning their evolutionary origins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010141906100
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  • 17
    Electronic Resource
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    Sex ratio of leopards taken in trophy hunting: genetic data from Tanzania (2000)
    Springer
    Conservation genetics 1 (2000), S. 169-171 
    Details
    ISSN: 1572-9737
    Keywords: conservation ; Panthera pardus ; sport hunting ; tourism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sex ratio of leopards, Panthera pardus, taken by trophyhunters in Tanzania is examined. We used sex specific molecularmarkers to analyze 77 samples collected from animals shot betweenthe years 1995–1998 and found that 28.6% were females, despitethe fact that only males are allowed on licenses and all skinswere tagged as males. The model used for quota setting assumesthat only males are shot, but the effect of this violation ofquotas is unknown. Off-take in Tanzania does not currently fillquotas, but when off-take approach maximum levels, compliancewith set quotas and regulations will be critical for sustainableharvest.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026543308136
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  • 18
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    Landscape change patterns in mountains, land use and environmental diversity, Mid-Norway 1960–1993 (2000)
    Springer
    Landscape ecology 15 (2000), S. 155-170 
    Details
    ISSN: 1572-9761
    Keywords: biodiversity ; conservation ; disturbance ; forest succession ; fragmentation ; grazing ; land use change ; mountain ; semi-natural grasslands ; sub-alpine ; sustainable agriculture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Norwegain mountains have had a central role in the subsistence agroecosystems by providing vast biological resources for humans and their livestock since 4000–3500 BP as indicated by paleoecological records. Later with the development of the summer farming system the use of the mountains was intensified. This long-term use of the mountains has shaped a montane cultural landscape by livestock grazing, mowing for hay, fuel collection and a variety of other uses. The result is a significant increase of the grassland areas at the expense of the forest. Those semi-natural grasslands and heathlands with specific biological diversity have until recently dominated the mountains but are today decreasing due to forest invasion – which in turn is a result of changes in human land use. The present paper focuses on changes in landscape pattern and differences in landscape development in two mountain valleys with summer farming activities, in Mid-Norway, over the period 1960s–1990s, and seeks to interpret the changes in relation to differential land use and environmental factors. This study contributes examples from human shaped ecosystems in mountains where the fragmentation of semi-natural habitats is addressed. A set of landscape pattern indices commonly used in landscape ecological studies is also used here, and their ecological relevance in the present context is dealt with. The implications of changed land use for biodiversity conservation in those mountains and the relationships to future sustainable agriculture is also briefly discussed.
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    URL: http://dx.doi.org/10.1023/A:1008173628016
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    Integrated Biodiversity Management in Paddy Fields: Shift of Paradigm From IPM Toward IBM (2000)
    Springer
    Integrated pest management reviews 5 (2000), S. 175-183 
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    ISSN: 1572-9745
    Keywords: paddy agroecosystem ; minor insects ; non-target insects ; conservation ; agroecology ; aquatic insects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The insect fauna in paddy fields is composed of resident, migratory and aquatic species each corresponding to the continuous cropping of rice in the same field, harvesting rice as an annual crop, and originating from still water habitats in wetlands. Although IPM is becoming popular in the control of rice pests, those ‘minor’ insects and aquatic insects that have no direct economic impact on rice production have received little attention. Consequently, some of them are in danger of extinction requiring conservation. A new concept, ‘Integrated biodiversity management (IBM)’, is proposed under which IPM and conservation are reconciled and made compatible with each other. As an operational concept in agroecology, premises for implementing IBM are suggested.
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    URL: http://dx.doi.org/10.1023/A:1011315214598
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    Gap analysis: concepts, methods, and recent results* (2000)
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    Landscape ecology 15 (2000), S. 5-20 
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    ISSN: 1572-9761
    Keywords: biodiversity ; conservation ; large-area mapping ; gap analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rapid progress is being made in the conceptual, technical, and organizational requirements for generating synoptic multi-scale views of the earth's surface and its biological content. Using the spatially comprehensive data that are now available, researchers, land managers, and land-use planners can, for the first time, quantitatively place landscape units – from general categories such as ‘Forests’ or ‘Cold-Deciduous Shrubland Formation’ to more categories such as ‘Picea glauca-Abies balsamea-Populus spp. Forest Alliance’ – in their large-area contexts. The National Gap Analysis Program (GAP) has developed the technical and organizational capabilities necessary for the regular production and analysis of such information. This paper provides a brief overview of concepts and methods as well as some recent results from the GAP projects. Clearly, new frameworks for biogeographic information and organizational cooperation are needed if we are to have any hope of documenting the full range of species occurrences and ecological processes in ways meaningful to their management. The GAP experience provides one model for achieving these new frameworks.
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    URL: http://dx.doi.org/10.1023/A:1008184408300
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    A survey of equid mitochondrial DNA: Implications for the evolution, genetic diversity and conservation of Equus (2000)
    Springer
    Conservation genetics 1 (2000), S. 341-355 
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    ISSN: 1572-9737
    Keywords: conservation genetics ; Equus ; evolution ; mitochondrial DNA control region ; mitochondrial 12S rRNA
    Source: Springer Online Journal Archives 1860-2000
    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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    Population structure and genetic variability of pearl oyster Pinctada mazatlanica along Pacific coasts from Mexico to Panama (2000)
    Springer
    Conservation genetics 1 (2000), S. 299-308 
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    ISSN: 1572-9737
    Keywords: conservation ; genetic variability ; isolation by distance ; mitochondrial DNA ; pearl oyster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Populations of the Calafia pearl oyster Pinctada mazatlanica ofthe American Pacific coasts have been considered endangeredbecause of overfishing and/or alteration to coastal areas. Weassessed genetic variability and the pattern of populationstructure among 9 samples collected from Mexico to Panama, usingmtDNA RFLP analysis of two genes: 12S rRNA and subunit one ofCytochrome oxydase (COI). Haplotype diversity varied from 0.000to 0.856. The Panama population appeared to be monomorphic, whilethe other samples exhibited a level of haplotypic variabilitysimilar to those reported in the literature for the same kind ofanalysis on other bivalves species. A test for the impact ofdemographic history on genetic diversity was applied on thesequence data, and the results were congruent with a recentdecline of population sizes. Genetic differentiation was shown tofollow a scheme of isolation by distance, with low levels ofdifferentiation at the scales of ten to one hundred kilometres,whereas stronger and significant genetic structure was detectedat a larger scale. Three significantly distinct groups could thenbe defined, which correspond to Northern Mexico, Southern Mexico,and Panama.
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    Last Judgment: The Visionary Biology of J. B. S. Haldane (2000)
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    Journal of the history of biology 33 (2000), S. 457-491 
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    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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    URL: http://dx.doi.org/10.1023/A:1004891323595
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    Sex, Death, and Evolution in Proto- and Metazoa, 1876–1913 (2000)
    Springer
    Journal of the history of biology 33 (2000), S. 221-246 
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    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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    The accumulation of geophysical data in digitized format may give glimpses into the evolution of the Earth (2000)
    Springer
    The environmentalist 20 (2000), S. 257-271 
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    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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    Genome Organization and Phylogenetic Distribution of a Novel Family of Ancient Murine Endogenous Proviruses with Evidence for Transposition-Mediated Proliferation (2000)
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    Biochemical genetics 38 (2000), S. 253-265 
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    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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    A multigene phylogeny of theGibberella fujikuroi species complex: Detection of additional phylogenetically distinct species (2000)
    Springer
    Mycoscience 41 (2000), S. 61-78 
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    ISSN: 1618-2545
    Keywords: biogeography ; calmodulin ; DNA sequence ; elongation factor EF-1α ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    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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    URL: http://dx.doi.org/10.1007/BF02464387
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    Papulosa amerospora accommodated in a new family (papulosaceae, sordariomycetes, ascomycota) inferred from morphological and molecular data (2000)
    Springer
    Mycoscience 41 (2000), S. 97-103 
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    ISSN: 1618-2545
    Keywords: Ascomycota ; evolution ; pyrenomycetes ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    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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    The joys of HexNAc. The synthesis and function of N-andO-glycan branches (2000)
    Springer
    Glycoconjugate journal 17 (2000), S. 465-483 
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    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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    Group Selection and the Limits to Altruism (2000)
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    Journal of bioeconomics 2 (2000), S. 9-23 
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    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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    Effects of flooding duration on species richness, floristic composition and forest structure in river margin habitat in Amazonian blackwater floodplain forests: implications for future design of protected areas (2000)
    Springer
    Biodiversity and conservation 9 (2000), S. 1-14 
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    ISSN: 1572-9710
    Keywords: Amazonia ; blackwater ; Brazil ; conservation ; community ordination ; floodplain forests ; forest structure ; species richness ; species distributions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rivers in central Amazonia experience annual water-level fluctuations of up to 14 m, flooding vast areas of adjacent forest for periods ranging from a few to 270 days per year. At different sites, variation in the duration and type of flooding results in a mosaic of habitats that includes lakes, grasslands, forests, and streams. To study the effects of flood duration on plant species richness and floristic composition, two river margin sites were surveyed on the rivers Jaú and Tarumã-Mirim. Both areas are seasonally flooded by blackwaters, and plots were made at different topographic levels (lower, middle and upper slopes). All woody plants with DBH 〉 5cm were inventoried in five 10 × 40 m plots in each of the three topographic levels, which varied in length of flood duration and mean water level. Plant species richness did not vary significantly between topographic levels, but species composition varied substantially. At both study sites, the species composition exhibited distinctive distribution patterns with respect to the three topographic levels and river site. Differences in the distribution of dominant species in both sites probably relate to the ability of species to withstand seasonal flooding, although other edaphic factors associated with the topographic levels may also be important, especially for less-dominant, locally rare, and habitat generalist species. Species composition overlap among topographic levels at the two sites was highly variable ranging from 15% to 43%. Knowledge about the complex pattern of species composition and distributions between and among topographic levels and river sites is important for the preservation of the diverse flora of the blackwater forests and for the creation of future conservation management plans and design of protected areas in this ecosystem that will maintain the biodiversity.
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    Bird species richness in vegetation fences and in strips of residual rain forest vegetation at Los Tuxtlas, Mexico (2000)
    Springer
    Biodiversity and conservation 9 (2000), S. 1399-1416 
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    ISSN: 1572-9710
    Keywords: bird diversity ; conservation ; corridors ; forest fragmentation ; Los Tuxtlas ; Mexico ; tropical rain forests
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fragmentation of the lowland tropical rain forest has resulted in loss of animal and plant species and isolation of remaining populations that puts them at risk. At Los Tuxtlas, Mexico, lowland rain forests are particularly diverse in the avian fauna they contain and while most of the forests have been fragmented by human activity, many of the fragments still harbor diverse assemblages of bird species. In these landscapes, linear strips of residual rain forest vegetation along streams as well as linear strips of vegetation fences (live fences) crossing the pastures might provide some connectivity to bird populations existed in forest fragments. We investigated bird species richness and relative abundance in one 6-km long section of live fences (LF) bordering a dirt road and in two 6-km long sections of residual forest vegetation along a river (MR) and one permanent stream (BS). We used point count procedures which resulted in the count of 2984 birds representing 133 species. At the LF site we detected 74% of the species, 72% at the BS site and 57% at the MR site. Only 38% of the species were common among sites. Neotropical migratory birds accounted for 34–41% of the species counted at all sites. While edge and open habitat birds accounted for 6–10% of the species and for 50% of the records at the three vegetation strips, about 90% of the species were forest birds. Distance to forest fragments and degree of disturbance of the vegetation seemed to negatively influence bird species presence at the BS and MR strips. Rarefaction analysis indicated that the LF strip was richer in species than the other two sites, but the occurrence of the three vegetation strips in the landscape seem to favor the presence of many more species. We discuss the value of these vegetation strips to birds as stepping stones in the fragmented landscape.
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    Evolutionary Epistemology, Social Epistemology, and the Demic Structure of Science (2000)
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    Biology and philosophy 15 (2000), S. 443-463 
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    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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    Complexity versus Uncertainty: The Question of Staying Alive (2000)
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    Biology and philosophy 15 (2000), S. 493-508 
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    ISSN: 1572-8404
    Keywords: complexity ; entropy balance ; environment independence ; evolution ; information fundamental identity ; uncertainty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Some real objects show a very particular tendency: that of becomingindependent with regard to the uncertainty of their surroundings. This isachieved by the exchange of three quantities: matter, energy andinformation. A conceptual framework, based on both Non-equilibriumThermodynamic and the Mathematical Theory of Communication is proposedin order to review the concept of change in living individuals. Three mainsituations are discussed in this context: passive independence inconnection with resistant living forms (such as seeds, spores, hibernation,...), active independence in connection with the life span of aliving individual (whether an ant or an ant farm), and the newindependence in connection with the general debate of biological evolution.
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    Functional Complexity in Organisms: Parts as Proxies (2000)
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    Biology and philosophy 15 (2000), S. 641-668 
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    ISSN: 1572-8404
    Keywords: complexity ; evolution ; function ; modularity ; parts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract The functional complexity, or the number of functions, of organisms hasfigured prominently in certain theoretical and empirical work inevolutionary biology. Large-scale trends in functional complexity andcorrelations between functional complexity and other variables, such assize, have been proposed. However, the notion of number of functions hasalso been operationally intractable, in that no method has been developedfor counting functions in an organism in a systematic and reliable way.Thus, studies have had to rely on the largely unsupported assumption thatnumber of functions can be measured indirectly, by using number ofmorphological, physiological, and behavioral “parts” as a proxy. Here, amodel is developed that supports this assumption. Specifically, the modelpredicts that few parts will have many functions overlapping in them, andtherefore the variance in number of functions per part will be low. If so,then number of parts is expected to be well correlated with number offunctions, and we can use part counts as proxies for function counts incomparative studies of organisms, even when part counts are low. Alsodiscussed briefly is a strategy for identifying certain kinds of parts inorganisms in a systematic way.
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    Darwinian Ethics and Error (2000)
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    Biology and philosophy 15 (2000), S. 713-732 
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    ISSN: 1572-8404
    Keywords: Darwin ; error theory ; ethics ; evolution ; evolutionary ethics ; Mackie ; naturalistic fallacy ; Ruse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Philosophy
    Notes: Abstract Suppose that the human tendency to think of certain actions andomissions as morally required – a notion that surely lies at the heart of moral discourse – is a trait that has been naturallyselected for. Many have thought that from this premise we canjustify or vindicate moral concepts. I argue that this is mistaken, and defend Michael Ruse's view that the moreplausible implication is an error theory – the idea thatmorality is an illusion foisted upon us by evolution. Thenaturalistic fallacy is a red herring in this debate,since there is really nothing that counts as a ‘fallacy’ at all. If morality is an illusion, it appears to followthat we should, upon discovering this, abolish moraldiscourse on pain of irrationality. I argue that thisconclusion is too hasty, and that we may be able usefullyto employ a moral discourse, warts and all, withoutbelieving in it.
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    URL: http://dx.doi.org/10.1023/A:1006742813396
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    Molecular phylogeny and radiation time of Erysiphales inferred from the nuclear ribosomal DNA sequences (2000)
    Springer
    Mycoscience 41 (2000), S. 437-447 
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    ISSN: 1618-2545
    Keywords: Ascomycota ; evolution ; molecular clock ; plant pathogen ; powdery mildew
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phylogenetic relationships of Erysiphales within Ascomycota were inferred from the newly determined sequences of the 18S rDNA and partial sequences of the 28S rDNA including the D1 and D2 regions of 10 Erysiphales taxa. Phylogenetic analyses revealed that the Erysiphales form a distinct clade among ascomycetous fungi suggesting that the Erysiphales diverged from a single ancestral taxon. The Myxotrichaceae of the Onygenales was distantly related to the other onygenalean families and was the sister group to the Erysiphales calde, with which it combined to form a clade. The Erysiphales/Myxotrichaceae clade was also closely related to some discomycetous fungi (Leotiales, Cyttariales and Thelebolaceae) including taxa that form cleistothecial ascomata. The present molecular analyses as well as previously reported morphological observations suggest the possible existence of a novel evolutionary pathway from cleistothecial discomycetous fungi to Erysiphales and Myxotrichaceae. However, since most of these fungi, except for the Erysiphales, are saprophytic on dung and/or plant materials, the questions of how and why an obligate biotroph like the Erysiphales radiated from the saprophytic fungi remain to be addressed. We also estimated the radiation time of the Erysiphales using the 18S rDNA sequences and the two molecular clockes that have been previously reported. The calculation showed that the Erysiphales split from the Myxotrichaceae 190–127 myr ago. Since the radiation time of the Erysiphales does not exceed 230 myr ago, even when allowance is made for the uncertainty of the molecular clocks, it is possible to consider that the Erysiphales evolved after the radiation of angiosperms. The results of our calculation also showed that the first radiation within the Erysiphales (138–92 myr ago) coincided with the date of a major diversification of angiosperms (130–90 myr ago). These results may support our early assumption that the radiation of the Erysiphales coincided with the evolution of angiosperm plants.
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    URL: http://dx.doi.org/10.1007/BF02461662
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    Comparison of genetic population structure of the large blue butterflies Maculinea nausithous and M. teleius (2000)
    Springer
    Biodiversity and conservation 9 (2000), S. 419-432 
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    ISSN: 1572-9710
    Keywords: allozymes ; conservation ; Lycaenidae ; Maculinea ; metapopulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We investigated the genetic population structure of two rare myrmecophilous lycaenid butterflies, Maculinea nausithous and M. teleius, which often live sympatrically and have similar biology. In Europe, both species occur in highly fragmented populations and are vulnerable to local extinction. The proportion of variable allozyme loci, average heterozygosity and genetic differentiation among populations was higher in M. nausithous than in sympatrically living M. teleius populations. We hypothesise that the differences in heterozygosity are mainly due to the known higher efficiency of typical host ant nests in rearing M. nausithous pupae compared to M. teleius pupae. This implies a larger probability of larval survival in M. nausithous, which buffers populations against environmental and demographic stochasticity. In contrast, the lower carrying capacity of ant nests in rearing M. teleius pupae requires higher nest-densities and makes M. teleius populations more prone to losing genetic variation through drift if this condition is not fulfilled. The single investigated Russian population of M. teleius showed much higher levels of heterozygosity than any of the Polish populations, suggesting a more viable and still intact metapopulation structure.
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    Mammal fauna of the Muni-Pomadze Ramsar site, Ghana (2000)
    Springer
    Biodiversity and conservation 9 (2000), S. 541-560 
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    ISSN: 1572-9710
    Keywords: biodiversity ; bushmeat ; conservation ; duikers ; hunting ; insectivores ; mammals ; monitoring ; rodents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A survey of the terrestrial mammal fauna of Muni-Pomadze Ramsar site along the Ghana coastline recorded 13 species, with 9 additional species reported by local villagers. Small mammal communities are most diverse in the grassland-thicket habitats surrounding the lagoons. Less diverse communities were present in and around managed Ecalyptus plantations or near villages. Duikers, antelope, bushbuck (Tragelaphus scriptus), and cane rats (Thryonomys swinderianus) are hunted (or trapped) for bushmeat. Bushbuck, in particular, play an important role in certain cultural ceremonies at Muni-Pomadze. Conservation efforts at these localities should focus on the management of bushmeat species and the establishment of a long-term monitoring program using small mammal communities as bioindicators of the health of the terrestrial habitats bordering Muni Lagoon.
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    URL: http://dx.doi.org/10.1023/A:1008964000018
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    Postmodernism and African conservation science (2000)
    Springer
    Biodiversity and conservation 9 (2000), S. 559-577 
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    ISSN: 1572-9710
    Keywords: Africa ; conservation ; deconstruction ; ecology ; knowledge ; science ; sociology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In Africa, the movement away from traditional protectionist conservation to community-based approaches is partially related to postmodernist influences. Proposed transfrontier conservation areas will incorporate local communities, and a clearer understanding of the limitations of community-based conservation is thus needed. The sustainability of community-based conservation projects is questioned on economic and other grounds, and many African countries lack the prerequisites (ecological, demographic and sociological) for successful programmes. The romanticisation of pre-colonial societies gives undue weight to traditional systems of resource management, and we challenge the postmodernist notion that traditional peoples practised sustainable harvesting of natural resources. It is suggested that this will occur only under unlikely conditions of low human population density, lack of access to modern technology, and limited exposure to consumerism. In agriculture, postmodernists interpret the overstocking of livestock as a rational socioeconomic response, thus giving the practice unjustified legitimacy. The allied proposition that peasants enjoy a rich diversity of farming practices is largely unfounded, at least in some parts of Africa. We conclude that postmodernist thinking has had a significant negative impact on conservation science in Africa, largely by marginalising the central issue of human population pressure. Towards more effective African conservation, we suggest roles for the ecologist, for the social scientist, and for the donor community.
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    Online Interactive Neuro-evolution (2000)
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    Neural processing letters 11 (2000), S. 29-38 
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    ISSN: 1573-773X
    Keywords: evolution ; online ; game ; neural ; network ; genetic ; real-time
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In standard neuro-evolution, a population of networks is evolved in a task, and the network that best solves the task is found. This network is then fixed and used to solve future instances of the problem. Networks evolved in this way do not handle real-time interaction very well. It is hard to evolve a solution ahead of time that can cope effectively with all the possible environments that might arise in the future and with all the possible ways someone may interact with it. This paper proposes evolving feedforward neural networks online to create agents that improve their performance through real-time interaction. This approach is demonstrated in a game world where neural-network-controlled individuals play against humans. Through evolution, these individuals learn to react to varying opponents while appropriately taking into account conflicting goals. After initial evaluation offline, the population is allowed to evolve online, and its performance improves considerably. The population not only adapts to novel situations brought about by changing strategies in the opponent and the game layout, but it also improves its performance in situations that it has already seen in offline training. This paper will describe an implementation of online evolution and shows that it is a practical method that exceeds the performance of offline evolution alone.
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    URL: http://dx.doi.org/10.1023/A:1009615730125
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    Phylogenetic Relationships Among Quolls Revisited: The mtDNA Control Region as a Useful Tool (2000)
    Springer
    Journal of mammalian evolution 7 (2000), S. 1-22 
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    ISSN: 1573-7055
    Keywords: Dasyurus ; marsupials ; control region ; mtDNA ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract There has been a great deal of interest in determining phylogenetic relationships within the family Dasyuridae due to the widespread distribution, ecological diversity, and relative plesiomorphy of this taxon within the Australasian marsupial radiation. In the past, it has been extremely problematic to determine the phylogenetic relationships among species within Dasyurus, with numerous studies using both morphological and molecular characters providing different topologies. Here, the mitochondrial DNA (mtDNA) control region is used as a novel set of characters in an attempt to identify relationships among the six closely related extant species. Sequences were obtained from multiple individuals representing all extant species of quolls including, when possible, individuals from different geographical regions. Sequences were analyzed using both parsimony criteria and neighbor-joining methods. Results presented here concur with those of Krajewski et al. (1997) in (1) placing D. geoffroii in a highly supported clade with D. spartacus, (2) resolving a monophyletic group of D. albopunctatus + D. geoffroii + D. spartacus, and (3) placing D. hallucatus as the sister taxon to all other species of quolls. Results also show two highly supported and geographically distinct clades of D. maculatus (Tasmanian and mainland) that do not correspond to the currently used subspecific nomenclature. Preliminary results also indicate that there are different clades among geographic groups of D. hallucatus that warrant further investigation. The mtDNA control region is a highly variable locus and may be used in forensic tests for species identification in this genus.
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    Diversity in the Integrase Coding Domain of a gypsy-like Retrotransposon Among Wild Relatives of Rice in the Oryza officinalis Complex (2000)
    Springer
    Genetica 110 (2000), S. 43-53 
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    ISSN: 1573-6857
    Keywords: evolution ; Oryza ; retrotransposon ; rice ; wild species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Oryza officinalis complex is a genetically diverse, tertiary genepool of rice. We analyzed part of the primary structure of the integrase coding domain (ICD) of a gypsy-like retrotransposon from species of the O. officinalis species complex. PCR was performed with degenerate primers that hybridized to conserved sequences in the integrase genes of gypsy-type retrotransposons, using total DNA from different species of the O. officinalis complex as templates. Cloning and sequencing of the PCR products showed that the amplified fragments are highly homologous to each other (75–90%) and belong to one family of retrotransposons that is related to the previously studied RIRE-2 element from rice. Two main subfamilies of 292 and 351 bp were distinguished. Analysis of primary sequence data supports previous reports that sequence divergence during vertical transmission has been the major influence on the evolution of gypsy-type retrotransposons in Oryza species. Based on sequence data phylogenetic relationships among species of the O. officinalis complex were estimated. The data suggests that O. eichingeri is more closely related to the ancestral species of the complex.
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    Biogeographic and Ecological Forces Responsible for Speciation in Ateles (2000)
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    International journal of primatology 21 (2000), S. 421-444 
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    ISSN: 1573-8604
    Keywords: phylogenetics ; biogeography ; speciation ; Ateles ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We used the results of phylogenetic analyses of relationships among spider monkeys (Ateles) based on mitochondrial and nuclear DNA to investigate questions of their evolutionary origins and speciation mechanisms. We employed the concept of a local molecular clock to date nodes of interest (corresponding to hypothesized species and subspecies) in the various phylograms for comparison to hypothesized biogeographical events that might have affected speciation. We considered various mechanisms—Pleistocene refuge formation, riverine barriers, geological fluctuations, and ecological changes associated with these mechanisms—for their contribution to speciation in Ateles. Most speciation among the various species of Ateles occurred during the middle to late Pliocene, suggesting that Pleistocene refuge formation was not a key speciation mechanism. However, it is likely that the genetic structure of populations of Ateles was modified to some extent by refuge formation. Additionally, riverine barriers do not seem to interrupt gene flow significantly among Ateles. No river formed a barrier among species of Ateles, with the exception of the lower Amazon and possibly some of the black-water rivers draining the Guianan highlands. Large-scale geographic changes associated with the continued rise of the eastern and western cordilleras of the northern Andes and associated changes in habitat were the most important causes of speciation in Ateles. The various factors that modify genetic structure in Ateles are important to consider in order to protect endangered primate genera in the Neotropics.
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    Distribution and Conservation of Slender Lorises (Loris tardigradus lydekkerianus) in Southern Andhra Pradesh, South India (2000)
    Springer
    International journal of primatology 21 (2000), S. 721-730 
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    ISSN: 1573-8604
    Keywords: Loris tardigradus lydekkerianus ; Andhra Pradesh ; South India ; conservation ; Eastern Ghats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Slender lorises live in forests of southern India and Sri Lanka. Little is known about their distribution patterns and relative densities. We report the results of a survey conducted in 6 forest divisions in the southern parts of the state of Andhra Pradesh, South India. Relatively high densities of lorises occurred in mixed deciduous forests and in adjoining farm lands interspersed with trees. Three distinct populations inhabit the study area. We recommend conservation measures for Loris tardigradus.
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    Primate Community Dynamics in Old Growth Forest over 23.5 Years at Ngogo, Kibale National Park, Uganda: Implications for Conservation and Census Methods (2000)
    Springer
    International journal of primatology 21 (2000), S. 269-286 
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    ISSN: 1573-8604
    Keywords: conservation ; censuses ; population dynamics ; primates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Few data exist regarding long-term changes in primate populations in old-growth, tropical forests. In the absence of this information, it is unclear how to assess population trends efficiently and economically. We addressed these problems by conducting line-transect censuses 23.5 years apart at the Ngogo study area in Kibale National Park, Uganda. We conducted additional censuses over short time intervals to determine the degree to which the temporal distribution of censuses affected estimates of primate numbers. Results indicate that two species, blue monkeys and red colobus, may have experienced significant reductions over the past 23.5 years at Ngogo. In contrast, five other species, baboons, black-and-white colobus, chimpanzees, mangabeys, and red-tailed guenons, have not changed in relative abundance. Additional findings indicate that different observers may vary significantly in their estimates of sighting distances of animals during censuses, thus rendering the use of measures of absolute densities problematic. Moreover, censuses conducted over short periods produce biased estimates of primate numbers. These results provide guidelines for the use of line-transect censuses and underscore the importance of protecting large blocks of forests for primate conservation.
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    URL: http://dx.doi.org/10.1023/A:1005477504728
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    Coping with Forest Fragmentation: The Primates of Kibale National Park, Uganda (2000)
    Springer
    International journal of primatology 21 (2000), S. 587-611 
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    ISSN: 1573-8604
    Keywords: forest fragmentation ; forest patches ; primate communities ; Colobus guereza ; Kibale National Park ; conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A goal of conservation biology is to determine which types of species are most susceptible to habitat disturbance and which types of disturbed habitats can support particular species. We studied 20 forest fragments outside of Kibale National Park, Uganda, to address this question. At each patch, we determined the presence of primate species, tree species composition, patch size, and distance to nearest patch. We collected demographic, behavioral, and dietary data for Abyssinian black-and-white colobus (Colobus guereza). Black-and-white colobus and red-tailed guenons (Cercopithecus ascanius) were in almost all fragments; Pennant's red colobus (Procolobus pennantii) and chimpanzees (Pan troglodytes) were in some fragments; and blue monkeys (Cercopithecus mitis) and gray-cheeked mangabeys (Lophocebus albigena) were absent from all fragments. No species characteristics—home range, body size, group size, or degree of frugivory—predicted the ability of species to live in patches. No characteristics of patches—area, distance to the nearest patch, distance to Kibale, or number of food trees present—predicted the presence of a particular species in a patch, but distance to Kibale may have influenced presence of red colobus. Black-and-white colobus group size was significantly smaller in the forest patches than in the continuous forest of Kibale. For a group of black-and-white colobus in one patch, food plant species and home range size were very different from those of a group within Kibale. However, their activity budget and plant parts eaten were quite similar to those of the Kibale group. The lack of strong predictive variables as well as differences between other studies of fragmentation and ours caution against making generalizations about primate responses to fragmentation.
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    Use of Vocal Fingerprinting for Specific Discrimination of Gray (Microcebus murinus) and Rufous Mouse Lemurs (Microcebus rufus) (2000)
    Springer
    International journal of primatology 21 (2000), S. 837-852 
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    ISSN: 1573-8604
    Keywords: vocalization ; sexual advertisement ; predator advertisement ; taxonomy ; evolution ; mouse lemur ; primate ; Madagascar
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Advertisement calls are often important noninvasive tools for discriminating cryptic species and for assessing specific diversity and speciation patterns in nature. We investigated the contribution of these calls to uncover specific diversity in nocturnal Malagasy lemurs. We compared sexual advertisement and predator advertisement calls of two mouse lemur species, western gray and eastern rufous mouse lemurs (Microcebus murinus and M. rufus, respectively) living in two contrasting habitats (dry deciduous vs. rain forest), and analyzed them statistically. Both species emitted several highly variable whistle calls in the context of predator-avoidance. Intrapopulation variation was high and overlapped interspecific variation. Sexual advertisement calls, given in the mating context, displayed a totally distinct, species-specific acoustic structure. Whereas gray mouse lemurs produced rapidly multifrequency modulated, long trill calls, rufous mouse lemurs gave slowly frequency-modulated short chirp calls. Our results suggest specific status for gray and rufous mouse lemurs and indicate the importance of predation and social needs in shaping vocal communication.
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    Evolutionary implications of host—pathogen specificity: the fitness consequences of host life history traits (2000)
    Springer
    Evolutionary ecology 14 (2000), S. 665-692 
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    ISSN: 1573-8477
    Keywords: disease ; evolution ; frequency-dependent selection ; genetic diversity ; life history ; lifespan ; polymorphism ; reproduction rate ; resistance ; specificity ; virulence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pathogens and parasites can be strong agents of selection, and often exhibit some degree of genetic specificity for individual host strains. Here we show that this host–pathogen specificity can affect the evolution of host life history traits. All else equal, evolution should select for genes that increase individuals' reproduction rates or lifespans (and thus total reproduction per individual). Using a simple host–pathogen model, we show that when the genetic specificity of pathogen infection is low, host strains with higher reproduction rates or longer lifespans drive slower-reproducing or shorter-lived host strains to extinction, as one would expect. However, when pathogens exhibit specificity for host strains with different life history traits, the evolutionary advantages of these traits can be greatly diminished by pathogen-mediated selection. Given sufficient host–pathogen specificity, pathogen-mediated selection can maintain polymorphism in host traits that are correlated with pathogen resistance traits, despite large intrinsic fitness differences among host strains. These results have two important implications. First, selection on host life history traits will be weaker than expected, whenever host fitness is significantly affected by genotype-specific pathogen attack. Second, where polymorphism in host traits is maintained by pathogen-mediated selection, preserving the genetic diversity of host species may require preserving their pathogens as well.
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    Vegetative propagation of three mangrove tree species by cuttings and air layering (2000)
    Springer
    Wetlands ecology and management 8 (2000), S. 281-286 
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    ISSN: 1572-9834
    Keywords: conservation ; excoecaria ; heritiera ; intsia ; mangroves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Large scale propagation of three mangrove species, Excoecaria agallocha, Heritiera fomesand Intsia bijugausing cuttings and air layering was attempted. The effect of auxins and season on rooting potential of these mangrove species was recorded. Maximum rooting was recorded when the cuttings and air layers were treated with IBA alone up to 2500 ppm in all the three species. October was found to be best followed by January for the plantation of cuttings and initiation of air layers. All the plants were hardened and field transferred into the mangrove forests of Pichavaram, Tamilnadu, India.
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    A phylogenetic analysis of the Illiciaceae based on sequences of internal transcribed spacers (ITS) of nuclear ribosomal DNA (2000)
    Springer
    Plant systematics and evolution 223 (2000), S. 81-90 
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    ISSN: 1615-6110
    Keywords: Cladistics ; evolution ; Illiciales ; Illicium ; ITS ; star anise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA were determined for 15 species ofIllicium (Illiciaceae) to examine phylogenetic relationships. The ITS trees show a major dichotomy between the two North American species (I. floridanum andI. parviflorum) and the remaining east Asian species. This suggests that the existing division between two sections (sect.Illicium and sect.Cymbostemon) ofIllicium based on tepal characters in unnatural. The ITS phylogeny shows congruence with palynology: of the species examined, the three species (I. angustisepalum, I. anisatum andI. fargesii) from sect.Illicium that possess trizonocolpate pollen consistently form a clade, although nesting within a clade consisting of the species of sect.Cymbostemon, which generally have trisyncolpate pollen. The low ITS sequence divergence and the close relationship among east Asian species suggest a recent diversification of this group of species or an unusual slowdown of sequence mutations.
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    The evolution of the ribosomal loci in the subgenusLeopoldia of the genusMuscari (Hyacinthaceae) (2000)
    Springer
    Plant systematics and evolution 221 (2000), S. 245-252 
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    ISSN: 1615-6110
    Keywords: In situ hybridization ; evolution ; NOR ; rDNA ; Muscari
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the subgenusLeopoldia of the genusMuscari, M. comosum is an exceptional species because it presents the most asymmetrical karyotype of the group and because its only active NOR is located in the fifth chromosome pair, while in the other species it is located in the first or second chromosome pairs (all the species have 2n = 18 chromosomes). SinceM. comosum has a derived karyotype different from those of the other species of the group, the resulting question is whether, in the first and second chromosome pair of this species, ribosomal cistrons persist. Observations after fluorescence in situ hybridization (FISH) using rDNA probes indicate that there are indeed ribosomal loci in the first and second chromosome pairs of this species, although these loci are inactive with respect to nucleolus organization. The location of rDNA regions in another three species of the same genus (M. atlanticum, M. dionysicum andM. matritensis) provides a basis for examining the significance of these findings in relation to the evolution of the ribosomal loci in this genus. Our observations indicate that in the genusMuscari, the largest sites for rRNA genes are not necessarily active, and, therefore, the activation of these regions is not related to the number of copies but to a specific regulation mechanism.
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    On the level of cooperative behavior in a local-interaction model (2000)
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    Journal of economics 71 (2000), S. 1-30 
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    ISSN: 1617-7134
    Keywords: evolution ; local interaction ; cooperation ; prisoner's dilemma ; Markov processes ; C78
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract We study local interaction within a population located on a connected graph. Subjects engage in several bilateral interactions during each round in a generalized Prisoners' Dilemma (PD). In each round of play one randomly selected player gets the possibility to update the action he plays in this PD. All individuals use the update rule “Win Cooperate, Lose Defect,” a multi-player variant of Tit-for-Tat. Theoretical results on the set of stable states of the associated dynamics are provided for the cases with and without rare mutations. Simulations provide insight into the probability distribution over these stable states. In both cases a rather high probability is assigned to stable states with a moderate level of cooperation implying that dominated strategies are used. Furthermore, the probability of reaching the stable state with Nash equilibrium play is small.
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    The promoter of rbcS in a C3 plant (rice) directs organ-specific, light-dependent expression in a C4 plant (maize), but does not confer bundle sheath cell-specific expression (2000)
    Springer
    Plant molecular biology 44 (2000), S. 99-106 
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    ISSN: 1573-5028
    Keywords: evolution ; C4 plant ; maize ; ribulose-bisphosphate carboxylase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The small subunit of ribulose-bisphosphate carboxylase (Rubisco), encoded by rbcS, is essential for photosynthesis in both C3 and C4 plants, even though the cell specificity of rbcS expression is different between C3 and C4 plants. The C3 rbcS is specifically expressed in mesophyll cells, while the C4 rbcS is expressed in bundle sheath cells, and not mesophyll cells. Two chimeric genes were constructed consisting of the structural gene encoding β-glucuronidase (GUS) controlled by the two promoters from maize (C4) and rice (C3) rbcS genes. These constructs were introduced into a C4 plant, maize. Both chimeric genes were specifically expressed in photosynthetic organs, such as leaf blade, but not in non-photosynthetic organs. The expressions of the genes were also regulated by light. However, the rice promoter drove the GUS activity mainly in mesophyll cells and relatively low in bundle sheath cells, while the maize rbcS promoter induced the activity specifically in bundle sheath cells. These results suggest that the rice promoter contains some cis-acting elements responding in an organ-pecific and light-inducible regulation manner in maize but does not contain element(s) for bundle sheath cell-specific expression, while the maize promoter does contain such element(s). Based on this result, we discuss the similarities and differences between the rice (C3) and maize (C4) rbcS promoter in terms of the evolution of the C4 photosynthetic gene.
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    The use of allozymes at three life stages influences genetic variation analysis and clustering in Cicer arietinum germplasm collections (2000)
    Springer
    Euphytica 112 (2000), S. 109-115 
    Details
    ISSN: 1573-5060
    Keywords: allozymes ; Bangladesh ; chickpea ; Cicer arietinum ; conservation ; genetics ; germplasm ; populations ; variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Levels of genetic variation using 6 enzyme systems for a total of 11 interpretable loci were examined in chickpea (Cicer arietinum) originating from 9locations in Bangladesh. The measurement of genetic variation at enzyme loci was carried out on the seed embryo, on the early leaves of seedlings and on the mature leaves at the vegetative stage. A total of 592individuals, including 240 seeds, 200 seedlings and152 mature leaves were investigated. Using electrophoretic data, chickpea was found to express higher percentages of polymorphic loci at the seed stage (36–64%) than at seedling (22–56%) or the vegetative stage (11–44%). The proportion of mean number of alleles and the average mean observed heterozygosity also were higher at the seed stage when compared to the seedling and vegetative stages. Unique alleles were absent, and only differences infrequencies could be noticed. Positive values of the fixation index were noted for pgm-1 and 6pg-1 for all stages and in both mnr loci for the seed embryo's. A trend towards lower genetic distances of all possible pairs of populations could be observed when comparing those of seed embryo's with seedlings or mature leaves. This trend was even more pronounced when pooling the data of 9 populations into their 3regions. Slight differences in genetic distances caused a separative clustering of population 3 at seed embryo, of population 2 at seedling and of population5 at vegetative stages. It is suggested that careful examination of enzyme polymorphisms at different developmental stages is a prerequisite before drawing conclusions on the genetic distance between germplasm collections from different origins since small differences in the data entry for clustering results in ties that may affect tree topologies.
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    URL: http://dx.doi.org/10.1023/A:1003851113039
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    Glutamine synthetase isoforms in Trientalis europaea: a biochemical and molecular approach (2000)
    Springer
    Plant and soil 221 (2000), S. 39-45 
    Details
    ISSN: 1573-5036
    Keywords: evolution ; glutamine synthetase ; sequences ; subunit composition ; Trientalis europaea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Ion-exchange chromatography of extracts from Trientalis europaea L. leaf tissue have been shown to contain two distinct isoforms of glutamine synthetase (GS). However, analysis by Western blotting has shown that the first peak to elute contains a mixture of large and small GS subunits, whilst the second peak is comprised entirely of a smaller subunit. This is contrary to the widespread assumptions concerning plant GS biochemistry. Isolation of intact chloroplasts and subsequent extraction of GS, followed by ion-exchange chromatography, has shown that the first peak to elute contains a large subunit, and the second chloroplastic peak is composed entirely of the small subunit. This smaller subunit may be present due to it being encoded by a separate chloroplastic GS gene, or it may be present as a product of post-translational modification. DNA sequencing has been used to try and determine which of these may be occurring. The three partial DNA sequences (505 nucleotides) we have obtained from T. europaea have been compared with 64 other sequences available on the NCBI database, which have mainly been obtained from crop species. Neighbour joining and parsimony analysis (1000 bootstrap) has shown support (∼30%) for the separation of plant GS from all other phyla. Within the plant phylum, there is total support for the separation of chloroplastic and cytosolic GS (100%), whilst the cytosolic sequences divide further into monocot and dicot species (77% support by NJ). Further subgroups of plants from the same families is also suggested. This is consistent with previous work containing fewer, but longer (∼1000 nucleotides) GS sequences. The addition of GS sequences obtained from wild plant species, such as T. europaea, to the large amount of information already available on the database, will permit a better understanding of the evolution of this important enzyme.
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    URL: http://dx.doi.org/10.1023/A:1004728005931
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    Micropropagation of the critically endangered Western Australian species, Symonanthus bancroftii (F. Muell.) L. Haegi (Solanaceae) (2000)
    Springer
    Plant cell, tissue and organ culture 63 (2000), S. 23-29 
    Details
    ISSN: 1573-5044
    Keywords: acclimatisation ; antioxidants ; conservation ; potassium citrate ; tissue browning ; tissue culture ; triazoles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A micropropagation protocol was developed for the conservation of the critically endangered Western Australian shrub,Symonanthus bancroftii. It was necessary to screen antioxidant treatments to prevent the occurrence of lethal browning of explants upon excision. Potassium citrate and citric acid (0.1% w/v in a 4:1 ratio) prevented oxidative browning and was superior to the untreated control or other antioxidant treatments tested. Half strength Murashige and Skoog (MS) medium containing 0.5 μM kinetin and 0.25 μM benzyladenine produced three-fold multiplication compared to 1.75×, 1.5×, 1.8× and 1× multiplication for 2.5 μM kinetin + 0.25 μM benzyladenine, 0.5 μM kinetin + 5 μM gibberellic acid, 1 μM kinetin + 3 μM gibberellic acid and half strength MS with no plant growth regulators, over 4 weeks. Root production was achieved with indole-3-butyric acid (IBA) and α-naphthaleneacetic acid (NAA) at 0.5/0.5 μM (31% rooting) and 1.0/1.0 μM (36% rooting), after four weeks. Paclobutrazol (PBZ) at 0, 3.4 (1 mg 1−1), 10.2 (3 mg 1−1), or 17 μM (5 mg 1−1) improved tolerance to desiccation after transfer ofin vitro rooted shoots to soil. PBZ at 10.2 μM increased survival to 90% compared to 50% for those plantlets not treated with PBZ. The acclimatisation period from the glasshouse to the shadehouse was 1 week for plantlets treated with PBZ compared to 4 weeks for plantlets without any PBZ. PBZ at 3.4 μM increased the number of roots per shoot compared to untreated controls.
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    Occurrence of C3 and C4 photosynthesis in cotyledons and leaves of Salsola species (Chenopodiaceae) (2000)
    Springer
    Photosynthesis research 63 (2000), S. 69-84 
    Details
    ISSN: 1573-5079
    Keywords: anatomy ; C3 and C4 photosynthesis ; Chenopodiaceae ; cotyledon ; deserts ; evolution ; leaf ; Salsola
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Most species of the genus Salsola (Chenopodiaceae) that have been examined exhibit C4 photosynthesis in leaves. Four Salsola species from Central Asia were investigated in this study to determine the structural and functional relationships in photosynthesis of cotyledons compared to leaves, using anatomical (Kranz versus non-Kranz anatomy, chloroplast ultrastructure) and biochemical (activities of photosynthetic enzymes of the C3 and C4 pathways, 14C labeling of primary photosynthesis products and 13C/12C carbon isotope fractionation) criteria. The species included S. paulsenii from section Salsola, S. richteri from section Coccosalsola, S. laricina from section Caroxylon, and S. gemmascens from section Malpigipila. The results show that all four species have a C4 type of photosynthesis in leaves with a Salsoloid type Kranz anatomy, whereas both C3 and C4 types of photosynthesis were found in cotyledons. S. paulsenii and S. richteri have NADP- (NADP-ME) C4 type biochemistry with Salsoloid Kranz anatomy in both leaves and cotyledons. In S. laricina, both cotyledons and leaves have NAD-malic enzyme (NAD-ME) C4 type photosynthesis; however, while the leaves have Salsoloid type Kranz anatomy, cotyledons have Atriplicoid type Kranz anatomy. In S. gemmascens, cotyledons exhibit C3 type photosynthesis, while leaves perform NAD-ME type photosynthesis. Since the four species studied belong to different Salsola sections, this suggests that differences in photosynthetic types of leaves and cotyledons may be used as a basis or studies of the origin and evolution of C4 photosynthesis in the family Chenopodiaceae.
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    A phenetic analysis of morphological variation in Citrullus lanatus in Namibia (2000)
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    Genetic resources and crop evolution 47 (2000), S. 385-393 
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    ISSN: 1573-5109
    Keywords: Citrullus lanatus ; cluster analysis ; evolution ; morphology ; watermelon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Morphological data recorded from field trials using Citrullus lanatus germplasm collected in Namibia were used to analyse and compare the various morphotypes of this species. The experiment comprised wild types and local landraces as well as commercial cultivars. Cluster analysis supported the indigenous classification system used in Namibia, in which Citrullus types are distinguished based on gross morphology, ecology and usage and grouped into seed, cooking and fresh-eating (watermelon) types. Commercial watermelon cultivars formed a distinct cluster. Wide variation was found within the local types whereas the genetic basis of the commercial type appears to be narrow. The commercial cultivars were most closely related to local watermelon types and more distantly related to the wild types, whereas the cooking melons form an intermediate group.
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    Multifunctions of the upper lip and a ventral reflecting organ in a bioluminescent ostracod Vargula hilgendorfii (Müller, 1890) (2000)
    Springer
    Hydrobiologia 419 (2000), S. 73-82 
    Details
    ISSN: 1573-5117
    Keywords: reflecting organ ; upper lip ; Myodocopa ; chemical cues ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Multifunctions of the upper lip in a bioluminescent myodocopid Vargula hilgendorfii were studied by video observation and histological method. The localization of luciferin and luciferase gland cells within the upper lip was partly successful. Two long protrusions of the upper lip, both of V. hilgendorfii and a non-luminescent species of the same family, immediately anterior to the mouth, were found to show very flexible movement especially while eating, as if smearing on the food surface a secretion from the protrusions (glands), which may support the hypothesized secretion of digestive enzymes from the upper lip. This hypothesis is further supported by the new finding of a pair of ducts which connect the basal part of the upper lip with the posterior digestive duct (stomach). Comparative studies of V. hilgendorfii with several sympatric non-luminescent species of the same family have also revealed that it has a characteristic reflecting organ immediately posterior to the anus. It is a conical small protrusion, as if dangling from the ventral edge of the abdomen at the apex of the cone. It is observable only in live specimens, when the furca, which is located outwardly to the organ, is sufficiently transparent. When illuminated, the reflecting organ reflects the distinct light. The diameter of the mirror (chemical composition provisionally analyzed) is about 6–8% of the carapace length. The organ develops from the very first stage of its ontogeny without reference to sex, which suggests that the function may be related to intraspecific signaling or predatory deterrence.
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    The ontogeny of the cypridid ostracod Eucypris virens (Jurine, 1820) (Crustacea, Ostracoda) (2000)
    Springer
    Hydrobiologia 419 (2000), S. 31-63 
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    ISSN: 1573-5117
    Keywords: morphology ; ontogeny ; Ostracoda ; evolution ; fifth limb ; crustacean phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The chaetotaxy (shape, structure and distribution of setae) of appendages and valve allometry during the post embryonic ontogeny of the cyprididine ostracod Eucypris virens are described. It is shown that the basic ontogenetic development of E. virens is very similar to that of other species of the family Cyprididae. During ontogeny, the chaetotaxy shows continual development on all podomeres of the limbs with the exception of the last podomere on the antennulae. The long setae on the exopodite and protopodite of the antennae have a natatory function until the actual natatory setae develop in later instars. Aesthetascs (presumed chemoreceptors) ya and y3 are the first to develop and may have an important function in the first instars. Cyprididae require a pediform limb in the posterior of the body presumably to help them to attach to substrates and this is reflected by the pediform nature of one limb at all times throughout all instars. This study has also shown that the fifth limb is most probably of thoracic origin and hence ostracods have only one pair of maxillae.
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    Preface: Ostracoda and the four pillars of evolutionary wisdom (2000)
    Springer
    Hydrobiologia 419 (2000), S. 7-11 
    Details
    ISSN: 1573-5117
    Keywords: morphology ; palaeontology ; ecology ; genetics ; Ostracoda ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Morphology, palaeontology, genetics and ecology are the main scientific domains contributing theories, concepts and new data to evolutionary biology. Ostracods are potentially very good model organisms for evolutionary studies because they combine an excellent fossil record with a wide extant distribution and, therefore, allow studies on both patterns and processes leading to extant diversity. This preface provides an overview of the 15 contributions to the present volume and concludes that this set of papers supports the claim that ostracod studies are situated in all main evolutionary domains.
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    Phylogenetic implications of the Crustacean nauplius (2000)
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    Hydrobiologia 417 (2000), S. 91-99 
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    ISSN: 1573-5117
    Keywords: evolution ; phylogeny ; larval characters ; morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The plesiomorphic mode of crustacean development is widely accepted to be via a larva called the nauplius. Extant taxa like the Cephalocarida, Branchiopoda, Ostracoda, Mystacocarida, Copepoda, Cirripedia, Ascothoracida, Facetotecta, Euphausiacea and Penaeidea hatch from an egg as a free-living nauplius. Other crustaceans show an embryonic phase of development suggestive of a naupliar organization. Several features of the nauplius larva have been proposed as diagnostic characters for the Crustacea: a median (nauplius) eye; at least three pairs of head appendages (antennules, antennae, mandibles); a posteriorly directed fold (the labrum) extending over the mouth and a cephalic (nauplius) shield. The relationship between trilobite protaspis with at least four appendages and the crustacean nauplius remains unclear, but reports of a copepod orthonauplius with four appendages are rejected. Swimming is suggested to represent the underived mode of locomotion for the crustacean nauplius, and that naupliar swimming directly results in naupliar feeding which also is underived.
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    Distribution and status of the medicinal leech (Hirudo medicinalis L.) in Turkey (2000)
    Springer
    Hydrobiologia 441 (2000), S. 37-44 
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    ISSN: 1573-5117
    Keywords: distribution ; status ; population assessment ; zoogeography ; conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A survey of all the major potential habitats in western Turkey showed that medicinal leeches, Hirudo medicinalis L., are widely distributed over the country and are not rare. They occur in practically all suitable habitats and the only region where they were found to be absent is that of the large river deltas in the south of the country (Çukurova deltas, Göksu delta). There may be zoogeographic reasons for this (Taurus mountains barrier). The application of a semi-quantitative survey method using collecting efficiency (number of leeches collected per hour by a single person) allowed a rapid assessment to be made of its status in a large number of wetlands. Leech density varied considerably from wetland to wetland, and the results enabled a ranking of the Turkish wetlands to be made according to their importance for medicinal leeches. Taking both the leech density and the size of leech habitats into account, the largest populations were identified on the Black Sea coast (Kizilirmak delta, Yeşilirmak delta and Karagöl Marshes near Sinop) and in inner and south-west Anatolia (Eber Gölü, Karamik and Sultan Marshes). Commercial exploitation for the pharmaceutical industry and for other purposes takes place at only a few places and does not appear to affect the population seriously. However, many populations are threatened by the draining of their habitats.
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    The detection of spatial variation in widespread marine species: methods and bias in the analysis of population structure in the crown of thorns starfish (Echinodermata: Asteroidea) (2000)
    Springer
    Hydrobiologia 420 (2000), S. 1-14 
    Details
    ISSN: 1573-5117
    Keywords: population genetics ; evolution ; allozymes ; DNA ; marine genetics ; Acanthaster planci
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The basic assumptions that widespread marine species should show little spatial variation in genetic structure, given their high potential for dispersal on ocean currents, is being questioned. This has taken some time because there are few studies of widespread marine species over oceanic scales, few data sets that have the high density of sampling required for the detection of fine population structure, and there is little incentive to look further if initial analyses suggest the expected result. The interpretation of the population genetic structure of crown-of-thorns starfish (Acanthaster planci) has been found to vary considerably depending on the sample set included in the analyses and on the method of analysis used. Scatter plots of genetic distance or θ, and spatial autocorrelation approaches gave markedly different results ranging from no structure to isolation by distance. Only visual examination of maps of patterns of variation in allele variation first detected that crown-of-thorns starfish occupy large regions with little between population differentiation, but between which there are markedly higher levels of differentiation. These findings highlight the care required in interpreting population structure, particularly where there are few sample points. Many marine species may have population structures where sharp genetic disjunctions, not associated with any obvious environmental boundaries, separate regions of relative genetic homogeneity. Such population structures are very different from those traditionally assumed and are not yet understood. Further advances in understanding the genetic structure of marine species will demand an iterative approach where a greater number of samples are collected over particular regions identified by earlier interpretations.
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    Molecular systematics of sponges (Porifera) (2000)
    Springer
    Hydrobiologia 420 (2000), S. 15-27 
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    ISSN: 1573-5117
    Keywords: phylogeny ; evolution ; allozymes ; rDNA ; DNA sequence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The first application of molecular systematics to sponges was in the 1980s, using allozyme divergence to dis-criminate between conspecific and congeneric sponge populations. Since this time, a fairly large database has been accumulated and, although the first findings seemed to indicate that sponge species were genetically more divergent than those of other marine invertebrates, a recent review of the available dataset indicates that levels of interspecific gene identities in most sponges fall within the normal range found between species of other invertebrates. Nevertheless, some sponge genera have species that are extremely divergent from each other, suggesting a possible polyphyly of these genera. In the 1990s, molecular studies comparing sequences of ribosomal RNA have been used to reappraise the phylogenetic relationships among sponge genera, families, orders and classes. Both the 18S small subunit and the 28S large subunit rRNA genes have been sequenced (41 complete or partial and 75 partial sequences, respectively). Sequences of 18S rRNA show good support for Porifera being true Metazoa, but they are not informative for resolving relationships among genera, families or orders. 28S rRNA domains D1 and D2 appear to be more informative for the terminal nodes and provide resolution for internal topologies in sufficiently closely related species, but the deep nodes between orders or classes cannot be resolved using this molecule. Recently, a more conserved gene, Hsp70, has been used to try to resolve the relationships in the deep nodes. Metazoan monophyly is very well supported. Nevertheless, the divergence between the three classes of Porifera, as well as the divergence between Porifera, Cnidaria and Ctenophora, is not resolved. Research is in progress using other genes such as those of the homeodomain, the tyrosine kinase domain, and those coding for the aggregation factor. For the moment the dataset for these genes is too restricted to resolve the phylogenetic relationships of these phyla. However, whichever the genes, the phylogenies obtained suggest that Porifera could be paraphyletic and that the phylogenetic relationships of most of the families and orders of the Demospongiae have to be reassessed. The Calcarea and Hexactinellida are still to be studied at the molecular level.
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    Genetics of marine bioinvasions (2000)
    Springer
    Hydrobiologia 420 (2000), S. 63-71 
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    ISSN: 1573-5117
    Keywords: ballast water ; conservation ; invasive species ; population structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Anthropogenic biological introductions have captured the attention of marine scientists and resource managers in recent years. Human-mediated marine bioinvasions are presently acknowledged as often ecologically and financially devastating events. Despite recent increases in scientific interest and financial resources devoted to nonindigenous nuisance species globally, fundamental questions pertaining to taxonomic identity, geographic source, introduction vector and invasive population dynamics frequently remain unanswered. Ecological surveys based on photometric and observational methods are unable to identify cryptogenic taxa, source populations, multiple introductions, or genetic diversity. The twofold goal of this paper is to discuss the application of molecular genetic techniques to fundamental ecological questions pertaining to bioinvasions and to demonstrate the utility of DNA technology in providing data useful in the development of predictive models for marine bioinvasion science.
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    URL: http://dx.doi.org/10.1023/A:1003929519809
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    Temporal Genetic Variation in a Population of Aphanius fasciatus (Cyprinodontidae) from a Brackish-water Habitat at Elba Island (Italy) (2000)
    Springer
    Environmental biology of fishes 57 (2000), S. 107-112 
    Details
    ISSN: 1573-5133
    Keywords: conservation ; allozymes ; generations ; genetic distance ; genetic drift ; selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Allozyme electrophoresis was used to assess temporal genetic variation in three successive generations of the Mediterranean killifish, Aphanius fasciatus. Samplings were carried out in 1995, 1996 and 1997 in a brackish-water habitat at Elba Island, Italy and a total of 212 specimens were collected. The five loci for which polymorphism has been detected in a previous study were assayed. Mean expected heterozygosity values [H=0.397 (SE 0.077), H=0.336 (SE 0.092) and H=0.313 (SE 0.092) in 1995, 1996 and 1997, respectively] were not significantly different by ANOVA test. Deviations from Hardy–Weinberg equilibrium were minimal, with only one out of the 15 probability tests showing a significant departure from the equilibrium; whereas genotypic linkage disequilibrium was not detected. Values of Nei's genetic distance were lower than 0.04. Temporal genetic variation in the A. fasciatus population at Elba Island was observed, with F-statistics indicating significant genetic divergence among samples (θ=0.035, SE 0.027, p〈0.001). Genetic drift acting on two loci (GPD-1 * and LDH-3 *) is presumably the main force determining the temporal genetic heterogeneity observed; however, the occurrence of selection on individual loci and/or sampling error cannot be excluded. The observed allelic variation among generations in a single population of A. fasciatus is much less than levels observed among geographically discrete samples in previous studies.
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    Predicting Population Recovery Rates for Endangered Western Atlantic Sawfishes Using Demographic Analysis (2000)
    Springer
    Environmental biology of fishes 58 (2000), S. 371-377 
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    ISSN: 1573-5133
    Keywords: largetooth sawfish ; Pristis perotteti ; smalltooth sawfish ; Pristis pectinata ; life tables ; conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sawfish are a group of endangered elasmobranchs that were common in tropical inshore, estuarine and freshwaters. The demography of two species of sawfish that occur in the western Atlantic – Pristis pectinata and P. perotteti – was investigated using age-structured life tables. Life history parameters for use in the life tables were obtained from published data. Five scenarios were tested for P. pectinata to incorporate uncertainties about life history data. Values of intrinsic rate of increase ranged from 0.08 to 0.13 yr−1, and population doubling times from 5.4 to 8.5 yrs. Eight scenarios were tested for P. perotteti. The most likely range for the intrinsic rate of increase was 0.05–0.07 yr−1, with population doubling times of 10.3–13.5 yrs. Four scenarios investigating the sensitivity to methods of estimating natural mortality produced similar results. The demographic results were sensitive to changes in reproductive periodicity and natural mortality. The results indicate that if effective conservation plans can be implemented for sawfish and sawfish habitats, recovery to levels where there is little risk of extinction will take at least several decades.
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    Barbus tanapelagius, A New Species from Lake Tana (Ethiopia): its Morphology and Ecology (2000)
    Springer
    Environmental biology of fishes 59 (2000), S. 1-9 
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    ISSN: 1573-5133
    Keywords: Cyprinidae ; piscivores ; prey fish ; small barbs ; species flock ; evolution ; speciation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The endemic cyprinid species flock in Lake Tana consists of 15 species of large hexaploid barbs, eight of which are piscivorous. Previously, it was assumed that all piscivores preyed on the same small barb species, Barbus trispilopleura. In this paper we present a description of morphology and ecology of a new abundant small barb species, Barbus tanapelagius sp. nova (holotype RMNH 33731) from Lake Tana, Ethiopia, which appears to be the major prey species for the large pelagic piscivorous barbs. B. tanapelagius differs clearly in morphology from the other 3 small, diploid Barbus species known from Lake Tana, B. trispilopleura Boulenger, 1902, B. humilis Boulenger, 1902 and B. pleurogramma Boulenger, 1902. Conspicuous differences are its elongated body, large eye diameter, prominent and hooked lower jaw contour and colouration. Preliminary data suggest that B. tanapelagius also differs ecologically from the other small Barbus spp. by its pelagic, strictly zooplanktivorous feeding and its occurrence mainly in the deeper, offshore waters. The other small Barbus species are most probably largely benthic feeders and dominant in the shallow inshore waters. Previous views about the evolution of the present 8 endemic piscivorous large barb species therefore require reconsideration, as the present paper shows a more complex scenario including several prey species.
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    URL: http://dx.doi.org/10.1023/A:1007608208630
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    An overview of marine fish cytogenetics (2000)
    Springer
    Hydrobiologia 420 (2000), S. 55-62 
    Details
    ISSN: 1573-5117
    Keywords: chromosomes ; evolution ; nucleolar organizer region
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The number of cytogenetic studies of marine fish has increased in recent years. Fish groups, such as Perciformes, which comprises many of the extant marine teleosts of economic importance, show little divergence in chromosome number and most species display a diploid number of 48 acrocentric chromosomes. In the Serranidae, Sparidae, Sciaenidae (Perciformes) and Mugilidae (Mugiliformes) small chromosome variations are restricted to subtle heterochromatin or nucleolar organizer region (NOR) modifications. There appears to exist a strict relationship between both absence of geographic barriers throughout the marine environment and high mobility of these animals (eggs, larvae, or adults), with a rarity of chromosome rearrangement at the macrostructural level. Moreover, a cellular homeostasis might also be important to karyotype maintenance among these fishes, limiting changes in the chromosome complement to cryptic chromosome rearrangements. Other groups, such as Blenniidae, Gobiidae and Scorpaenidae, for instance, show more extensive chromosome diversity, which is probably related to limited mobility. Numerical and structural chromosome polymorphisms and several sexual chromosome systems are recurrent among these fishes. A wide karyotypic diversification also characterizes the Tetraodontiformes, an interesting fish group with peculiar morphological, physiological and ecological characteristics.
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    URL: http://dx.doi.org/10.1023/A:1003977418900
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    Does Parental Fin Digging Improve Feeding Opportunities for Offspring in the Convict Cichlid? (2000)
    Springer
    Environmental biology of fishes 57 (2000), S. 443-449 
    Details
    ISSN: 1573-5133
    Keywords: parental care ; feeding behaviour ; evolution ; trade-off ; individual differences ; fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The function of the fin digging behaviour in increasing food availability for the offspring was analysed in the convict cichlid, Cichlasoma (Archocentrus) nigrofasciatum. Consistent individual differences in the frequency of fin digging were found in the parental fish. Examination of the gastrointestinal tract of young revealed that higher frequency of parental fin digging was associated with higher consumption of large and more profitable prey (Diptera larvae), which inhabited deep horizons of the bottom substrate and possibly were difficult to access without parental assistance. Thus, parental fin digging was initially associated with a significant increase of the offspring growth rate. However, at later brood intervals, when parental care ceased, the young of the high-digging parents were characterised by a poorer consumption of small larvae that were most accessible for them without parental aid and represented an increasingly more important component of their ration than large larvae. Offspring of the low-digging parents, on the other hand, presumably as a result of their individual experience, showed a considerably better consumption of small larvae, increasing their growth rate. As a consequence, prior parental fin digging did not affect the offspring body size after independence. Thus, there exist pronounced individual differences and alternative parental styles in the convict cichlid.
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    URL: http://dx.doi.org/10.1023/A:1007654729430
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    Decline of Native Freshwater Fishes in a Mediterranean Watershed on the Iberian Peninsula: A Quantitative Assessment (2000)
    Springer
    Environmental biology of fishes 59 (2000), S. 11-19 
    Details
    ISSN: 1573-5133
    Keywords: conservation ; distribution ; environmental degradation ; endangered species ; introduced species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We examined changes in the distribution of 9 native and 18 introduced freshwater fishes in the south-eastern Pyrenees watershed, Iberian Peninsula, using data from 1996, 1984–1988 and historical information. This region suffers many modifications to its freshwater ecosystems that are linked to human activity in the Mediterranean regions. Fish communities, stream physical habitat and environmental degradation were assessed at 168 sites from 11 basins in 1996. Seven native species (78%) showed decline from previous data, one of which became extirpated in the first half of the 20th century. On the other hand, introduced species are expanding. As a consequence, intact native communities are increasingly rare, declining from presence in 22% of river courses in 1984–1988 to 15% in 1996. The most typical community type is a mixture of native and introduced species occupying 30% of river courses. Stream degradation seems to be the main cause of this process because fish communities differed between degraded streams and streams suffering less impact. A principal component analysis showed that water pollution and modifications to the habitat were the two anthropogenic factors that accounted for most changes in the fish community integrity. Habitat alteration, primarily through construction of dams and water diversions, has fragmented habitats and isolated native fish communities in headwater streams. Current protection measures do not offer effective conservation of threatened species and communities. A global conservation and restoration programme from an ecosystem-based approach is essential to reverse the trend affecting native freshwater fishes in this Mediterranean region.
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    URL: http://dx.doi.org/10.1023/A:1007618517557
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    Knots in the family tree: evolutionary relationships and functions of knox homeobox genes (2000)
    Springer
    Plant molecular biology 42 (2000), S. 151-166 
    Details
    ISSN: 1573-5028
    Keywords: evolution ; homeodomain protein ; knox gene ; meristem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Knotted-like homeobox (knox) genes constitute a gene family in plants. Class I knox genes are expressed in shoot apical meristems, and (with notable exceptions) not in lateral organ primordia. Class II genes have more diverse expression patterns. Loss and gain of function mutations indicate that knox genes are important regulators of meristem function. Gene duplication has contributed to the evolution of families of homeodomain proteins in metazoans. We believe that similar mechanisms have contributed to the diversity of knox gene function in plants. Knox genes may have contributed to the evolution of compound leaves in tomato and could be involved in the evolution of morphological traits in other species. Alterations in cis-regulatory regions in some knox genes correlate with novel patterns of gene expression and distinctive morphologies. Preliminary data from the analysis of class I knox gene expression illustrates the evolution of complex patterns of knox expression is likely to have occurred through loss and gain of domains of gene expression.
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    URL: http://dx.doi.org/10.1023/A:1006384122567
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    A short history of MADS-box genes in plants (2000)
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    Plant molecular biology 42 (2000), S. 115-149 
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    ISSN: 1573-5028
    Keywords: angiosperm ; development ; evolution ; fern ; gymnosperm ; MADS-box gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evolutionary developmental genetics (evodevotics) is a novel scientific endeavor which assumes that changes in developmental control genes are a major aspect of evolutionary changes in morphology. Understanding the phylogeny of developmental control genes may thus help us to understand the evolution of plant and animal form. The principles of evodevotics are exemplified by outlining the role of MADS-box genes in the evolution of plant reproductive structures. In extant eudicotyledonous flowering plants, MADS-box genes act as homeotic selector genes determining floral organ identity and as floral meristem identity genes. By reviewing current knowledge about MADS-box genes in ferns, gymnosperms and different types of angiosperms, we demonstrate that the phylogeny of MADS-box genes was strongly correlated with the origin and evolution of plant reproductive structures such as ovules and flowers. It seems likely, therefore, that changes in MADS-box gene structure, expression and function have been a major cause for innovations in reproductive development during land plant evolution, such as seed, flower and fruit formation.
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    URL: http://dx.doi.org/10.1023/A:1006332105728
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    The evolution of nodulation (2000)
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    Plant molecular biology 42 (2000), S. 181-194 
    Details
    ISSN: 1573-5028
    Keywords: actinorhiza ; endomycorrhizae ; evolution ; Frankia ; haemoglobins ; nod factors ; nodulation ; phylogeny ; rhizobia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this review we will first describe the different steps leading to nodule formation, and these will be compared with processes of non-symbiotic plant development and growth. In general, aspects of both actinorhizal as well as rhizobial symbiosis are described, but in several cases, the emphasis will be on the Rhizobium-legume symbiosis because more knowledge of this system is available. Subsequently, the phylogeny of nodulating plants is described and a comparison is made between several aspects of legume and actinorhizal nodulation. At the end of this paper the relationship between nodule symbiosis and endomycorrhizal symbiosis is described, and it is discussed to what extent the development of root nodules involves unique properties, or whether processes and genes have been recruited from common plant development and the endomycorrhizal symbiosis.
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    URL: http://dx.doi.org/10.1023/A:1006396525292
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    Quaternary Structure of Nucleoside Diphosphate Kinases (2000)
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    Journal of bioenergetics and biomembranes 32 (2000), S. 227-236 
    Details
    ISSN: 1573-6881
    Keywords: NDP kinase ; subunit interaction ; quaternary structure ; evolution ; mixed oligomers ; Dictyostelium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Nucleoside (NDP) diphosphate kinases are oligomeric enzymes. Most are hexameric, but somebacterial enzymes are tetrameric. Hexamers and tetramers are constructed by assemblingidentical dimers. The hexameric structure is important for protein stability, as demonstratedby studies with natural mutants (the Killer-of-prune mutant ofDrosophila NDP kinase andthe S120G mutant of the human NDP kinase A in neuroblastomas) and with mutants obtainedby site-directed mutagenesis. It is also essential for enzymic activity. The function of the tetrameric structure is unclear.
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    URL: http://dx.doi.org/10.1023/A:1005580828141
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    Ty1-copia-retrotransposon Behavior in a Polyploid Cotton (2000)
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    Chromosome research 8 (2000), S. 73-76 
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    ISSN: 1573-6849
    Keywords: evolution ; genome ; Gossypium ; polyploidization ; repetitive element ; retrotransposon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Retrotransposons constitute a ubiquitous and dynamic component of plant genomes. Intragenomic and intergenomic comparisons of related genomes offer potential insights into retrotransposon behavior and genomic effects. Here, we have used fluorescent in-situ hybridization to determine the chromosomal distributions of a Ty1-copia-like retrotransposon in the cotton AD-genome tetraploid Gossypium hirsutum and closely related putative A- and D-genome diploid ancestors. Retrotransposon clone A108 hybridized to all G. hirsutum chromosomes, approximately equal in intensity in the A- and D-subgenomes. Similar results were obtained by hybridization of A108 to the A-genome diploid G. arboreum, whereas no signal was detected on chromosomes of the D-genome diploid G. raimondii. The significance and potential causes of these observations are discussed.
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    URL: http://dx.doi.org/10.1023/A:1009239522541
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    Common Mechanisms of Y Chromosome Evolution (2000)
    Springer
    Genetica 109 (2000), S. 105-111 
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    ISSN: 1573-6857
    Keywords: Drosophila ; evolution ; heterochromatin ; Y chromosome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Y chromosome evolution is characterized by the expansion of genetic inertness along the Y chromosome and changes in the chromosome structure, especially the tendency of becoming heterochromatic. It is generally assumed that the sex chromosome pair has developed from a pair of homologues. In an evolutionary process the proto-Y-chromosome, with a very short differential segment, develops in its final stage into a completely heterochromatic and to a great extends genetically eroded Y chromosome. The constraints evolving the Y chromosome have been the objects of speculation since the discovery of sex chromosomes. Several models have been suggested. We use the exceptional situation of the in Drosophila mirandato analyze the molecular process in progress involved in Y chromosome evolution. We suggest that the first steps in the switch from a euchromatic proto-Y-chromosome into a completely heterochromatic Y chromosome are driven by the accumulation of transposable elements, especially retrotransposons inserted along the evolving nonrecombining part of the Y chromosome. In this evolutionary process trapping and accumulation of retrotransposons on the proto-Y-chromosome should lead to conformational changes that are responsible for successive silencing of euchromatic genes, both intact or already mutated ones and eventually transform functionally euchromatic domains into genetically inert heterochromatin. Accumulation of further mutations, deletions, and duplications followed by the evolution and expansion of tandem repetitive sequence motifs of high copy number (satellite sequences) together with a few vital genes for male fertility will then represent the final state of the degenerated Y chromosome.
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    URL: http://dx.doi.org/10.1023/A:1026584016524
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    Reciprocal chromosome painting illuminates the history of genome evolution of the domestic cat, dog and human (2000)
    Springer
    Chromosome research 8 (2000), S. 393-404 
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    ISSN: 1573-6849
    Keywords: cat ; chromosome painting ; comparative mapping ; dog ; evolution ; human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Domestic cats and dogs are important companion animals and model animals in biomedical research. The cat has a highly conserved karyotype, closely resembling the ancestral karyotype of mammals, while the dog has one of the most extensively rearranged mammalian karyotypes investigated so far. We have constructed the first detailed comparative chromosome map of the domestic dog and cat by reciprocal chromosome painting. Dog paints specific for the 38 autosomes and the X chromosomes delineated 68 conserved chromosomal segments in the cat, while reverse painting of cat probes onto red fox and dog chromosomes revealed 65 conserved segments. Most conserved segments on cat chromosomes also show a high degree of conservation in G-banding patterns compared with their canine counterparts. At least 47 chromosomal fissions (breaks), 25 fusions and one inversion are needed to convert the cat karyotype to that of the dog, confirming that extensive chromosome rearrangements differentiate the karyotypes of the cat and dog. Comparative analysis of the distribution patterns of conserved segments defined by dog paints on cat and human chromosomes has refined the human/cat comparative genome map and, most importantly, has revealed 15 cryptic inversions in seven large chromosomal regions of conserved synteny between humans and cats.
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    URL: http://dx.doi.org/10.1023/A:1009210803123
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    Aquarium Maintenance of Reef Octocorals Raised from Field Collected Larvae (2000)
    Springer
    Aquarium sciences and conservation 2 (2000), S. 227-236 
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    ISSN: 1573-1448
    Keywords: aquarium ; conservation ; Eilat ; planula larvae ; soft corals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of standardized and sustainable aquaculture techniques for the cultivation of marine organisms offers many advantages: it would help reduce the quantity of living material harvested from coral reefs; it could be used as an efficient means of rehabilitating impoverished reef ecosystems (e.g. by reseeding depleted natural stocks of corals); it would provide an educational and research tool for the intensive study of marine animal biology under controlled laboratory conditions. Here, we present the results of aquarium maintenance of 3 Red Sea soft coral species (Clavularia hamra, Nephthea sp., Litophyton arboreum) raised from field collected larvae. Planulae settlement was enhanced when dead coral fragments and stones freshly collected from the sea were added to the settlement dishes. Young colonies (n=106, 258, 60; respectively) were monitored for 307, 475 and 207 days, respectively. The survival rate at the end of the observations ranged between 17% and 30%. Growth rates of colonies differed and showed species-specific variations. The most successful growth was recorded in Nephthea where the average colony size reached 324.5 polyps. Current aquaculture techniques for alcyonarian corals not only reveal that these organisms can thrive in aquaria but also provide significantly improved yields of colonies, as compared with yields under field conditions. Our studies have shown that various steps involved in the cultivation of young corals in captivity may need to be specifically tailored to suit the coral species in question.
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    URL: http://dx.doi.org/10.1023/A:1009627313037
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    Preliminary success in closing the life cycle of exploited seahorse species, Hippocampus spp., in captivity (2000)
    Springer
    Aquarium sciences and conservation 2 (2000), S. 179-196 
    Details
    ISSN: 1573-1448
    Keywords: seahorses ; Hippocampus ; conservation ; trade ; husbandry ; aquaculture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The trade in seahorses for aquarium fishes is contributing to the depletion of many wild populations of these animals. Many seahorses are sold to replace those that have died in captivity as a result of husbandry problems. It can be particularly difficult to rear the young seahorses, because of their need for varied live food and their vulnerability to disease. We here report a pilot study on rearing broods from males of three species (H. fuscus, H. barbouri, and H. kuda) that had mated in the wild and gave birth in captivity. The new-born seahorses were fed an initial diet of enriched Artemia until 7 days, after which copepods were added to the diet. From 5 weeks, frozen mysids were gradually phased in to replace both other food items. Scrupulous hygiene was maintained. We achieved 100% survival of the partial broods we reared for all three species and achieved life cycle closure in two of these during the experimental period. Of the three species, H. kuda grew to be largest and longest, and H. barbouri grew least. However, H. kuda were the slowest to mature and reproduce while H. fuscus (intermediate in growth) were the fastest. Techniques used in this work should be more generally applicable, both for aquarium husbandry and for small-scale aquaculture to help provide alternative incomes for small-scale fishers who are otherwise dependent on catching wild seahorses.
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    URL: http://dx.doi.org/10.1023/A:1009629130932
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    Ex situ Culture of Colonial Marine Ornamental Invertebrates: Concepts for Domestication (2000)
    Springer
    Aquarium sciences and conservation 2 (2000), S. 237-250 
    Details
    ISSN: 1573-1448
    Keywords: aquarium industry ; conservation ; coral reef ; domestication ; marine ornamental invertebrates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The worldwide market for ornamental saltwater invertebrates supplies the needs of millions of aquarium hobbyists, as well as for public exhibition (zoos, aquaria), universities, and research institutions. The large-scale continuous collection of marine organisms is responsible, in many places, for the destruction of habitats, including coral reefs. The perceived expansion of the animal trade further threatens these fragile habitats. In the present paper, several concepts for the domestication of marine ornamental invertebrates (mainly colonial species) are discussed, offering an alternative commercial approach. The major rationale is based on future ex situ propagation, not field collections; a strategy aimed to circumvent the need for wild-harvested animals. This strategy is based on: (1) collection, settlement and metamorphosis of large numbers of larvae from marine organisms or of naturally shed germ cells under aquarium conditions, where survivorship exceeds several orders of magnitude than that in nature; (2) fragmentation of very small pieces (such as the size of a single polyp in colonial corals or blood vessel ampullae in tunicates) for the production of new colonies; (3) the development of replicates and inbred-lines from chosen ornamental species; (4) the use of cryopreservation of larvae and germ cells which will support the supply of material year-round; (5) several concepts for husbandry methods. Some benefits and deficiencies associated with the strategy for ex situ cultures are discussed, revealing its importance to the future of the trade.
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    URL: http://dx.doi.org/10.1023/A:1009664907098
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    Plant Secondary Compounds and Grasshoppers: Beyond Plant Defenses (2000)
    Springer
    Journal of chemical ecology 26 (2000), S. 1773-1794 
    Details
    ISSN: 1573-1561
    Keywords: Grasshoppers ; polyphagy ; graminivory ; evolution ; secondary compound ; peritrophic envelope ; midgut ceca ; learning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Modern grasshoppers probably evolved from polyphagous ancestors endowed with the ability to tolerate many plant secondary compounds. This tolerance involves various behavioral and anatomical adaptations. Polyphagous grasshoppers have a relatively low level of sensitivity to the taste of many secondary compounds, and, if they do respond to the taste, have the capacity to habituate. This gives time for the induction of detoxifying enzymes so that unpalatable but potentially nutritious plants may be eaten safely. Associative learning involving secondary compounds may be important in food aversion learning, enabling the insects to avoid foods that have inappropriate nutrients, for example. Learning is also involved when grasshoppers develop associations between the taste of chemicals in the surface waxes of plants and internal leaf chemistry, enabling them to make faster decisions about the acceptability of a plant. Anatomically, the midgut ceca of polyphagous grasshoppers have well-developed posterior arms, and it is possible that these are especially important in detoxification, while some species, in addition, have a specialized pocket region in which macromolecules accumulate to be eliminated from the body when the lining of peritrophic envelope is drawn out. Polyphagous species also have thick peritrophic envelopes to which various phenolics become adsorbed. Finally, the midgut environment contains surfactants that reduce tannin–protein complexing except at very high tannin concentrations. Some polyphagous species can utilize secondary compounds as defensive substances or, in one case, in cuticular sclerotization. Grass feeding has evolved on numerous occasions from these polyphagous ancestors, and it has been associated with a loss of many of the characters providing protection from secondary compounds.
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    A System of Two Polymerases – A Model for the Origin of Life (2000)
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    Origins of life and evolution of the biospheres 30 (2000), S. 459-466 
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    ISSN: 1573-0875
    Keywords: biogenesis ; biological ; coevolution ; evolution ; models ; origin of life
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract What was the first living molecule – RNA or protein?This question embodies the major disagreement instudies on the origin of life. The fact that incontemporary cells RNA polymerase is a protein andpeptidyl transferase consists of RNA suggests theexistence of a mutual catalytic dependence betweenthese two kinds of biopolymers. I suggest that thisdependence is a `frozen accident', a remnant from thefirst living system. This system is proposed to be acombination of an RNA molecule capable of catalyzingamino acid polymerization and the resulting proteinfunctioning as an RNA-dependent RNA polymerase. Thespecificity of the protein synthesis is thought to beachieved by the composition of the surrounding mediumand the specificity of the RNA synthesis – by Watson– Crick base pairing. Despite its apparent simplicity,the system possesses a great potential to evolve intoa primitive ribosome and further to life, as it isseen today. This model provides a possible explanationfor the origin of the interaction between nucleicacids and protein. Based on the suggested system, Ipropose a new definition of life as a system ofnucleic acid and protein polymerases with a constantsupply of monomers, energy and protection.
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    Phylogenetic analysis of newly described Neosartorya species (2000)
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    Antonie van Leeuwenhoek 77 (2000), S. 235-239 
    Details
    ISSN: 1572-9699
    Keywords: Aspergillus section Fumigati ; β-tubulin gene ; evolution ; phylogenetic analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Isolates representing newly described Neosartorya species, and isolates with abnormal morphologies from Aspergillus section Fumigati were examined by phylogenetic analysis of sequences of part of their β-tubulin gene. Phylogenetic analyses supported the earlier suggestions that heterothallism is a derived character, and that sexuality was lost several times during the evolution of Aspergillus section Fumigati. The heterothallic N. fennelliae and N. udagawae strains were found to be closely related to the homothallic Neosartorya sp. NRRL 4179 and N. aureola, respectively. Aspergillus sp. FRR 1266, which was earlier described as a variant of A. fumigatus, was found to be closely related to A. viridinutans. Another abnormal asexual isolate was found to be closely related to A. fumigatus and N. fischeri. Phylogenetic relationships among newly described Neosartorya species and other taxa were successfully established based on phylogenetic analysis of β-tubulin sequences.
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    Geographical perspectives on Polish tourism (2000)
    Springer
    GeoJournal 50 (2000), S. 173-179 
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    ISSN: 1572-9893
    Keywords: conservation ; employment ; leisure ; Lower Silesia ; Poland ; recreation ; regulation ; tourism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract Like other sectors of the Polish economy, the tourist industry is going through a radical restructuring process which began at the start of the 1990s and reached a new stage with the 1998 Tourist Services Act. The business is now firmly market-oriented and standards are being set in line with EU norms. Tourism is of great importance for Poland because, through the promotion of attractive natural and cultural landscapes of international importance, it plays a central role in the search for a more sustainable economy and it also enhances the potential for development in many of the country's poorer regions. Employment in the industry is increasing both relatively and absolutely. This paper examines the opportunities with particular reference to Lower Silesia where the tourism potential offers an important approach to the solution of the region's economic and social problems. Particular reference is made to the refurbishment of historic buildings for tourist use and the significance of the restoration of Krobielowice Palace near Wroclaw is fully evaluated.
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    Shifting Cultivation and Conservation of Biological Diversity in Tripura, Northeast India (2000)
    Springer
    Human ecology 28 (2000), S. 605-629 
    Details
    ISSN: 1572-9915
    Keywords: shifting cultivation ; biological diversity ; conservation ; Northeast India ; Tripura
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Ethnic Sciences
    Notes: Abstract Shifting cultivation (jhooming) has been identified as one of the main human impacts influencing biodiversity in Tripura, Northeast India. Over the last few years a new class of shifting cultivators has emerged that has adopted non-traditional forms of jhooming, which have been responsible for the loss of biological diversity in the state. This paper describes the successes achieved by the state government in providing the jhumias (tribes practicing jhooming) with various non-jhooming options. Recommendations include the need for short and long term control measures, improvement of existing jhooming methods, and integration of traditional knowledge with new practices.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026491831856
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  • 89
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    Romania's Apuseni Mountains: Safeguarding a cultural heritage (2000)
    Springer
    GeoJournal 50 (2000), S. 285-304 
    Details
    ISSN: 1572-9893
    Keywords: accessibility ; conservation ; cultural landscape ; demography ; light industry ; rural planning ; rural settlement ; tourism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract The Apuseni Mountains are unusual on account of the extreme fragmentation of the settlement pattern particularly in the upper Aries valley. Not only is hamlet settlement very much the rule, but these small units of settlement may be quite widely separated from each other by distance and altitude. Such networks have evolved through clearance of the high surfaces which cannot be efficiently farmed from the valleys in which modern infrastructure has been concentrated over the last century. Important questions therefore arise with regard to the survival capacity of communities which are critical elements in a cultural landscape that constitutes a valuable resource for both Romania and Europe. In other parts of the region dispersal is not so extreme, but there are still depopulation tendencies which are potentially damaging for the cultural landscape. The paper examines the lifestyles associated with outlying settlements and the extent to which centralising tendencies have been resisted in recent times. In the context of the present transition it considers the actions being considered to safeguard fragile mountain communities in a vulnerable area exposed to growing commercial penetration associated with cross-border cooperation on the Hungarian- Romanian frontier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007170018729
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  • 90
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    Environmental economics of the Khangchendzonga National Park in the Sikkim Himalaya, India (2000)
    Springer
    GeoJournal 50 (2000), S. 329-337 
    Details
    ISSN: 1572-9893
    Keywords: contingent valuation ; bidding game ; biodiversity ; protected areas ; conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract A contingent valuation survey was conducted involving local community members, domestic and foreign visitors to estimate the environmental economics of the Khangchendzonga National Park and to elicit their willingness-to-pay (WTP) for its maintenance and conservation. Using a random survey, the average WTP was US$ 8.84 for foreign visitors per visit, followed by US$ 6.20 per household per year by local community members and US$ 1.91 per domestic visitor per visit for improvement in environmental conservation. The WTP was strongly influenced by age, education and income. The present study demonstrated that the contingent valuation method (CVM) is a promising approach, however it lacks inclusion of non-monetary contributions. The WTP for environmental management by the local communities was mostly in kind or time for services. The CVM can be a useful tool for decision-makers regarding investment and policy purposes for management of biodiversity hot spots and protected areas in developing countries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011032813319
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  • 91
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    Policies for rural Eastern Europe in transition: The case of Slovakia (2000)
    Springer
    GeoJournal 50 (2000), S. 235-247 
    Details
    ISSN: 1572-9893
    Keywords: conservation ; cross-border cooperation ; land use ; regional development ; restructuring ; rural development ; rural policies ; small and medium sized enterprises
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract After losing much of their demographic vitality under communism, rural areas of Eastern Europe are now handicapped by greatly reduced commuting opportunities and by a lack of foreign investment in the countryside. Although restitution and privatisation has placed much of the land under the control of private farmers, there is a need to modernise agriculture and rural infrastructure generally and also to increase the scope for pluriactivity. At the same time, functional links with the towns must be restored through a growth of employment linked with the central place system. Despite the importance of private enterprise under the conditions of a market economy, the government must take a lead and this paper deals with initiatives taken in rural Slovakia to mobilise the human resources of the countryside. The paper is heavily oriented towards research by the geographers at Nitra who have been much involved with the transformation of their local area. It is evident that while there has been no shortage of ideas, progress has been limited on account of low investment and the tensions associated with a series of three Meciar governments which have dominated Slovak politics through the 1990s.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007149431025
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  • 92
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    Characterization of the Porphyridium cruentum Chl a-binding LHC by in vitro reconstitution: LHCaR1 binds 8 Chl a molecules and proportionately more carotenoids than CAB proteins (2000)
    Springer
    Photosynthesis research 63 (2000), S. 85-96 
    Details
    ISSN: 1573-5079
    Keywords: chlorophyll a ; Chl a-binding protein ; evolution ; light-harvesting complex ; LHC I ; Porphyridium cruentum ; reconstitution ; red alga ; zeaxanthin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Porphyridium cruentum light harvesting complex (LHC) binds Chl a, zeaxanthin and β-carotene and comprises at least 6 polypeptides of a multigene family. We describe the first in vitro reconstitution of a red algal light-harvesting protein (LHCaR1) with Chl a/carotenoid extracts from P. cruentum. The reconstituted pigment complex (rLHCaR1) is spectrally similar to the native LHC I, with an absorption maximum at 670 nm, a 77 K fluorescence emission peak at 677 nm (ex. 440 nm), and similar circular dichroism spectra. Molar ratios of 4.0 zeaxanthin, 0.3 β-carotene and 8.2 Chl a per polypeptide for rLHCaR1 are similar to those of the native LHC I complex (3.1 zeaxanthin, 0.5 β-carotene, 8.5 Chl a). The binding of 8 Chl a molecules per apoprotein is consistent with 8 putative Chl-binding sites in the predicted transmembrane helices of LHCaR1. Two of the putative Chl a binding sites (helix 2) in LHCaR1 were assigned to Chl b in Chl a/b-binding (CAB) LHC II [Kühlbrandt et al. (1994) Nature 367: 614–21]. This suggests either that discrimination for binding of Chl a or Chl b is not very specific at these sites or that specificity of binding sites evolved separately in CAB proteins. LHCaR1 can be reconstituted with varying ratios of carotenoids, consistent with our previous observation that the carotenoid to Chl ratio is substantially higher in P. cruentum grown under high irradiance. Also notable is that zeaxanthin does not act as an accessory light-harvesting pigment, even though it is highly likely that it occupies the position assigned to lutein in the CAB LHCs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006357107247
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  • 93
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    Population diversity of the Vicia sativa agg. (Fabaceae) in the flora of the former USSR deduced from RAPD and seed protein analyses (2000)
    Springer
    Genetic resources and crop evolution 47 (2000), S. 171-183 
    Details
    ISSN: 1573-5109
    Keywords: evolution ; genetic resources ; RAPDs ; seed protein electrophoresis ; taxonomy ; Vicia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The genetic diversity of 58 wild and weedy populations representing taxa within the V. sativa aggregate from the former USSR, 4 cultivars of V. sativa, 2 accessions of V. cordata and 3 accessions of V. macrocarpa from Mediterranean countries were analysed using randomly amplified DNA fragments (RAPDs) and seed protein electrophoresis (SDS-PAGE). Interspecific variation between taxa in the V. sativa aggregate could readily be detected using both techniques. RAPDs and seed protein patterns were found to be an effective means of identifying accessions that cannot be identified clearly by morphological criteria alone. RAPD and seed protein analysis revealed a clear relationship between observed genetic variation of populations and their geographical distribution. Populations from each region had their own gene pools. Geographical variation was detected in V. segetalis. The degree of genetic divergence between local populations was usually related to proximity. In several locations where wild and weedy populations of different V. sativa agg. taxa grow sympatrically, intermediate forms could be detected at the DNA and protein levels. Both RAPD and seed protein analysis support the view that the V. sativa aggregate consists of 8 taxa warranting recognition at the species level. Several species in this aggregate are evolving intra-specific groups which can readily be detected at the molecular level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008756420011
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  • 94
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    In vitro storage of Eucalyptus grandis germplasm under minimal growth conditions (2000)
    Springer
    Plant cell, tissue and organ culture 61 (2000), S. 161-164 
    Details
    ISSN: 1573-5044
    Keywords: alginate ; axillary buds ; conservation ; E. grandis ; forestry ; shoot cultures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Slow growth-storage, for up to 10 months, has been achieved for Eucalyptus grandis shoot cultures by either the addition of 10 mg l−1 abscisic acid to the growth medium or by the halving of nutrient supply (half MS) and removal of exogenous plant growth regulators. Reduction of light intensity or the addition of mannitol to the media were less effective in reducing growth rate. Isolated in vitro axillary buds encapsulated in calcium alginate and stored under low temperature and low light intensities survived for up to 3 months without loss in viability. Storage of such encapsulated fresh axillary buds at higher temperature resulted in a loss in viability. These methods have immediate applications to forestry breeding and clonal programs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006447506869
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  • 95
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    Application of individual growth and population models of Daphnia pulex to Daphnia magna, Daphnia galeata and Bosmina longirostris (2000)
    Springer
    Hydrobiologia 421 (2000), S. 141-155 
    Details
    ISSN: 1573-5117
    Keywords: cladocerans ; life history ; demography ; size structure ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Daphnia models for individual growth and population dynamics have been developed in the manner of models developed by Gurney, McCauley, Andersen and others. All or most of the earlier models were parameterized for Daphnia pulex; we have used the D. pulex model as a baseline model for other species of Daphnia such as magna, galeata and also Bosmina longirostris. Because of the lack of ample data for D. magna, D. galeata and B. longirostris, some of the physiological data had to be relied on the other species whose data were available and in some case calibrated. We were able to produce reasonable results for individual growth as well as population dynamics under the controlled laboratory conditions. Most of the results were compared with the available laboratory data for population as well as growth. All the simulations have been done under high and low food concentrations. The animals are assumed to be feeding on green algae (Chlamydomonas reinhardtti) under the laboratory conditions of 18–20°C. The continuous growth until the end of the life was observed in smaller B. longirostris, whereas rapid growth in the beginning and slower after the start of the reproduction was observed in Daphnia species. The smaller species matured earlier than larger species. B. longirostris population sustained better than Daphnia species in medium food concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003955308697
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  • 96
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    The development of integrated methods for assessing river conservation value (2000)
    Springer
    Hydrobiologia 422-423 (2000), S. 413-428 
    Details
    ISSN: 1573-5117
    Keywords: rivers ; conservation ; integrated ; evaluation ; SERCON
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In recent years the conceptual barriers between river `management' and river `conservation' have begun to erode. As the environmental aspirations of water managers and conservationists broaden, there is a need for integrated methods of conservation assessment which can be of value to both groups. This paper considers the requirements inherent in such methods, and explores some of the problems in their design, using for illustration the development of SERCON (System for Evaluating Rivers for Conservation) in the UK. The design of integrated assessment methods, including the selection of attributes for evaluation, must be closely related to the objectives of any conservation activity. For example, selecting a representative series of rivers for statutory protection may require more focused assessment techniques than those needed for setting river conservation management objectives. In the European Union, the Habitats Directive provides a good example of the former approach, in which specific river types and species listed in the Directive must be evaluated for selecting Special Areas of Conservation. In contrast, the forthcoming Water Framework Directive will need to rely on a more comprehensive method of integrated assessment to ensure that `good ecological quality' can be reliably defined, monitored and maintained. Attempts at developing integrated conservation assessment methods need to address six main issues: (i) differences in perception of conservation `value'; (ii) defining conservation criteria (such as `naturalness'), many of which are to an extent subjective; (iii) establishing weighting systems to differentiate important from less important conservation features; (iv) ensuring that methods are rigorous and consistent; (v) the need for extensive datasets to allow comprehensive assessment; and (vi) providing clear guidance on interpreting the outputs. This paper illustrates these problems using experience gained in the UK. It concludes that the inevitable search for pragmatism should not detract from the need for an inclusive approach to river conservation assessment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017054908152
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  • 97
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    Ecology of the River Dolphin (Platanista gangetica) in the Upper Brahmaputra (2000)
    Springer
    Hydrobiologia 430 (2000), S. 97-111 
    Details
    ISSN: 1573-5117
    Keywords: Brahmaputra river ; hydrology ; aquafauna ; fishes ; river dolphin ; conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract There are nearly 200 species of aquatic vertebrates, almost exclusively fishes, in the Brahmaputra River System. This faunal composition includes not only a wide variety of food-fishes, but also about 50 varieties of aquarium fishes. The most spectacular animal in the Brahmaputra is undoubtedly the river dolphin, Platanista gangetica. The population of many species, particularly of the dolphin, is in steady decline. River dolphins, mostly juveniles, often entangle themselves in gill and drift nets, while feeding on trapped fishes. Proper implementation of Indian Fisheries Act, especially a total ban on destructive nets and on killing of brooders and juveniles by explosives and poisoning should be strictly implemented. Poor communication facilities in remote riverbank areas and lack of funds are two important reasons for the slow progress of the conservation of river dolphin and this endangered species is now on the verge of extinction. The anthropogenic activities and their impact on the habitat of river dolphin are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004077215276
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  • 98
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    Alu Elements and the Human Genome (2000)
    Springer
    Genetica 108 (2000), S. 57-72 
    Details
    ISSN: 1573-6857
    Keywords: Alu ; evolution ; human specific ; polymorphism ; retroposition ; SINES ; 7SL RNA ; YAP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Aluinsertional elements, the most abundant class of SINEs in humans are dimeric sequences approximately 300 bp in length derived from the 7SL RNA gene. These sequences contain a bipartite RNA pol III promoter, a central poly A tract, a 3′ poly A tail, numerous CpG islands and are bracketed by short direct repeats. An estimated 500,000 to 1 × 106units are dispersed throughout the human haploid genome primarily in AT rich neighborhoods located within larger GC dense chromosomal regions via a mechanism known as retroposition. Retroposition activity of Aluelements is determined by both internal and flanking regulatory elements as well as distant genes affecting transcription or transcript stability. Aluelements impact the organization and expression of the human genome at many levels including the processes of recombination, transcription and translation. Twelve subfamilies of Aluare defined by distinct patterns of diagnostic base substitutions. Subfamilies may be classified as young, intermediate or old reflecting the time since the start of retroposition by their members. Some insertions of the youngest subfamilies are not yet fixed in the human species and represent polymorphic loci. Alus are excellent molecular markers for a variety of reasons. They aid in tracing the complex pattern of duplication and rearrangements that occurred during the evolution of primate genome. Unlike other mutations, Alusequences are rarely lost completely once retroposed, have a defined ancestral state and are free from homoplasy since independent and identical insertions are highly unlikely. Because of these characteristics, Alus are literally molecular fossils. Polymorphic Aluloci are especially useful in studies of human genetic diversity and in pedigree and forensicanalysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004099605261
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  • 99
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    The Reintroduction and Reinterpretation of the Wild (2000)
    Springer
    Journal of agricultural and environmental ethics 13 (2000), S. 144-165 
    Details
    ISSN: 1573-322X
    Keywords: Wild ; domestic ; animal ; conservation ; farming ; hunting ; tourism ; France
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Philosophy
    Notes: Abstract This paper is concerned with changing social representations of the ``wild,'' in particular wild animals. We argue that within a contemporary Western context the old agricultural perception of wild animals as adversarial and as a threat to domestication, is being replaced by an essentially urban fascination with certain emblematic wild animals, who are seen to embody symbols of naturalness and freedom. On closer examination that carefully mediatized ``naturalness'' may be but another form of domestication. After an historical overview of the human-animal, domestic-wild construction, an anthropological approach is used to interpret the social representation of wild animals held by different social actors – farmers, hunters, and tourists – within the context of an inhabited National Park, that of the Cévennes in south east France. Within the Park, the domestic and the wild, along with agriculture, hunting, conservation, re-introduced wild animals, and tourists co-habit. It is argued that changes in the representation of ``wildness'' may well be an important indicator ofchanges in the social representation of nature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009593919595
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  • 100
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    Biology and conservation of sturgeon and paddlefish (2000)
    Springer
    Reviews in fish biology and fisheries 10 (2000), S. 355-392 
    Details
    ISSN: 1573-5184
    Keywords: Acipenseriformes ; conservation ; paddlefish ; phylogeny ; sturgeon ; threatened status
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The Acipenseriformes (sturgeon and paddlefish)live in the Northern Hemisphere; half of thesespecies live in Europe, mostly in thePonto-Caspian region, one third in NorthAmerica, and the rest in East Asia and Siberia.They reproduce in freshwater and most of themmigrate to the sea, either living in brackishwater (Caspian, Azov, Black and Baltic Seas) orin full seawater on the oceanic continentalshelf. Most species feed on benthic organisms.Puberty usually occurs late in life (5–30 yearsof age) and adult males and females do notspawn on an annual basis. Adults continue togrow and some species such as the beluga (Huso huso) have reached 100 years of age andmore than 1,000 kg weight. Stocks of sturgeonsare dramatically decreasing, particularly inEurasia; the world sturgeon catch was nearly28,000 t in 1982 and less than 2,000 t by 1999.This decline resulted from overfishing andenvironmental degradation such as: accumulationof pollutants in sediments, damming of rivers,and restricting water flows, which becomeunfavorable to migration and reproduction.Several protective measures have beeninstituted; for example, fishing regulation,habitat restoration, juvenile stocking, and theCITES listing of all sturgeon productsincluding caviar. In addition, sturgeon farmingpresently yields more than 2,000 t per year(equivalent to wild sturgeon landings) andabout 15 t of caviar. Hopefully, thisartificial production will contribute to areduction of fishing pressure and lead to therehabilitation of wild stocks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012231526151
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