bluuebunny/crossref_metadata_2025 huggingface dataset:
Overfishing and the Common Fisheries Policy: (un)successful results from TAC regulation?
Authors: Villasante Sebastián , do Carme García‐Negro María , González‐Laxe Fernando , Rodríguez Gonzalo Rodríguez
Published: August 2010

This paper combines official data from 1990–2007 for (i) the Total Allowable Catchs (TACs) recommended by International Council for the Exploration for the Sea (ICES) scientists and the proposed and approved TACs and (ii) biomass, recruitment, catches, fishing effort, and current exploitation rates for all marine populations subjected to TAC regulation. The differences between the fishing quotas and the scientific recommendations provided by the ICES were calculated to be 19% after the first CFP reform (1992–2001) and 21% after the second one (2002–2008). In some species, these differences showed a three‐fold increase, in particular those currently considered to be beyond the biological safety limits.

Regarding the most important index of abundance, the results also indicate a biomass and recruitment reduction of ∼75–85% of the stocks and 90% of catches, whereas the fishing mortality increased in 35% of stocks. In addition, of all populations analysed under TAC regulation, 20% presents an increase in the current exploitation rate, 17% did not show significant changes, and the remaining 63% presented a reduction between 1990 and 2007. These results could contribute to the recovery of stocks. However, following the methodology used by Worm et al. who reported that 6 out of the 10 (60%) marine ecosystems examined showed current exploitation rate values that were significantly higher than those that provide the maximum sustainable yield, this study demonstrates that 86% of the populations regulated by TACs present values higher than exploitation rates that give maximum sustainable yield, following an alarming pattern of exploitation.
Production of biologically active recombinant human factor H in Physcomitrella
Authors: Büttner‐Mainik Annette , Parsons Juliana , Jérôme Hanna , Hartmann Andrea , Lamer Stephanie , Schaaf Andreas , Schlosser Andreas , Zipfel Peter F. , Reski Ralf , Decker Eva L.
Published: August 2010

The human complement regulatory serum protein factor H (FH) is a promising future biopharmaceutical. Defects in the gene encoding FH are associated with human diseases like severe kidney and retinal disorders in the form of atypical haemolytic uremic syndrome (aHUS), membranoproliferative glomerulonephritis II (MPGN II) or age‐related macular degeneration (AMD). There is a current need to apply intact full‐length FH for the therapy of patients with congenital or acquired defects of this protein. Application of purified or recombinant FH (rFH) to these patients is an important and promising approach for the treatment of these diseases. However, neither protein purified from plasma of healthy individuals nor recombinant protein is currently available on the market. Here, we report the first stable expression of the full‐length human FH cDNA and the subsequent production of this glycoprotein in a plant system. The moss Physcomitrella patens perfectly suits the requirements for the production of complex biopharmaceuticals as this eukaryotic system not only offers an outstanding genetical accessibility, but moreover, proteins can be produced safely in scalable photobioreactors without the need for animal‐derived medium compounds. Transgenic moss lines were created, which express the human FH cDNA and target the recombinant protein to the culture supernatant via a moss‐derived secretion signal. Correct processing of the signal peptide and integrity of the moss‐produced rFH were verified via peptide mapping by mass spectrometry. Ultimately, we show that the rFH displays complement regulatory activity comparable to FH purified from plasma.
The production of artemisinin precursors in tobacco
Authors: Zhang Yansheng , Nowak Goska , Reed Darwin W. , Covello Patrick S.
Published: August 2010

Artemisinin, in the form of artemisinin‐based combination therapies (ACTs), is currently the most important compound in the treatment of malaria. The current commercial source of artemisinin is Artemisia annua, but this represents a relatively expensive source for supplying the developing world. In this study, the possibility of producing artemisinin in genetically modified plants is investigated, using tobacco as a model. Heterologous expression of A. annua amorphadiene synthase and CYP71AV1 in tobacco led to the accumulation of amorphadiene and artemisinic alcohol, but not artemisinic acid. Additional expression of artemisinic aldehyde Δ11(13) double‐bond reductase (DBR2) with or without aldehyde dehydrogenase 1 (ALDH1) led to the additional accumulation dihydroartemisinic alcohol. The above‐mentioned results and in vivo metabolic experiments suggest that amorphane sesquiterpenoid aldehydes are formed, but conditions in the transgenic tobacco cells favour reduction to alcohols rather than oxidation to acids. The biochemical and biotechnological significance of these results are discussed.
Use of doubled haploid technology for development of stable drought tolerant bread wheat (Triticum aestivum L.) transgenics
Authors: Chauhan Harsh , Khurana Paramjit
Published: August 2010

Anther culture–derived haploid embryos were used as explants for Agrobacterium‐mediated genetic transformation of bread wheat (Triticum aestivum L. cv CPAN1676) using barley HVA1 gene for drought tolerance. Regenerated plantlets were checked for transgene integration in T0 generation, and positive transgenic haploid plants were doubled by colchicine treatment. Stable transgenic doubled haploid plants were obtained, and transgene expression was monitored till T4 generation, and no transgene silencing was observed over the generations. Doubled haploid transgenic plants have faster seed germination and seedling establishment and show better drought tolerance in comparison with nontransgenic, doubled haploid plants, as measured by per cent germination, seedling growth and biomass accumulation. Physiological evaluation for abiotic stress by assessing nitrate reductase enzyme activity and plant yield under post‐anthesis water limitation revealed a better tolerance of the transgenics over the wild type. This is the first report on the production of double haploid transgenic wheat through anther culture technique in a commercial cultivar for a desirable trait. This method would also be useful in functional genomics of wheat and other allopolyploids of agronomic importance.
Developmentalities and Calculative Practices: The Millennium Development Goals
Authors: Ilcan Suzan , Phillips Lynne
Published: August 2010

Abstract:  This paper focuses on wide‐ranging governmental discourses that enable new ways of shaping social and economic affairs in the field of development. Directing particular attention to the Millennium Development Goals, we refer to these discourses as developmentalities. As a form of governmentality produced through these Goals, developmentalities draw on the turn of the century to recast certain development problems and offer reformulated solutions to these problems. We argue that they rely on three forms of neoliberal rationalities of government—information profiling, responsibilization, and knowledge networks, and their calculative practices, to shape global spaces and new capacities for individuals and social groups. Our analysis is based on extensive policy documents, reports, and development initiatives affiliated with the United Nations and other organizations, as well as insights derived from in‐depth interviews and conversations with United Nations policy and research personnel from the Food and Agricultural Organization (FAO) and the United Nations Educational, Scientific, and Cultural Organization (UNESCO).
Smoke and Mirrors: Inverting the Discourse on Tobacco
Authors: Waterstone Marv
Published: August 2010

Abstract:  Understanding the mechanisms that construct and maintain the taken‐for‐granted, “common sense” understandings of everyday life is an essential prerequisite for reconfiguring conditions in more progressive directions. Highlighting particular moments, when these processes can be made visible, and drawing appropriate insights from such interrogations is useful not only for illuminating the fundamental malleability of “common sense” (itself a crucial element of change), but also for providing suggestive strategies and tactics for effectuating change. Here the construction and reconstruction of the “common sense” around tobacco is offered as an instructive case.
Antagonism, Neo‐liberalism and Movements: Six Impossible Things Before Breakfast
Authors:   The Free Association
Published: August 2010

Abstract:  The “movement of movements” has reached an impasse, from which innovation and expansion appear out of reach. Given these circumstances a re‐examination of concepts such as antagonism and class hatred might be timely. Antagonism has never disappeared. It is present in climate‐change politics as much as in those of the Black Bloc—both examples we discuss here. Indeed antagonism permeates capitalism and drives capitalist development. But a politics founded purely on antagonism quickly comes up against its own limits. The transformative power of love—whilst simultaneously coupled in productive tension with antagonism—offers the possibility of exodus.
Royal Patronage and the Earls in the Reign of Edward I
Authors: SPENCER ANDREW M.
Published: August 2010

Despite his reputation as one of the most successful English monarchs of the middle ages, Edward I has never been seen as a generous king. This article looks afresh at the accepted view of Edward I as a miserly king and, by examining his relationship with his earls, seeks to demonstrate that Edward had a sophisticated and judicious approach to patronage which was based upon rewarding good service. The article attempts to place Edward I's patronage in line with the later template of Edward III. In reassessing the judgements of K. B. McFarlane and M. C. Prestwich, the article reconsiders Edward's policy of land grants in England, Wales and Scotland, and also draws upon new material such as the king's grants of deer from the royal forests, charters of free warren and the remission of debts to the exchequer.
Narrow band UVB: is it effective and safe for paediatric psoriasis and atopic dermatitis?
Authors: Pavlovsky M , Baum S , Shpiro D , Pavlovsky L , Pavlotsky F
Published: August 2010

Background  Phototherapy has a time‐honoured place in the treatment of variety of skin diseases in adults. The use of this modality in children is limited mainly due to concerns about long‐term carcinogenic potential. Only a few clinical trials have been performed on the efficacy and safety of phototherapy in children.

Objectives  To determine the efficacy and safety of NB‐UVB phototherapy in children with atopic dermatitis (AD) and psoriasis.

Methods  This is a retrospective review of the treatment outcomes of 129 children with psoriasis and AD, who were treated with NB‐UVB between 1998 and 2006 at our institute.

Results  Fifty per cent of the psoriatic patients and 25% of patients with AD achieved clearance by the end of the treatment. NB‐UVB phototherapy was well‐tolerated, with no serious adverse effects except one doubtful case of melanoma in situ.

Conclusions  NB‐UVB may be considered as a viable therapeutic option in children with psoriasis and AD. Children who are treated by phototherapy should remain under annual dermatologic observation. To determine true carcinogenic risk of UV therapy, longer follow‐up is essential.
COLLOIDAL STRUCTURE AND ITS BIOLOGICAL SIGNIFICANCE1
Authors: LLOYD D. JORDAN
Published: August 2010

To sum up the evidence which we have considered here on the close relation between colloidal structure and biological function, we find that we pass over a series of possibilities. At the one end we get highly active tissues such as primitive connective tissue, growing tissues and generative cells. In these there is a high percentage of water, the percentage decreasing with age; the proteins are present as colloid sols, probably uni‐molecular, each molecule consisting of a back‐bone which is not highly hydrated, carrying at periodic intervals side chains or limbs which are of varied character, often lengthy and of complex chemical structure, highly polar, heavily hydrated and undoubtedly playing an important rôle in the metabolic activities of the cells. Next we get biologically inactive tissues such as mesenteries, tendons and skin, which are built up mainly of connective tissue fibres which have a skeletal but not a metabolic function. Here we find a low percentage of water and the protein molecules are arranged in a compact and orderly manner to form fibres; the backbone of the molecule is still the same, it is very little if at all hydrated and carries at periodic intervals the side chains or limbs, but these are now for the most part shorter and of a much simpler molecular structure, less polar, probably less hydrated and playing little if any part in any metabolic cycle. Finally, we get tissues such as the keratinous layer of the epidermis in animals, cellulose cell walls in plants, external fibres, such as wool and cotton hairs, internal fibres such as bast fibres. The biological function of these tissues is purely mechanical; chemical activity is not desired. Here the importance of the backbone of the colloid is paramount; the chemical potentialities of the limbs are of little significance and we find in these tissues, as might have been anticipated, compact, stable ring structures which leave very little space for the entry of water or any other disturbing molecule. In the animal world, these resistant fibres are protein; in the plant world carbohydrate. For biological stability either material is equally effective.
UNIT CHARACTERS IN FOSSILS
Authors: SWINNERTON H. H.
Published: August 2010

1. This article is concerned only with visible features, or unit characters, and not with the invisible factors which control their expression.

2. The methods used in establishing a gens are explained, and it is shown that well‐established gentes provide suitable material for the study of unit characters.

3. The work of Ford and Huxley upon Gammarus furnishes an invaluable link between the investigations of geneticists and those of palaeontologists.

4. For the palaeontologist the study of the behaviour of unit characters in development is fundamental. Peculiarities of such behaviour, long known to palaeontologists, are seen to characterise the development of such a typical Mendelian unit as that investigated by Ford and Huxley. It is inferred therefore that the two classes of units are comparable.

5. This inference is greatly strengthened by the fact that conclusions arrived at by Ford and Huxley concerning the relationship of certain Mendelian units to one another in holometabolous insects had already been independently expressed in palaeontological writings upon the same topic.

6. The correlation of the results of palaeontological and experimental methods of enquiry leads to the discovery of evidence that the terms “ mutation” and “transient” merely express different aspects of the behaviour of the same unit.

7. The distinction between a unit character and a combination of unit characters makes it possible to separate the elements of truth and error in the Theory of Recapitulation from one another.

8. It is suggested that parallelism between the behaviour of a character in development and in evolution is a corollary of the factorial hypothesis.
THE BIOLOGY OF LEPIDOPTERA INFESTING STORED PRODUCTS, WITH SPECIAL REFERENCE TO POPULATION DYNAMICS
Authors: BENSO1 J. F.
Published: August 2010

I. This review provides a background to those aspects of the biology and behaviour of Lepidoptera infesting stored products which may be important in terms of population dynamics.

2. The general biologies of four common species of Phycitid moth are described.

3. Both the fecundity and the fertility of the adult can be influenced by the diet of the female, the size of the female, the numbers of adults per unit area and a variety of environmental factors.

4. Egg mortality may be caused by sterility or cannibalism. Larval mortality may be caused by starvation or cannibalism. Crowding leads to emigration, reduced size and extended developmental period. Pupal and adult mortalities are of minor importance. Pupae may suffer developmental disorders and adults are killed by spiders and lost by emigration.

5. Parasitoids, predators and diseases, which also contribute to mortality of eggs, larvae, pupae and adults, are described.

6. The importance of planning and sampling in order to obtain detailed data on populations are discussed, together with the analysis of the data.

7. It is shown that Lepidoptera which infest stored products and the parasitoids associated with them have proved convenient experimental tools for the elucidation of certain aspects of population dynamics. A small number of studies have succeeded in identifying the main factors or processes responsible for fluctuation or regulation of the densities of these moths.
NON‐SHIVERING THERMOGENESIS AND ITS THERMOREGULATORY SIGNIFICANCE
Authors: JANSKý L.
Published: August 2010

1. Non‐shivering thermogenesis (NST) is a heat‐production mechanism participating in the chemical thermoregulation of mammals.

2. NST is additional to shivering and takes place at temperatures close to the thermoneutral zone.

3. NST occurs in newborn mammals and in those that hibernate. In some adult mammals it can be induced by adaptation to cold.

4. In small mammals NST produces approximately the same amount of heat as shivering. It becomes less important with increasing body weight of the animals.

5. NST is regulated by the hypothalamus and it is based predominantly on the calorigenic action of noradrenaline released from sympathetic nerve‐endings.

Participation of other calorigenic substances and of the specific dynamic action of food cannot be excluded.

6. NST is localized mainly in skeletal muscles and in brown adipose tissue. Small amounts of NST may come from liver, intestine, heart and brain.

7. The biochemical basis of the calorigenic action of noradrenaline has not yet been fully elucidated.
THE NATURAL HISTORY OF AMPHIBIAN SKIN SECRETIONS, THEIR NORMAL FUNCTIONING AND POTENTIAL MEDICAL APPLICATIONS
Authors: CLARKE B. T.
Published: August 2010

Amphibians occupy a wide range of habitat types from arid deserts to deep freshwater lakes; they may spend most of their life underground or high in cloud forest canopy. Some are found north of the Arctic Circle and can tolerate freezing conditions, while others have evolved a range of adaptations to avoid desiccation in some of the hotter areas of the world. The skin plays key roles in the everyday survival of amphibians and their ability to exploit a wide range of habitats and ecological conditions. The normal functions of the skin are surveyed and Eisner's biorational approach to chemical prospecting – seeking clues from an animal's behaviour and its interactions with its environment to reveal the presence of chemical compounds with potential medical or veterinary applications – is applied to amphibians. The biology and natural history of amphibian skin, its glands and their secretions are briefly reviewed. Four categories of compounds are found in the granular or poison glands, these are: biogenic amines, bufodienolides (bufogenins), alkaloids and steroids, peptides and proteins. Toads, particularly members of the genus Bufo, are identified as a particularly convenient and useful source of granular gland secretions. The potential medical‐pharmaceutical significance of products derived from amphibian skin secretions is discussed. The need for a humane approach to this work is noted.
THE RELATIONSHIP BETWEEN EVOLUTIONARY THEORY AND PHYLOGENETIC ANALYSIS
Authors: LEE MICHAEL S. Y. , DOUGHTY PAUL
Published: August 2010

The relationship between phylogenetic reconstruction and evolutionary theory is reassessed. It is argued here that phylogenies, and evolutionary principles, should be analysed initially as independently from each other as possible. Only then can they be used to test one another. If the phylogenies and evolutionary principles are totally consistent with one another, this consilience of independent lines of evidence increases confidence in both. If, however, there is a conflict, then one should assess the relative support for each hypothesis, and tentatively accept the more strongly supported one. We review examples where the phylogenetic hypothesis is preferred over the evolutionary principle, and vice versa, and instances where the conflict cannot be readily resolved. Because the analyses of pattern and process must initially be kept separate, the temporal order in which they are performed is unimportant. Therefore, the widespread methodology of always proceeding from cladogram to evolutionary ‘scenario’ cannot be justified philosophically. Such an approach means that cladograms cannot be properly tested against evolutionary principles, and that evolutionary ‘scenarios’ have no independent standing. Instead, we propose the ‘consilience’ approach where phylogenetic and evolutionary hypotheses are formulated independently from each other and then examined for agreement.
DEVELOPMENTAL STABILITY, DISEASE AND MEDICINE
Authors: THORNHILL RANDY , MØLLER ANDERS PAPE
Published: August 2010

Developmental stability reflects the ability of a genotype to undergo stable development of a phenotype under given environmental conditions. Deviations from developmental stability arise from the disruptive effects of a wide range of environmental and genetic stresses, and such deviations are usually measured in terms of fluctuating asymmetry and phenodeviants. Fluctuating asymmetry is the most sensitive indicator of the ability to cope with stresses during ontogeny. There is considerable evidence that developmental stability, and especially fluctuating asymmetry, is a useful measure of phenotypic and genetic quality, because it covaries negatively with performance in multiple fitness domains in many species, including humans. It is proposed that developmental stability is an important marker of human health. Our goal is to initiate formally the integration of the sciences of evolutionary biology, developmental biology and medicine. We believe that this integrative framework provides a significant addition to the growing field of Darwinian medicine. The literature linking developmental stability and disease in humans is reviewed. Recent biological theoretical treatments pertaining to developmental stability are applied to a range of human health issues such as genetic diseases, ageing and survival, subfertility, abortion, child maltreatment by parents, cancer, infectious diseases, physiological and mental health, and physical attractiveness as a health certification.
Origin and evolution of animal life cycles
Authors: NIELSEN CLAUS
Published: August 2010

The ‘origin of larvae’ has been widely discussed over the years, almost invariably with the tacit understanding that larvae are secondary specializations of early stages in a holobenthic life cycle.

Considerations of the origin and early radiation of the metazoan phyla have led to the conclusion that the ancestral animal (= metazoan) was a holopelagic organism, and that pelago‐benthic life cycles evolved when adult stages of holopelagic ancestors became benthic, thereby changing their life style, including their feeding biology.

The literature on the larval development and phylogeny of animal phyla is reviewed in an attempt to infer the ancestral life cycles of the major animal groups. The quite detailed understanding of larval evolution in some echinoderms indicates that ciliary filter‐feeding was ancestral within the phylum, and that planktotrophy has been lost in many clades. Similarly, recent studies of the developmental biology of ascidians have demonstrated that a larval structure, such as the tail of the tadpole larva, can easily be lost, viz. through a change in only one gene. Conversely, the evolution of complex structures, such as the ciliary bands of trochophore larvae, must involve numerous genes and numerous adaptations.

The following steps of early metazoan evolution have been inferred from the review.

The holopelagic ancestor, blastaea, probably consisted mainly of choanocytes, which were the feeding organs of the organism. Sponges may have evolved when blastaea‐like organisms settled and became reorganized with the choanocytes in collar chambers.

The eumetazoan ancestor was probably the gastraea, as suggested previously by Haeckel. It was holopelagic and digestion of captured particles took place in the archenteron. Cnidarians and ctenophores are living representatives of this type of organization. The cnidarians have become pelago‐benthic with the addition of a sessile, adult polyp stage; the pelagic gastraea‐like planula larva is retained in almost all major groups, but only anthozoans have feeding larvae.

Within the Bilateria, two major lines of evolution can be recognized: Protostomia and Deuterostomia. In protostomes, trochophores or similar types are found in most spiralian phyla; trochophore‐like ciliary bands are found in some rotifers, whereas all other aschelminths lack ciliated larvae. It seems probable that the trochophore was the larval type of the ancestral, pelago‐benthic spiralian and possible that it was ancestral in all protostomes. Most of the non‐chordate deuterostome phyla have ciliary filter‐feeding larvae of the dipleurula type, and this strongly indicates that the ancestral deuterostome had this type of larva.
Can video images imitate real stimuli in animal behaviour experiments?
Authors: D'EATH RICHARD B.
Published: August 2010

The use of video images in place of natural stimuli in animal behaviour experiments is reviewed. Unlike most other artificial means of stimulus presentation, video stimuli can depict complex moving objects such as other animals, preserving the temporal and spatial patterns of movement precisely as well as colour and sounds for repeated playback. Computer editing can give flexibility and control over all elements of the stimulus. A variety of limitations of video image presentation are also considered. Televisions and video monitors are designed with human vision in mind, and some non‐human animals that differ in aspects of visual processing such as their colour vision, critical flicker‐fusion threshold, perception of depth and visual acuity, may perceive video images differently to ourselves. The failure of video stimuli to interact with subjects can be a drawback for some studies. For video to be useful, it is important to confirm that the subject animal responds to the image in a comparable way to the real stimulus, and the criteria used to assess this are discussed. Finally, the contribution made by video studies to date in the understanding of animal visual responses is considered, and recommendations as to the future uses of video are made.
Frugivory and seed dispersal by vertebrates in the Oriental (Indomalayan) Region
Authors: CORLETT RICHARD T.
Published: August 2010

Current knowledge of frugivory and seed dispersal by vertebrates in the Oriental Region is summarized. Some degree of frugivory has been reported for many fish and reptile species, almost half the genera of non‐marine mammals and more than 40% of bird genera in the region. Highly frugivorous species, for which fruit dominates the diet for at least part of the year, occur in at least two families of reptiles, 12 families of mammals and 17 families of birds. Predation on seeds in fleshy fruits is much less widespread taxonomically: the major seed predators are colobine monkeys and rodents among the mammals, and parrots, some pigeons, and finches among the birds. Most seeds in the Oriental Region, except near its northern margins, are dispersed by vertebrate families which are endemic to the region or to the Old World. Small fruits and large, soft fruits with many small seeds are consumed by a wide range of potential seed dispersal agents, including species which thrive in small forest fragments and degraded landscapes. Larger, bigger‐seeded fruits are consumed by progressively fewer dispersers, and the largest depend on a few species of mammals and birds which are highly vulnerable to hunting, fragmentation and habitat loss.
The dynamics of predation onGammarusspp. (Crustacea: Amphipoda)
Authors: MACNEIL CALUM , DICK JAIMIE T. A. , ELWOOD ROBERT W.
Published: August 2010

Gammarusspp. (Crustacea: Amphipoda) are widespread throughout a diverse range of marine, freshwater and estuarine/brackish habitats, often dominating benthic macroinvertebrate communities in terms of both numbers and/or biomass.Gammarusspp. are the dominant macroinvertebrate prey items of many fish, whether as a seasonal food source or a year‐round staple. Selective predation by fish onGammarusspp. is often linked to parasitism and the body size of the prey.Gammarusspp. populations are under increasing threat from both pollution and replacement/displacement by introduced species. Loss of populations and species invasions/replacements could have significant impacts on native predator species if the predator(s) cannot successfully adapt their feeding patterns to cope with non‐indigenousGammarusprey species. Despite this, many fish predation studies do not identifyGammarusprey to species level. This lack of precision could be important, asGammarusspp. exhibit wide variations in physiochemical tolerances, habitat requirements, abilities to invade and susceptibility to replacement. Although rarely acknowledged, the impacts of nonpiscean predators (particularly macroinvertebrates) onGammarusprey species may frequently be stronger than those exerted by fish. A major aim of this review is to ascertain the current importance ofGammarusas a prey species, such that the implications of changes inGammarusspp. populations can be more accurately assessed by interested groups such as ecologists and fisheries managers. We also review the dynamics ofGammarusspp. as prey to a diverse array of mammals, birds, amphibians, insects, flatworms, other crustaceans such as crabs and crayfish and, perhaps most importantly, otherGammarusspp.
Conodont affinity and chordate phylogeny
Authors: DONOGHUE PHILIP C. J. , FOREY PETER L. , ALDRIDGE RICHARD J.
Published: August 2010

Current information on the conodontsClydagnathus windsorensis(Globensky) andPromissum pulchrumKovács‐ Endrödy, together with the latest interpretations of conodont hard tissues, are reviewed and it is concluded that sufficient evidence exists to justify interpretation of the conodonts on a chordate model. A new phylogenetic analysis is undertaken, consisting of 17 chordate taxa and 103 morphological, physiological and biochemical characters; conodonts are included as a primary taxon. Various experiments with character coding, taxon deletion and the use of constraint trees are carried out. We conclude that conodonts are cladistically more derived than either hagfishes or lampreys because they possess a mineralised dermal skeleton and that they are the most plesiomorphic member of the total group Gnathostomata. We discuss the evolution of the nervous and sensory systems and the skeleton in the context of our optimal phylogenetic tree. There appears to be no simple evolution of free to canal‐enclosed neuromasts; organised neuromasts within canals appear to have arisen at least three times from free neuromasts or neuromasts arranged within grooves. The mineralised vertebrate skeleton first appeared as odontodes of dentine or dentine plus enamel in the paraconodont/euconodont feeding apparatus. Bone appeared later, co‐ordinate with the development of a dermal skeleton, and it appears to have been primitively acellular. Atubular dentine is more primitive than tubular dentine. However, the subsequent distribution of the different types of dentine (e.g. mesodentine, orthodentine), suggests that these tissue types are homoplastic. The topology of relationships and known stratigraphic ranges of taxa in our phylogeny predict the existence of myxinoids and petromyzontids in the Cambrian.
A critical reappraisal of the fossil record of the bilaterian phyla
Authors: BUDD GRAHAM E. , JENSEN SÖREN
Published: August 2010

It has long been assumed that the extant bilaterian phyla generally have their origin in the Cambrian explosion, when they appear in an essentially modern form. Both these assumptions are questionable. A strict application of stem‐ and crown‐group concepts to phyla shows that although the branching points of many clades may have occurred in the Early Cambrian or before, the appearance of the modern body plans was in most cases later: very few bilaterian phyla sensu stricto have demonstrable representatives in the earliest Cambrian. Given that the early branching points of major clades is an inevitable result of the geometry of clade diversification, the alleged phenomenon of phyla appearing early and remaining morphologically static is seen not to require particular explanation. Confusion in the definition of a phylum has thus led to attempts to explain (especially from a developmental perspective) a feature that is partly inevitable, partly illusory. We critically discuss models for Proterozoic diversification based on small body size, limited developmental capacity and poor preservation and cryptic habits, and show that the prospect of lineage diversification occurring early in the Proterozoic can be seen to be unlikely on grounds of both parsimony and functional morphology. Indeed, the combination of the body and trace fossil record demonstrates a progressive diversification through the end of the Proterozoic well into the Cambrian and beyond, a picture consistent with body plans being assembled during this time. Body‐plan characters are likely to have been acquired monophyletically in the history of the bilaterians, and a model explaining the diversity in just one of them, the coelom, is presented. This analysis points to the requirement for a careful application of systematic methodology before explanations are sought for alleged patterns of constraint and flexibility.
The grand game of metazoan phylogeny: rules and strategies
Authors: JENNER RONALD A. , SGHRAM FREDERICK R.
Published: August 2010

Many cladistic analyses of animal phylogeny have been published by authors arguing that their results are well supported. Comparison of these analyses indicates that there can be as yet no general consensus about the evolution of the animal phyla. We show that the various cladistic studies published to date differ significantly in methods of character selection, character coding, scoring and weighting, ground‐pattern reconstructions, and taxa selection. These methodological differences are seldom made explicit, which hinders comparison of different studies and makes it impossible to assess a particular phylogeny outside its own scope. The effects of these methodological differences must be considered before we can hope to reach a morphological reference framework needed for effective comparison and combination with the evidence obtained from molecular and developmental genetic studies.
Tunicate tails, stolons, and the origin of the vertebrate trunk
Authors: LACALLI THURSTON C.
Published: August 2010

Tunicates are primitive chordates that develop a transient ‘tail’ in the larval stage that is generally interpreted as a rudimentary version of the vertebrate trunk. Not all tunicates have tails, however. The groups that lack them, salps and pyrosomes, instead have a trunk‐like reproductive stolon located approximately where the tail would otherwise be. In salps, files of blastozooids are formed along the sides of the stolon. The tail and caudal trunk in more advanced chordates could have evolved from a stolon of this type, an idea referred to here as the ‘stolon hypothesis’. This means the vertebrate body could be a composite structure, since there is the potential for each somite to incorporate elements originally derived from a complete functional zooid. If indeed this has occurred, it should be reflected in some fashion in gene expression patterns in the vertebrate trunk. Selected morphological and molecular data are reviewed to show that they provide some circumstantial support for the stolon hypothesis. The case would be stronger if it could be demonstrated that salps and/or pyrosomes are ancestral to other tunicates. The molecular phylogenies so far available generally support the idea of a pelagic ancestor, but offer only limited guidance as to which of the surviving pelagic groups most closely resembles it. The principal testable prediction of the stolon hypothesis is that head structures (or their homologues) should be duplicated in series in the trunk in advanced chordates, andvice versa, i.e. trunk structures should occur in the head. The distribution of both rhabdomeric photoreceptors and nephridia in amphioxus conform with this prediction. Equally striking is the involvement of thePax2gene in the development of both the inner ear and nephric ducts in vertebrates. The stolon hypothesis would explain this as a consequence of the common origin of otic capsules and excretory ducts from atrial rudiments: from the paired rudiments of the parent oozooid in the case of the otic capsule (these expressPax2according to recent ascidian data), and from tubular rudiments in the stolon in the case of the excretory ducts.
Ovoviviparity and viviparity in the Diptera
Authors: MEIER RUDOLF , KOTRBA MARION , FERRAR PAUL
Published: August 2010

The taxonomic distribution and evolution of viviparity in Diptera is critically reviewed. The phenomenon ranges from ovoviviparity (eggs deposited at an advanced stage of embryonic development; larva emerges immediately after deposition), through viviparity (larva hatches inside female before deposition) to pupiparity (offspring deposited as pupa). Some Diptera are known to be facultatively viviparous, which is hypothesized to be a step towards the evolution of obligate viviparity. Obligate viviparity is found to comprise unilarviparity (single large larva in maternal uterus) which evolved many times independently, the rare oligolarviparity (more than one but not more than 12 larvae) and multilarviparity (large numbers of developing eggs or larvae in uterus) which is typical for the two largest clades of viviparous Diptera. Unilarviparity is either lecithotrophic (developing larva nourished by yolk of egg) or pseudo‐placental (larva nourished by glandular secretions of mother). Viviparity has clearly evolved on many separate occasions in Diptera. It is recorded in 22 families, and this review identifies at least 61 independent origins of viviparity. Six families appear to have viviparity in their ground‐plan. Some families have a single evolution of viviparity, others multiple evolutions. Guimaraes' model for the evolution of viviparity in Diptera is tested against phylogenetic information and the adaptive significance of viviparity is reviewed in detail. Possible correlations with life‐history parameters (coprophily, parasitism, breeding in ephemeral plant parts, malacophagy and adult feeding habits – especially haematophagy) are analysed critically, as are potential advantages (shorter larval life, less investment in yolk by mother, protection of vulnerable stages, better access to breeding substrates, predation on competitors). Morphological constraints, adaptations and exaptations are reviewed, including the provision of an incubation space for the egg(s), the positioning of the egg(s) in the uterus, and maternal glands. The main morphological adaptations include greater egg size, reduction of egg respiratory filaments, thinning of chorion, modified larval respiratory system and mouthparts, and instar skipping. Female morphology and behaviour is particularly strongly modified for viviparity. The terminalia are shortened, the vagina is more muscular and tracheated, and the ovaries of unilarviparous species have a reduced number of ovarioles with alternate ovulation. Many of the final conclusions are tentative, and a plea is made for more detailed morphological and experimental study of many of the viviparous species. Viviparity in Diptera provides a fascinating example of multiple parallel evolution, and a fertile field for future research.
The ethological analysis of imitation
Authors: MIKLÓSI ÁDÁM
Published: August 2010

Theorists and experimental researchers have long debated whether animals are able to imitate. A variety of definitions of imitation have been proposed to describe this complex form of social learning. Experimental research on imitation has often been hampered by either a too loose ‘anthropomorphic’ approach or by too narrow ‘behaviourist’ definitions. At present neither associative nor cognitive theories are able to offer an exhaustive explanation of imitation in animals. An ethological approach to imitation offers a different perspective. By integrating questions on function, mechanism, development and evolution one can identify possible directions for future research. At present, however, we are still far from developing a comprehensive theory of imitation.

A functional approach to imitation shows that, despite some evidence for imitative learning in food processing in apes, such learning has not been shown to be involved in the social transmission of either tool‐use skills or communicative signals. Recently developed procedures offer possible ways of clarifying the role of imitation in tool use and visual communication. The role of imitation in explorative play in apes is also investigated and the available data suggest that copying during play might represent a behavioural homologue of human imitation.

It is proposed that the ability to copy the behaviour of a companion is under a strong genetic influence in many social species. Many important factors have not been examined experimentally, e.g. the effect of the demonstrator, the influence of attention and memory and the ability to generalize. The potential importance of reinforcement raises the possibility that copying abilities serving divergent functions might be partly under the control of different mechanisms.
The evolution of fitness in life‐history theory
Authors: BROMMER JON E.
Published: August 2010

Theory concerning the evolution of life history (the schedule of reproduction and survival) focuses on describing the life history which maximises fitness. Although there is an intuitive link between life history and fitness, there are in fact several measures of the ‘black box’ concept of fitness. There has been a debate in the bio‐mathematical literature on the predictive difference between the two most commonly used measures; intrinsic rate of increase r and net reproductive ratio R0. Although both measures aim to describe fitness, models using one of the measures may predict the opposite of similar models using the other measure, which is clearly undesirable. Here, I review the evolution of these fitness measures over the last four decades, the predictive differences between these measures and the resulting shift of the fitness concept. I focus in particular on some recent developments, which have solved the dilemma of predictive differences between these fitness measures by explicitly acknowledging the game‐theoretical nature of life‐history evolution.
Individual feeding specialisation in shorebirds: population consequences and conservation implications
Authors: DURELL SARAH E. A. LE V. DIT
Published: August 2010

Individual feeding specialisation in shorebirds is reviewed, and the possible mechanisms involved in such specialisations. Any specialisation can be seen as an individual strategy, and the optimum strategy for any given individual will be conditional upon its specific priorities and constraints. Some specialisations are related to social status and some to individual skills. Some are also probably frequency‐dependent. However, most shorebird specialisations are constrained to a large extent by individual morphology, particularly bill morphology. For example, larger birds are able to handle larger prey, and birds with longer bills are able to feed on more deeply buried prey. Sex differences in bill length are uncommon in the Charardriidae, which are surface peckers, but are common in the Scolopacidae, which feed by probing in soft substrates. Sex differences in bill morphology are frequently associated with sex differences in feeding specialisation. There is evidence that different feeding specialisations are associated with different payoffs, in which case the probability of failing to reproduce or of dying will not be distributed equally throughout the population. I consider the population consequences of such feeding specialisations, particularly the different risks and benefits associated with different habitats or diets. I also consider the way in which individuals may differ in their response to habitat loss or change. I suggest that population models designed to predict the effect of habitat loss or change on shorebirds should have the ability to investigate the differential response of certain sections of the population, particularly different ages or sexes, that specialise in different diets or feeding methods.
The functional significance of silk decorations of orb‐web spiders: a critical review of the empirical evidence
Authors: HERBERSTEIN M. E. , CRAIG C. L. , CODDINGTON J. A. , ELGAR M. A.
Published: August 2010

A number of taxonomically diverse species of araneoid spiders adorn their orb‐webs with conspicuous silk structures, called decorations or stabilimenta. The function of these decorations remains controversial and several explanations have been suggested. These include:(1)stabilising and strengthening the web;(2) hiding and concealing the spider from predators;(3) preventing web damage by larger animals, such as birds;(4) increasing foraging success; or (5) providing a sunshield. Additionally, they may have no specific function and are a consequence of stress or silk regulation. This review evaluates the strength of these explanations based on the evidence. The foraging function has received most supporting evidence, derived from both correlative field studies and experimental manipulations. This contrasts with the evidence provided for other functional explanations, which have not been tested as extensively. A phylogenetic analysis of the different decoration patterns suggests that the different types of decorations are as evolutionary labile as the decorations themselves: the analysis shows little homology and numerous convergences and independent gains. Therefore, it is possible that different types of decorations have different functions, and this can only be resolved by improved species phylogenies, and a combination of experimental and ultimately comparative analyses.