共查询到20条相似文献,搜索用时 78 毫秒
1.
Peter Godfrey-Smith 《Biology & philosophy》2007,22(3):429-437
Jablonka and Lamb's claim that evolutionary biology is undergoing a ‘revolution’ is queried. But the very concept of revolutionary
change has uncertain application to a field organized in the manner of contemporary biology. The explanatory primacy of sequence
properties is also discussed.
相似文献
Peter Godfrey-SmithEmail: |
2.
Studies on the effects of a variety of exogenous and anthropogenic environmental factors, including endocrine disruptors,
heavy metals, UV light, high temperature, and others, on marine organisms have been presented at the 2nd Bilateral Seminar
Italy–Japan held in November 2006. Reports were discussed in order to reveal the current situation of marine ecosystems, aiming
at evaluation and prediction of environmental risks.
相似文献
V. MatrangaEmail: |
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4.
The evolutionary origin of vertebrates has been debated ad nauseam by anatomists, paleontologists, embryologists, and physiologists,
but it is only now that molecular phylogenetics is providing a more rigorous framework for the placement of vertebrates among
their invertebrate relatives that we can begin to arrive at concrete conclusions concerning the nature of ancient ancestors
and the sequence in which characteristic anatomical features were acquired. Vertebrates tunicates and cephalochordates together
comprise the chordate phylum, which along with echinoderms and hemichordates constitute the deuterostomes. The origin of vertebrates
and of jawed vertebrates is characterized by a doubling of the vertebrate genome, leading to hypotheses that this genomic
event drove organismal macroevolution. However, this perspective of evolutionary history, based on living organisms alone,
is an artifact. Phylogenetic trees that integrate fossil vertebrates among their living relatives demonstrate the gradual
and piecemeal assembly of the gnathostome body plan. Unfortunately, it has not been possible to demonstrate gradual assembly
of the vertebrate body plan. This is not because vertebrates are irreducibly complex but because many of the characters that
distinguish vertebrates from invertebrates are embryological and cellular and, therefore, inherently unfossilizable.
相似文献
Philip C. J. DonoghueEmail: |
5.
Anya Plutynski 《Biology & philosophy》2008,23(5):605-623
The discussion of the adaptive landscape in the philosophical literature appears to be divided along the following lines.
On the one hand, some claim that the adaptive landscape is either “uninterpretable” or incoherent. On the other hand, some
argue that the adaptive landscape has been an important heuristic, or tool in the service of explaining, as well as proposing
and testing hypotheses about evolutionary change. This paper attempts to reconcile these two views.
相似文献
Anya PlutynskiEmail: |
6.
Stavros Ioannidis 《Biology & philosophy》2008,23(4):567-578
Evolutionary developmental biology (Evo-Devo) is a new and rapidly developing field of biology which focuses on questions
in the intersection of evolution and development and has been seen by many as a potential synthesis of these two fields. This
synthesis is the topic of the books reviewed here. Integrating Evolution and Development (edited by Roger Sansom and Robert
Brandon), is a collection of papers on conceptual issues in Evo-Devo, while From Embryology to Evo-Devo (edited by Manfred
Laubichler and Jane Maienschein) is a history of the problem of the relations between ontogeny and phylogeny.
相似文献
Stavros IoannidisEmail: |
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8.
Causal Explanation of Indonesian Forest Fires: Concepts, Applications, and Research Priorities 总被引:1,自引:0,他引:1
Andrew P. Vayda 《Human ecology: an interdisciplinary journal》2006,34(5):615-635
Problems with studies, claims, and assumptions that have been made about the causes of fires in Indonesia's tropical moist forests are identified, and the kinds of concepts, methods, prioritizing, and data needed to resolve the problems are discussed. Separate sections are devoted to studying ignitions, studying fire susceptibility and fire behavior, and using the goal of causal explanation to guide interdisciplinary research.
相似文献
Andrew P. VaydaEmail: |
9.
Sub-Antarctic Marion Island has had a permanent research station for 50 years and the islands Wandering Albatrosses have been intensively studied for 20 years. The reactions of breeding birds to approaches by a human on foot were recorded. Three response variables were calculated: intensity of vocal reaction (IVR), intensity of non-vocal reaction (INR) and overall response index (ORI). At 5 m from the nest, twice as many birds stood and/or vocalised as at 15 m. Nearest neighbour distance, age and gender did not explain individual variability of responses. Study colony birds had higher IVR scores than non-study colony birds; birds at colonies closest to the station had the highest ORI scores. A better breeding record was associated with lower IVR and ORI scores, but a causative relationship remains to be demonstrated. A minimum viewing distance of 25 m is recommended for breeding Wandering Albatrosses.
相似文献
Marienne S. de VilliersEmail: Fax: +27-21-6503434 |
John CooperEmail: |
Peter G. RyanEmail: |
10.
Antibodies are very often used as specific cell and/or tissue markers. An example of this is anti-horseradish peroxidase (HRP),
an antibody raised against a plant glycoprotein, which was shown some twenty-five years ago to specifically stain neural tissue
in an animal, Drosophila melanogaster. This peculiar finding was later expanded to other invertebrate species including Caenorhabditis elegans, which were also shown to bear anti-HRP epitopes. Initial experiments indicated that the epitopes recognised by anti-HRP
in invertebrates are of carbohydrate nature. Indeed, more recent experiments have characterised relevant core α1-3-fucosylated
N-glycan structures that act as epitopes in various model and parasitic organisms. Moreover, a number of enzymes required
for the synthesis of such structures have been identified. Over the years, medically-relevant roles of these structures have
become apparent as regards allergenicity and immunoregulation. Although major advances have been made in understanding of
the underlying mechanisms and structures related to the anti-HRP epitope, the in vivo role of the relevant epitopes in neural and other tissues is yet to be resolved. Current understanding of the anti-HRP epitopes
synthesis and their relevance is discussed and elaborated.
相似文献
Katharina PaschingerEmail: |
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12.
Methanogens growing on C-1 substrates synthesize 2-carbon acetyl groups in the form of acetyl-CoA for carbon assimilation
using the multienzyme complex acetyl-CoA decarbonylase/synthase (ACDS) which contains five different subunits encoded within
an operon. In species growing on acetate ACDS also functions to cleave the acetate C-C bond for energy production by methanogenesis.
A number of species of Methanosarcina that are capable of growth on either C-1 compounds or acetate contain two separate ACDS operons, and questions have been
raised about whether or not these operons play separate roles in acetate synthesis and cleavage. Methanosarcina thermophila genomic DNA was analyzed for the presence of two ACDS operons by PCR amplifications with different primer pairs, restriction
enzyme analyses, DNA sequencing and Southern blot analyses. A single ACDS operon was identified and characterized, with no
evidence for more than one. MALDI mass spectrometric analyses were carried out on ACDS preparations from methanol- and acetate-grown
cells. Peptide fragmentation patterns showed that the same ACDS subunits were present regardless of growth conditions. The
evidence indicates that a single form of ACDS is used both for acetate cleavage during growth on acetate and for acetate synthesis
during growth on C-1 substrates.
Electronic Supplementary Material Supplementary material is available for this article at
相似文献
David A. Grahame (Corresponding author)Email: |
Edward DeMoll (Corresponding author)Email: |
13.
In the Indian state of Goa, communally owned agricultural land has persisted through indigenous state rule, colonial occupation
and postcolonial liberation. We show that in Goa, and indeed elsewhere in the world, communally owned land provides protection
against scarcity, risk, and state revenue demands in wet rice agriculture. When wet rice agriculture is the primary agricultural
activity, communally owned land is an effective way to utilize resources. These findings add to the literature that challenges
the inevitability of the tragedy of commonly owned resources.
相似文献
Paul AxelrodEmail: |
14.
Coral reef marine protected areas (MPA) are widely distributed around the globe for social and ecological reasons. Relatively
few of these MPAs are well managed. This review examines the governance of coral reef MPAs and the means to improve coral
reef MPA management. It highlights common governance challenges, such as confused goals, conflict, and unrealistic attempts
to scale up beyond institutional capacity. Recommendations, based on field experience and empirical evidence from around the
world, are made for best practices at various stages of MPA implementation.
相似文献
A. T. WhiteEmail: |
15.
T. Ryan Gregory 《Evolution》2008,1(3):259-273
The occurrence, generality, and causes of large-scale evolutionary trends—directional changes over long periods of time—have
been the subject of intensive study and debate in evolutionary science. Large-scale patterns in the history of life have also
been of considerable interest to nonspecialists, although misinterpretations and misunderstandings of this important issue
are common and can have significant implications for an overall understanding of evolution. This paper provides an overview
of how trends are identified, categorized, and explained in evolutionary biology. Rather than reviewing any particular trend
in detail, the intent is to provide a framework for understanding large-scale evolutionary patterns in general and to highlight
the fact that both the patterns and their underlying causes are usually quite complex.
相似文献
T. Ryan GregoryEmail: |
16.
We develop a formal framework for the optimal allocation of limited resources that includes and clarifies the interplay between
individual optimization and the resulting effects at the population level. As an example, in regard to the evolution of sexual
recombination, the paradox of the twofold cost of sex is avoided by distinguishing between the evolution of recombination
and the subsequent emergence and stability of different mating types as a result of individual optimization within a population
that benefits from recombination.
相似文献
John PepperEmail: |
17.
The recent contribution by Jarmila Kukalová-Peck on Hennigian phylogenetics and hexapod limb evolution is critically evaluated.
相似文献
Michael S. Engel (Corresponding author)Email: |
18.
This paper focuses on evolution as a unifying theme in biology education. Our aim is to argue that the different topics taught
in secondary school biology classes should be enriched with and linked together by means of accounts of the history of life.
We named this approach a “natural history perspective” on biology education. An essential aspect of the natural history perspective
is the claim that evolutionary history forms the context for the development of an understanding of evolutionary processes.
While there are some indications that a natural history perspective can function as a context for understanding micro-evolutionary
processes, more research is called for.
相似文献
Esther M. van DijkEmail: |
19.
Terry Harmer 《Cluster computing》2007,10(3):277-285
Gridcast is an R&D project investigating grid ideas and technologies in the broadcasting technical infrastructure. In this
paper I discuss the business and technical issues in building infrastructures to support broadcasters and outline the structure
of the Gridcast grid-based service oriented architecture for broadcasting playout support.
相似文献
Terry HarmerEmail: |
20.
To our knowledge, this paper is the first record/report of a juvenile light-coloured Weddell seal (Leptonychotes weddellii) at Cape Shirreff, Livingston Island in January 1998, determining that it was an albino individual. Based on available literature,
three cases of albino seals have been reported exclusively for Harbour seal pups, and no albino has been reported for Antarctic
pagophilic true seals. Therefore, this is the first confirmed case of albinism in Antarctic pagophilic true seals species,
indicating that this phenomenon is indeed of a rare occurrence.
相似文献
Daniel TorresEmail: |