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1.
The debate about the biological species concept - a review 总被引:1,自引:0,他引:1
C. L. HÄUSER 《Journal of Zoological Systematics and Evolutionary Research》1987,25(4):241-257
The importance of the species concept in biology has led to a continuing debate about the definition of species. This paper summarizes the recent literature in relation to the ‘biological species concept’ (MAYR 1942). Among the general attributes demanded, possible limitations of the universality and applicability of a species definition are discussed. Three different areas of criticism of the biological species concept are considered: 1. The impracticability of the criterion of reproductive isolation. The demand for more practical criteria is rejected, because reproductive isolation is seen as the factor that produces and maintains species as discrete entities in nature. 2. The inapplicability to non-bisexual organisms. A brief survey of modes of uniparental reproduction and their relative importance suggests that obligatory apomicts are of little evolutionary significance. 3. The inapplicability to multidimensional situations. Despite practical difficulties, the biological species concept is held to apply to organisms separated in space. The impossibility to delimit species in time by reproductive isolation is recognized. Out of two ways to divide continuous evolutionary lineages in time, the phylogenetic approach, which considers only speciation events (cladogenesis), is preferred as it is more objective. A list of recently published alternative definitions of species, none of which is found acceptable, is given. It is concluded that the biological species concept needs not be changed or dismissed on the basis of the discussed criticisms. 相似文献
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We report the isolation and characterization of two new genomic loci corresponding to the mouse Dishevelled (Dvl) genes Dvl2 and Dvl3. The Dvl genes are homologs of the Drosophila dsh segment polarity gene, and are involved in the Wnt/wingless signal transduction pathway. Dvl2 and Dvl3 genomic clones were isolated from a mouse 129 strain λFIXII genomic library and have identical exon/intron organization to Dvll. All three Dishevelled genes span 15 exons and 14 introns and have a number of conserved splice junction sites. 相似文献
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Corine Vernet Joëlle Boretto Marie-Geneviève Mattéi Masahide Takahashi Lucinda J. W. Jack Ian H. Mather Sylvie Rouquier Pierre Pontarotti 《Journal of molecular evolution》1993,37(6):600-612
Summary During a search for novel coding sequences within the human MHC class I region (chromosome 6p21.3), we found an exon (named B30-2) coding for a 166-amino-acid peptide which is very similar to the C-terminal domain of several coding sequences: human 52-kD Sjögren's syndrome nuclear antigen A/Ro (SS-A/Ro) and ret finger protein (RFP), Xenopus nuclear factor 7 (XNF7), and bovine butyrophilin. The first three of these proteins share similarities over the whole length of the molecule whereas butyrophilin is similar in the C-terminal domain. The N-terminal domain of butyrophilin is similar to rat myelin/oligodendrocyte glycoprotein (MOG) and chicken B blood group system (B-G) protein. These domains are components of a new subfamily of the immunoglobulin superfamily (IgSF). Butyrophilin is thus a mosaic protein composed of the MOG/B-G Ig-like domain and the C-terminal domain of 52-kD SS-A/Ro, RFP, and XNF7 (1330-2-like domain). Moreover, in situ hybridization shows that RFP, butyrophilin, and MOG map to the human chromosome 6p2l.3-6p22 region and are thus close to the MHC class I genes. It is therefore possible that the butyrophilin gene is the product of an exon shuffling event which occurred between ancestors of the RFP and MOG genes. To our knowledge, this is the first example of the colocalization of a chimeric gene and its putative progenitors. Finally, regulatory protein T-lymphocyte 1 (Rpt-1) shares similarities with the N-terminal halves of RFP, 52-kD SS-A/Ro, and XNF7, but not with the B30-2-like domain. We show that the ancestral Rpt-l gene evolved by overprinting.
Correspondence to: P. Pontarotti 相似文献
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Allyson Tucker Dilks Joanne Gilchrist Yik Lam Nathan Nicholes Brad Stanley 《Biotechnology progress》2023,39(4):e3351
No-salt flowthrough hydrophobic interaction chromatography (HIC) has been shown to effectively remove process and product-related impurities from bioprocess streams. In this publication, a panel of six antibodies has been used to demonstrate operating principles for the application of no-salt flowthrough HIC in antibody purification processes. The results indicate that no-salt flowthrough HIC provides robust aggregate clearance across operating conditions including flow rate, and variations in resin ligand density. Additionally, HMW reduction has an optimal pH range relative to the isoelectric point of each molecule and high molecular weight (HMW) reduction can be improved by altering the total protein load and/or HMW concentration to drive binding of high molecular weight species to the resin. 相似文献
6.
Ralph M. Perhac Jr. 《人类与生态风险评估》1996,2(2):381-392
The public thinks about (i.e., defines) environmental human health risks in different terms than the “experts.”; And because the manner in which we conceive of risk goes a long way in determining how risk management is conceived and carried out, any definition of risk has important normative elements. I argue that environmental policy based on the public's conception of risk fails to adequately protect fundamental human rights to health and liberty, by taking undue account of certain psychological factors that enter into the public's perception of risk. A survey of some of these factors is offered in an attempt to determine their policy relevance. The traditional scientific conception of risk, although not adequate to entirely define risk policy, serves as an important anchor for the protection of these rights by focusing on the probability or number of adverse health effects. 相似文献
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Research efforts have intensified to foresee the prospects for marine biomes under climate change and anthropogenic drivers over varying temporal and spatial scales. Parallel with these efforts is the utilization of terminology, such as ‘ocean acidification’ (OA) and ‘ocean deoxygenation’ (OD), that can foster rapid comprehension of complex processes driving carbon dioxide (CO2) and oxygen (O2) concentrations in the global ocean and thus, are now widely used in discussions within and beyond academia. However, common usage of the terms ‘acidification’ and ‘deoxygenation’ alone are subjective and, without adequate contextualization, have the potential to mislead inferences over drivers that may ultimately shape the future state of marine ecosystems. Here we clarify the usage of the terms OA and OD as global, climate change‐driven processes and discuss the various attributes of elevated CO2 and reduced O2 syndromes common to coastal ecosystems. We support the use of the existing terms ‘coastal acidification’ and ‘coastal deoxygenation’ because they help differentiate the sometimes rapid and extreme nature of CO2 and O2 syndromes in coastal ecosystems from the global, climate change‐driven processes of OA and OD. Given the complexity and breadth of the processes involved in altering CO2 and O2 concentrations across marine ecosystems, we provide a workflow to enable contextualization and clarification of the usage of existing terms and highlight the close link between these two gases across spatial and temporal scales in the ocean. These distinctions are crucial to guide effective communication of research within the scientific community and guide policymakers responsible for intervening on the drivers to secure desirable future ocean states. 相似文献
9.
Carl D. Mitchell Vernon C. Bleich R. Terry Bowyer James R. Heffelfinger Kelley M. Stewart Paula A. White 《The Journal of wildlife management》2021,85(3):418-422
Reported effects of trophy harvest often are controversial. The subject is nuanced and many studies lack details necessary to place their results in context. Consequently, many studies are misunderstood or their conclusions misapplied. We propose that all dialogues about trophy hunting include a definition of how they use the term trophy, details of variables measured and why they were selected, and explanations of temporal and spatial scales employed. Only with these details can potential effects of trophy hunting be understood in context and used for management and policy decisions. © 2021 The Wildlife Society. 相似文献
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