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Menzel PT 《Bioethics》1992,6(2):158-165
[In his review essay in this issue of Bioethics,] Julian Savulescu lucidly summarizes and assesses each essay in Strong Medicine. I would like to clarify a few important general points about prior consent as a conceptual framework for the ethical rationing of health care, correct several specific misreadings, and defend my basic claim despite some acknowledged problems.  相似文献   

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Primates - This essay summarizes some of my findings while studying primates in the field from 1962 to 2018. Although I have studied primates throughout the tropics, I focused on Africa, primarily...  相似文献   

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Directionality theory suggests that demographic entropy, defined in a way analogous to thermodynamic entropy, is as important as the Malthusian parameter in determining life history evolution in an age-structured population. In particular, it suggests that entropy should increase in equilibrium species and decrease in opportunistic species. This theory has been applied to explain the evolution of body size and of senescence. It has been claimed recently that this theory has been validated by a simulation study, but it is argued here that this study reveals substantial flaws in directionality theory and that the Malthusian parameter rather than entropy is the appropriate tool in the study of life history evolution.  相似文献   

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A method of phylogenetic reconstruction as proposed by a number of scientists of the Senckenberg Research Institute is discussed. The method is based on functional-morphological studies, the evolutionary adaptation principle of Bock and Von Wahlert (1965) and so-called model reconstruction. It is argued in this paper that direction of the adaptation process cannot be determined because of lack of knowledge about particular selective forces and that theories of model reconstruction are not open to contradiction in the sense of Popperian falsification. Although it has been claimed that the method provides the only valid directional argument for morphoclines in cladistic studies, it remains unclear how to proceed when morphoclines show contradictory polarities. Moreover, it is doubtful whether polarities of morphoclines can be determined independently of phylogenetic hypotheses, and also whether the use of multistate morphoclines is methodologically valid. By relying on a particular evolutionary theory, i.e. the neo-Darwinian theory, and consequently assigning natural selection as the major agent of directional progress, the Senckenburg method of phylogenetic reconstruction restricts itself to microevolutionary change and, therefore, cannot be used when other hypotheses on the evolutionary process appear to explain the speciation process more plausibly, i.e. hypotheses on macroevolution. Furthermore, it is an unproved statement that evolution always proceeds according to the principle of economy.  相似文献   

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Functional genomics provides new opportunities to address issues of fundamental interest in evolutionary biology and suggests many new research directions that are ripe for evolutionary investigation. New types of data, and the ability to study biological processes from a whole genome perspective, are likely to have a profound impact on evolutionary biology and ecology. To illustrate, we discuss how genomewide gene expression studies can be used to reformulate questions about trade-offs and pleiotropy. We then touch on some of the new research opportunities that the application of functional genomics affords to evolutionary biologists. We end with some brief notes about how evolutionary biology and comparative approaches will probably have an impact on functional genomics.  相似文献   

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Economists and psychologists have been testing Nash equilibrium predictions of game theory models of human behavior. In many instances, humans do not conform to the predictions. These results are of great interest to biologists because they also raise questions about well-known ESS models of cooperation. Cooperation in certain one-shot, anonymous interactions, and a willingness to punish others at a net cost to oneself are some of the most intriguing deviations from standard theory. One proposed explanation for these results that is receiving increasing attention invokes the cultural group selection of 'other regarding' social norms. We critically review this explanation. We conclude that experimental results reveal limits in two implicit models of cognitive structure commonly employed by economists and evolutionary biologists.  相似文献   

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Bacterial taxonomy: a critique   总被引:1,自引:0,他引:1  
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Quantitative genetics: a critique   总被引:2,自引:0,他引:2  
E A Murphy 《Social biology》1979,26(2):126-141
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Like any other society France is increasingly diversified culturally and in terms of collective identities. Clearly it is a multicultural, multi-identificational society, but it is not often willing to discuss openly the changes needed to accommodate its diversity and its de facto multicultural character. Michel Wieviorka has been courageous in trying to launch this crucial debate. In France his work is often appreciated but it is also often held to be ‘politically incorrect’ precisely because it questions the validity of the French republican model and its adequacy for the deep social changes at work in French society, and also because it raises the issue of the necessity of building a French multiculturalism. In this article the most important insights of Wieviorka's perspectives on multiculturalism are presented and some of the problems it implies are discussed.  相似文献   

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H A Saroff 《Biochemistry》1991,30(42):10085-10090
Ligand-dependent site-site (or subunit-subunit) interactions provide the basis for explaining cooperativity in chemical reactions. Even in the simplest possible nonaggregating system, interpretation of the interactions in terms of structural details requires an explicit assumption (or model) for the binding of the ligand to the sites when there are no interactions. This paper develops in detail the processes by which aggregation will yield ligand-dependent cooperativity. Two conceptually distinct free energy differences may contribute to cooperativity in an aggregation reaction. One is the free energy difference in ligand binding between the monomer and the aggregate. The other is derived from ligand-dependent interactions between the sites of the aggregate. In this analysis an explicit distinction is made between the experimentally accessible constants and those derived from assumed models. Experimental measurements of an aggregation cycle in which all of the species in equilibrium are defined do not allow for an evaluation of the energies of interaction without some model (or assumption). In the analysis presented, an explicit assumption is employed relating the constant for binding of the ligand to the isolated monomer and the constant for the binding of the ligand to aggregate under conditions where there are no ligand-dependent interactions.  相似文献   

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