Cytology and mendelism: early connection between Michael F. Guyer's contribution

This paper examines the contribution of the PhD dissertation of the American cytologist Michael F. Guyer (1874-1959) to the early establishment (in 1902-1903) of the parallel relationship between cytological chromosome behaviour in meiosis and Mendel's laws. Guyer's suggestions were among the first, which attempted to relate the variation observed in the offspring in hybridisation studies by a coherent cytological chromosome mechanism to meiosis before the rediscovery of Mendel's principles. This suggested for the first time that the chromosome mechanism involved a conjugation of maternal and paternal chromosomes during the synapsis followed by a segregation of parental chromosomes in the final germ cells and a random union of the final germ cells in the fertilization. It shows that this early suggestion was similar to William Austin Cannon's later chromosome proposal attempting to explain Mendel's principles and had some influence on Walter Sutton's cytological suggestion explaining correctly the behaviour of Mendel's particle by 1903.     

Ruse's Darwinian meta-ethics: A critique

Michael Ruse, in Taking Darwin Seriously seeks to establish that taking Darwin seriously requires us to treat morality as subjective and naturalistic. I argue that, if morality is not objective, then we have no good reason for being moral if we can avoid detection and punishment. As a consequence, we will only continue to behave morally as long as we remain ignorant of Ruse's theory, that is, as long as the cat is not let out of the bag. Ruse offers a number of arguments to show that his theory can overcome such problems. I argue that they all fail. Ruse also argues that he can offer a naturalistic account of ethics which steps around the naturalistic fallacy and avoids the confusion of reasons with causes. His principal argument for this view is an analogy between spiritualism and morality. I argue that this analogy fails.     

On a functional-morphological approach to phylogenetic reconstruction: A critique

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.     

On a naturalist theory of health: a critique

This paper examines the most influential naturalist theory of health, Christopher Boorse’s ‘biostatistical theory’ (BST). I argue that the BST is an unsuitable candidate for the rôle that Boorse has cast it to play, namely, to underpin medicine with a theoretical, value-free science of health and disease. Following the literature, I distinguish between “real” changes and “mere Cambridge changes” in terms of the difference between an individual’s intrinsic and relational properties and argue that the framework of the BST essentially implies a Cambridge-change criterion. The examination reveals that this implicit criterion commits the BST to the troubling view that an individual could go from being diseased to healthy, or vice versa, without any physiological change in that individual. Two problems follow: (1) the current framework of the BST is ill-equipped to formally embrace Cambridge changes and (2) it is theoretically dubious. The arguments advanced here are not limited to the BST; I suggest they extend to any naturalist claim to underpin medical practice with a value-free theory of health and disease defined in terms of an evolutionary view of biological fitness.     

Wieviorka's view on multiculturalism: a critique

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.     

Ligand-dependent aggregation and cooperativity: a critique

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.