Many groups of closely related species have reticulate phylogenies. Recent genomic analyses are showing this in many insects and vertebrates, as well as in microbes and plants. In microbes, lateral gene transfer is the dominant process that spoils strictly tree‐like phylogenies, but in multicellular eukaryotes hybridization and introgression among related species is probably more important. Because many species, including the ancestors of ancient major lineages, seem to evolve rapidly in adaptive radiations, some sexual compatibility may exist among them. Introgression and (...) reticulation can thereby affect all parts of the tree of life, not just the recent species at the tips. Our understanding of adaptive evolution, speciation, phylogenetics, and comparative biology must adapt to these mostly recent findings. Introgression has important practical implications as well, not least for the management of genetically modified organisms in pest and disease control. (shrink)

Historians and philosophers of science agree that Darwin had an understanding of species which led to a workable theory of their origins. To Darwin species did not differ essentially from ‘varieties’ within species, but were distinguishable in that they had developed gaps in formerly continuous morphological variation. Similar ideas can be defended today after updating them with modern population genetics. Why then, in the 1930s and 1940s, did Dobzhansky, Mayr and others argue that Darwin failed to understand species and speciation? (...) Mayr and Dobzhansky argued that reproductively isolated species were more distinct and ‘real’ than Darwin had proposed. Believing species to be inherently cohesive, Mayr inferred that speciation normally required geographic isolation, an argument that he believed, incorrectly, Darwin had failed to appreciate. Also, before the sociobiology revolution of the 1960s and 1970s, biologists often argued that traits beneficial to whole populations would spread. Reproductive isolation was thus seen as an adaptive trait to prevent disintegration of species. Finally, molecular genetic markers did not exist, and so a presumed biological function of species, reproductive isolation, seemed to delimit cryptic species better than character-based criteria like Darwin’s. Today, abundant genetic markers are available and widely used to delimit species, for example using assignment tests: genetics has replaced a Darwinian reliance on morphology for detecting gaps between species. In the 150th anniversary of The Origin of Species , we appear to be returning to more Darwinian views on species, and to a fuller appreciation of what Darwin meant. (shrink)

This paper reports on the meeting of the Sounding Board of the EU Reprogenetics Project that was held in Budapest, Hungary, 6–9 November 2005. The Reprogenetics Project runs from 2004 until 2007 and has a brief to study the ethical aspects of human reproductive cloning and germline gene therapy. Discussions during The Budapest Meeting are reported in depth in this paper as well as the initiatives to involve the participating groups and others in ongoing collaborations with the goal of forming (...) an integrated network of European resources in the fields of ethics of science. (shrink)

This paper reports on the meeting of the Sounding Board of the EU Reprogenetics Project that was held in Budapest, Hungary, 6–9 November 2005. The Reprogenetics Project runs from 2004 until 2007 and has a brief to study the ethical aspects of human reproductive cloning and germline gene therapy. Discussions during The Budapest Meeting are reported in depth in this paper as well as the initiatives to involve the participating groups and others in ongoing collaborations with the goal of forming (...) an integrated network of European resources in the fields of ethics of science. (shrink)

The balance between births and deaths in an age-structured population is strongly influenced by the spatial distribution of sub-populations. Our aim was to describe the demographic process of a fish population in an hierarchical dendritic river network, by taking into account the possible movements of individuals. We tried also to quantify the effect of river network changes (damming or channelling) on the global fish population dynamics. The Salmo trutta life pattern was taken as an example for.We proposed a model which (...) includes the demographic and the migration processes, considering migration fast compared to demography. The population was divided into three age-classes and subdivided into fifteen spatial patches, thus having 45 state variables. Both processes were described by means of constant transfer coefficients, so we were dealing with a linear system of difference equations. The discrete case of the variable aggregation method allowed the study of the system through the dominant elements of a much simpler linear system with only three global variables: the total number of individuals in each age-class. (shrink)

Normal fetal development is dependent upon an intricate exchange between mother and embryo. Several maternal and embryonic elements can influence this intimate interaction, including genetic, environmental or epigenetic factors, and have a significant impact on embryo development. The interaction of the genetic program of both mother and embryo, within the uterine environment, can shape the development of an individual. Accumulating data from animal models indicate that prenatal events may well initiate long‐term changes in the expression of the embryo genetic program, (...) which persist, or may only become apparent, much later in the individual's life. Also, environmental conditions during prenatal development may prompt the adoption of different developmental pathways, leading to alternative life histories. This review focuses on environmental factors, specifically maternally derived molecules, to illustrate how they can influence in utero embryonic development and, by extension, adult life. (shrink)

La survenue d’une maladie grave chez l’enfant vient percuter et modifier de manière considérable les liens intrafamiliaux. C’est à partir du moment inaugural de l’annonce diagnostique, dans un échange de regards avec ses parents, que l’enfant prendra conscience de la gravité de sa maladie. C’est aussi en fonction de la réaction à venir de ses parents, au fil de l’évolution de la maladie et au gré des traitements, que l’enfant va lui-même, en tant que sujet porteur de sa propre histoire, (...) éprouver les effets psychiques de cette maladie et lui conférer un sens particulier. D’un point de vue de psychologue exerçant en oncologie pédiatrique, il s’agit ici d’éclairer les enjeux psychiques liés à l’irruption d’un cancer chez l’enfant en portant une attention particulière sur la manière dont cet événement éprouvant est vécu par ses parents et dont on peut en retrouver les effets dans le discours de l’enfant. La possibilité pour l’enfant de dire ce qu’il perçoit dans le regard meurtri de ses parents porté sur lui nous semble contribuer à l’appropriation de l’épreuve de la maladie, voire au dépassement de celle-ci. (shrink)

In Ancient Greece, the relation between war and peace used to have an ambiguous meaning. War was considered as a normal state and peace was seen only as an exception or a temporary truce during a long lasting conflict. But peace and political stability were also valued: the aim of war was never the total annihilation of the opponent. Besides this opposition, there was a balance between war and peace during these times and this conception, inherited from the heroic times, (...) lasted until the beginning of the Peloponnesian War. This event redefined the relation between war and peace. The meaning of conflict moved from polemos, as codified conflict between cities, to stasis, as civil war. War was less perceived as something positive and more people valued peace and stability. Plato’s political thought was developed in this context as a potential answer to this redefinition of conflict as well as the threat of an excessive and radical conception of war. However, Plato had to face an exigent challenge. No political regime was able to establish peace anymore, so Plato needed to create a brand new political system to solve the problems raised by the Peloponnesian War. The goal of this paper will be to present Plato’s response to these political challenges by showing that his response is deeply innovative for his time but also profoundly rooted in a traditional conception of conflict that was already obsolete when he wrote his masterpieces. (shrink)

Information and communication technologies , with their increasing and widespread utilization in daily life, may exert an important impact on brain performances. The development of their use for improving several cerebral processes, by abolishing the brain/machine interface, is envisaged and is subject to debate. The scientific research on brain implants and brain gene transfer aiming to restore central nervous system functions, altered by disease or trauma, may contribute to this debate. Indeed, the advances that are enabling non drug-mediated approaches for (...) direct interventions on the brain are raising the possibility not only of restoring neural functions for therapeutic purposes, but also of monitoring, controlling and ultimately modifying from the outside these functions for enhancement. This paper gives an overview of the state of the art of brain implants and brain gene transfer for neurological diseases with a particular emphasis on Parkinson’s disease and a forecast on their possible application for other conditions. In doing so, the authors, who are neuroscientists working in the field of gene transfer for neuropsychiatric diseases, aim to establish a scientifically, medically and technically realistic framework to open up discussion on relevant ethical issues in this domain. (shrink)

This paper reports on the meeting of the Sounding Board of the EU Reprogenetics Project that was held in Budapest, Hungary, 6–9 November 2005. The Reprogenetics Project runs from 2004 until 2007 and has a brief to study the ethical aspects of human reproductive cloning and germline gene therapy. Discussions during The Budapest Meeting are reported in depth in this paper as well as the initiatives to involve the participating groups and others in ongoing collaborations with the goal of forming (...) an integrated network of European resources in the fields of ethics of science. (shrink)

L'ambition de cet ouvrage est d'illustrer à la fois comment la philosophie conceptualise le conflit et comment elle s'efforce d'en résoudre les dangers inhérents. Plutôt que de proposer un aperçu purement abstrait de la notion de « conflit », l'ensemble des travaux se focalise sur la confrontation des philosophes à des problèmes historiques tels que la guerre, la dissension sociale, la tyrannie, ou encore le sport. -/- .