With regard to the theoretical place of environmental factors in development, three approaches to evolution and development can be distinguished. One is the neo-Darwinist approach in which ‘genetic programs’ are central. The other two present themselves as alternatives to the gene-centrism in present-day biology. I discuss pairwise similarities and differences between the three approaches. Goodwin's approach differs from neo-Darwinism in its favoured types of causes, but shares the internalist perspective on embryological development. The ‘constructionist’ alternative proposes to enlarge the developmental (...) system to include external factors, and shares with neo-Darwinism the emphasis on contingent causes. Thus there is neither a grand dichotomy in biology, between neo-Darwinism and its alternative, nor a grand trichotomy. Different purposes make different approaches useful. I conclude by arguing that environmental influences should have a more prominent place in developmental biology. (shrink)

"Au cœur de la Révolution scientifique, philosophes et naturalistes tentent de concevoir les modèles les plus aptes à rendre compte du vivant. Les schèmes hérités de l'Antiquité médicale et philosophique sous-tendent encore les théories originales de Van Helmont et de Harvey. Si le mécanisme s'instaure avec le modèle de l'animal-machine chez Descartes, les audaces et les limites du projet cartésien infléchiront toute démarche ultérieure, comme en témoigne la notion spinoziste d'intégration corporelle. Gassendi suggère, pour sa part, d'associer la modélisation mécaniste (...) et la téléologie immanente des processus. Les néo-platoniciens More et Cudworth évoquent le 'principe hylarchique' ou la 'nature plastique', afin de traduire, por delà les insuffisances du mécanisme, l'émergence des organisations vitales. Lorsque le débat se transpose aux microstructures, Malpighi promeut l'analyse physiologique selon le modèle de 'petites machines' diversement combinées et emboîtées ; Glisson attribue la perception et la réactivité aux fibres élémentaires. Les phénomènes de la génération, que l'on a d'abord expliqués par l'épigenèse, s'interprètent principalement en termes de préformation et de préexistence des germes. Mais, à l'encontre de toute construction hypothétique, Locke privilégie une médecine limitée à l'observation des seuls phénomènes vitaux. La critique de mécanisme suscite en outre les modèles 'animistes' de Perrault et de Stahl. En une remarquable tentative, Leibniz repense alors les concepts fondamentaux de la théorie physiologique et suggère les voies d'analyse pur une science de l'organisme'."--taken from back cover. (shrink)

The practical criteria by which developmental biologists choose their model systems have evolutionary correlates. The result is a sample that is not merely small, but biased in particular ways, for example towards species with rapid, highly canalized development. These biases influence both data collection and interpretation, and our views of how development works and which aspects of it are important.

The tacit standard view that development ends once reproductive capacity is acquired (reproductive boundary, or ‘‘RB,’’ thesis) has recently been challenged by biologists and philosophers of biology arguing that development continues until death (death boundary, or ‘‘DB,’’ thesis). The relevance of these two theses is difficult to assess because the fact that there is no precise definition of development makes the determination of its temporal boundaries problematic. Taking into account this difficulty, this article tries to develop a new species-dependent perspective (...) on temporal boundaries of development. This species-dependent account stands against both RB and DB theses since neither of them reflects the differences between species in the temporality of their development. In this perspective, I propose to use stem cells as a tool to analyze (1) the different developmental capacities of an organism during its life; and (2) the different developmental temporal capacities between species. In particular, I will show that stem cells enable four distinct temporal developmental patterns to be distinguished, i.e., four distinct temporal boundaries of development in the living. I show how these four patterns can be interpreted differently depending on the perspective one has on the definition of development. (shrink)

No comprehensive theory of development is available yet. Traditionally, we regard the development of animals as a sequence of changes through which an adult multicellular animal is produced, starting from a single cell which is usually a fertilized egg, through increasingly complex stages. However, many phenomena that would not qualify as developmental according to these criteria would nevertheless qualify as developmental in that they imply nontrivial (e.g., non degenerative) changes of form, and/or substantial changes in gene expression. A broad, comparative (...) approach is badly needed. In the Cnidaria, for example, even the boundary between generations is problematic. Describing their life cycle in terms of metagenesis (alternation between polyp generation and medusa generation) or in terms of metamorphosis (polyp as larva or juvenile) are matters of semantics more than biology. The life cycle of other metazoans, described in textbooks in terms of larva-to-adult metamorphosis, is hardly different from a typical metagenetic life cycle of cnidarians. This applies to holometabolous insects and to marine invertebrates like sea urchins, where most of the larval cells are discarded at metamorphosis. The uncertain temporal and spatial boundaries of individual development are also shown by the widespread lack of a strict correspondence between adult and mature. A comprehensive theory of development should start with a zero principle of “developmental inertia,” corresponding to an indeterminate local self-perpetuation of cell-level dynamics. Indeterminate growth, scale-invariance, segmentation, and regeneration provide examples of developmental dynamics close to that. (shrink)

Phenotypic plasticity integrates the insights of ecological genetics, developmental biology, and evolutionary theory. Plasticity research asks foundational questions about how living organisms are capable of variation in their genetic makeup and in their responses to environmental factors. For instance, how do novel adaptive phenotypes originate? How do organisms detect and respond to stressful environments? What is the balance between genetic or natural constraints (such as gravity) and natural selection? The author begins by defining phenotypic plasticity and detailing its history, including (...) important experiments and methods of statistical and graphical analysis. He then provides extended examples of the molecular basis of plasticity, the plasticity of development, the ecology of plastic responses, and the role of costs and constraints in the evolution of plasticity. A brief epilogue looks at how plasticity studies shed light on the nature/nurture debate in the popular media. (shrink)

In the six decades since the publication of Julian Huxley's Evolution: The Modern Synthesis, spectacular empirical advances in the biological sciences have been accompanied by equally significant developments within the core theoretical framework of the discipline. As a result, evolutionary theory today includes concepts and even entire new fields that were not part of the foundational structure of the Modern Synthesis. In this volume, sixteen leading evolutionary biologists and philosophers of science survey the conceptual changes that have emerged since Huxley's (...) landmark publication, not only in such traditional domains of evolutionary biology as quantitative genetics and paleontology but also in such new fields of research as genomics and EvoDevo. Most of the contributors to Evolution—The Extended Synthesis accept many of the tenets of the classical framework but want to relax some of its assumptions and introduce significant conceptual augmentations of the basic Modern Synthesis structure—just as the architects of the Modern Synthesis themselves expanded and modulated previous versions of Darwinism. This continuing revision of a theoretical edifice the foundations of which were laid in the middle of the nineteenth century—the reexamination of old ideas, proposals of new ones, and the synthesis of the most suitable—shows us how science works, and how scientists have painstakingly built a solid set of explanations for what Darwin called the "grandeur" of life. (shrink)

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. (shrink)

Embryonic development and ontogeny occupy whatis often depicted as the black box betweengenes – the genotype – and the features(structures, functions, behaviors) of organisms– the phenotype; the phenotype is not merelya one-to-one readout of the genotype. Thegenes home, context, and locus of operation isthe cell. Initially, in ontogeny, that cell isthe single-celled zygote. As developmentensues, multicellular assemblages of like cells(modules) progressively organized as germlayers, embryonic fields, anlage,condensations, or blastemata, enable genes toplay their roles in development and evolution.As modules, condensations are (...) fundamentaldevelopmental and selectable units ofmorphology (morphogenetic units) that mediateinteractions between genotype and phenotype viaevolutionary developmental mechanisms. In ahierarchy of emergent processes, gene networksand gene cascades (genetic modules) link thegenotype with morphogenetic units such ascondensations, while epigenetic processes suchas embryonic inductions, tissue interactionsand functional integration, link morphogeneticunits to the phenotype. To support theseconclusions I distinguish units of heredityfrom units of transmission and discussepigenetic inheritance by tracing the historyof relationship between embryology andevolution, especially the role(s) assigned tocells or to cellular components in generatingtheories of morphological change in evolution.The concept of cells as modular morphogeneticunits is modeled and illustrated using themammalian dentary bone. (shrink)

Embryos, cells, genes, and organisms : reflections on the history of evolutionary developmental biology / Manfred D. Laubichler and Jane Maienschein The organismic systems approach : streamlining the naturalistic agenda / Werner Callebaut, Gerd B. Müller, and Stuart A. Newman Complex traits : genetics, development, and evolution / H. Frederik Nijhout Functional and developmental constraints on life-cycle evolution : an attempt on the architecture of constraints / Gerhard Schlosser Legacies of adaptive development / Roger Sansom Evo-devo meets the mind : (...) toward a developmental evolutionary psychology / Paul E. Griffiths Reproducing entrenchments to scaffold culture : the central role of development in cultural evolution / William C. Wimsatt and James R. Griesemer. (shrink)