An Interpretation of Biological Development (original) (raw)
Related papers
Explaining embryological development: Should integration be the goal
Biology & Philosophy, 1993
Two approaches to an integration of evolution and development are often distinguished, one “neo-Darwinian” and the other “structuralist”. Should these approaches in turn be integrated? Kelly Smith recently stated that we need a “more complete” theory of biological order, suggesting integration as the ideal. In response to him, I argue that a recognition of different types of scientific questions and causal explanation is more urgent. Do we understand development when we know the crucial factors in the process of differentiation, or rather when we know the laws that govern the transformations of fields? Without a recognition of these different explanatory ideals, “integration” is likely to have the character of annexation.
Managing variation in the investigation of organismal development: problems and opportunities
This paper aims to clarify the consequences of new scientific and philosophical approaches for the practical-theoretical framework of modern developmental biology. I highlight normal development, and the instructive-permissive distinction, as key parts of this framework which shape how variation is conceptualised and managed. Furthermore, I establish the different dimensions of biological variation: the units, temporality and mode of variation. Using the analytical frame established by this, I interpret a selection of examples as challenges to the instructive-permissive distinction. These examples include the phenomena of developmental plasticity and transdifferentiation, the role of the microbiome in development, and new methodological approaches to standardisation and the assessment of causes. Furthermore, I argue that investigations into organismal development should investigate the effects of a wider range of kinds of variation including variation in the units, modes and temporalities of development. I close by examining various possible opportunities for producing and using normal development free of the assumptions of the instructive-permissive distinction. These opportunities are afforded by recent developments, which include new ways of producing standards incorporating more natural variation and being based on function rather than structure, and the ability to produce, store, and process large quantities of data.
The Organism in Developmental Systems Theory
Biological Theory 5(3): 216-222, 2010
In this paper, I address the question of what the Developmental Systems Theory (DST) aims at explaining. I distinguish two lines of thought in DST, one which deals specifically with development, and tries to explain the development of the individual organism, and the other which presents itself as a reconceptualization of evolution, and tries to explain the evolution of populations of developmental systems (organism-environment units). I emphasize that, despite the claiming of the contrary by DST proponents, there are two very different definitions of the ‘developmental system’, and therefore DST is not a unified theory of evolution and development. I show that the DST loses the most interesting aspects of its reconceptualization of development when it tries to reconceptualize evolutionary theory. I suggest that DST is about development per se, and that it fails at offering a new view on evolution.
Is it possible, and in the first place is it even desirable, to define what “development” means, and to determine the scope of the field called “developmental biology”? Though these questions appeared crucial for the founders of “developmental biology” in the 1950s, there seems to be no consensus today about the need to address them. Here, in a combined biological, philosophical, and historical approach, we ask whether it is possible and useful to define biological development, and, if such a definition is indeed possible and useful, which definition(s) can be considered as the most satisfactory.
Do We Need a 'Theory' of Development?
Biology & Philosophy, 2016
Edited by Alessandro Minelli and Thomas Pradeu, Towards a Theory of Development gathers essays by biologists and philosophers, which display a diversity of theoretical perspectives. The discussions not only cover the state of art, but broaden our vision of what development includes and provide pointers for future research. Interestingly, all contributors agree that explanations should not just be gene-centered, and virtually none use design and other engineering metaphors to articulate principles of cellular and organismal organization. I comment in particular on the issue of how to construe the notion of a ‘theory’ and whether developmental biology has or should aspire to have theories, which four of the contributions discuss in detail while taking opposing positions. Beyond construing a theory in terms of its empirical content (established knowledge about biological phenomena), my aim is to shift the focus toward the role that theories have for guiding future scientific theorizing and practice. Such a conception of ‘theory’ is particularly important in the context of development, because arriving at a theoretical framework providing guidance for the discipline of developmental biology as a whole is more plausible than a unified representation of development across all taxa.
The role and limits of a gradient based explanation of morphogenesis: a theoretical consideration
Theoretical Paper, 2006
Development of an organism is a multi-dimensional process leading to the generation of complex species-specific structures. This specificity suggests machine-like organisation. The uneven distribution (gradient) of soluble substances (morphogens) and specific receptor-ligand interactions are known to cause differential gene expression. Therefore gradients of morphogens are used as a causal explanation of developmental processes. However each attempt to describe development causally should take into account both the local fine organisation and global robustness of morphogenesis. The classical view of the role of morphogens will be critically considered and possible alternative proposed. The core idea of my proposal is that the main function of morphogenetic substances could be a context dependent modification of cell behaviour. Both history and different features of morphogenetic fields create the framework for the activity of morphogenes. Causality and explanation: the role of boundary conditions The issue of the causal factors in morphogenesis and development is both fascinating and fuzzy. In order to clarify some important concepts of developmental biology it seems appropriate to make some general statements about explanation and causation. In philosophy the metaphysics of causation is subject of never ending discussion. At the same time the natural sciences, especially biology, use this concept in an oversimplified manner. In my opinion the high complexity of biological questions and the enormous knowledge accumulated in the last few decades calls upon natural scientists to be more careful with our explanations. At the same time I believe that philosophical discussions will benefit from the clarification made feasible by increasing interdis-ciplinary discussion. Natural science has come of age and is increasingly able to use complex causal explanation. In order to understand developmental processes we need insight into mathematics , as Gilbert and Sarkar (2000) have recently argued: the " combination of microarray and computer technology may finally allow us to have a multivariable developmental biology of the kind that Bertalanffy and Weiss would have appreciated ". This however makes it necessary to re-evaluate our theoretical approaches to biology in general and to development in particular. Hence theoretical and philosophical suggestions cannot be ignored. The explanation of any event in nature requires a description of its