How the Leopard Changed Its Spots : The Evolution of Complexity
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Do genes explain life? Can advances in evolutionary and molecular biology account for what we look like, how we behave, and why we die? In this powerful intervention into current biological thinking, Brian Goodwin argues that such genetic reductionism has important limits.
Drawing on the sciences of complexity, the author shows how an understanding of the self-organizing patterns of networks is necessary for making sense of nature. Genes are important, but only as part of a process constrained by environment, physical laws, and the universal tendencies of complex adaptive systems. In a new preface for this edition, Goodwin reflects on the advances in both genetics and the sciences of complexity since the book's original publication.
of those rare, enduring achievements of the scientific imagination. Darwin's vision of evolution by random variation of inherited characteristics in organisms and by selection of the fitter variants is so simple and so convincing that once you have grasped it, you feel you are in possession of a universal truth. And indeed, this idea, or simple variations of it, tend to be applied to everything in our culture that is complex and changing-to the evolution of social and economic systems, to
morphogenesis, we preferred to work with a simpler model and see how far it could take us. We failed to find conditions that gave a structure like the cap of Acetabularia. What we did get was a large, bulbous terminal structure, not the parasol-like form of the Mermaid's Cap. Evidently this form is not so easy to find, and it is quite likely that changes will be required 104 Living Form in the Making in our model before such a shape is generated. Remember, however, that caps are latecomers on
ideas have influenced me, I have to acknowledge them collectively here and specifically by reference in the text itself. Science is a collective enterprise, an outcome of the type of relational order that underlies all creative activity, so my own contribution is minimal. However, someone has to take responsibility for the limitations of the work, and that can only be me. My grateful thanks go to all those with whom it has been my privilege to interact over the years. XX How the Leopard
then expect that if C is Figure 5 12 The spatial patterns of the three main categories of homeotic gene involved in determining the structure of the flower organs in Arabidopsis, deduced from the mutants. 137 How the Leopard Changed Its Spots absent, A would extend its region of influence across the whole meristem. And this is how the agamous mutant seems to work. In the absence of C, the sequence is A AB AB A sepals petals petals sepals So far so good. Now for B. When this mutates
mechanisms, animals and plants are remarkably similar. Homeotic Mutants Among the set of possible forms of tetrapod limbs are the abnormal structures classified as monsters and mutants. Despite sometimes gross deformation, monsters are nevertheless recognized as belonging to the same set of forms as those classified as normal. William Bateson made very effective use of abnormal forms to make important deductions about the principles of morphogenesis, particularly the significance of symmetries