The dichotomy between Nature and Nurture, which has been dismantled within the framework of development, remains embodied in the notions of plasticity and evolvability. We argue that plasticity and evolvability, like development and heredity, are neither dichotomous nor distinct: the very same mechanisms may be involved in both, and the research perspective chosen depends to a large extent on the type of problem being explored and the kinds of questions being asked. Epigenetic inheritance leads to transgenerationally extended plasticity, and developmentally-induced (...) heritable epigenetic variations provide additional foci for selection that can lead to evolutionary change. Moreover, hereditary innovations may result from developmentally induced large-scale genomic repatterning events, which are akin to Goldschmidtian “systemic mutations”. The epigenetic mechanisms involved in repatterning can be activated by both environmental and genomic stress, and lead to phylogenetic as well as ontogenetic changes. Hence, the effects and the mechanisms of plasticity directly contribute to evolvability. (shrink)

'...a challenging and useful book, both because it provokes a careful scrutiny of one's own basic ideas regarding evolutionary theory, and because it cuts across so many biological disciplines.' -The Quarterly Review of Biology 'In my view, this work exemplifies Theoretical Biology at its best...here is rampant speculation that is consistently based on cautious reasoning from the available data. Even more refreshing is the absence of sloganeering, grandstanding, and 'isms'.' -Biology and Philosophy 'Epigenetics is fundamental to understanding both development and (...) gene expression, and not surprisingly, evolutionary biologists have long been fascinated with its proper place in evolutionary theory...Enter Jablonka and Lamb, who provide a thoughtful review of the recent molecular literature and suggest a number of potential consequences.' -EvolutionSince first publication of this controversial book, much of the initial opposition to the ideas it contained has been replaced by a general, although often grudging, acceptance of them. Advances in knowledge, especially at the molecular level, have enhanced general awareness and interest in epigenetics and the evolution of systems that store and transmit information and put any of the authors' speculations on a more solid basis. This paperback edition contains a new Preface that sets out the major changes in the scientific world and in the authors' own thinking that have occurred since the book was published. A new Appendix provides a selected bibliography of the many books and articles about epigenetic inheritance and its role in evolution that have appeared since first publication. (shrink)

Explores the development of the ideas of evolutionary biology, particularly as affected by the increasing understanding of genetics and of the chemical basis of inheritance.

In 1809--the year of Charles Darwin's birth--Jean-Baptiste Lamarck published Philosophie zoologique, the first comprehensive and systematic theory of biological evolution. The Lamarckian approach emphasizes the generation of developmental variations; Darwinism stresses selection. Lamarck's ideas were eventually eclipsed by Darwinian concepts, especially after the emergence of the Modern Synthesis in the twentieth century. The different approaches--which can be seen as complementary rather than mutually exclusive--have important implications for the kinds of questions biologists ask and for the type of research they conduct. (...) Lamarckism has been evolving--or, in Lamarckian terminology, transforming--since Philosophie zoologique's description of biological processes mediated by "subtle fluids." Essays in this book focus on new developments in biology that make Lamarck's ideas relevant not only to modern empirical and theoretical research but also to problems in the philosophy of biology. Contributors discuss the historical transformations of Lamarckism from the 1820s to the 1940s, and the different understandings of Lamarck and Lamarckism; the Modern Synthesis and its emphasis on Mendelian genetics; theoretical and experimental research on such "Lamarckian" topics as plasticity, soft (epigenetic) inheritance, and individuality; and the importance of a developmental approach to evolution in the philosophy of biology. The book shows the advantages of a "Lamarckian" perspective on evolution. Indeed, the development-oriented approach it presents is becoming central to current evolutionary studies--as can be seen in the burgeoning field of Evo-Devo. Transformations of Lamarckism makes a unique contribution to this research. (shrink)