This paper evaluates and criticises the developmental systems conception of evolution and develops instead an extension of the gene's eye conception of evolution. We argue (i) Dawkin's attempt to segregate developmental and evolutionary issues about genes is unsatisfactory. On plausible views of development it is arbitrary to single out genes as the units of selection. (ii) The genotype does not carry information about the phenotype in any way that distinguishes the role of the genes in development from that other factors. (...) (iii) There is no simple and general causal criterion which distinguishes the role of genes in development and evolution. (iv) There is, however, an important sense in which genes but not every other developmental factor represent the phenotype. (v) The idea that genes represent features of the phenotype forces us to recognise that genes are not the only, or almost the only, replicators. Many mechanisms of replication are involved in both development and evolution. (vi) A conception of evolutionary history which recognises both genetic and non-genetic replicators, lineages of replicators and interactors has advantages over both the radical rejection of the replicator/interactor distinction and the conservative restriction of replication to genetic replication. (shrink)

Developmental systems theory (DST) is a general theoretical perspective on development, heredity and evolution. It is intended to facilitate the study of interactions between the many factors that influence development without reviving `dichotomous' debates over nature or nurture, gene or environment, biology or culture. Several recent papers have addressed the relationship between DST and the thriving new discipline of evolutionary developmental biology (EDB). The contributions to this literature by evolutionary developmental biologists contain three important misunderstandings of DST.

The Developmental Systems approach to evolution is defended against the alternative extended replicator approach of Sterelny, Smith and Dickison (1996). A precise definition is provided of the spatial and temporal boundaries of the life-cycle that DST claims is the unit of evolution. Pacé Sterelny et al., the extended replicator theory is not a bulwark against excessive holism. Everything which DST claims is replicated in evolution can be shown to be an extended replicator on Sterelny et al.s definition. Reasons are given (...) for scepticism about the heuristic value claimed for the extended replicator concept. For every competitive, individualistic insight the replicator theorist has a cooperative, systematic blindspot. (shrink)

Developmental systems theory is an attempt to sum up the ideas of a research tradition in developmental psychobiology that goes back at least to Daniel Lehrman’s work in the 1950s. It yields a representation of evolution that is quite capable of accommodating the traditional themes of natural selection and also the new results that are emerging from evolutionary developmental biology. But it adds something else - a framework for thinking about development and evolution without the distorting dichotomization of biological processes (...) into gene and non-gene and the vestiges of the ‘black-boxing’ of developmental processes in the modern synthesis, such as the asymmetric use of the concept of information. Phenomena that are marginalized in current gene-centric conceptions, such as extra-genetic inheritance, niche construction and phenotypic plasticity are placed center stage. (shrink)

Many scientists and philosophers of science are troubled by the relative isolation of developmental from evolutionary biology. Reconciling the science of development with the science of heredity preoccupied a minority of biologists for much of the twentieth century, but these efforts were not corporately successful. Mainly in the past fifteen years, however, these previously dispersed integrating programmes have been themselves synthesized and so reinvigorated. Two of these more recent synthesizing endeavours are evolutionary developmental biology and developmental systems theory. While the (...) former is a bourgeoning and scientifically well-respected biological discipline, the same cannot be said of DST, which is virtually unknown among biologists. In this review, we provide overviews of DST and EDB, summarize their key tenets, examine how they relate to one another and to the study of epigenetics, and survey the impact that DST and EDB have had on biological theory and practice. (shrink)

Developmental systems theory is a general theoretical perspective on development, heredity and evolution. It is intended to facilitate the study of interactions between the many factors that influence development without reviving `dichotomous' debates over nature or nurture, gene or environment, biology or culture. Several recent papers have addressed the relationship between DST and the thriving new discipline of evolutionary developmental biology. The contributions to this literature by evolutionary developmental biologists contain three important misunderstandings of DST.

The question “What is an organism?”, formerly considered as essential in biology, has now been increasingly replaced by a larger question, “What is a biological individual?”. On the grounds that i) individuation is theory-dependent, and ii) physiology does not offer a theory, biologists and philosophers of biology have claimed that it is the theory of evolution by natural selection which tells us what counts as a biological individual. Here I show that one physiological field, immunology, offers a theory, which makes (...) possible a biological individuation based on physiological grounds. I give a new answer to the question of the individuation of an organism by linking together the evolutionary and the immunological approaches to biological individuation. (shrink)

One of our most brilliant evolutionary biologists, Richard Lewontin has also been a leading critic of those--scientists and non-scientists alike--who would misuse the science to which he has contributed so much. In The Triple Helix, Lewontin the scientist and Lewontin the critic come together to provide a concise, accessible account of what his work has taught him about biology and about its relevance to human affairs. In the process, he exposes some of the common and troubling misconceptions that misdirect and (...) stall our understanding of biology and evolution.The central message of this book is that we will never fully understand living things if we continue to think of genes, organisms, and environments as separate entities, each with its distinct role to play in the history and operation of organic processes. Here Lewontin shows that an organism is a unique consequence of both genes and environment, of both internal and external features. Rejecting the notion that genes determine the organism, which then adapts to the environment, he explains that organisms, influenced in their development by their circumstances, in turn create, modify, and choose the environment in which they live.The Triple Helix is vintage Lewontin: brilliant, eloquent, passionate, and deeply critical. But it is neither a manifesto for a radical new methodology nor a brief for a new theory. It is instead a primer on the complexity of biological processes, a reminder to all of us that living things are never as simple as they may seem. (shrink)