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)

The themes, problems and challenges of developmental systems theory as described in Cycles of Contingency are discussed. We argue in favor of a robust approach to philosophical and scientific problems of extended heredity and the integration of behavior, development, inheritance, and evolution. Problems with Sterelny's proposal to evaluate inheritance systems using his `Hoyle criteria' are discussed and critically evaluated. Additional support for a developmental systems perspective is sought in evolutionary studies of performance and behavior modulation of fitness.

Kenneth C. Schaffner's paper is an important contribution to the literature on behavioral genetics and on genetics in general. Schaffner has a long record of injecting real molecular biology into philosophical discussions of genetics. His treatments of the reduction of Mendelian to molecular genetics first drew philosophical attention to the problems of detail that have fuelled both anti-reductionism and more sophisticated models of theory reduction. An injection of molecular detail into discussions of genetics is particularly necessary at the present time, (...) when so many philosophers seem happy to discuss the philosophical and ethical implications of molecular biology using gene concepts derived from evolutionary biology ). Schaffner has long advocated the view that the philosophy of biology should be more than the philosophy of evolution. This paper shows how radically a picture of gene action derived from molecular biology undercuts the popular picture associated with a more evolutionary view of genes as units of heredity or as ‘difference-makers’ mediated by the ‘black box’ of development. (shrink)

In reworking a variety of biological concepts, Developmental Systems Theory (DST) has made frequent use of parity of reasoning. We have done this to show, for instance, that factors that have similar sorts of impact on a developing organism tend nevertheless to be invested with quite different causal importance. We have made similar arguments about evolutionary processes. Together, these analyses have allowed DST not only to cut through some age-old muddles about the nature of development, but also to effect a (...) long-delayed reintegration of development into evolutionary theory. Our penchant for causal symmetry, however (or 'causal democracy', as it has recently been termed), has sometimes been misunderstood. This paper shows that causal symmetry is neither a platitude about multiple influences nor a denial of useful distinctions, but a powerful way of exposing hidden assumptions and opening up traditional formulations to fruitful change. (shrink)