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. (shrink)

In this article, I address the question of what Developmental Systems Theory aims at explaining. I distinguish two lines of thought in DST, one that deals specifically with development and tries to explain the development of the individual organism, and the other that presents itself as a reconceptualization of evolution and tries to explain the evolution of populations of developmental systems. I emphasize that, despite the claim 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 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. (shrink)

August Weismann is famous for having argued against the inheritance of acquired characters. However, an analysis of his work indicates that Weismann always held that changes in external conditions, acting during development, were the necessary causes of variation in the hereditary material. For much of his career he held that acquired germ-plasm variation was inherited. An irony, which is in tension with much of the standard twentieth-century history of biology, thus exists – Weismann was not a Weismannian. I distinguish three (...) claims regarding the germ-plasm: (1) its continuity, (2) its morphological sequestration, and (3) its variational sequestration. With respect to changes in Weismann’s views on the cause of variation, I divide his career into four stages. For each stage I analyze his beliefs on the relative importance of changes in external conditions and sexual reproduction as causes of variation in the hereditary material. Weismann believed, and Weismannism denies, that variation, heredity, and development were deeply intertwined processes. This article is part of a larger project comparing commitments regarding variation during the latter half of the nineteenth century. (shrink)

On the basis of findings from developmental biology, some researchers have argued that evolutionary theory needs to be significantly updated. Advocates of such a “developmental update” have, among other things, suggested that we need to re-conceptualize units of selection, that we should expand our view of inheritance to include environmental as well as genetic and epigenetic factors, that we should think of organisms and their environment as involved in reciprocal causation, and that we should reevaluate the rates of evolutionary change. (...) However, many of these same conclusions could be reached on the basis of other evidence, namely from microbiology. In this paper, I ask why microbiological evidence has not had a similarly large influence on calls to update biological theory, and argue that there is no principled reason to focus on developmental as opposed to microbiological evidence in support of these revisions to evolutionary theory. I suggest that the focus on developmental biology is more likely attributable to historical accident. I will also discuss some possible room for overlap between developmental and microbiology, despite the historical separation of these two subdisciplines. (shrink)

The main purpose of this article is to consider the significance of different types of memory and non-genetic inheritance and different biosemiotic systems for the origin and evolution of language. It presents language and memory as distributed, heteronomous and system-determined processes implemented in biological and social domains. The article emphasises that language and other sign systems are both ecological and inductive systems that were caused by and always correlate with the environment and deductive systems that are inherited by and depend (...) on the internal development of organisms, individuals, and societies. The article also claims that the origin, re-occurrence and evolution of naturally-emerging sign systems presuppose their retention and accumulation in physical, biological, individual, and social types of memory and reinforcement and maintenance by conventional and deliberate social regulation and accumulation. All of this allows language and other sign systems to be situation-relevant and to be transmitted through generations without their constant reinvention. The novelty of the proposed theory of language origin and evolution is in interdisciplinary integration of biosemiotic studies, systems approaches to language and studies of inheritance systems presented by ‘Extended evolutionary synthesis’. (shrink)

Evolutionary developmental biology (evo-devo) offers both an account of developmental processes and also new integrative frameworks for analyzing interactions between development and evolution. Biologists and philosophers are keen on evo-devo in part because it appears to offer a comfort zone between, on the one hand, what some take to be the relative inability of mainstream evolutionary biology to integrate a developmental perspective; and, on the other hand, what some take to be more intractable syntheses of development and evolution. In this (...) article, I outline core concerns of evo-devo, distinguish theoretical and practical variants, and counter Sterelny's recent argument that evo-devo's attention to development, while important, offers no significant challenge to evolutionary theory as we know it. (shrink)

This is a critical notice of Evolution's Eye by Susan Oyama, focusing on developmental systems theory primarily in relation to the nature-nurture debates and the explanation of behaviour.

In 2002, Evolution and Human Behavior published a study purporting to show that the differences in toy preferences commonly attributed to girls and boys can also be found in male and female vervet monkeys, tracing the origin of these differing preferences back to a common ancestor. Despite some flaws in its design and the prima facie implausibility of some of its central claims, this research received considerable attention in both scientific circles and the popular media. In what follows, I survey (...) some of the problems with this study that seem to be characteristic of research into sex differences in a particular research program in evolutionary psychology. I suggest that an epistemology of ignorance is at work that suppresses the methods and insights of an earlier research program, which emphasized the complexity and contingency that ultimately grounds the variety of human behaviors, in favor of one that has been widely criticized as empirically flawed and politically pernicious. I conclude with some speculative remarks on the persistence of this problematic research program in evolutionary psychology. (shrink)

Review by Alan Love of "Keywords & Concepts in Evolutionary Developmental Biology." Hall, Brian K. and Wendy M. Olson (Eds), Cambridge, Harvard University Press. Hb. 476+xvi pp.

There is a trend within philosophy of biology to concentrate on questions that are strongly related to particular biological research programs rather than on the general scope of the field and its relation to other sciences. Projects of the latter kind, of course, are followed as well but will not be the topic of this review. Shifting the focus to particular research programs reflects philosophers’ increased interest in knowledge of, and contribution to, actual biological research, which is organized in such (...) programs. It is accompanied by the increasing enthusiasm of biologists to involve philosophers in the conceptual work of theoretical biology. I concentrate on the philosophies of four biological research programs, three of which are devoted to evolutionary biology, which is still the main field of interest among philosophers of biology: adaptationism, EvoDevo, and the developmental systems approach. In addition, a short sketch of the newly emerging philosophy of systems biology is given. Several lines of philosophical inquiry can be found in all of the fields considered here: philosophy contributes to the conceptual development of biological research programs, it analyzes structures and delineations of particular research programs, and sometimes it is involved in a comparative assessment of biological programs as well. Philosophical projects that start from the level of a particular research program may give rise to a bottom-up perspective on biology and allow for an integrative view of biological research. This may open up the opportunity to tackle “larger” questions again in an altered and fruitful manner. (shrink)

With Carl Gegenbaur and Ernst Haeckel, inspiredby Darwin and the cell theory, comparativeanatomy and embryology became established andflourished in Jena. This tradition wascontinued and developed further with new ideasand methods devised by some of Haeckelsstudents. This first period of innovative workin evolutionary morphology was followed byperiods of crisis and even a disintegration ofthe discipline in the early twentieth century.This stagnation was caused by a lack ofinterest among morphologists in Mendeliangenetics, and uncertainty about the mechanismsof evolution. Idealistic morphology was stillinfluental in (...) Germany, which prevented a fullappreciation of the importance of Darwinstheory of natural selection for comparativemorphology. Evolutionary morphology andembryology failed to contribute significantlyto the modern synthesis of evolutionarybiology, thereby probably delaying theintegration of developmental biology intomodern evolutionary biology. However, Haeckelsstudent Oscar Hertwig, as well as Victor Franzand Alexej N. Sewertzoff from a youngergeneration, all tried to forge their ownsynthetic approaches in which (inspired byHaeckels work) embryology played an importantrole. Important for all three researchers wereattempts to refine, and sometimes redefine, thebiogenetic law, and to find new scientificexplanations for it (and for the manyexceptions to it). Their research was latermore or less forgotten, and had littleinfluence on the architects of the modernsynthesis. As the relationship betweenevolutionary and developmental biology is nowagain rising in importance in the form ofEvo-Devo, we would like to draw attention tohow this earlier research tradition grappledwith similar questions to those now on theagenda, albeit from sometimes quite differentperspectives. (shrink)

Embryonic development and ontogeny occupy whatis often depicted as the black box betweengenes – the genotype – and the features(structures, functions, behaviors) of organisms– the phenotype; the phenotype is not merelya one-to-one readout of the genotype. Thegenes home, context, and locus of operation isthe cell. Initially, in ontogeny, that cell isthe single-celled zygote. As developmentensues, multicellular assemblages of like cells(modules) progressively organized as germlayers, embryonic fields, anlage,condensations, or blastemata, enable genes toplay their roles in development and evolution.As modules, condensations are (...) fundamentaldevelopmental and selectable units ofmorphology (morphogenetic units) that mediateinteractions between genotype and phenotype viaevolutionary developmental mechanisms. In ahierarchy of emergent processes, gene networksand gene cascades (genetic modules) link thegenotype with morphogenetic units such ascondensations, while epigenetic processes suchas embryonic inductions, tissue interactionsand functional integration, link morphogeneticunits to the phenotype. To support theseconclusions I distinguish units of heredityfrom units of transmission and discussepigenetic inheritance by tracing the historyof relationship between embryology andevolution, especially the role(s) assigned tocells or to cellular components in generatingtheories of morphological change in evolution.The concept of cells as modular morphogeneticunits is modeled and illustrated using themammalian dentary bone. (shrink)

According to Chomsky and his followers, language as a biological phenomenon is a property of individual minds and brains; its status as a social phenomenon is merely epiphenomenal and not a proper object of scientific study. On a rival view, the individual's biological capacity for language cannot be properly understood in isolation from the linguistic environment, which it both depends on for its operation and—in collaboration with other speakers—builds and shapes for future generations. I argue here for the rival view (...) by demonstrating firstly its greater consonance with several themes in current biological theory, and secondly its ability to answer two well‐known philosophical challenges to generative linguistics due to Quine and Kripke. (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.

Since its appearance, Evolutionary Developmental Biology (EvoDevo) has been called an emerging research program, a new paradigm, a new interdisciplinary field, or even a revolution. Behind these formulas, there is the awareness that something is changing in biology. EvoDevo is characterized by a variety of accounts and by an expanding theoretical framework. From an epistemological point of view, what is the relationship between EvoDevo and previous biological tradition? Is EvoDevo the carrier of a new message about how to conceive evolution (...) and development? Furthermore, is it necessary to rethink the way we look at both of these processes? EvoDevo represents the attempt to synthesize two logics, that of evolution and that of development, and the way we conceive one affects the other. This synthesis is far from being fulfilled, but an adequate theory of development may represent a further step towards this achievement. In this article, an epistemological analysis of EvoDevo is presented, with particular attention paid to the relations to the Extended Evolutionary Synthesis (EES) and the Standard Evolutionary Synthesis (SET). (shrink)