Online research in philosophy

One foundational question in contemporarybiology is how to `rejoin evolution anddevelopment. The emerging research program(evolutionary developmental biology or`evo-devo) requires a meshing of disciplines,concepts, and explanations that have beendeveloped largely in independence over the pastcentury. In the attempt to comprehend thepresent separation between evolution anddevelopment much attention has been paid to thesplit between genetics and embryology in theearly part of the 20th century with itscodification in the exclusion of embryologyfrom the Modern Synthesis. This encourages acharacterization of evolutionary developmentalbiology as the marriage of evolutionary theoryand embryology via developmental genetics. Butthere remains a largely untold story about thesignificance of morphology and comparativeanatomy (also minimized in the ModernSynthesis). Functional and evolutionarymorphology are critical for understanding thedevelopment of a concept central toevolutionary developmental biology,evolutionary innovation. Highlighting thediscipline of morphology and the concepts ofinnovation and novelty provides an alternativeway of conceptualizing the `evo and the `devoto be synthesized.

The study of evolutionary developmental biology (“evo‐devo”) has recently experienced a dramatic surge in popularity among researchers and theorists concerned with evolution. However, some biologists and philosophers remain skeptical of the claims of evo‐devo. This paper discusses and responds to the recent high profile criticisms of evo‐devo presented by biologists Hopi E. Hoekstra and Jerry A. Coyne. I argue that their objections are unconvincing. Indeed, empirical research supports the main tenets of evo‐devo, including the claim that morphological evolution is the result of cis ‐regulatory change and the distinction that evo‐devo draws between morphological and physiological traits. *Received January 2008; revised March 2009. †To contact the author, please write to: Department of Philosophy, University of Cincinnati, Cincinnati, OH 45221; e‐mail: craiglr@email.uc.edu.

This article reviews the recent reissuing of Richard Owen’s On the Nature of Limbs and its three novel, introductory essays. These essays make Owen’s 1849 text very accessible by discussing the historical context of his work and explaining how Owen’s ideas relate to his larger intellectual framework. In addition to the ways in which the essays point to Owen’s relevance for contemporary biology, I discuss how Owen’s unity of type theory and his homology claims about fins and limbs compare with modern views. While the phenomena studied by Owen are nowadays of major interest to evolutionary developmental biology, research in evo devo has largely shifted from homology (which was Owen’s concern) towards evolutionary novelty, e.g., accounting for fins as a novelty. Still, I argue that questions about homology are important and raise challenges even for explanations of novelty.

This article reviews the recent reissuing of Richard Owen’s On the Nature of Limbs and its three novel, introductory essays. These essays make Owen’s 1849 text very accessible by discussing the historical context of his work and explaining how Owen’s ideas relate to his larger intellectual framework. In addition to the ways in which the essays point to Owen’s relevance for contemporary biology, I discuss how Owen’s unity of type theory and his homology claims about fins and limbs compare with modern views. While the phenomena studied by Owen are nowadays of major interest to evolutionary developmental biology, research in evo-devo has largely shifted from homology (which was Owen’s concern) towards evolutionary novelty, e.g., accounting for fins as a novelty. Still, I argue that questions about homology are important and raise challenges even for explanations of novelty.

This article reviews the recent reissuing of Richard Owen’s On the Nature of Limbs and its three novel, introductory essays. These essays make Owen’s 1849 text very accessible by discussing the historical context of his work and explaining how Owen’s ideas relate to his larger intellectual framework. In addition to the ways in which the essays point to Owen’s relevance for contemporary biology, I discuss how Owen’s unity of type theory and his homology claims about fins and limbs compare with modern views. While the phenomena studied by Owen are nowadays of major interest to evolutionary developmental biology, research in evo-devo has largely shifted from homology (which was Owen’s concern) towards evolutionary novelty, e.g., accounting for fins as a novelty. Still, I argue that questions about homology are important and raise challenges even for explanations of novelty.

One foundational question in contemporary biology is how to integrate evolution and development. The emerging synthesis (evolutionary developmental biology or ‘evo-devo’) requires a meshing of disciplines, concepts, and explanations (inter alia) that have been developed largely in independence over the past century. The nature of the hoped for synthesis is not wholly agreed upon due to divergent viewpoints resulting from this disciplinary independence and, consequently, the mechanics for accomplishing the task are not clearly specified. This paper utilizes historical investigation for philosophical purposes in order to explore the question of synthesizing evolutionary and developmental biology. In the attempt to comprehend the present separation between evolution and development much attention has been paid to the split between genetics and embryology in the early part of the century with its codification in the exclusion of embryology from the Modern Synthesis. This encourages a characterization of "evo-devo" as the integration of developmental genetics with Neo-Darwinism. But there is a largely untold story about the significance of morphology and comparative anatomy (also minimized in the Modern Synthesis). I will attempt to reconstruct part of this story, focusing on the rebirth of functional (and evolutionary) morphology after the 1950s. Functional morphology is critical for understanding the development of a concept central to "evo-devo", evolutionary innovation. Understanding the story about morphology and innovation reveals a different conception of the foundational problem, providing alternative ways of conceptualizing the "evo" and the "devo" to be synthesized.

Evolutionary psychologists claim that the mind contains “hundreds or thousands” of “genetically specified” modules, which are evolutionary adaptations for their cognitive functions. We argue that, while the adult human mind/brain typically contains a degree of modularization, its “modules” are neither genetically specified nor evolutionary adaptations. Rather, they result from the brain’s developmental plasticity, which allows environmental task demands a large role in shaping the brain’s information-processing structures. The brain’s developmental plasticity is our fundamental psychological adaptation, and the “modules” that result from it are adaptive responses to local conditions, not past evolutionary environments. If different individuals share common environ- ments, however, they may develop similar “modules,” and this process can mimic the development of genetically specified modules in the evolutionary psychologist’s sense.

Evolutionary developmental biology (Evo-Devo) is a new and rapidly developing field of biology which focuses on questions in the intersection of evolution and development and has been seen by many as a potential synthesis of these two fields. This synthesis is the topic of the books reviewed here. Integrating Evolution and Development (edited by Roger Sansom and Robert Brandon), is a collection of papers on conceptual issues in Evo-Devo, while From Embryology to Evo-Devo (edited by Manfred Laubichler and Jane Maienschein) is a history of the problem of the relations between ontogeny and phylogeny.

Sound comparative psychology and modern evolutionary and developmental biology (often called evo-devo) emphasize powerful effects of developmental conditions on the expression of genetic endowment. Both demand that evolutionary theorists recognize these effects. Instead, Tomasello et al. compares studies of normal human children with studies of chimpanzees reared and maintained in cognitively deprived conditions, while ignoring studies of chimpanzees in cognitively appropriate environments.

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.