Online research in philosophy

Evolutionary developmental biology (“evo-devo”) may provide insights and new methods for studies of cognition and cultural evolution. For example, I propose using cultural selection and individual learning to examine constraints on cultural evolution. Modularity, the idea that traits vary independently, can facilitate evolution (increase “evolvability”), because evolution can act on one trait without disrupting another. I explore links between cognitive modularity, evolutionary modularity, and cultural evolvability. (Published Online November 9 2006).

In the evolutionary biology of the Modern Synthesis the study of patterns refers to how to identify and systematise order in lineages, looking for hierarchies or for branching/splitting events in the tree of life, whereas the resulting order is supposed to be due to underlying processes or mechanisms. But patterns and processes play distinct roles in evo-devo: four different views on the role of patterns and processes in descriptions and explanations of development and evolution: A) transformational; B) generative; C) processual; and D) complex are reviewed in this paper. Then, this discussion is related to two issues in evo-devo: homology and variation.

Recent years have seen increased interest in the question of whether it is possible to provide an evolutionary game theoretic explanation for certain kinds of social norms. These explanatory approaches often rely on the fact that, in certain evolutionary models, the basin of attraction of "fair" or "just" strategies occupies a certain percentage of the state space. I sketch a proof of a general representation theorem for a large class of evolutionary game theoretic models played on a social network, in the hope that this will contribute to a greater understanding of the basins of attraction of such models -- and hence the evolution of social norms. More precisely, I show how many kinds of social networks can be translated into random boolean networks. The interesting and useful part of this result is that, for many social networks, one can find a bijection $f$ between the state space of the social network and the state space of the random boolean network, such that the state $S`$ follows the state $S$ under the dynamical laws of the social network if and only if $f(S`)$ follows the state $f(S)$ under the dynamics of the random boolean network. In some cases, it is not possible to find such a bijection; in these cases, one can find an injection $f$ with the property that if $S`$ follows $S$ under the dynamics of the social network, then $f(S`)$ follows $f(S)$ under the dynamics of the random boolean network. I then use this method to catalog all the basins of attraction for some simple two-strategy games (the prisoner`s dilemma and the stag hunt) played on a ring, drawing on the work of Wuensche and Lesser (1992).

Evolutionary Developmental Biology (Evo-Devo) is philosophically fascinating because of its plurality of scientific “cultures” of practice and theory that continue making progress towards a better understanding of complex biological reality. In this chapter, through an examination of a variety of the scientific cultures pertinent to Evo-Devo, I show that Evo-Devo can be usefully understood as a /trading zone/ (Galison 1997). That is, a variety of disciplines, styles, and paradigms negotiate heavily with each other in the domain of Evo-Devo. I am concerned with the differences, the interactions, and the relative openness and flexibility of these cultures. When are the cultures acting—individually or collectively—in ways that further research, empirically, theoretically, and ethically? When do they become imperialistic, in the sense of excluding and subordinating other cultures? I wish to develop a critical /assumption archeology/ (my term, following Michel Foucault, Ian Hacking, and Michael Friedman), which explores some of the key presuppositions standing behind or under or within each of these cultures. These assumptions ground the concepts, methods, and models of each culture. The goal of this chapter is to identify six cultures of Evo-Devo (three styles and three paradigms), and provide an initial archeology of their internal structure, and mutual relations, through the concept of trading zone. My main excavation site is Bonner (1982), founding text of Evo-Devo and product of the 1981 Dahlem “Evolution and Development” workshop, on which this 2011 anthology (and workshop) was also based.

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.

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.

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.

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.

There is increasing evidence for epigenetically mediated transgenerational inheritance across taxa. However, the evolutionary implications of such alternative mechanisms of inheritance remain unclear. Herein, we show that epigenetic mechanisms can serve two fundamentally different functions in transgenerational inheritance: (i) selection-based effects, which carry adaptive information in virtue of selection over many generations of reliable transmission; and (ii) detection-based effects, which are a transgenerational form of adaptive phenotypic plasticity. The two functions interact differently with a third form of epigenetic information transmission, namely information about cell state transmitted for somatic cell heredity in multicellular organisms. Selection-based epigenetic information is more likely to conflict with somatic cell inheritance than is detection-based epigenetic information. Consequently, the evolutionary implications of epigenetic mechanisms are different for unicellular and multicellular organisms, which underscores the conceptual and empirical importance of distinguishing between these two different forms of transgenerational epigenetic effect.

To explore the potential evolutionary relevance of heritable epigenetic variation, the National Evolutionary Synthesis Center recently hosted a catalysis meeting that brought together molecular epigeneticists, experimental evolutionary ecologists, and theoretical population and quantitative geneticists working across a wide variety of systems. The group discussed the methods available to investigate epigenetic variation and epigenetic inheritance, and how to evaluate their importance for phenotypic evolution. We found that understanding the relevance of epigenetic effects in phe- notypic evolution will require clearly delineating epigenetics within existing terminology and expanding research efforts into ecologically relevant circumstances across model and nonmodel organisms. In addition, a critical component of understanding epigenetics will be the development of new and current statistical approaches and expansion of quantitative and population genetic theory. Although the importance of heritable epigenetic effects on evolution is still under discussion, investigating them in the context of a multidisciplinary approach could transform the field.