David Wake, Organism-Based Research, and the Rise of Evo-Devo

In two recent papers, philosopher of science Jim Griesemer of U.C. Davis discusses how David Wake’s salamander-based research played a key role in the unfolding of evolutionary developmental biology and the advance of evolutionary biology.

Griesemer’s theme is that in contradiction to much of what we are taught about how science is conducted, organism-based research programs are fundamentally important by providing a means of crossing disciplinary boundaries and linking different fields. He illustrates this thesis by discussing Wake’s career-long focus on plethodontid salamanders.

One paper, published last year in Studies in History and Philosophy of Biological and Biomedical Sciences, is a general treatment of the role of organism-based research programs in evolutionary biology, whereas the other explicitly discusses the role Wake’s program played in the development of evo-devo–this paper just appeared as a chapter in a new book on the famous Dahlem conference on evo-devo in 1981 (both papers may be accessed by visiting Griesemer’s webpage, scrolling down and clicking on the appropriate paper’s link).

I think one point in particular captured the essence of the papers. Quoting Wake from a 1982 paper: “it will be increasingly important for morphologists to work as developmental biologists, biomechanical engineers, mathematical biologists, molecular biologists, and even population and community ecologists. Not for a moment do I advocate departing from morphology to these areas. Rather, I believe that instead of making morphology relevant to these areas, it is morphologists who must take the lead in making neighboring disciplines relevant to morphology.’’

The papers make fascinating reading and I highly recommend checking both out. I’ll paste the abstract and part of the conclusion of the 2013 paper below.

But before doing so, I need to address one point. Some Anole Annals readers may wonder why we are using our precious pages to report on papers by a salamander biologist. There are two answers. The first, of course, is that following the lead of Ernest Williams, many anole biologists take a similar, organism-based approach to studying diverse evolutionary questions. Indeed, Wake’s work has been an inspiration to many of us in the field, from anole evolutionists to anole developmental biologists to anole natural historians.

But if that’s not enough, consider that Wake was co-author on the description of a remarkable new genus of Central American salamander named Nyctanolis and pictured below. The biology of this endangered species (N. pernix, the only species in the genus) is little known and we can only speculate to which ecomorph it belongs. Moreover, the species description was published in the festschrift honoring Ernest Williams. Clearly, David Wake is an honorary anolologist and we suggest that there is nothing left to know about salamanders and thus he should start working on anoles.

Nyctanolis pernix. Photo by Tim Herman

Abstract of Griesemer. 2013. Integration of approaches in David Wake’s model-taxon research platform for evolutionary morphology

What gets integrated in integrative scientific practices has been a topic of much discussion. Traditional views focus on theories and explanations, with ideas of reduction and unification dominating the conversation. More recent ideas focus on disciplines, fields, or specialties; models, mechanisms, or methods; phenomena, problems. How integration works looks different on each of these views since the objects of integration are ontologically and epistemically various: statements, boundary conditions, practices, protocols, methods, variables, parameters, domains, laboratories, and questions all have their own structures, functions and logics. I focus on one particular kind of scientific practice, integration of ‘‘approaches’’ in the context of a research system operating on a special kind of ‘‘platform.’’ Rather than trace a network of interactions among people, practices, and theoretical entities to be integrated, in this essay I focus on the work of a single investigator, David Wake. I describe Wake’s practice of integrative evolutionary biology and how his integration of approaches among biological specialties worked in tandem with his development of the salamanders as a model taxon, which he used as a platform to solve, re-work and update problems that would not have been solved so well by non-integrative approaches. The larger goal of the project to which this paper contributes is a counter-narrative to the story of 20th century life sciences as the rise and march of the model organisms and decline of natural history.

Part of Concluding Section:

In a 1982 general essay for Perspectives on Biology and Medicine, ‘‘Functional and Evolutionary Morphology,’’ Wake assessed the history of decline of anatomy in Britain and the US and the renaissance of morphology, which he attributed in part to the combination of comparative methods with experimental methods. Indeed, he defined the field in terms of that combination: ‘‘I define functional and evolutionary morphology as that field of science which examines the evolution of form by combining comparative and experimental methods of analysis’’ (1982a, p. 605). He contrasted biomechanical and adaptationist approaches to the explanation of form and both of these to the approach based on the idea that there is an independent science of form: ‘‘there is more to an independent field of science,’’ Wake writes, ‘‘than utility to some other field!’’ (p. 613). He suggests that ‘‘functional morphologists have a unique opportunity to integrate their studies into evolutionary biology’’ (p. 614) by demonstrating morphological constraints on adaptation, as he and colleage Eric Lombard had done in the tongue evolution papers. He endorses his student, Pere Alberch’s, studies in this vein, though suggesting that studies of the evolution of complex morphologies using his methods should be complemented by biochemical and immunological approaches (p. 615), and then goes beyond his initial formulation of the field as a combination of comparative and experimental methods to suggest that ‘‘it will be increasingly important for morphologists to work as developmental biologists, biomechanical engineers, mathematical biologists, molecular biologists, and even population and community ecologists. Not for a moment do I advocate departing from morphology to these areas. Rather, I believe that instead of making morphology relevant to these areas, it is morphologists who must take the lead in making neighboring disciplines relevant to morphology’’ (p. 616). He then proposes that morphologists should re-do Boag and Grant’s 1981 study of natural selection in Darwin’s Finches to examine the genetic and developmental basis and functional significance of morphological differences among individuals and how these translate into adaptive radiation of the group. Such ambitions for integrative biology require anchoring. I have argued that in Wake’s case, the ambition developed in tandem with the anchor: a model platform rich enough to anchor an integration of approaches that span the morphological specialties.

I have argued that a combination of factors contributed to the integrative practice that I have called an integration of approaches, following the language of my subject, David Wake. Wake worked at the leading edge of evolutionary morphology, a specialty that resulted from an intersection of comparative anatomy,f functional morphology, systematics, and evolutionary biology, but drew in many others and helped define the emerging field of evolutionary developmental biology. Wake’s commitment to salamanders as a research platform, and especially the monophyletic family Plethodontidae, together with his move from an anatomy department to a natural history museum, lowered the opportunity cost for reworking empirical results as new methods, concepts, theories, and data became available. Some of these methods, concepts, theories, and data, were the products of other specialties, such as phylogenetic systematics, molecular genetics, and developmental biology. Re-working thus helps drive interest in integrative approaches in order to take advantage of opportunities that arise outside the core specialty. Work organized around a system makes it easier to change (or add) problems rather than requiring a shift to new platforms. Moreover, because organisms and clades are themselves causally integrated, pursuit of interest in one problem tends to lead to discovery and pursuit of many others because the problems come in causally connected packages.

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Jonathan Losos

Professor of Biology and Director of the Living Earth Collaborative at Washington University in Saint Louis. I've spent my entire professional career studying anoles and have discovered that the more I learn about anoles, the more I realize I don't know.

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