The Epistemology of Development, Evolution, and Genetics: Selected Essays (review)

The Epistemology of Development, Evolution, and Genetics contains 11 essays by Richard Burian, a philosopher and historian of biology at Virginia Polytechnic Institute and State University. Burian recognizes that the philosophy of biology, like philosophy generally, "should begin with wonder at the phenomena that require understanding" (p. 1). He advocates a philosophy of biology that addresses issues of concern to biologists. Finally, he understands the importance of situating scientific problems in their historical and social contexts. For the most part, Burian's essays embody these virtues and show the contributions that philosophy can make to biology.

The introductory section, on methodological issues, sets the tone for the book. Biologists choose to study "the right organisms for the job." As a result of evolutionary processes, however, species contain many historically contingent properties, and each species is unique. There is, then, a tension "between working with organisms that offer special advantages and attempting to gain unobscured access to 'basic principles' pertaining, ideally, to large classes of organisms or to organisms in general" (p. 16). The study of model organisms, which have been domesticated to make them especially suitable for specific kinds of investigations, only heightens this tension. How can we extrapolate research on model organisms to humans? With caution.

For much of their history, the disciplines of evolutionary biology, genetics, and developmental biology were at odds. Naturalists and paleontologists were convinced that evolution was a slow and gradual progress, while geneticists identified mutations with large phenotypic effects and argued that evolution must be discontinuous or saltational. Geneticists focused on nuclear and genetic control of development, while developmental biologists (who were then called embryologists) stressed the importance of the cytoplasm and of epigenetic mechanisms. The evolutionary synthesis of the 1930s and 1940s, which integrated paleontology and genetics, ignored the problem of development. These disciplinary conflicts resulted not only from different conceptual foundations, but also from the study of different organisms and the use of different methods. A fuller and more satisfying understanding of biological phenomena requires an integration of disciplinary perspectives. Burian stresses the importance of research that crosses disciplinary boundaries—including the transfer of organisms and methods across these boundaries—in overcoming the epistemological limitations of individual disciplines. He places great hope in evolutionary development biology, or "evo-devo," as the approach that will finally provide a unified view of evolution, genetics, and development. The growth of "evo-devo" was fueled in part by the development of methods that enabled biologists to use drosophila, one of the classical organisms of genetic research, for studies of development.

One of the ways in which philosophers can contribute to biology is by providing what Burian calls "conceptual clarity." His discussion of the different meanings of adaptation is a model of conceptual clarity and is the best discussion of the issues involved in the meaning of this term that I have read. His analysis could have resolved or prevented a number of conflicts that have arisen because of confusions over the definition of adaptation. On the other hand, Burian's discussion of the definition of gene falls flat. Here he ignores his own advice to focus on problems of concern to biologists. Philosophers worry a lot about the definition of gene, but most biologists go about their business just fine without attention to the different meanings of this word. Yes, "genetic material," to use Burian's preferred term, may be DNA or RNA, coding sequences may be contiguous or interrupted by introns, and for some purposes it may be useful to include regulatory sequences, together with coding sequences, as genes. But these distinctions don't lead to confusion or hinder research.

Burian recognizes the paradox that reductionism is a productive research strategy in biology, and yet the attempt to reduce explanation of biological phenomena to one "level," be it genes, molecules, or cells, is bound to fail, because organisms are multilayered products of historical processes that have acted at many levels of biological organization...