3 - Optimality and Phylogeny: A Critique of Current Thought

Summary

When new linkages are formed between previously unconnected disciplines of science, a bidirectional flow of insights eventually results. However, initial contact between disciplines often is characterized not so much by reciprocal enlightenment as by argumentation and, often, attempts by practitioners of each discipline to annex part or all of the other. In the ensuing debates, advocates for the competing disciplines critically scrutinize each other's methods. Gradually, exaggerated and unsupportable claims about the primacy of one discipline's methods for addressing the questions of the other are replaced by mutual understanding (or at least tolerance), and improved methods of investigation arise at the intersection of the two disciplines.

Such conflict has been particularly characteristic of contacts between adaptation-minded evolutionary biologists and social scientists (Alexander 1979; Crawford 1993; Sherman and Reeve 1997). Less visible have been similar conflicts between adaptationists and both developmental biologists and dynamical systems theorists. For example, initial exchanges between modern developmental biologists and adaptationists were debates over the importance of developmental processes in constraining adaptive evolution and thus the utility of developmental methods for inferring a trait's adaptiveness or lack thereof (Maynard Smith et al. 1985). Now it appears to be more widely recognized that developmental constraints represent a special form of, and not an alternative to, selection and can be studied as fitness costs arising from perturbations to existing developmental programs (Reeve and Sherman 1993). Similarly, some students of self-organization (mainly dynamical systems theorists from physics and engineering) originally claimed that many presumed adaptations are instead only surprisingly ordered epiphenomena of simple underlying mechanistic processes (Kauffman 1993).