Stability, sensitivity, science and heurism

摘要

We examine recently proposed justifications of sensitivity analysis sensu Wheeler (1995), here referred to as weighted-classes sensitivity analysis (WCSA). We refute Giribet's (2003a) claim that WCSA is the strictest possible test for a given phylogenetic hypothesis. Giribet's (2003a) classification of data exploration methods as evaluating "nodal stability" or "nodal support" is arbitrary, at odds with common usage and actually obscures the relationships between the methods he examined, all of which seek to assess the sensitivity of results to variation in analytical conditions. Stability, whether statistical or taxonomic, is not a goal of phylogenetic science. Statistical stability necessarily involves trial repetition, which is impossible in ideographic sciences like phylogenetics. Taxonomic stability can be nothing more than an unintended by-product of scientific inquiry, i.e., the repeated failure to refute a hypothesis. Schulmeister's (2003) "robust-choice" defense of WCSA does not succeed in placing non-arbitrary bounds on parameters, and her interpretation of this approach as simultaneously verificationist and falsificationist is logically inconsistent. WCSA is neither scientific nor heuristic and therefore does not contribute to the advancement of objective knowledge claims. (C) The Willi Hennig Society 2005.