Verification, falsification versus

Thorp, J.H., and H. Itagaki Verification versus Falsification of Existing Theory Analysis of Possible Chemical Communication in Crayfish. J. Chem. Ecol. 8, 1073-1077 (1982). 

The central tenets of the falsificationist philosophy of Karl R. Popper are reviewed in detail, and the way they do or do not apply to systematics and phylogeny reconstruction is analyzed. Cladistic analysis, cast in either maximum parsimony or in maximum likelihood approaches, is not compatible with Popperian falsificationism. The main reasons are the absence of a deductive link between a hypothesis of phylogenetic relationships and character distribution on a tree, which translates into the absence of the basic asymmetry of falsification versus verification. This sets Popper s philosophy of science apart from inductive systems. In cladistic analysis, falsification (disconfirmation) is symmetrical to verification (confirmation), which reveals an inductive and hence probabilistic background. The basic problem of systematics as an empirical science resides in character conceptualization and its critical evaluation. 

The reason that our expectation of a logically subordinated hierarchy cannot fail in the application of parsimony analysis lies in the fact that it is not subject to the fundamental asymmetry of falsification versus verification relative to universal statements that Popper discovered in his solution to the logical problem of induction. This conclusion evidently requires some explanation. 

Bonde (1974 563) early on recognized the absence of the asymmetry of falsification versus verification in parsimony analysis, and he concluded,... 

The asymmetry of falsification versus verification discovered by Popper in his solution to the logical problem of induction transcends Hume s skepticism. As was shown by Popper, a justification of any theory on grounds of positive reasons is impossible without taking recourse to special knowledge (Popper, 1983 19, 21, 54-55,1989 29). Instead of justifying a theory by providing positive reasons, it is — in principle — possible to defend (rather than justify) the preference for one over other competing theories on the basis of critical reasons (Popper, 1983 21). 

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