 Long-branch attraction is more than just an operational problem, it also challenges the falsificationist underpinnings of parsimony (Haber 2009). Recall that on Wiley’s (1975) influential account, phylogenetic trees are subject to being falsified as more data (characters) are discovered or added  (§2.3).  If a more parsimonious tree is available to explain those data, the previously most parsimonious tree is treated as falsified (or as containing more ad hoc hypotheses of homoplasy). Felsenstein’s discovery was that in some circumstances, as more characters are included in a parsimony analysis, parsimony will be prone to rejecting hypotheses that report the actual phylogenetic relations, while corroborating more parsimonious—but incorrect—phylogenetic hypotheses. This undermines the logical justification of parsimony analysis.