10 - Narrative Shortcuts and Phylogenetic Faux Pas

Summary

In this chapter I show that although hypothetical ancestors largely lost their epistemic power as deliberately constructed phylogenetic tools after the spread of modern phylogenetics, narrative phylogenetic reasoning persists. A conspicuous and widespread example of employing narrative shortcuts in evolutionary storytelling today is the attempt to use the phylogenetic position of taxa to predict the presence of ancestral character states. In close analogy to the historical use of the label ‘lower’ to designate taxa that are presumed primitive, modern authors use a range of evocative adjectives to promote the presumed presence of ancestral character states in their favoured taxa. ‘Basal’ is the most frequently used label, and many authors think that its link to the phylogenetic position of taxa gives it predictive power over whether these are likely to have retained ancestral states. I explain that phylogenetic and evolutionary theory provide no convincing rationale for this argument, and argue instead that basal taxa can be especially misleading about the nature of their character states. Proper lineage thinking can help one avoid this conceptual mistake.