CHARACTER DEFINITIONS AND CHARACTER STATE DELINEATION: THE BETE NOIRE OF PHYLOGENETIC INFERENCE

Area of Science:

• Systematic Entomology
• Phylogenetic Inference
• Molecular Evolution

Background:

• Current phylogenetic inference methods often use a "synthetic" approach to define character states, which can lead to inaccuracies.
• This synthetic method, applied to North American Cochylini (Lepidoptera: Tortricidae), suggested these moths were not monophyletic.
• Theoretical limitations in handling multistate characters contribute to the prevalence of the synthetic method.

Purpose of the Study:

• To investigate flaws in character state delineation within phylogenetic inference.
• To develop and apply a "reflective" character definition method that accounts for observed variation.
• To reassess the monophyly of North American Cochylini using improved character definition and phylogenetic analysis.

Main Methods:

• Comparison of "synthetic" versus "reflective" character definition methods.
• Application of three transformation series derivation methods: unordered outgroup, morphocline analysis, and Transformation Series Analysis (TSA).
• Utilized cladogram characters, nearest neighbor matrices, and positional subtrees for analyzing and summarizing phylogenetic results.

Main Results:

• The "synthetic" method proved deficient due to forcing variable features into limited states.
• All three transformation methods applied to the "reflective" character set supported the monophyly of Cochylini.
• Transformation Series Analysis (TSA) yielded the most internally consistent results among the tested methods.

Conclusions:

• The "reflective" character definition method offers a more robust approach to phylogenetic inference.
• Phylogenetic analyses using the reflective method and TSA confirm the monophyly of North American Cochylini.
• Positional subtrees provide a valuable tool for summarizing complex phylogenetic structures from multiple analyses.